Method for regulating flow rate of a gaseous fuel injector for an aerobic combustion chamber

Abstract

Disclosed is a gaseous fuel injector for an aerobic combustion chamber (10), comprising an injection nozzle (12) and a measuring device (14) comprising an upstream pressure sensor (14A) configured to measure the pressure of the gaseous fuel upstream of the nozzle (12), a temperature sensor (14B) configured to measure the temperature of the gaseous fuel upstream of the nozzle (12), and a downstream pressure sensor (14C) configured to measure the pressure of the gaseous fuel downstream of the nozzle (12), the flow rate measuring device (14) being configured to estimate the flow rate of gaseous fuel at the outlet (S) of the nozzle (12) on the basis of the measurements of the pressure of the gaseous fuel upstream of the injection nozzle (12), the temperature of the gaseous fuel upstream of the nozzle (12) and the pressure of the gaseous fuel downstream of the nozzle (12).

Description

Description Title of the invention: Gaseous fuel injector for an aerobic combustion chamber and method for regulating the flow rate of such an injector Technical Field

[0001] This presentation relates to a gaseous fuel injector for an aerobic combustion chamber, in particular for an aeronautical turbomachine combustion chamber, an assembly comprising such an injector, a flow regulator and an aerobic combustion chamber, an aeronautical turbomachine equipped with such an assembly, as well as a method for regulating the gaseous fuel flow of such an injector.

[0002] The term "aeronautical turbomachine" refers to all gas turbine devices that produce motive power. Among these, a distinction is made between turbojets and ramjets, which provide the thrust necessary for propulsion by reacting to the high-speed ejection of gases, and turboshaft engines, in which motive power is supplied by the rotation of a drive shaft. For example, turboshaft engines are used as engines for helicopters or as turbogenerators to generate electricity within an aircraft. As another example, turboprop engines (turboshaft engines driving a propeller) are turboshaft engines used as aircraft engines. Previous technique

[0003] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by different countries. In particular, an ambitious standard applies to both new types of aircraft and those already in operation, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.

[0004] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Holder takes into account the factors impacting all phases of design and development to obtain less environmentally friendly aeronautical components and products. Energy-efficient, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental impacts, with the aim of improving aircraft energy efficiency. Consequently, the Holder is constantly working to reduce its climate impact by employing virtuous development and manufacturing methods and processes that minimize greenhouse gas emissions to the absolute minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and finally aviation biofuels.

[0006] In this context, within a turbomachine, and particularly an aeronautical turbomachine, controlling the amount of fuel injected into the combustion chamber is generally essential to guarantee both the expected performance level (target thrust) and the required safety and reliability during startup (or restart) phases. To achieve this, it is crucial to be able to know the effective mass flow rate of fuel within the combustion chamber with a relatively reliable and precise method.

[0007] When the turbomachine operates using a liquid fuel such as kerosene, the effective mass flow rate of fuel delivered to the combustion chamber can be easily determined and regulated via a positive displacement fuel pump, where the amount of fuel pumped is proportional to the pump's control setpoint. Regulation on this basis is generally satisfactory, given that liquid fuels have a virtually constant density regardless of the surrounding temperature and pressure conditions.

[0008] When the turbomachine operates on a gaseous fuel such as dihydrogen, the effective mass flow rate of fuel delivered within the combustion chamber is relatively complex to determine and regulate and generally requires dedicated equipment (for example a flow meter) which can be sources of added mass, bulk and / or pressure loss in the gaseous fuel supply circuit undesirable and whose implementation can be relatively restrictive.

[0009] Therefore, there is a need in this regard. Description of the invention

[0010] One embodiment relates to a gaseous fuel injector for an aerobic combustion chamber, comprising an injection nozzle and a flow measurement device comprising an upstream pressure sensor configured to measure the pressure of the gaseous fuel upstream of the injection nozzle, a temperature sensor configured to measure the temperature of the gaseous fuel upstream of the injection nozzle, and a downstream pressure sensor configured to measure the pressure of the gaseous fuel downstream of the injection nozzle, the flow measurement device being configured to estimate the gaseous fuel flow rate at the outlet of the injection nozzle based on measurements of the pressure of the gaseous fuel upstream of the injection nozzle, the temperature of the gaseous fuel upstream of the injection nozzle and the pressure of the gaseous fuel downstream of the injection nozzle.

