Hydrogen combustors, hydrogen combustor systems, jet engines, and power generation equipment

Abstract

To provide a hydrogen combustor, a hydrogen combustor system, a jet engine, and a power generation device, which can maintain a hydrogen flame over a wide operation range.SOLUTION: A hydrogen combustor according to an embodiment of the present invention comprises at least one fuel injector module and a hydrogen supply pipe. The at least one fuel injector module is configured by forming a module from a plurality of fuel injectors. The fuel injectors each comprise: an air introduction pipe that has a swirler for causing air to swirl; a hydrogen injection pipe that injects gaseous hydrogen approximately perpendicularly to the air swirling through the swirler such that the hydrogen collides with an inner wall of the air introduction pipe; and a flame stabilizing part that expands a flow path of a mixed gas of the air and the hydrogen stepwise. The hydrogen supply pipe supplies the hydrogen by dividing a plurality of supply systems to the hydrogen injection pipes of the plurality of fuel injectors constituting the fuel injector module.SELECTED DRAWING: Figure 7

Description

Technical Field

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[0001] The present invention relates to a hydrogen combustor, a hydrogen combustor system, a jet engine, and a power generation device that use hydrogen as fuel.

Background Art

[0002] Since a hydrogen combustor does not emit carbon dioxide during combustion, it is attracting attention as a technology that can suppress global warming and the like. On the other hand, hydrogen is a fuel that burns more easily than hydrocarbon fuels and the like, and technologies have been developed to suppress the generation of nitrogen oxides (NOx) associated with local high-temperature combustion and to prevent reverse combustion phenomena and the like.

[0003] For example, Patent Document 1 describes a combustion device that generates minute hydrogen flames at multiple points to prevent local high-temperature combustion and reduce the NOx emission amount. Non-Patent Document 1 describes a combustor that realizes rapid mixing by utilizing a vortex generated by introducing a fuel containing hydrogen and air into the same through-hole and generates a lifted flame with a small NOx emission amount. Non-Patent Document 2 describes a combustor that prevents the occurrence of backfire and the like by making the injection holes of a fuel injector that mixes and injects hydrogen and air finer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] Under certain operating conditions, hydrogen combustors may have difficulty maintaining a hydrogen flame. For example, when hydrogen combustors are installed in aircraft, changes in air pressure and temperature can cause the hydrogen flame to become unstable. Therefore, there is a need for technology that can maintain a hydrogen flame over a wide range of operating conditions.

[0007] In view of the above circumstances, the object of the present invention is to provide a hydrogen combustor, a hydrogen combustor system, a jet engine, and a power generation device capable of maintaining a hydrogen flame over a wide operating range. [Means for solving the problem]

[0008] To achieve the above objective, a hydrogen combustor according to one embodiment of the present invention comprises at least one fuel injector module and a hydrogen supply pipe. The aforementioned at least one fuel injector module is configured by modularizing a plurality of fuel injectors, each having an air inlet pipe with a swirler for swirling air, a hydrogen injection pipe that injects gaseous hydrogen substantially perpendicular to the swirling air passing through the swirler so as to collide with the inner wall of the air inlet pipe, and a flame-holding section that widens the flow path of the mixed gas of air and hydrogen in a step-like manner. The hydrogen supply pipe supplies hydrogen to the hydrogen injection pipes of the multiple fuel injectors constituting the fuel injector module by dividing the supply into multiple supply systems.

[0009] This hydrogen combustor is equipped with a fuel injector module that modularizes multiple fuel injectors. In each fuel injector, hydrogen is injected nearly perpendicular to the swirling air so as to collide with the inner wall of the air intake pipe, and the air and hydrogen are thoroughly mixed. The mixed gas is injected from a stepped flame holder. This allows each fuel injector to operate over a wide operating range. Furthermore, each fuel injector in the fuel injector module is supplied with hydrogen from multiple supply systems. This expands the control patterns of fuel injection and mixing throughout the combustor, making it possible to maintain a hydrogen flame over a wide operating range.

[0010] The aforementioned at least one fuel injector module may include a plurality of fuel injector modules. In this case, the hydrogen supply pipe may supply hydrogen to each of the plurality of fuel injector modules by separating the supply system.

[0011] The plurality of fuel injector modules may be arranged in a ring shape.

[0012] The hydrogen combustor may have a liner head that supports the plurality of fuel injector modules, and a combustor liner connected to the liner head that surrounds a combustion region formed downstream of the plurality of fuel injector modules.

[0013] At least one of the liner head and the combustor liner may have a plurality of first air vents provided between adjacent fuel injector modules.

[0014] The combustor liner may have a plurality of second air holes that allow the air to flow in substantially perpendicular to the flow of the hydrogen flame in the combustion region.

[0015] A hydrogen combustor system according to one embodiment of the present invention comprises a hydrogen combustor and a control unit. The aforementioned hydrogen combustor is A fuel injector module comprising at least one fuel injector module, each having an air inlet pipe with a swirler for swirling air, a hydrogen injection pipe for injecting gaseous hydrogen substantially perpendicular to the swirling air passing through the swirler so as to collide with the inner wall of the air inlet pipe, and a flame-holding section for widening the flow path of the mixed gas of air and hydrogen in a stepped manner, The fuel injector module comprises a hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the plurality of fuel injectors by dividing them into a plurality of supply systems. The control unit controls the amount of hydrogen supplied to the plurality of supply systems based on operating information relating to the operation of the hydrogen combustor.

[0016] The plurality of fuel injectors may include at least one first fuel injector and a plurality of second fuel injectors connected to a different supply system than the first fuel injector. In this case, the fuel injector module may be configured with the first fuel injector positioned in the center and the second fuel injectors arranged in a ring around the first fuel injector.

[0017] The control unit may supply the hydrogen to only one of the first fuel injector or the second fuel injector.

[0018] The control unit may, when starting the hydrogen combustor, supply hydrogen only to the first fuel injector, thereby operating the first fuel injector as a pilot injector.

[0019] During operation of the hydrogen combustor, the control unit may make the supply amount of hydrogen to the first fuel injector smaller than the supply amount of hydrogen to the second fuel injector.

[0020] When the hydrogen flame goes out in a state where the atmospheric pressure is lower than a predetermined level, the control unit may make the supply amount of hydrogen to the first fuel injector larger than the supply amount to the second fuel injector.

[0021] The control unit may control the supply amount of hydrogen so that either a diffusion flame or a premixed flame, which is one of the flame forms formed in the combustion in the fuel injector, becomes dominant.

[0022] When a sign of combustion vibration is detected, the control unit may control the supply amount of hydrogen so that the combustion vibration is suppressed.

[0023] A jet engine according to one embodiment of the present invention includes a compressor, a hydrogen combustor, and a turbine. The compressor compresses air. The hydrogen combustor At least one fuel injector module in which a plurality of fuel injectors each having a swirler for swirling air from the compressor, a hydrogen injection pipe for injecting gaseous hydrogen substantially perpendicular to the swirling air passing through the swirler so as to collide with the inner wall of the air introduction pipe, and a flame holding part for expanding the flow path of the mixed gas of the air and the hydrogen in a stepped manner are modularized, And a hydrogen supply pipe for supplying hydrogen by dividing a plurality of supply systems to the hydrogen injection pipes of the plurality of fuel injectors constituting the fuel injector module. The turbine drives the compressor using the combustion gas from the hydrogen combustor as a driving source and discharges the combustion gas to generate thrust.

[0024] A power generation device according to one embodiment of the present invention includes a compressor, a hydrogen combustor, and a turbine. The compressor compresses air. The hydrogen combustor At least one fuel injector module comprising multiple fuel injectors, each having an air inlet pipe with a swirl mechanism for swirling air from the compressor, a hydrogen injection pipe for injecting gaseous hydrogen substantially perpendicular to the swirling air passing through the swirl mechanism so as to collide with the inner wall of the air inlet pipe, and a flame-holding section that widens the flow path of the mixed gas of air and hydrogen in a stepped manner, The fuel injector module comprises a hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the plurality of fuel injectors by dividing them into a plurality of supply systems. The turbine drives the compressor and the generator using the combustion gas from the hydrogen combustor as a power source. [Effects of the Invention]

[0025] As described above, the present invention makes it possible to maintain a hydrogen flame over a wide operating range. The effects described herein are not necessarily limited, and any of the effects described in this disclosure may also be present. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram showing an example of an aircraft equipped with a jet engine including a hydrogen combustor system according to one embodiment of the present invention. [Figure 2] This is a block diagram showing an example configuration of a jet engine, including a hydrogen combustor system. [Figure 3] This is a schematic cross-sectional view showing an example of a fuel injector configuration. [Figure 4] This is a plan view showing an example configuration of a fuel injector module. [Figure 5] This is a plan view showing an example of the arrangement of fuel injector modules in a hydrogen combustor. [Figure 6] This is a perspective view showing an example of a combustor liner that makes up a hydrogen combustor. [Figure 7] This is a cross-sectional view showing an example of the configuration of a fuel injector module in a hydrogen combustor. [Figure 8] This is a schematic diagram showing an example of the configuration of the first air vent. [Figure 9] This is a schematic diagram showing an example of the configuration of the second air vent. [Figure 10] This is a schematic diagram showing an example of a hydrogen supply line. [Figure 11] This is a schematic diagram showing an example of a hydrogen supply line according to another embodiment. [Modes for carrying out the invention]

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Jet engine including hydrogen combustion system] Figure 1 is a schematic diagram showing an example of an aircraft equipped with a jet engine including a hydrogen combustor system according to one embodiment of the present invention. The aircraft 10 consists of a fuselage 11, main wings 12, a vertical stabilizer 13, a horizontal stabilizer 14, etc. Engine nacelles 15 are located on each of the left and right main wings 12. Each engine nacelle 15 is equipped with a jet engine 20 including a hydrogen combustor system 100 that uses hydrogen as fuel.

