CRYOGENIC FUEL SYSTEM WITH REGULATED HEATING FOR TRANSITIVE VEHICLES

Abstract

A fuel system (300) supplies the combustion chamber of an aircraft turbomachine. It comprises a liquid cryogenic fuel storage tank (110) connected by a pipeline (120) to the combustion chamber, a heating element (112) to bring the cryogenic fuel to a temperature that allows its evaporation, a fuel accumulator (310) in the gaseous state, and an injection system (114) controlling the injection of the gaseous fuel into the combustion chamber. Since the thermal inertia of the heating element may not be sufficient to maintain the fuel within an acceptable temperature range, the fuel accumulator (310) includes an internal heating element (311) for the gaseous fuel. This additional element provides supplementary thermal energy to the gaseous fuel in the event of a flow transient.It also allows for more precise control of the temperature of the gaseous fuel actually injected into the combustion chamber. Figure for the abbreviation: [Fig 3].

Description

Title of the invention: CRYOGENIC FUEL SYSTEM WITH REGULATED HEATING FOR TRANSITORS technical field

[0001] The present invention relates to the field of aircraft turbomachinery, and more particularly to a fuel system supplying the combustion chamber of an aircraft turbomachine, as well as to an aircraft turbomachine operating with cryogenic fuel and equipped with such an installation. Prior art

[0002] The use of cryogenic fuel to power the combustion chamber of an aircraft turbomachine is known. Such cryogenic fuel is, for example, liquid natural gas (known by the acronym "LNG") or liquid hydrogen (known by the designation "LH2").

[0003] While cryogenic fuels are less expensive than conventional kerosene, they primarily allow for a greater reduction in CO2 emissions.

[0004] On the one hand, LNG emits 25% less CO2 per unit of energy.

[0005] On the other hand, LH2 no longer emits CO2. Aeronautical propulsion by hydrogen combustion is therefore a major challenge in the decarbonization of the aviation sector.

[0006] Cryogenic fuel is stored in liquid form, generally at low pressure (2-3 bars) and low temperature (113K or -160°C for LNG, 20K or -253°C for LH2), to limit its volume to be transported.

[0007] However, it is injected into the combustion chamber in a gaseous state.

[0008] The so-called "fuel" system is the set of components from the storage tank that allow the distribution and metering of fuel to the combustion chamber, in order to meet a given engine performance requirement.

[0009] Figure 1 schematically illustrates such a fuel system 100. This includes a tank 110 for storing cryogenic fuel in liquid form, connected to injectors 117 placed in the combustion chamber by a supply line or conduit 120. Mounted on the conduit 120 from the tank 110 are a pressurization device 111 maintaining an injection pressure, a heating device 112 raising the cryogenic fuel to a temperature to allow its evaporation into gaseous fuel, a gaseous fuel accumulator 113 acting as a buffer and an injection system 114 controlling the injection of the gaseous fuel from the accumulator 113 into the combustion chamber.

[0010] The injection system 114 includes a metering device 115 metering the mass flow of gaseous fuel at the inlet of the combustion chamber, an optional shut-off valve 116 and the injector(s) 117.

[0011] These different organs are controlled according to measurements taken through sensors, such as a temperature sensor 130 upstream of the dosing organ 115, a pressure sensor 131 also upstream of the dosing organ 115 and a flow sensor 132 as close as possible to the injectors 117.

[0012] The gaseous fuel must remain within a range of temperatures permissible for its combustion, a range which is generally limited. Therefore, regulating the fuel temperature in the fuel system is a significant challenge.

[0013] Various types of heating elements 112 bringing the cryogenic fuel to its injection temperature are discussed and described in the context of the fuel system in publication FR3110938A1, referred to as a cryogenic fuel heating system. This publication focuses in particular on heat exchanger-type elements.

[0014] A heat exchanger is known, for example, through which air from the exhaust gases exiting the turbomachine nozzle circulates, or through which lubricating oil for the accessories in said turbomachine circulates. Also known from this publication is a closed-circuit heat transfer fluid exchanger that recovers heat from one or more of the following: air taken from the turbomachine compressor outlet, lubricating oil for the accessories, cooling air for the turbine blades, and exhaust gases exiting the nozzle.

[0015] Fuel temperature regulation is traditionally achieved by adjusting the intensity of heat transfer (i.e., the power exchanged), for example by varying the flow rate of the heat transfer fluid. Indeed, the heat exchanged depends on the flow rates of the two fluids, their heat capacities, and the temperature difference between the two fluids.