[0011] Hereafter and unless otherwise indicated, "injector" means "gaseous fuel injector for aerobic combustion chamber", "combustion chamber" means "aerobic combustion chamber", "fuel" means "gaseous fuel", "nozzle" means "injection nozzle", "flow rate" means "gaseous fuel flow rate at nozzle outlet", "measuring device" means "flow rate measuring device", and "pressure / temperature" means "gaseous fuel pressure / temperature".

[0012] Upstream and downstream are considered according to the direction of fuel flow in normal operation within the injector, and more generally within the injection circuit, with fuel flowing from upstream to downstream.

[0013] The measuring device may include a computer configured to estimate the flow rate from various measurements, for example, within the FADEC (Full Authority Digital Engine Control) of an aircraft turbomachine. The measuring device can perform the flow rate estimation in real time. The measuring device can be configured to estimate the gaseous fuel flow rate at the injection nozzle based solely on measurements of the gaseous fuel pressure upstream of the injection nozzle, the gaseous fuel temperature upstream of the injection nozzle, and the gaseous fuel pressure downstream of the injection nozzle. In other words, in this case, no other measurements are required by the measuring device to estimate the fuel flow rate.

[0014] In the context of aerobic combustion chambers for gaseous fuels, such as those in aircraft turbomachinery, the pressure differential between the pressure upstream of the nozzle and the pressure downstream or at the nozzle outlet is relatively small. For example, the injector can be configured so that the pressure drop downstream of the nozzle is between 5% and 40% of the pressure upstream of the nozzle. In other words, the pressure downstream of the nozzle, Pav, is equal to the pressure upstream of the nozzle, Pam, minus k% of the pressure upstream of the nozzle, Pam, where k is between 5 and 40 (i.e., Pav = Pam - k% Pam).

[0015] The combustion chamber injectors of aeronautical turbomachinery are precision components with very tight manufacturing tolerances. Therefore, the physical characteristics of such injectors, and in particular their fluid permeability, can be considered virtually invariant (i.e., constant) from one injector to another produced according to the same technical requirements. Furthermore, such injectors are generally stationary components, i.e., they have no moving parts, so their physical characteristics, and especially their fluid permeability, remain constant regardless of the operating conditions. As a reminder, fluid permeability is a physical characteristic representing the ability of a fluid to pass through a given pressure differential.

[0016] By measuring the pressure drop between the upstream and downstream sides of the nozzle, i.e., by measuring the pressure upstream and downstream of the nozzle, and by measuring the temperature upstream of the nozzle, the injector (or an injection system comprising an injection rail and a plurality of injectors, at least one of which is specified in this document), whose fluid permeability can be considered reliably known and invariant from one unit to another for a given type or model of injector (or given injection system), can be used as a calibrated orifice for determining the mass flow rate of fuel at the nozzle outlet. The injector described here thus has an integrated flow meter function, eliminating the need for dedicated equipment in the prior art.Furthermore, using the injector as a flow meter improves the reliability and responsiveness of flow rate measurement, as well as the responsiveness of flow regulation, since the measuring device also performs the injection. There is therefore a synergy between the two functions of flow measurement and injection provided by the injector, resulting in excellent flow regulation performance. Such an injector (or injection system) provides reliable and repeatable measurements from one unit to another and can be easily implemented on an industrial scale at a controlled cost.

[0017] In some embodiments, the flow measurement device is configured to estimate the gaseous fuel flow rate at the outlet of the injection nozzle on the basis of a mathematical law, for example the Saint Venant Barré law.

[0018] Using a mathematical formula, the fuel flow rate can be immediately estimated based on direct post-processing. This post-processing can be performed in a computer. This can contribute to the reliability and responsiveness of the flow rate measurement, the simplicity of the system, while minimizing size and added mass.

[0019] Saint-Venant's law is recalled in the following mathematical relationship:

[0020] [Math. 1]

[0021] The terms C p etc v mentioned above are respectively the isobaric and isochoric calorific (or thermal) capacity of the fuel (in JK' 1The upstream fuel temperature, in combination with the upstream pressure and the fuel's known thermofluidic properties, allows us to calculate the upstream fuel density using the mathematical relationship above. Fluid permeability appears in this mathematical relationship as the product of the coefficients of air (CdA). The dependence of this mathematical relationship solely on fluid permeability as a material-related parameter minimizes the model calibration requirements. Indeed, the fluid permeability can be fixed during the equipment design phase, verified on a production prototype, and then systematically implemented during the industrial production phase.