[0028] Figure 2 is a block diagram showing an example configuration of a jet engine 20 including a hydrogen combustor system 100. The jet engine 20 has a compressor 21, a hydrogen combustor 22, and a turbine 23. The aircraft 10 equipped with the jet engine 20 is also equipped with a hydrogen tank 24, a hydrogen supply line 25, and a control unit 26. Of these, the hydrogen tank 24, the hydrogen supply line 25, the hydrogen combustor 22, and the control unit 26 constitute the hydrogen combustor system 100.

[0029] The jet engine 20 is a propulsion engine that obtains thrust by burning oxygen from the air and hydrogen 1 stored in a hydrogen tank 24 in a hydrogen combustor 22, and producing a jet of combustion gases. The jet engine 20 is typically configured as a turbofan engine, and the hydrogen combustor 22 functions as a high-pressure combustor mounted on the turbofan engine. The size of the jet engine 20 is not particularly limited, but the present invention can be applied to, for example, a turbofan engine for a passenger aircraft with 50 seats or more. The jet engine 20 according to the present invention also includes cases in which a jet is generated, rotational force is generated using a turbine, and this is converted into lift for a propeller or fan and used as thrust.

[0030] In recent years, hydrogen aircraft technology, which emits no carbon dioxide during combustion, has attracted attention as a promising means of mitigating the impact of aircraft operations on global warming. The hydrogen combustor 22 according to this embodiment is a combustor that uses hydrogen as fuel, which emits no carbon dioxide, and is intended to operate over a wide range of operating conditions, similar to a jet engine 20.

[0031] The compressor 21 compresses the air taken into the jet engine 20. The compressor 21 is connected to the turbine 23 (described later) via a rotating shaft 27 and is driven by the rotation of the turbine 23 (rotating shaft 27). The specific configuration of the compressor 21 is not limited, and any type of compressor such as an axial flow compressor, centrifugal compressor, or mixed flow compressor may be used.

[0032] The hydrogen combustor 22 burns compressed air from the compressor 21 with hydrogen fuel to inject high-pressure combustion gas. The combustion gas is sent to the turbine 23 located downstream of the hydrogen combustor 22. In this embodiment, the hydrogen combustor 22 is configured by arranging multiple fuel injector modules, each module containing multiple fuel injectors. The specific configuration of the hydrogen combustor 22 will be described in detail later.

[0033] The turbine 23 uses combustion gases from the hydrogen combustor 22 as a driving source to drive the compressor 21 and discharge the combustion gases to generate thrust. The turbine 23, receiving the combustion gases, rotates together with the rotating shaft 27, and the rotating shaft 27 rotates the compressor 21. The combustion gases that have passed through the turbine 23 are discharged from the main nozzle at the rear of the engine nacelle 15, generating thrust.

[0034] The hydrogen tank 24 is a tank for storing hydrogen, which will be used as fuel for the hydrogen combustor 22. For example, the hydrogen tank 24 may be an insulated container configured to store liquefied hydrogen.

[0035] The hydrogen supply line 25 is a supply line that supplies hydrogen stored in the hydrogen tank 24 to the hydrogen combustor 22. The hydrogen supply line 25 is composed of a hydrogen pump, shut-off valves (safety valves), distribution valves, flow control valves, and piping connecting each part. As will be described later, in this embodiment, the hydrogen supply line 25 is provided with multiple supply systems that can independently adjust the amount of hydrogen supplied (see Figures 10 and 11, etc.).

[0036] The control unit 26 is configured using a computer with a CPU (Central Processing Unit) and memory. The control unit 26 controls the operation of the hydrogen combustor 22 by controlling the hydrogen supply line 25. The control unit 26 may be a FADEC (Full Authority Digital Engine Control) or the like that outputs the amount of fuel supplied (flow rate instruction). The control unit 26 sets the amount of fuel supplied according to, for example, the amount of throttle operation performed by the pilot of the aircraft 10 or the operating status of the jet engine 20.

[0037] In this embodiment, the control unit 26 controls the amount of hydrogen supplied to multiple supply systems of the hydrogen supply line 25 based on operating information related to the operation of the hydrogen combustor 22. Operating information refers to information related to the operation of the hydrogen combustor 22. Operating information may include operational information such as the throttle lever, fuel shut-off lever, ignition switch, and de-icing switch. Operating information may also include sensing information detected by predetermined sensors, such as temperature and pressure at various parts of the engine (engine inlet, compressor inlet, compressor outlet, hydrogen combustor, turbine inlet, turbine outlet, etc.), exhaust temperature, and rotational speed of the rotating shaft. Operating information may also include environmental information related to the operating environment of the hydrogen combustor 22, such as ambient temperature and pressure.

[0038] Based on this operating information, the control unit 26 sets the supply amount for each supply system that enables proper operation of the hydrogen combustor 22.

[0039] [Fuel injector configuration] Figure 3 is a schematic cross-sectional view showing an example of a fuel injector configuration. The fuel injector 30 is a nozzle that injects gaseous hydrogen 1 together with air 2. The fuel injector 30 has an air inlet pipe 31, a hydrogen injection pipe 32, and a flame retaining section 33. The fuel injector 30 shown in Figure 3 is also provided with a combustion cylinder 34.

[0040] The air inlet pipe 31 and the hydrogen injection pipe 32 are cylindrical members extending in one direction. The outer diameter of the hydrogen injection pipe 32 is smaller than the inner diameter of the air inlet pipe 31, and the hydrogen injection pipe 32 is positioned so that its central axis coincides with the inside of the air inlet pipe 31. Here, the three mutually orthogonal axial directions are referred to as the X direction, Y direction, and Z direction, with the direction in which the air supply pipe and hydrogen supply pipe 56 extend being defined as the X direction. Figure 3 shows a cross-sectional view of the fuel injector 30 cut in the XY plane passing through the central axis of the air inlet pipe 31 (hydrogen injection pipe 32).

[0041] The air inlet pipe 31 is a pipe through which compressed air 2 from the compressor 21 is introduced, and a circular pipe member with open ends is used. As described above, the hydrogen injection pipe 32 is arranged coaxially inside the air inlet pipe 31, and the space between the inner wall 31b of the air inlet pipe 31 and the outer wall 32a of the hydrogen injection pipe 32 becomes the flow path for the air 2. Note that the cross-sectional shape of the air inlet pipe 31 is not limited to a circle, and a tubular member with any cross-sectional shape, such as a polygon or an ellipse, may be used.

[0042] The air intake pipe 31 has an inlet end 35, an outlet end 36, and a swivel mechanism 37. The inlet end 35 is an open end into which compressed air 2 flows. The outlet end 36 is an open end on the opposite side from the inlet end 35. A mixed gas of compressed air 2 and hydrogen 1 from the hydrogen injection tube 32 is injected from the outlet end 36.

[0043] The swirler 37 is a mechanism (swirler) that swirls the air 2 flowing in from the inlet end 35. The swirler 37 is constructed, for example, by arranging a plate member (fixed wing) diagonally with respect to the flow path between the inner wall 31b of the air inlet pipe 31 and the outer wall 32a of the hydrogen injection pipe 32. The air 2 that has passed through the swirler 37 becomes swirling air and is sent to the outlet end 36. A space (injection area 40) for injecting hydrogen 1 is provided between the swirler 37 and the outlet end 36. Therefore, the swirler 37 is positioned at a predetermined distance inward from the outlet end 36.

[0044] The hydrogen injection tube 32 is a tube that injects hydrogen 1 supplied from a predetermined supply system, and is constructed by providing an injection hole 41 in a circular tube member that is open at one end and closed at the other end. The length of the hydrogen injection tube 32 is set to be longer than that of the air inlet tube 31. The cross-sectional shape of the hydrogen injection tube 32 is not limited to a circle, and a tubular member with any cross-sectional shape, such as a polygon or an ellipse, may be used.