[0022] In some embodiments, the gaseous fuel injector for an aerobic combustion chamber comprises an injector body in which the pressure sensor Upstream, the temperature sensor and downstream pressure sensor are mounted on the injector body.

[0023] The injector body may include a mounting base on an injection rail, the injection nozzle, an optional swirler at the outlet of the injection nozzle, etc.

[0024] The sensors can thus be integrated within the injector body. This can contribute to the reliability and responsiveness of flow measurement by measuring as close as possible to the nozzle, and to the simplicity of the system, while minimizing size and added weight. This can, for example, easily allow for multiple sets of sensors and ensure a degree of redundancy and reliability within an injection system comprising several injectors, each with its own set of integrated sensors.

[0025] An embodiment relates to an assembly comprising at least one gaseous fuel injector for an aerobic combustion chamber according to any one of the embodiments described in this exposition, a flow regulator configured to adjust the gaseous fuel supply flow rate of the injector, and an aerobic combustion chamber, the injector being configured to supply the aerobic combustion chamber with gaseous fuel, in which the upstream pressure sensor is disposed downstream of the flow regulator, the temperature sensor is disposed downstream of the flow regulator and the downstream pressure sensor is disposed within the combustion chamber.

[0026] The flow regulator can be a metering valve, a pilot-operated regulator, a dome regulator, or any other suitable device known to a person in the trade.

[0027] Within the assembly, considered according to the direction of fuel flow, the flow regulator is located upstream of the injector. The injector partially protrudes into the combustion chamber. The combustion of the fuel injected by the injector takes place downstream of the injector, within the combustion chamber. The combustion chamber can be configured so that combustion occurs in a predetermined area called the fire zone. For example, the downstream pressure sensor can be located outside the fire zone. The downstream pressure sensor can be integrated into the injector body or mounted within the aerobic combustion chamber.

[0028] The assembly may include a plurality of injectors, the plurality of injectors comprising, for example, a single injector as described herein, the other injectors being without the measuring device. Indeed, the injectors of the plurality of injectors may be mounted on an injection rail and share a common supply while all opening into the same chamber. Combustion. The estimated flow rate of a single injector can be representative of the flow rate of all other injectors in the plurality of injectors. According to one variant, the plurality of injectors can include at least two injectors as described herein, to ensure redundancy in flow rate measurement and enhance safety and reliability.

[0029] By positioning the upstream pressure sensor and the downstream temperature sensor of the flow regulator, the corresponding physical quantities are measured as close as possible to the nozzle, upstream of the nozzle, within the fuel supply circuit, and in an area where there are no further changes in the fuel flow before it enters the injector and nozzle. This can contribute to the reliability and responsiveness of the flow measurement, the simplicity of the system, while minimizing size and added weight.

[0030] In some embodiments, the assembly includes an injection rail, the pressure and temperature of the gaseous fuel upstream of the injection nozzle being respectively the pressure and temperature of the gaseous fuel within the injection rail.

[0031] The upstream pressure sensor and / or temperature sensor can be located anywhere downstream of the flow control valve and upstream of the injection nozzle. For example, the upstream pressure sensor can be integrated into the injector or mounted on the fuel rail. For example, the temperature sensor can be integrated into the injector or mounted on the fuel rail. For example, the assembly can include, from upstream to downstream in the direction of fuel flow, a flow control valve, a shut-off valve, a fuel rail, and a plurality of injectors. For example, the upstream pressure sensor and / or temperature sensor can be located upstream of the shut-off valve, downstream of the shut-off valve, on a section connecting the shut-off valve to the fuel rail, on the fuel rail, at the interface between the fuel rail and an injector, or within an injector, on the injector body.The upstream pressure sensor and the temperature sensor are not necessarily located in the same place.

[0032] Such a choice of parameters, (or the positioning of associated sensors) can contribute to the reliability and responsiveness of flow measurement, to the simplicity of the system, while minimizing bulk and added mass.