[0045] The hydrogen injection tube 32 has an open end 42, a closed end 43, and an injection hole 41. The open end 42 is connected to a hydrogen supply pipe, which will be described later, and functions as a supply port for supplying gaseous hydrogen 1 into the hydrogen injection pipe 32. The closed end 43 is a closed end located on the opposite side from the open end 42. The hydrogen supply pipe 56 is positioned inside the air inlet pipe 31 such that the closed end 43 is on the same side as the outlet end 36 of the air inlet pipe 31. At this time, the position of the end face of the closed end 43 in the X direction and the position of the end face of the outlet end 36 in the X direction are set to be the same. Therefore, the hydrogen injection pipe 32 has the end faces of the closed end 43 and the outlet end 36 coinciding, and the open end 42 protrudes from the inlet end 35 side of the air inlet pipe 31. The closed end 43 may be a one-piece structure cut so as not to penetrate using a drill or the like, or it may be a structure in which the opening portion is closed with a cover member.

[0046] The injection holes 41 are provided on the side of the hydrogen injection tube 32 near the closed end 43 and are through holes that penetrate the inner wall 32b and outer wall 32a of the hydrogen injection tube 32. The injection holes 41 are located facing the injection region 40 between the swivel 37 and the outlet end 36 of the air intake tube 31. Multiple injection holes 41 are provided at equal intervals along the circumferential direction of the hydrogen injection tube 32.

[0047] The hydrogen 1 supplied from the open end 42 is blocked by the inner surface of the closed end 43 and injected from the injection hole 41. Here, a conical recess is formed on the inner surface of the closed end 43, making it easier for the hydrogen 1 to flow into the injection hole 41. The inner surface of the closed end 43 may also be flat. Air 2, which has passed through the swirl 37 and swirled, is supplied to the location where the injection port 41 is provided (injection region 40). Hydrogen 1 is injected approximately perpendicular to this swirling air 2. In addition, the inner wall 31b of the air intake pipe 31 is located opposite the injection port 41. Therefore, the hydrogen 1 injected from the injection port 41 collides with the inner wall 31b.

[0048] In this manner, the hydrogen injection tube 32 injects gaseous hydrogen 1 approximately perpendicular to the swirling air 2 passing through the swirl mechanism 37 so as to collide with the inner wall 31b of the air intake tube 31. By utilizing the collision between the swirling air 2 and the inner wall 31b, it becomes possible to sufficiently diffuse and mix the hydrogen 1 and the air 2. In other words, the fuel injector 30 also functions as a mixer for mixing hydrogen 1 and air 2. This makes it possible to achieve a stable premixed flame with a simple configuration.

[0049] The combustion cylinder 34 is a component that encloses the combustion region where the hydrogen flame 4 is generated. In the example shown in Figure 3, the cylindrical combustion cylinder 34 is fitted into a spacer member 38 that surrounds the outer wall 31a of the air intake pipe 31. The spacer member 38 may also be provided with air holes or the like to supply air in order to obtain an airflow straightening effect and a cooling effect on the fuel injector 30. The combustion chamber 34 corresponds to the combustor liner 51 (see Figures 6 and 7, etc.) in the configuration of the hydrogen combustor 22, which will be described later. In a fuel injector module in which the fuel injectors 30 are modularized, it is not necessary to provide a combustion chamber 34 for each fuel injector 30.

[0050] The flame-holding section 33 is the part that holds the hydrogen flame 4. In the fuel injector 30, the flame-holding section 33 is formed by the air intake pipe 31 and the hydrogen injection pipe 32. As described above, the exit end 36 of the air intake pipe 31 and the closed end 43 of the hydrogen injection pipe 32 have their respective end faces on the same plane. Therefore, the flow path of the mixed gas mixture mixed in the injection region 40 widens rapidly at the end face of the exit end 36 (closed end 43). In other words, the fuel injector 30 is provided with a flame-holding section 33 that widens the flow path of the mixed gas of air 2 and hydrogen 1 in a stepped manner. This makes it possible to rapidly change the flow velocity of the mixed gas, and to keep the distribution of the hydrogen flame 4 within an appropriate range.

[0051] Thus, the hydrogen combustor 22 is configured using a fuel injector 30 that has a flame-holding section 33 at a stepped cylindrical outlet, in which hydrogen fuel injected perpendicularly into a swirling airflow is promoted to diffuse and mix by impact with the inner wall 31b. The inventors have confirmed that the fuel injector 30 configured in this way can perform combustion operation by appropriately setting the operating conditions in various operating ranges, such as stationary operation on the ground and operation in environments where the airflow exceeds the speed of sound. Therefore, by using the fuel injector 30 according to this embodiment, it is possible to realize a hydrogen combustor 22 that can operate over a wide range of operating conditions.

[0052] The shape, size, material, etc. of each part of the fuel injector 30 can be appropriately set according to the expected output, weight, and other specifications. The inner diameter of the air inlet pipe 31 is preferably set to a range of 4 mm to 10 mm. More preferably, the inner diameter of the air inlet pipe 31 is set to 6 mm or less. This makes it possible to achieve proper diffusion mixing. Setting it to 4 mm or more makes it possible to ensure a sufficient amount of air inflow. The outer diameter of the hydrogen injection tube 32 is less than or equal to the inner diameter of the air inlet tube 31, and is preferably set in the range of 2 mm to 6 mm. More preferably, the outer diameter of the hydrogen injection tube 32 is set to 4 mm or less. This makes it possible to make the size of the injector compact while ensuring an air passage. Furthermore, by setting it to 2 mm or more, it is possible to ensure a sufficient hydrogen inflow rate and to process the injection holes 41 and other parts with appropriate precision. The diameter of the injection holes 41 provided in the hydrogen injection pipe 32 is preferably set in the range of 0.2 mm to 1.5 mm. By setting it to 1.5 mm or less, it becomes possible to locally inject hydrogen while ensuring a predetermined momentum flow velocity during hydrogen injection. As a result, it becomes possible to collide hydrogen with the inner wall 31b of the air inlet pipe 31 near the design point, thereby effectively achieving diffusion mixing with swirling air. Furthermore, by setting the diameter of the injection holes 41 to 1 mm or less, it becomes possible to sufficiently prevent backflow and flashback into the hydrogen injection pipe through the fuel injection holes. The hydrogen injection volume from the hydrogen injection tube 32 can be adjusted by the size and number of injection holes 41. For example, the number of injection holes 41 arranged around the circumference is set to match the diameter of the injection holes 41 so that an appropriate hydrogen injection volume is achieved. The number of injection holes 41 is typically set to about 4 to 10, considering the number that can be arranged around the circumference and ensuring uniformity of the injected hydrogen. In addition, the number of injection holes 41 is not limited and may be set arbitrarily, for example, to ensure a desired hydrogen injection volume.

[0053] [Fuel Injector Module Configuration] Figure 4 is a plan view showing an example of the configuration of a fuel injector module. The hydrogen combustor 22 is provided with at least one fuel injector module 45, which is a modularized unit comprising multiple fuel injectors 30. In this embodiment, the hydrogen combustor 22 is provided with multiple fuel injector modules 45 (see Figures 5 and 6, etc.). Figure 4 shows an example of a plan view of the fuel injector module 45 as seen from the outlet side (the side where the outlet end 36 and the closed end 43 of the fuel injector 30 are located) from which the fuel mixture is injected. The fuel injector module 45 has a plurality of fuel injectors 30 and a holding part 46 that holds each fuel injector 30.

[0054] In the fuel injector module 45 shown in Figure 4, multiple fuel injectors 30 are arranged in a ring shape around one in the center. Hereafter, the fuel injector 30 located in the center will be referred to as the central fuel injector 30a, and the fuel injectors 30 arranged in a ring shape will be referred to as the peripheral fuel injectors 30b. In other words, the fuel injector module 45 is configured with a central fuel injector 30a positioned in the center and peripheral fuel injectors 30b arranged in a ring around the central fuel injector 30a.

[0055] Furthermore, the central fuel injector 30a and the multiple peripheral fuel injectors 30b are connected to different supply systems. That is, the central fuel injector 30a at the center of the module is supplied with fuel from a fuel piping independent of the surrounding injector group. Since the multiple peripheral fuel injectors 30b are each connected to a common supply system, the amount of hydrogen 1 supplied to each peripheral fuel injector 30b is approximately equal to each other. In this embodiment, the central fuel injector 30a corresponds to the first fuel injector. The multiple peripheral fuel injectors 30b correspond to multiple second fuel injectors connected to a different supply system than the first fuel injector.

[0056] In this way, by making the supply system of the central fuel injector 30a independent, it becomes possible to change the flow rate ratio of hydrogen fuel to air in the central and peripheral parts of the module. Furthermore, by controlling the fuel injector module 45 using, for example, two different supply amounts as parameters, it becomes possible to broaden the control variations. As a result, it becomes possible to realize various combustion patterns according to the operating conditions of the jet engine 20 (hydrogen combustor 22).

[0057] The retaining portion 46 holds the central fuel injector 30a and the multiple peripheral fuel injectors 30b, respectively. Here, the retaining portion 46 is a circular-shaped member with insertion holes for inserting each fuel injector 30. The configuration of the retaining portion 46 is not limited, and a retaining portion 46 with a hollow structure or a bridging structure may be used. Furthermore, a structure in which the central part and the peripheral part are separated may be used so that the central fuel injector 30a can be removed independently.