[0033] An embodiment relates to an aeronautical turbomachine comprising an assembly according to any one of the embodiments described in this presentation.

[0034] One embodiment relates to a method for regulating the gaseous fuel flow of a gaseous fuel injector for an aerobic combustion chamber according to any one of the embodiments described in this exposition, in which the pressure of the gaseous fuel upstream of the injection nozzle is measured, the temperature of the gaseous fuel upstream of the injection nozzle is measured and the pressure of the gaseous fuel downstream of the injection nozzle is measured; the actual gaseous fuel flow delivered by the injector is estimated on the basis of these measurements; and the gaseous fuel flow delivered by the injector is regulated according to the estimated actual flow.

[0035] Regulation can be achieved, for example, by controlling a flow regulator based on the estimated actual fuel flow rate.

[0036] In some embodiments, the gaseous fuel flow delivered by the injector is regulated according to the estimated actual flow only during a start-up or restart phase; and the gaseous fuel flow delivered by the injector is regulated according to another regulation law during a stabilized operating regime.

[0037] Starting or restarting can be defined as the initiation of fuel combustion within the combustion chamber, from a state where no combustion is occurring. For example, starting can be a typical phase when operating an aircraft turbomachine that is stationary and mechanical assistance is required to rotate its moving parts. Restarting can occur during an accidental combustion failure within the combustion chamber (i.e., while the turbomachine is running) and no mechanical assistance is needed to rotate its moving parts. Both starting and restarting may require specific control of fuel injection.

[0038] A stabilized regime can be a regime where combustion within the combustion chamber is stable, for example determined by a temperature and / or pressure greater than or equal to a predetermined temperature and / or pressure respectively, a high-pressure shaft rotation speed greater than or equal to a predetermined speed, or a predetermined law depending for example on operational conditions such as altitude, outside temperature, outside pressure, etc.

[0039] In some embodiments, the regulation of the gaseous fuel flow delivered by the injector is maintained during the stabilized operating conditions, based on the actual flow rate. estimated for a predetermined time after starting or restarting before regulating the flow of gaseous fuel delivered by the injector according to the other regulation law.

[0040] Such a delay in switching from one control mode to another can help ensure that the stabilized regime is sustainable before changing the control mode. This can contribute to strengthening the reliability and safety of the control system.

[0041] In some embodiments, the control method can be implemented within an aeronautical turbomachine, in which the other law is a law based on the regime of the aeronautical turbomachine and / or a temperature within the aeronautical turbomachine.

[0042] The turbomachine's operating speed can, for example, be the rotational speed of the gas generator shaft, such as the low-pressure shaft for a twin-spool turbomachine, which includes a high-pressure and a low-pressure section. The temperature within the turbomachine can be measured at any point, for example, the temperature of the exhaust gases within the combustion chamber and / or at the turbine outlet, such as the low-pressure turbine outlet for a twin-spool turbomachine, which includes a high-pressure and a low-pressure section. Brief description of the drawings

[0043] The purpose and advantages of this presentation will be better understood upon reading the detailed description below of various embodiments given as non-limiting examples. This description refers to the attached figure pages, on which:

[0044] [Fig. 1] Figure 1 schematically represents an aeronautical turbomachine,

[0045] [Fig. 2] Figure 2 schematically represents the gaseous fuel injection system of the aeronautical turbomachine in Figure 1, and

[0046] [Fig. 3] Figure 3 represents a flowchart of a process for regulating the flow of gaseous fuel within the aeronautical turbomachine of Figure 1. Description of the implementation methods

[0047] Figure 1 shows a schematic cross-sectional view of an aeronautical turbomachine 50, in this example a twin-spool turbofan engine. An aeronautical turbomachine 50 comprises a fan 52, which may be shrouded or unshrouded, and a gas generator 54, the X-axis of the turbomachine 50 defining an axial direction. In this example, the gas generator 54 comprises, from upstream to downstream, a compressor 54A (or compressor section 54A), a combustion chamber 54B, and a turbine 54C (or turbine section 54C). The fan 52 may be driven in rotation directly by a shaft of the gas generator 54, for example, a shaft of a low-pressure body, or via a speed reducer (not shown).

[0048] The gas generator 54 may be of the twin-spool type and comprise a low-pressure spool 60A and a high-pressure spool 60B. The low-pressure spool 60A may comprise a low-pressure compressor 62A rotationally coupled to a low-pressure turbine 66A via a low-pressure shaft 63A. The high-pressure spool 60B may comprise a high-pressure compressor 62B located downstream of the low-pressure compressor 62A and upstream of the combustion chamber 54B, and a high-pressure turbine 66B located downstream of the combustion chamber 54B and upstream of the low-pressure turbine 66A, and rotationally coupled to the high-pressure compressor 62B via a high-pressure shaft 63B. The compressor 54A of the gas generator 54 may comprise the low-pressure and high-pressure compressors 62A and 62B. The 54C turbine of the 54 gas generator can include the low and high pressure turbines 66A and 66B.Figure 1 is schematic, each compressor and each turbine may have one or more stages, each stage comprising a moving wheel and a stator or rectifier.

[0049] Figure 2 is a detailed view of combustion chamber 54B. Combustion chamber 54B of the aeronautical turbomachine 50 is an example of an aerobic combustion chamber.The combustion chamber 54B is equipped with a gaseous fuel injector for an aerobic combustion chamber 10, comprising an injection nozzle 12 and a flow measurement device 14 comprising an upstream pressure sensor 14A configured to measure the gaseous fuel pressure upstream of the injection nozzle 12, a temperature sensor 14B configured to measure the gaseous fuel temperature upstream of the injection nozzle 12, and a downstream pressure sensor 14C configured to measure the gaseous fuel pressure downstream of the injection nozzle 12, for example within the combustion chamber 54B, the flow measurement device 14 being configured to estimate the gaseous fuel flow rate at the outlet S of the injection nozzle 12 based on measurements of the gaseous fuel pressure upstream of the injection nozzle 12, the gaseous fuel temperature upstream of the injection nozzle 12, and the fuel pressure gaseous downstream of injection nozzle 12. In this example, the measuring device 14 may include a computer 15, for example the FADEC of the turbomachine 50, to which are connected the upstream pressure sensor 14A, the temperature sensor 14B and the downstream pressure sensor 14C. Flow rate estimation can be performed in real time, for example, solely based on measurements of upstream pressure, temperature, and downstream pressure. In this example, the flow measurement device 14 can be configured to estimate the gaseous fuel flow rate at outlet S of the injection nozzle 12 based on a mathematical law, in this example, the Saint-Venant law.

[0050] In this example, the injector 10 comprises an injector body 10A and the upstream pressure sensor 14A, with the temperature sensor 14B and the downstream pressure sensor 14C being mounted on the injector body 10A.

[0051] More generally, Figure 2 represents an assembly 40 comprising at least one gaseous fuel injector for an aerobic combustion chamber 10, in this example two injectors 10 (only one injector 10 being shown), a flow regulator 20, in this example a metering valve 20, configured to adjust the gaseous fuel supply flow rate of the injector 10, the aerobic combustion chamber 54B, the injector 10 being configured to supply the aerobic combustion chamber 54B with gaseous fuel, in which the upstream pressure sensor 14A is disposed downstream of the flow regulator 20, the temperature sensor 14B is disposed downstream of the flow regulator 20 and the downstream pressure sensor 14C is disposed within the aerobic combustion chamber 54B.

[0052] The hatched area Z within the combustion chamber 54B represents the area where the gaseous fuel from the injector 10 burns, referred to as the combustion zone. The downstream pressure sensor 14C can be located outside the combustion zone. For example, the downstream pressure sensor 14C can be flush with the surface of the injector, which is located within the chamber. In another example (not shown), the downstream pressure sensor can be flush with the internal surface of the combustion chamber 54B. In yet another example (not shown), the downstream pressure sensor can be located remotely to measure the pressure via a capillary tube, either fluidically connected to one of the points mentioned above or opening into the combustion chamber without being flush. The capillary tube can be a dedicated thin tube or a bore in the injector body parallel to the fuel injection channels.

[0053] In this example, the assembly may include an injection rail 22, and the pressure and temperature of the gaseous fuel upstream of the injection nozzle 12 are respectively the pressure and temperature of the gaseous fuel within the rail injection 22. In this example, the injection rail 22 and the injector 10 are in direct fluidic communication, so that even when mounted on the injector body 10A, the upstream pressure sensor 14A and the temperature sensor 14B respectively measure the pressure and temperature of the gaseous fuel within the injection rail 22.