[0058] [Configuration of a hydrogen combustion system] Figure 5 is a plan view showing an example of the arrangement of fuel injector modules in a hydrogen combustor. Figure 6 is a perspective view showing an example of a combustor liner that constitutes a hydrogen combustor. Here, we will describe the arrangement of the fuel injector modules 45 in a hydrogen combustor 22 that is composed of multiple fuel injector modules 45. The hydrogen combustor 22 includes a plurality of fuel injector modules 45, a liner head 50, and a combustor liner 51.

[0059] The liner head 50 is a component that supports multiple fuel injector modules 45. In this embodiment, a plurality of fuel injector modules 45 are arranged in a ring shape. These fuel injector modules 45 are supported by a liner head 50. As shown in Figure 5, the liner head 50 is a component with a planar shape that is annular. In this configuration, 16 fuel injector modules 45 are arranged in an annular shape at equal intervals within the annular portion. The number of fuel injector modules 45 is not limited. The injection directions of each fuel injector module 45 (fuel injector 30) are set to be parallel to each other, but they may also be arranged so that, for example, each injection direction converges or diverges.

[0060] The combustor liner 51 is connected to the liner head 50 and is a component that surrounds the combustion region 5 formed downstream of the multiple fuel injector modules 45. In other words, the inside of the combustor liner 51 is used as the combustion region 5. As shown in Figure 6, the combustor liner 51 has an inner liner 52, an outer liner 53, and a combustion gas outlet 54. The inner liner 52 is a cylindrical member connected to the inner circumference of the annular liner head 50. The outer liner 53 is a cylindrical member connected to the outer circumference of the annular liner head 50 and surrounding the inner liner 52. The combustion gas outlet 54 is an annular opening formed on the opposite side from the liner head 50, sandwiched between the inner liner 52 and the outer liner 53.

[0061] Thus, the region enclosed by the inner liner 52 and the outer liner 53 of the combustor liner 51 becomes the combustion region 5 of the hydrogen combustor 22. The space enclosed by the inner liner 52 (the inner circumference of the liner head 50) is, for example, through which the rotating shaft 27 of the jet engine 20 passes.

[0062] Figure 7 is a cross-sectional view showing an example configuration of a fuel injector module 45 in a hydrogen combustor 22. Figure 7 schematically illustrates a cross-sectional view of the hydrogen combustor 22 cut along line AA, which passes through the center of one fuel injector module 45 in Figure 6. In Figure 7, the flow of air 2 and the flow of hydrogen 1 are schematically illustrated using white and black arrows, respectively.

[0063] The hydrogen combustor 22 is equipped with a hydrogen supply pipe 56 that supplies hydrogen to multiple fuel injector modules 45. The hydrogen supply pipe 56 supplies hydrogen to the hydrogen injection pipes 32 of the multiple fuel injectors 30 that make up the fuel injector module 45 by dividing the supply into multiple supply systems. Specifically, the hydrogen supply line 56 includes multiple supply lines connected to multiple supply systems, each capable of independently adjusting the amount of hydrogen 1 supplied. Fuel injectors 30 connected to supply lines leading to different supply systems have their hydrogen 1 supply adjusted separately. On the other hand, fuel injectors 30 connected to supply lines leading to the same supply system have their hydrogen 1 supply adjusted to similar values.

[0064] In this embodiment, the hydrogen supply pipe 56 has a first supply pipe 57a and a second supply pipe 57b. The hydrogen supply pipe 56 also has a first supply main pipe 58a and a second supply main pipe 58b. The first supply pipe 57a is connected to the hydrogen injection pipe 32 of the central fuel injector 30a of the fuel injector module 45. The first supply pipe 57a is inserted from the outside of the hydrogen combustor 22 and connected to the hydrogen injection pipe 32 of the central fuel injector 30a via a predetermined joint 59. The second supply pipe 57b is connected to each hydrogen injection pipe 32 of the multiple peripheral fuel injectors 30b of the fuel injector module 45. The second supply pipe 57b is inserted from the outside of the hydrogen combustor 22 and has a branch section 60 at its tip. The branch section 60 is an annular pipe, and the second supply pipe 57b is connected to each hydrogen injection pipe 32 of the multiple peripheral fuel injectors 30b via the branch section 60. The hydrogen injection pipe 32 of the central fuel injector 30a passes through the center of the branch section 60.

[0065] The first supply main pipe 58a and the second supply main pipe 58b are pipes that supply hydrogen to the first supply pipe 57a and the second supply pipe 57b connected to each fuel injector module 45. The first supply main pipe 58a and the second supply main pipe 58b are configured, for example, as annular pipes arranged along the outside of the hydrogen combustor 22. The first supply main pipe 58a and the second supply main pipe 58b are connected to different supply systems. Therefore, the amount of hydrogen 1 supplied can be independently adjusted in the first supply main pipe 58a and the second supply main pipe 58b (first supply pipe 57a and second supply pipe 57b). This makes it possible to connect multiple supply systems to each fuel injector module 45. In this manner, the hydrogen supply pipe 56 supplies hydrogen 1 to each of the multiple fuel injector modules 45 by separating the supply system.

[0066] As shown in Figure 7, the hydrogen combustor 22 has a liner head 50 that supports the multiple fuel injector modules 45 described above, and a combustor liner 51 that surrounds the combustion area 5. The hydrogen combustor 22 also has a casing 65 that houses the liner head 50 and the combustor liner 51, and an ignition unit (not shown) for igniting the fuel injector modules 45. The ignition unit is located, for example, inside the combustor liner 51, and ignites the mixture of hydrogen 1 and air 2. The number and arrangement of the ignition units are not limited. The casing 65 constitutes a passage for compressed air 2 around the liner head 50 and the combustor liner 51. In the following, the left side of the diagram will be referred to as the upstream side, and the right side as the downstream side.

[0067] The casing 65 has an inner case 66, an outer case 67, and a compressed air inlet 68. The inner case 66 is a cylindrical member that forms the inner wall surface of the casing 65. The downstream side of the inner case 66 is inserted into the central part of the combustor liner 51 (inner liner). An annular opening (compressed air inlet 68) for introducing compressed air 2 is formed on the upstream side of the inner case 66. The outer case 67 is a cylindrical member that forms the outer wall surface of the casing 65. The first supply pipe 57a and the second supply pipe 57b described above are arranged to penetrate the outer case 67, and the first supply main pipe 58a and the second supply main pipe 58b are arranged to surround the outer case 67. A flow path for air 2 is formed between the inner case 66 and the inner liner 52, and between the outer case 67 and the outer liner 53.

[0068] The compressed air inlet 68 introduces compressed air 2 output from the compressor 21 into the casing 65. In the example shown in Figure 7, the compressed air inlet 68 is formed upstream of the center of the fuel injector module 45. A portion of the air 2 introduced from the compressed air inlet 68 passes through the hydrogen supply pipes 56 and flows into the air inlet pipe 31 of the fuel injector module 45, while another portion flows along the flow path formed between the casing 65 and the combustor liner 51. The specific configuration of the compressed air inlet 68 is not limited, and for example, a swirler for circulating the air 2 may be provided.

[0069] [Air vents] The following describes the air vents for introducing air 2 into the combustion region 5 surrounded by the liner head 50 and the combustor liner 51.

[0070] Figure 8 is a schematic diagram showing an example of the configuration of the first air vent. The first air vent 71 is an air vent located between adjacent fuel injector modules 45. More specifically, the first air vent 71 is a number of minute air vents located between each module. For example, the diameter of the first air vent 71 is set to be sufficiently smaller than the diameter of each fuel injector 30 (the diameter of the air intake pipe 31). The first air vent 71 can be described as a primary air vent located upstream of the combustion region 5.

[0071] In the example shown in Figure 8, numerous tiny first air holes 71 are provided between adjacent fuel injector modules 45 in the liner head 50. This makes it possible to supply air 2 to the hydrogen flame 4 produced by each fuel injector module 45 relatively gently and stably. Furthermore, since the airflow is generated along the injection direction of the fuel mixture from the fuel injector 30, it is possible to compact the hydrogen flame 4 and suppress the occurrence of flashbacks, etc. As a result, it becomes possible to stabilize the hydrogen flame 4. As shown in Figure 8, the first air vents 71 may be provided not only between adjacent fuel injector modules 45, but also along the inside and outside of each fuel injector module 45. This allows air to be introduced to surround each fuel injector module 45, sufficiently stabilizing the hydrogen flame 4. It becomes possible to do so.

[0072] The location of the first air holes 71 is not limited to the liner head 50. In Figure 7, multiple first air holes 71 are provided in the combustor liner 51. In the example shown in Figure 7, the first air holes 71 are shown located inside or outside (below or above in the figure) the fuel injector modules 45, and the air 2 supplied to the combustion region 5 through the first air holes 71 is illustrated by fine dotted arrows. Of course, the first air holes 71 may also be provided in the portion of the combustor liner 51 between each fuel injector module 45. Thus, at least one of the liner head 50 and the combustor liner 51 has a plurality of first air holes 71 provided between adjacent fuel injector modules.