[0054] In the example in Figure 2, the assembly 40 may include a shut-off valve 21 downstream of the flow regulator 20 and upstream of the injection rail 22. According to an example not shown, the upstream pressure sensor 14A and / or the temperature sensor 14B may be located upstream of the shut-off valve 21, downstream of the shut-off valve 21, on a portion connecting the shut-off valve 21 to the injection rail 22, on the injection rail 22, or at the interface between the injection rail 22 and the injector body 10A. The upstream pressure sensor 14A and the temperature sensor 14B are not necessarily located in the same place.

[0055] In this example, the combustion chamber 54B and the injection rail 22 both have an annular geometry around the X axis. The combustion chamber 54B can be equipped with a plurality of injectors (not shown), all of the injectors being mounted on the injection rail 22. For example, the plurality of injectors can include one or two injectors 10 and one or more other injectors without a measuring device (not shown).

[0056] For example, the flow control unit 20 can be controlled by the computer 15. The arrows connected to the flow control unit 20 schematically represent the gaseous fuel supply circuit, for example dihydrogen, and the direction of flow of the gaseous fuel from upstream to downstream within this circuit, up to the outlet S of the injector 10.

[0057] An implementation of the injector 10 within a gaseous fuel flow regulation process PR will now be described with reference to Figure 3.

[0058] In the method for regulating the gaseous fuel flow rate PR of a gaseous fuel injector for an aerobic combustion chamber 10, the gaseous fuel pressure upstream of the injection nozzle 12 is measured in step E1, the gaseous fuel temperature upstream of the injection nozzle 12 is measured in step E2, and the gaseous fuel pressure downstream of the injection nozzle 12 is measured in step E3. The three steps E1, E2, and E3 can be simultaneous or sequential in any order. The actual gaseous fuel flow rate delivered by the injector 10 is then estimated based on these measurements during a step E4, for example, using the flow measurement device 14. The gaseous fuel flow rate is then regulated. delivered by injector 10 during step E5, for example using flow control 20, based on the actual flow rate estimated during step E4. For example, to regulate the flow rate during step E5, the estimated flow rate during step E4 can be compared to a DC setpoint flow rate. In this example, the control command from step E5 is transmitted directly to the flow control 20.

[0059] Optionally, at the end of step E4, and in parallel with step E5, it can be verified during step E6 that the estimated flow rate remains within a predetermined range of values, for example, based on other engine parameters measured during step E7 (which can, for example, be simultaneous with steps E1 / E2 / E3 and / or E4), such as the rotational speed of the low-pressure shaft, the temperature of the gases at the low-pressure turbine outlet, the temperature of the gases within the combustion chamber, etc. If the estimated flow rate falls outside the predetermined range of values, the gaseous fuel supply can, for example, be stopped as a safety measure, for example by closing the flow control valve 20 or any other dedicated component such as the optional shut-off valve 21, allowing the fuel supply to be cut off and the fuel supply circuit to be isolated from the rest of the turbomachine, during step ST.

[0060] For example, the gaseous fuel flow delivered by injector 10 can be regulated based on the estimated actual flow rate only during a start-up or restart phase; and the gaseous fuel flow delivered by injector 10 is regulated according to a different control law during steady-state operation. For example, during an engine sequence detection step ES, it is detected whether the turbomachine 50 is in a start-up or restart phase, or in steady-state operation. If it is detected during step ES that the turbomachine 50 is in a start-up or restart phase, the command from step E5 described above is selected. If it is detected during step ES that the turbomachine 50 is in steady-state operation, the command from step E8 described below is selected to control the flow control valve 20.

[0061] For example, during steady-state operation, the gaseous fuel flow rate delivered by injector 10 can be regulated according to the estimated actual flow rate for a predetermined period after starting or restarting (steps E4 and E5) before regulating the gaseous fuel flow rate delivered by the injector according to the other control law (step E8). For example, the predetermined period can be between 0.1 s (one-tenth of a second) and 10 s (ten seconds).

[0062] In this example, since the process is implemented within the aeronautical turbomachine 50, the other law can be a law based on the turbomachine's operating regime. aeronautical 50 and / or a temperature within the aeronautical turbomachine 50 during step E8. For example, the measurements provided during step E7 can also be used within step E8, and compared to setpoint values ​​VC.