[0073] Figure 9 is a schematic diagram showing an example of the configuration of the second air vent. The second air vent 72 is an air vent that allows air to flow in approximately perpendicular to the flow of the hydrogen flame 4 in the combustion region 5. Typically, the second air vent 72 is located in the combustor liner 51, in the intermediate portion between the liner head 50 and the combustion gas outlet 54. The diameter of the second air vent 72 is not limited; for example, it may be about the same as the diameter of the first air vent 71, or it may be larger than the diameter of the fuel injector 30 (the diameter of the air intake pipe 31). The second air vent 72 can be described as a vertical-intake type secondary air vent.

[0074] As shown in Figure 7, the middle section of the combustor liner 51 has a side surface that is parallel to the X direction (the direction of flow of the hydrogen flame 4) from which the gas mixture is injected. In this way, the second air hole 72 is formed perpendicular to the side surface that is aligned with the flow of the hydrogen flame 4. This makes it possible to introduce air almost perpendicular to the hydrogen flame 4. In the example shown in Figure 9, a number of relatively small through-holes are formed as the second air holes 72. In Figure 9, the general shape of the combustor liner 51 is shown with a dotted line. Here, the second air holes 72 are formed at positions between the fuel injector modules 45, but the design is not limited to this, and the second air holes 72 may be formed at positions overlapping each fuel injector module 45.

[0075] Figure 7 also shows a second air vent 72 with a relatively large diameter, located on the side along the flow of the hydrogen flame 4. The air 2 supplied to the combustion region 5 through the second air vent 72 is illustrated by a coarse dotted arrow. Here, a grommet-shaped guide tube is used to guide the air 2. By using this guide tube, it is possible to introduce air almost perpendicular to the hydrogen flame 4, regardless of the shape of the side of the combustor liner 51.

[0076] By providing multiple second air vents 72 and introducing air 2 almost perpendicularly to the hydrogen flame 4 produced by each fuel injector module 45, it becomes possible to shorten the recirculation flame-holding region (recirculation region) containing high-temperature combustion gases that is formed behind the flame-holding section 33. This reduces the region with locally high temperatures, making it possible to achieve a compact and stable flame with low NOx emissions. Furthermore, even if the operating conditions of the hydrogen combustor 22 change, for example, the expansion of the hydrogen flame 4 can be sufficiently suppressed.

[0077] In addition to the first air hole 71 and the second air hole 72, the combustor liner 51 shown in Figure 7 is also provided with various other air holes for introducing air 2. For example, through holes or slits provided on the side, or guide pipes that penetrate the combustor liner may be appropriately provided as air holes. In Figure 7, the air flowing in from these various air holes is schematically illustrated by solid arrows.

[0078] Thus, the hydrogen combustor 22 modularizes the fuel injector 30, as explained with reference to Figure 3, and divides the fuel supply system into two stages, a central part and a peripheral part, thereby expanding the control range of the hydrogen fuel injection and mixing pattern. Furthermore, by arranging numerous two-stage fuel injector modules in a ring-like configuration, a fine and stable hydrogen flame 4 is realized as a temperature field with minimal distribution. Furthermore, in order to complete the hydrogen flame 4 within a small volume over a wide operating range, air inlet holes (first air hole 71 and second air hole 72) are provided around the fuel injector 30 and on the side of the combustor liner 51. By designing the distribution of the air flow 2 flowing in from these air holes to accommodate a wide operating range, it is possible to ensure sufficient stabilization of the hydrogen flame 4.

[0079] [Configuration of the hydrogen supply line] Figure 10 is a schematic diagram showing an example of a hydrogen supply line. The hydrogen supply line 25 includes a hydrogen pump 80, a first shut-off valve 81, a second shut-off valve 82, a distribution valve 83, and a plurality of flow control valves 84. Each of these parts of the hydrogen supply line 25 is controlled by a control unit 26, which was described with reference to Figure 2. In Figure 10, the fuel injector module 45 is schematically illustrated using one central fuel injector 30a and two peripheral fuel injectors 30b.

[0080] The hydrogen pump 80 sends the hydrogen 1 stored in the hydrogen tank 24 to a line located downstream. Here, the hydrogen pump 80 is directly connected to the hydrogen tank 24, but a buffer tank or buffer container may also be provided. Since cryogenic liquefied hydrogen can be used for cooling, more than the required amount is pooled in a buffer tank or buffer container, and the required amount of hydrogen is sent downstream from there.

[0081] Furthermore, in the hydrogen supply line 25, it is assumed that hydrogen 1 is supplied in gaseous form at the combustor inlet (open end 42 of the hydrogen injection pipe 32). However, from the perspective of supplying and managing cryogenic liquefied hydrogen, the hydrogen pump 80 is configured to pump supercritical hydrogen 1 from upstream. The supercritical hydrogen 1 changes into a gas before reaching the combustor inlet. For example, a liquid hydrogen evaporator or the like is provided downstream of the flow control valve 84, and the hydrogen 1 vaporizes after flow control.

[0082] The first shut-off valve 81 and the second shut-off valve 82 are both valves that shut off the flow of hydrogen 1 and stop the supply of hydrogen 1, and for example, two-way solenoid valves are used. The first shut-off valve 81 and the second shut-off valve 82 are installed in this order downstream of the hydrogen pump 80. In this way, the hydrogen supply line 25 is equipped with a double set of shut-off valves downstream of the hydrogen pump 80 to shut off the fuel in an emergency.

[0083] The distribution valve 83 is connected downstream of the second shut-off valve 82 and is a valve that divides the hydrogen 1 supply system. Here, the distribution valve 83 forms two supply systems (a first supply system 85a and a second supply system 85b). The first supply system 85a is a system that supplies hydrogen 1 to the central fuel injector 30a of each fuel injector module 45. The second supply system 85a is a system that supplies hydrogen 1 to the peripheral fuel injectors 30b of each fuel injector module 45. The distribution valve 83 may be, for example, a branching pipe, or it may be configured to combine a branching pipe with a solenoid valve to cut off the hydrogen supply to each supply system.

[0084] Multiple flow control valves 84 are connected to the piping that constitutes each supply system separated by distribution valves, and adjust the amount (flow rate) of hydrogen 1 supplied to each supply system. For example, cryogenic electromagnetic flow control valves are used as flow control valves 84.

[0085] In the example shown in Figure 10, multiple flow control valves 84 are provided, including a first flow control valve 84a connected to the first supply system 85a and a second flow control valve 84b connected to the second supply system 85a. The first flow control valve 84a and the second flow control valve 84b are connected to the first supply main pipe 58a and the second supply main pipe 58b, respectively, as described with reference to Figure 7. Each flow control valve 84 adjusts the total amount of hydrogen in the connected supply system 85. These two flow control valves 84 enable a two-stage fuel supply for all fuel injector modules 45.

[0086] In addition to adjusting the hydrogen supply amount using the flow control valve 84, the hydrogen supply line 25 can also adjust the hydrogen supply amount by adjusting the pressure of the hydrogen pump 80. For example, by adjusting the pressure during pumping by the hydrogen pump 80, the amount of hydrogen supplied to the fuel injector 30 can be adjusted. Alternatively, pressure regulating valves or the like may be provided in each supply system to adjust the pressure in the piping.

[0087] In the configuration shown in Figure 10, the multiple fuel injector modules 45 may be divided into groups, and the hydrogen supply amount and combustion pattern may be controlled for each group. For example, each group may be provided with a distribution valve 83 and two flow control valves 84 (a first flow control valve 84a and a second flow control valve 84b). Alternatively, for example, a distribution valve 83 that forms two supply systems for each group may be used. In this case, if the number of groups is N, then a distribution valve 83 that forms N × 2 supply systems will be used. This makes it possible to use only some of the fuel injector modules 45, enabling fuel-efficient operation.

[0088] [Operation of the hydrogen combustion system] The control unit 26, as described with reference to Figure 2, controls the operation of the multiple fuel injectors 30 (fuel injector module 45) installed in the hydrogen combustor 22 by controlling the hydrogen pump 80, flow control valve 84, distribution valve 83, etc. The control of the hydrogen combustor 22 by the control unit 26 will be described below.

[0089] The control unit 26 may supply hydrogen 1 to only one of either the central fuel injector 30a or the peripheral fuel injector 30b. For example, the control unit 26 controls the distribution valve 83 so that hydrogen 1 is supplied to either the first supply system 85a connected to the central fuel injector 30a or the second supply system 85b connected to the peripheral fuel injector 30b. Alternatively, the control unit 26 may control either the first flow control valve 84a connected to the central fuel injector 30a or the second flow control valve 84b connected to the peripheral fuel injector 30b so that the flow rate becomes zero.

[0090] This allows for operation in which, for example, when the remaining amount of hydrogen 1 (fuel) is low or when there is a limited supply of hydrogen 1, either the central fuel injector 30a or the peripheral fuel injector 30b is used. For example, a decrease in the amount of hydrogen 1 supplied to the fuel injector 30 can lead to unstable combustion. By limiting the number of fuel injectors 30 used, it becomes possible to ensure a sufficient supply of hydrogen 1 to the fuel injectors 30 actually in use, thereby suppressing unstable combustion.

[0091] <Control during startup> The control unit 26 may, when starting the hydrogen combustor 22, supply hydrogen 1 only to the central fuel injector 30a, thereby operating the central fuel injector 30a as a pilot injector. The start-up of the hydrogen combustor 22 refers to the timing when the combustion operation that generates the hydrogen flame 4 in the hydrogen combustor 22, which had been stopped until then, begins. For example, the hydrogen combustor 22 is started when the jet engine 20 of the aircraft 10 is started. When the engine start switch is turned ON, for example, the control unit 26 supplies hydrogen from the first supply system 85a to the central fuel injector 30a. However, hydrogen 1 is not supplied from the second supply system 85b to the peripheral fuel injectors 30b.

[0092] When the jet engine 20 is started, the airflow rate supplied to the hydrogen combustor 22 is low. In this condition, it is difficult to operate all the fuel injectors 30 properly. Furthermore, operating all the fuel injectors 30 when thrust is not required will result in the unnecessary consumption of hydrogen 1. Therefore, when starting the jet engine 20, by supplying hydrogen 1 only to the central fuel injector 30a of the fuel injector module 45, it is possible to make the central fuel injector 30a function as the only operating pilot injector. The peripheral fuel injectors 30b, which are not supplied with hydrogen 1, function as air vents that supply air 2 to the central fuel injector 30a. This makes it possible to reliably generate a stable hydrogen flame 4 when starting the jet engine 20.

[0093] Furthermore, during operation of the jet engine 20 (hydrogen combustor 22), it is also possible to control the system so that hydrogen 1 is supplied only to the peripheral fuel injectors 30b, and the central fuel injector 30a is not activated. In this case, the central fuel injector 30a functions as a supply port for swirling air that does not inject hydrogen 1, and contributes to stabilizing the hydrogen flame 4 formed by the peripheral fuel injectors 30b.

[0094] <Control during operation> The control unit 26 may, during operation of the hydrogen combustor 22, reduce the amount of hydrogen 1 supplied to the central fuel injector 30a to less than the amount of hydrogen 1 supplied to the peripheral fuel injectors 30b. The operation of the hydrogen combustor 22 refers to the period during which the hydrogen flame 4 is continuously generated within a predetermined output range in the hydrogen combustor 22, and is typically the period during normal operation of the hydrogen combustor 22. During such a period, the amount of hydrogen 1 supplied to the central fuel injector 30a is set to be less than that supplied to the surrounding fuel injectors 30b. This control operation may be switched ON / OFF by selecting an operating mode.

[0095] In the hydrogen combustor 22 according to this embodiment, each fuel injector 30 is configured to perform rapid mixing and combustion as a partial premix combustor. That is, by controlling the amount of hydrogen 1 supplied, it is possible to control the flow rate ratio of hydrogen 1 to air 2 in each fuel injector 30, and the distribution and characteristics of the hydrogen flame 4 can be controlled individually. Specifically, the hydrogen flame 4 formed by two types of fuel injectors 30, a central fuel injector 30a and peripheral fuel injectors 30b, is controlled.

[0096] For example, if hydrogen 1 is supplied to all fuel injectors 30 constituting the fuel injector module 45 at the same supply rate, a hydrogen flame 4 with localized high temperatures may be formed, given that the fuel injectors 30 are located close together. In contrast, if the amount of hydrogen 1 supplied to the central fuel injector 30a is reduced compared to the surrounding fuel injectors 30b, the central portion of the hydrogen flame 4 formed by each fuel injector module 45 becomes thinner. This makes it possible to eliminate localized high-temperature combustion areas and suppress the generation of harmful gases such as nitrogen oxides (NOx).

[0097] In the operation described above, the amount of hydrogen 1 supplied to each fuel injector 30 is appropriately set according to the required engine output, etc., such that the amount of hydrogen 1 supplied to the central fuel injector 30a is less than that supplied to the surrounding fuel injectors 30b. Furthermore, the number of central fuel injectors 30a is significantly less than the number of peripheral fuel injectors 30b. Therefore, even if the amount of hydrogen 1 supplied to the central fuel injectors 30a is reduced, it is possible to control the overall output with ample margin.

[0098] <Control to prevent flashback> The control unit 26 may control the amount of hydrogen 1 supplied to the fuel injector 30 so as to prevent flashback of the hydrogen flame 4. The hydrogen combustor 22 mounted on the aircraft 10 is required to operate under a wide range of combustor inlet conditions (pressure, temperature, and wind speed). By maintaining an appropriate fuel flow rate and flow velocity inside the fuel injector 30 (hydrogen injection tube 32) for each of these conditions, it is possible to form a hydrogen flame 4 that does not cause flashback even when using hydrogen fuel with a high combustion rate.

[0099] For example, flashback can be avoided by increasing the supply of hydrogen 1 and thereby increasing the flow velocity. Also, for example, if the flow velocity (wind speed) of air 2 is sufficiently high, flashback can be avoided even if the flow velocity of hydrogen 1 is slightly reduced. In addition, the conditions under which flashback occurs differ depending on the pressure and temperature conditions.

[0100] The control unit 26 acquires parameters (pressure, temperature, wind speed) for these conditions from various sensors and sets the hydrogen 1 supply amount based on the acquired information to prevent flashback of the hydrogen flame 4. The hydrogen 1 supply amount is set for both the first supply system 85a and the second supply system 85b, for example. This makes it possible to form a stable hydrogen flame 4 that does not cause flashback under a wide range of operating conditions.

[0101] <Control to switch combustion methods> The control unit 26 may control the amount of hydrogen 1 supplied so that the flame form formed in the combustion of the fuel injector 30 is predominantly either a diffusion flame or a premixed flame. As described above, the fuel injector 30, which functions as a partial premixed combustor, can realize a flame configuration in which either a diffusion flame or a premixed flame is dominant, depending on how the air 2 and hydrogen 1 are mixed. The control unit 26 switches between the diffusion flame and the premixed flame by adjusting the amount of hydrogen 1 supplied.

[0102] A diffusion flame is a type of combustion (diffusion combustion) in which air 2 (oxygen) is supplied by diffusion from the outside of the hydrogen 1 flame. For example, if the amount of hydrogen 1 supplied to the fuel injector 30 is reduced, and the flow rate and velocity of hydrogen 1 are low, a flame will form without sufficient mixing of air 2 and hydrogen 1. The flame generated in this state is a diffusion flame associated with diffusion combustion, and it is a relatively safe flame with limited spread.

[0103] A premixed flame is a flame formed by a combustion mode (premixed combustion) in which a mixture of air 2 and hydrogen 1 burns to form a flame. For example, by increasing the amount of hydrogen 1 supplied to the fuel injector 30 and ensuring that the flow rate and velocity of hydrogen 1 are sufficiently high, rapid mixing of air 2 and hydrogen 1 is achieved. The mixture gas produced by this rapid mixing burns to form a flame. The flame generated in this state is a premixed flame associated with premixed combustion, and is, for example, a hotter flame with a wider spread than a diffusion flame.

[0104] For example, when a diffusion flame is dominant, control is performed to reduce the supply amount of hydrogen 1 according to the combustor inlet conditions, etc. When a premixed flame is dominant, control is performed to increase the supply amount of hydrogen 1 according to the combustor inlet conditions, etc. During normal operation of the hydrogen combustor 22, a hydrogen flame 4 in which a premixed flame is dominant is basically formed. In this way, control may be performed to arbitrarily change the minute flame structure formed by each fuel injector 30 to either a diffusion flame or a premixed flame.

[0105] <Control during high-altitude ignition> The hydrogen combustor 22 mounted on aircraft 10 requires re-ignition (high-altitude ignition) at an altitude where atmospheric pressure is sufficiently low (for example, around 1000m). As a control mechanism to achieve such high-altitude ignition, the control unit 26 may, if the hydrogen flame 4 is extinguished when the atmospheric pressure is below a predetermined level, increase the amount of hydrogen 1 supplied to the central fuel injector 30a compared to the amount supplied to the peripheral fuel injectors 30b.

[0106] Specifically, if the atmospheric pressure detected using an atmospheric pressure sensor or the like is below a predetermined threshold and the hydrogen flame 4 disappears, the amount of hydrogen 1 supplied to the central fuel injector 30a is set to be greater than that supplied to the surrounding fuel injectors 30b. Typically, the supply of hydrogen 1 to the peripheral fuel injectors 30b is cut off, and the supply of hydrogen 1 to the central fuel injector 30a is increased.

[0107] When igniting at high altitude, the amount of diluted air flowing into the combustor liner 51 is relatively less compared to ignition at ground level or relatively low altitudes, which can make re-ignition difficult. Thus, when the amount of diluting air is relatively low, as described above, supplying a large amount of fuel to the central fuel injector 30a makes it possible to achieve a fuel-rich fuel injection function in an environment with relatively little air using the central fuel injector 30a.

[0108] Furthermore, the surrounding nozzles (peripheral fuel injectors 30b) are either cut off from fuel supply or receive relatively little fuel. As a result, the peripheral fuel injectors 30b create a structure in which the fuel flow from the central fuel injector 30a is enveloped by a strong swirling airflow. This makes it possible to properly ignite and maintain the flame in a limited area, even under conditions where the overall amount of air flowing into the combustor liner 51 is low.