[0063] In parallel with step E8, step E6 can optionally verify that the estimated flow rate remains within a predetermined range of values, as described above. Step E6 can be implemented only during start-up or restart phases, or continuously throughout the entire operating time of the turbomachine.

[0064] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0065] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Method for regulating the gaseous fuel (PR) flow rate of a gaseous fuel injector for an aerobic combustion chamber (10) of an aircraft turbomachine (50), the aircraft turbomachine (50) comprising at least one injector (10) and an aerobic combustion chamber (54B), the injector (10) being configured to supply the aerobic combustion chamber (54B) with gaseous fuel, the injector (10) comprising an injection nozzle (12) and a flow measurement device (14) comprising an upstream pressure sensor (14A) configured to measure the gaseous fuel pressure upstream of the injection nozzle (12), a temperature sensor (14B) configured to measure the gaseous fuel temperature upstream of the injection nozzle (12), and a downstream pressure sensor (14C) configured to measure the gaseous fuel pressure downstream of the injection nozzle (12),the flow measurement device (14) being configured to estimate the gaseous fuel flow rate at the outlet (S) of the injection nozzle (12) on the basis of measurements of the gaseous fuel pressure upstream of the injection nozzle (12), the gaseous fuel temperature upstream of the injection nozzle (12) and the gaseous fuel pressure downstream of the injection nozzle (12), method in which the gaseous fuel pressure upstream of the injection nozzle (12) is measured (E1), the gaseous fuel temperature upstream of the injection nozzle (12) is measured (E2) and the gaseous fuel pressure downstream of the injection nozzle (12) is measured (E3); the actual gaseous fuel flow rate delivered by the injector (10) is estimated (E4) on the basis of these measurements; and the flow rate of gaseous fuel delivered by the injector (10) is regulated (E5) according to the estimated actual flow rate.

2. Method of regulating the gaseous fuel (PR) flow rate of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to claim 1, wherein the gaseous fuel flow rate delivered by the injector (10) is regulated (E5) according to the estimated actual flow rate only during a start-up or restart phase; and the gaseous fuel flow rate delivered by the injector (10) is regulated (E8) according to another regulation law during a stabilized operating regime.

3. A method for regulating the gaseous fuel (PR) flow rate of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to claim 2, wherein the regulation (E5) of the gaseous fuel flow rate delivered by the injector (10) is maintained during the stabilized operating regime as a function of the estimated actual flow rate for a predetermined duration after starting or restarting before regulating (E8) the flow of gaseous fuel delivered by the injector (10) according to the other regulation law.

4. Method of regulating gaseous fuel (PR) flow of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to claim 2 or 3, wherein the other law is a law based on the regime of the aeronautical turbomachine (50) and / or a temperature within the aeronautical turbomachine (50).

5. Method for regulating the gaseous fuel flow (PR) of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to any one of claims 1 to 4, wherein the gaseous fuel flow at the outlet (S) of the injection nozzle (12) is estimated (E4) on the basis of a mathematical law, for example the Saint Venant Barré law.

6. Method of regulating gaseous fuel (PR) flow of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to any one of claims 1 to 5, wherein the injector (10) comprises an injector body (10A), the upstream pressure sensor (14A), the temperature sensor (14B) and the downstream pressure sensor (14C) are mounted on the injector body (10A).

7. Method for regulating the gaseous fuel (PR) flow rate of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to any one of claims 1 to 6, the aeronautical turbomachine (50) comprising a flow control device (20) configured to regulate the gaseous fuel supply flow rate of the injector (10), in which the upstream pressure sensor (14A) is disposed downstream of the flow control device (20), the temperature sensor (14B) is disposed downstream of the flow control device (20) and the downstream pressure sensor (14C) is disposed within the aerobic combustion chamber (54B).

8. Method for regulating the flow of gaseous fuel (PR) of a gaseous fuel injector for an aerobic combustion chamber (10) of an aeronautical turbomachine (50) according to claim 7, wherein the pressure and temperature of the gaseous fuel upstream of the injection nozzle (20) are respectively the pressure and temperature of the gaseous fuel within the injection rail (22).

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