[0109] <Control to suppress the increase of combustion vibrations> Combustion oscillations are pressure oscillations that occur, for example, when pressure and flames interact in a way that amplifies each other's fluctuations within the combustion region 5 (combustor liner 51). Combustion oscillations occur when various conditions such as the operating state of the hydrogen combustor 22 and external environmental conditions such as atmospheric pressure, temperature, and wind speed are met. As a control measure to suppress such combustion vibrations, the control unit 26 may control the amount of hydrogen 1 supplied so as to suppress fuel vibrations when signs of combustion vibrations are detected.

[0110] For example, the pressure and temperature of various parts of the hydrogen combustor 22 (casing 65 and combustor liner 51) are monitored. Based on these monitoring results, it is possible to predict the occurrence of combustion oscillations by performing combustion oscillation prediction processing using machine learning or the like. In addition, vibrations that occur in the initial stages of combustion oscillations may also be detected. When the control unit 26 detects such signs of combustion oscillation, it changes the amount of hydrogen 1 supplied to each supply system to prevent the occurrence of combustion oscillation in advance.

[0111] For example, the supply of hydrogen 1 to at least one of the central fuel injector 30a or the peripheral fuel injector 30b is restricted so that the diffusion flame described above becomes dominant. This changes the combustion state and makes it possible to avoid the occurrence of combustion oscillations. Alternatively, the supply of hydrogen 1 to at least one of the central fuel injector 30a or the peripheral fuel injector 30b may be cut off. In this way, by changing the fuel distribution for each fuel injector module 45, it is possible to suppress the occurrence of combustion oscillations.

[0112] As described above, the hydrogen combustor 22 according to this embodiment is provided with a fuel injector module 45 that modularizes a plurality of fuel injectors 30. In each fuel injector 30, hydrogen 1 is injected substantially perpendicular to the swirling air 2 so as to collide with the inner wall 31b of the air intake pipe 31, and the air 2 and hydrogen 1 are thoroughly mixed. The mixed gas is injected from a step-shaped flame-holding section 33. This allows each fuel injector 30 to operate over a wide operating range. In addition, hydrogen 1 is supplied to each fuel injector 30 of the fuel injector module 45 from multiple supply systems. This broadens the control patterns of fuel injection and mixing throughout the combustor, making it possible to maintain the hydrogen flame 4 over a wide operating range.

[0113] In aircraft engines using jet fuel, which is a hydrocarbon fuel similar to kerosene, operation that satisfies a wide range of operating conditions has been achieved. On the other hand, when using hydrogen as fuel, it is difficult to achieve a stable hydrogen flame while suppressing emissions of NOx and other pollutants using the same design standards as before.

[0114] For example, in a method that aims to reduce NOx emissions by forming a diffuse flame similar to that of a candle at multiple points (see Patent Document 1), the combustion field that forms the diffuse flame at multiple points is mainly realized by the shape of the combustor, and there are few operational control parameters. For this reason, it is difficult to apply to a wide range of operating conditions. Furthermore, in a method that uses fluid vortices to rapidly mix hydrogen fuel and air, and then forms a rising flame to reduce NOx emissions (see Non-Patent Literature 1), the rapid mixing depends on the structure of the fluid, making it difficult to form an appropriate rising flame over a wide operating range. Furthermore, in a method for preventing flashbacks and other issues in an injector that mixes and injects hydrogen and air, the injection holes must be made into a fine, integrated structure, which may reduce manufacturability and structural stability.

[0115] In this embodiment, the hydrogen combustor 22 is constructed by arranging a ring-shaped module consisting of multiple fuel injectors 30, each of which maintains a relatively small flame zone. In each fuel injector 30, a hydrogen injection pipe 32 is positioned inside the air intake pipe 31. From the injection holes 41 in the hydrogen injection pipe 32, hydrogen 1 is injected approximately perpendicularly to the swirling air that has passed through the swirl mechanism 37 of the air intake pipe 31. At this time, the hydrogen 1 collides with the inner wall of the air intake pipe 31, promoting rapid mixing with the air 2.

[0116] Thus, each fuel injector 30 achieves rapid mixing through its mechanical structure, and even when the operating range changes, a stable flame can be easily achieved by changing the amount of hydrogen 1 supplied. Furthermore, by reducing the amount of hydrogen 1 supplied, it is possible to switch between a premixed flame and a diffusion flame, making it possible to change the combustion mode according to the situation.

[0117] In a fuel injector module 45 with multiple fuel injectors 30 arranged in multiple stages, the central fuel injector 30a and the multiple peripheral fuel injectors 30b are each connected to different supply systems. This makes it possible to achieve various combustion patterns for each fuel injector module 45 by appropriately setting the supply amounts for the two supply systems.

[0118] For example, during steady-state operation, it is possible to reduce NOx emissions by using a combustion pattern that prevents the formation of localized high-temperature areas. Also, for example, even in situations with low air intake, it is possible to form a stable flame by selectively activating the central fuel injector 30a. In this way, by controlling the fuel injectors 30 by separating the supply systems, it becomes possible to maintain a stable hydrogen flame 4 over a wide operating range.

[0119] Furthermore, the hydrogen combustor 22 according to this embodiment can be initially designed by combining a number of relatively simple design units (fuel injectors 30). This makes it possible to significantly improve manufacturability and structural stability. In addition, it is possible to easily install and replace each fuel injector 30, thereby improving maintainability.

[0120] <Other Embodiments> The present invention is not limited to the embodiments described above, and various other embodiments can be realized.

[0121] Figure 11 is a schematic diagram showing an example of a hydrogen supply line according to another embodiment. In the hydrogen supply line 125 shown in Figure 11, the supply system is divided for each fuel injector module 45 downstream of the first shut-off valve 81 and the second shut-off valve 82, and a flow control valve 84 and a distribution valve 83 are provided for each supply system in this order.

[0122] Here, the distribution valve 83 controls the distribution pattern to the central fuel injector 30a and the peripheral fuel injectors 30b. This enables patterns such as distributing fuel to either the central fuel injector 30a or the peripheral fuel injectors 30b, distributing fuel to both, and distributing fuel to neither. Furthermore, the flow control valve 84 adjusts the total amount of hydrogen 1 supplied to each fuel injector module 45.

[0123] This makes it possible to control the amount of hydrogen fuel supplied to each of the multiple fuel injector modules 45. In addition, it makes it possible to control the combustion pattern of the central fuel injector 30a and the peripheral fuel injectors 30b in each fuel injector module 45.

[0124] In the above embodiment, only one central fuel injector is provided in the fuel injector module. However, the embodiment is not limited to this, and a single fuel injector module may be provided with multiple central fuel injectors. In this case, the multiple central fuel injectors are positioned in the center of the module, and the multiple peripheral fuel injectors are positioned around them. The multiple central fuel injectors are connected to a first supply system, and the multiple peripheral fuel injectors are connected to a second supply system.

[0125] The arrangement of fuel injector modules (nozzle modules) in a hydrogen combustor can be set arbitrarily. For example, in Figures 5 to 7, an annular-type hydrogen combustor is constructed using fuel injector modules as units. For example, a can-type hydrogen combustor 22 may be constructed by providing a cylindrical combustion can (combustor liner) to each fuel injector module and arranging them individually. Alternatively, an annular-type hydrogen combustor 22 may be constructed by arranging fuel injector modules with combustion cans in a ring shape.

[0126] Alternatively, only one fuel injector module may be provided. For example, a fuel injector module may be configured with multiple fuel injectors arranged in a ring shape on both the inside and outside. In this case, the inner and outer fuel injectors are connected to separate supply systems. The number and configuration of fuel injector modules are not limited.

[0127] In the above example, a hydrogen combustor was installed in a jet engine that generates thrust. However, the invention is not limited to this, and a hydrogen combustor may also be configured as a combustor for a gas turbine. For example, the present invention can be applied to a gas turbine combustor for a power generation device installed in an aircraft with an electric propulsion system. The power generation device includes a compressor for compressing air, a hydrogen combustor, and a turbine that drives the compressor and generator using the combustion gas from the hydrogen combustor as a power source. This is a device that generates electricity by driving the generator using the rotating shaft of a jet engine, as explained with reference to Figure 2.

[0128] Power generators installed on aircraft have high power extraction requirements and operate under a wide range of conditions during aircraft operation (air pressure, temperature, etc.). Therefore, they need to maintain a robust and stable flame over a wider operating range compared to stationary gas turbines. By applying the present invention to such power generators, it becomes possible to provide a stable power supply over a wide operating range.

[0129] The present invention may also be applied to stationary power generation equipment. For example, the hydrogen combustor according to the present invention can be used as a gas turbine combustor in power generation equipment installed in factories or homes. This makes it possible to achieve a stable hydrogen flame with suppressed NO emissions and maintain clean operation, even when the load on the power generation equipment fluctuates due to, for example, a sudden change in electricity demand.

[0130] It is also possible to combine at least two of the feature features of the present invention described above. In other words, the various feature features described in each embodiment may be combined arbitrarily without distinction between embodiments. Furthermore, the various effects described above are merely examples and are not limiting, and other effects may also be exhibited. [Explanation of Symbols]

[0131] 4…Hydrogen flame 5…Combustion region 10...Aircraft 20... Jet engine 21... Compressor 22…Hydrogen Combustor 23... Turbine 26... Control Unit 30…Fuel injector 30a…Central fuel injector 30b... Peripheral fuel injectors 31... Air intake pipe 32…Hydrogen injection tube 33…Flame holding part 37...Swivel 45…Fuel injector module 50...Linahead 51... Combustor liner 56…Hydrogen supply pipe 71…First air vent 72...Second air vent 100…Hydrogen Combustion System

Claims

1. A plurality of fuel injector modules, Each fuel injector module is composed of multiple fuel injectors arranged in a modular design. Each fuel injector includes an air intake pipe having a swirl mechanism for swirling air, a hydrogen injection pipe that injects gaseous hydrogen substantially perpendicular to the swirling air passing through the swirl mechanism so as to collide with the inner wall of the air intake pipe, and a flame holder that widens the flow path of the mixed gas of air and hydrogen in a stepped manner. Multiple fuel injector modules, An annular liner head that supports the plurality of fuel injector modules in an annular shape, A combustor liner connected to the liner head and integrally enclosing the combustion region formed downstream of the plurality of fuel injector modules, A casing that houses the liner head and the combustor liner, A hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the multiple fuel injectors constituting the fuel injector module, by dividing the supply system into multiple supply systems. It is equipped with, At least one of the liner head and the combustor liner is provided between adjacent fuel injector modules and has a plurality of first air holes that communicate with the combustion region and generate an airflow along the injection direction of the fuel mixture from the plurality of fuel injectors, The casing has a compressed air inlet and forms a flow path for the compressed air around the liner head and the combustor liner so that the compressed air can be supplied to the air inlet pipe and the first air hole. Hydrogen combustion device.

2. A hydrogen combustor according to Claim 1, The liner head supports the plurality of fuel injector modules so that their respective injection directions are parallel to each other. Hydrogen combustion device.

3. A hydrogen combustor according to claim 1, The hydrogen supply pipe supplies hydrogen to each of the multiple fuel injector modules by separating the supply system. Hydrogen combustion device.

4. A hydrogen combustor according to Claim 1, The liner head has an annular arrangement surface directed toward the combustion region, The plurality of fuel injector modules are arranged with their front ends aligned with the arrangement surface. Hydrogen combustion device.

5. A hydrogen combustor according to claim 4, The plurality of first air holes are provided on the arrangement surface. Hydrogen combustion device.

6. A hydrogen combustor according to Claim 1, The hydrogen injection pipe is inserted inside the air intake pipe. A cylindrical flow path is formed between the air intake pipe and the hydrogen injection pipe, and has a constant cross-sectional shape perpendicular to the extending direction of the air intake pipe. The swivel is provided on the cylindrical flow path. Hydrogen combustion device.

7. A hydrogen combustor according to claim 1, The combustor liner has a plurality of second air holes that allow the air to flow in substantially perpendicular to the flow of the hydrogen flame in the combustion region. Hydrogen combustion device.

8. A plurality of fuel injector modules, Each fuel injector module is composed of multiple fuel injectors arranged in a modular design. Each fuel injector includes an air intake pipe having a swirl mechanism for swirling air, a hydrogen injection pipe that injects gaseous hydrogen substantially perpendicular to the swirling air passing through the swirl mechanism so as to collide with the inner wall of the air intake pipe, and a flame holder that widens the flow path of the mixed gas of air and hydrogen in a stepped manner. Multiple fuel injector modules, An annular liner head that supports the plurality of fuel injector modules in an annular shape, A combustor liner connected to the liner head and integrally enclosing the combustion region formed downstream of the plurality of fuel injector modules, A casing that houses the liner head and the combustor liner, A hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the multiple fuel injectors constituting the fuel injector module, by dividing the supply system into multiple supply systems. A hydrogen combustor having, A control unit controls the amount of hydrogen supplied in the plurality of supply systems based on operational information relating to the operation of the hydrogen combustor. It is equipped with, At least one of the liner head and the combustor liner is provided between adjacent fuel injector modules and has a plurality of first air holes that communicate with the combustion region and generate an airflow along the injection direction of the fuel mixture from the plurality of fuel injectors, The casing has a compressed air inlet and forms a flow path for the compressed air around the liner head and the combustor liner so that the compressed air can be supplied to the air inlet pipe and the first air hole. Hydrogen combustion system.

9. A hydrogen combustor system according to claim 8, The plurality of fuel injectors includes at least one first fuel injector and a plurality of second fuel injectors connected to a different supply system than the first fuel injector. The fuel injector module is configured such that the first fuel injector is positioned in the center and the second fuel injectors are arranged in a ring around the first fuel injector. Hydrogen combustion system.

10. A hydrogen combustor system according to claim 9, The control unit supplies the hydrogen to either the first fuel injector or the second fuel injector. Hydrogen combustion system.

11. A hydrogen combustor system according to claim 9, The control unit, when starting the hydrogen combustor, supplies hydrogen only to the first fuel injector, causing the first fuel injector to operate as a pilot injector. Hydrogen combustion system.

12. A hydrogen combustor system according to claim 9, The control unit, during operation of the hydrogen combustor, reduces the amount of hydrogen supplied to the first fuel injector to less than the amount of hydrogen supplied to the second fuel injector. Hydrogen combustion system.

13. A hydrogen combustor system according to claim 9, The control unit, when the hydrogen flame is extinguished while the atmospheric pressure is below a predetermined level, increases the amount of hydrogen supplied to the first fuel injector to the amount supplied to the second fuel injector. Hydrogen combustion system.

14. A hydrogen combustor system according to any one of claims 8 to 13, The control unit controls the amount of hydrogen supplied so that the flame form formed in the combustion of the fuel injector is predominantly either a diffusion flame or a premixed flame. Hydrogen combustion system.

15. A hydrogen combustor system according to any one of claims 8 to 13, The control unit, when it detects signs of combustion vibration, controls the hydrogen supply amount to suppress the combustion vibration. Hydrogen combustion system.

16. A compressor that compresses air, Multiple fuel injector modules, Each fuel injector module is composed of multiple fuel injectors arranged in a modular design. Each fuel injector includes an air intake pipe having a swirl mechanism for swirling air from the compressor, a hydrogen injection pipe that injects gaseous hydrogen substantially perpendicular to the swirling air passing through the swirl mechanism so as to collide with the inner wall of the air intake pipe, and a flame holder that widens the flow path of the mixed gas of air and hydrogen in a stepped manner. Multiple fuel injector modules, An annular liner head that supports the plurality of fuel injector modules in an annular shape, A combustor liner connected to the liner head and integrally enclosing the combustion region formed downstream of the plurality of fuel injector modules, A casing that houses the liner head and the combustor liner, A hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the multiple fuel injectors constituting the fuel injector module, by dividing the supply system into multiple supply systems. A hydrogen combustor having, A turbine drives the compressor using the combustion gas from the hydrogen combustor as a driving source and discharges the combustion gas to generate thrust. It is equipped with, At least one of the liner head and the combustor liner is provided between adjacent fuel injector modules and has a plurality of first air holes that communicate with the combustion region and generate an airflow along the injection direction of the fuel mixture from the plurality of fuel injectors, The casing has a compressed air inlet and forms a flow path for the compressed air around the liner head and the combustor liner so that the compressed air can be supplied to the air inlet pipe and the first air hole. Jet engine.

17. A compressor that compresses air, Multiple fuel injector modules, Each fuel injector module is composed of multiple fuel injectors arranged in a modular design. Each fuel injector includes an air intake pipe having a swirl mechanism for swirling air from the compressor, a hydrogen injection pipe that injects gaseous hydrogen substantially perpendicular to the swirling air passing through the swirl mechanism so as to collide with the inner wall of the air intake pipe, and a flame holder that widens the flow path of the mixed gas of air and hydrogen in a stepped manner. Multiple fuel injector modules, An annular liner head that supports the plurality of fuel injector modules in an annular shape, A combustor liner connected to the liner head and integrally enclosing the combustion region formed downstream of the plurality of fuel injector modules, A casing that houses the liner head and the combustor liner, A hydrogen supply pipe that supplies hydrogen to the hydrogen injection pipes of the multiple fuel injectors constituting the fuel injector module, by dividing the supply system into multiple supply systems. A hydrogen combustor having, A turbine that drives the compressor and generator using the combustion gas from the hydrogen combustor as a driving source. It is equipped with, At least one of the liner head and the combustor liner is provided between adjacent fuel injector modules and has a plurality of first air holes that communicate with the combustion region and generate an airflow along the injection direction of the fuel mixture from the plurality of fuel injectors, The casing has a compressed air inlet and forms a flow path for the compressed air around the liner head and the combustor liner so that the compressed air can be supplied to the air inlet pipe and the first air hole. A power generator.

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