[0016] However, regulating the fuel temperature in known heat exchangers is not satisfactory during sudden flow rate variations (or rapid transients) due to the thermal inertia of the heat exchanger 112, i.e., its response time in supplying thermal energy to the fuel. This inertia results in particular from the reaction time of the pump regulating the flow rate of the heat transfer fluid and the mass of the solid elements (e.g., walls at the exchange interface) used to transmit thermal power. Typically, the new thermal power required in the event of a rapid transient in the pipe 120 cannot be supplied instantaneously. There is therefore a risk that the gaseous fuel will fall outside the narrow range of temperatures permissible for its combustion, which could leading to a decrease in turbomachine efficiency, or even a malfunction or deterioration of the combustion chamber.

[0017] There is therefore a need to improve known fuel systems, in particular to have new fuel systems that are more responsive and capable of more finely regulating the temperature of the gaseous fuel, in order to maintain it within a range of permissible temperatures.

[0018] Such fuel systems would thus enable the development of more sustainable, environmentally friendly turbomachines (operating on cryogenic fuel). Description of the invention

[0019] The invention aims to overcome at least some of the aforementioned drawbacks and to provide an improved fuel system, and in particular a more responsive fuel system capable of more finely regulating the temperature of the gaseous fuel, in order to maintain it within an acceptable temperature range.

[0020] Such a fuel system would be more durable over time. It would therefore promote the development of environmentally friendly turbomachinery powered by cryogenic fuel.

[0021] To this end, the invention relates firstly to a fuel system supplying the combustion chamber of an aircraft turbomachine, the fuel system comprising: - a cryogenic fuel storage tank in liquid form, connected by a supply line to said combustion chamber, - a first heating element on the supply pipe, to bring the cryogenic fuel to a temperature allowing its evaporation into fuel in a gaseous state, - a fuel accumulator in a gaseous state, and - an injection system configured to control the injection of fuel in gaseous state from the accumulator into the combustion chamber.

[0022] Better control of the temperature of the gaseous fuel is obtained when the fuel accumulator includes an internal element for heating the fuel in the gaseous state.

[0023] In this way, the additional thermal power that the first heating element is unable to provide instantaneously to the cryogenic fuel during a sudden demand for fuel flow can be provided by the heater within the gaseous fuel accumulator.

[0024] Positioning this additional heating element within the accumulator is advantageous for several reasons. Firstly, the power required to heat the fuel in the accumulator can be lower. than at the level of the first heating element during a rapid transient, due to the volume of gas in the accumulator which, through its thermal inertia, reduces the reactivity constraints (for example, of several seconds) compared to the first heating element. On the other hand, its positioning closer to the injection system offers more precise control of the temperature of the gaseous fuel actually injected into the combustion chamber.

[0025] A fuel system according to the invention therefore offers better responsiveness to rapid transients in fuel flow, as well as an improved ability to finely regulate the injection temperature.

[0026] According to one embodiment, the internal heating element is controlled based on measurements of the fuel temperature in the gaseous state. The internal heating of the accumulator is thus regulated according to the temperature of the fuel to be injected into the combustion chamber. This makes it possible to maintain the injection temperature within the permissible temperature range.

[0027] According to one embodiment, the fuel system includes a temperature sensor in the supply line downstream of the accumulator, configured to provide temperature measurements.

[0028] Alternatively, the fuel system includes an internal temperature sensor in the accumulator, to provide temperature measurements.

[0029] According to another embodiment, the internal heating element is controlled based on fuel flow information in the supply line. This information may simply be a command to modify the fuel flow rate. Alternatively, it may consist of fuel flow measurements in the supply line downstream of the accumulator.

[0030] In particular, the internal heating element is configured to activate when an increase in fuel flow in the supply line exceeds a first threshold value within a given time period. In other words, the internal heating is activated when the second derivative (acceleration) of the flow rate over time exceeds the threshold value. This value may, in particular, correspond to the detection conditions of a sudden surge in fuel flow requiring the additional heat input from the internal heating element. This value can be determined based on the thermal characteristics of the first heating element (heat exchanger) that limit instantaneous heat exchange.

[0031] Symmetrically, the internal heating element is configured to be deactivated when the fuel flow rate in the supply line falls below a second threshold value within a given time period. The internal heater is thus switched off when the first heating element is able to provide sufficient thermal power to heat the cryogenic fuel, despite its thermal inertia.

[0032] In particular, the second threshold may be equal to the first threshold.

[0033] According to one embodiment, the internal heating element is an electric heater. This configuration has the advantage of easy integration into an aeronautical environment, due to the compactness of such a solution and the availability of electrical power in an aircraft.

[0034] In particular, the electric heater may include a heating rod disposed inside the accumulator or one or more heating wires disposed on an internal wall of the accumulator.

[0035] According to one embodiment, the cryogenic fuel in liquid state is liquid dihydrogen.

[0036] Another aspect of the invention relates to an aircraft turbomachine, comprising a combustion chamber and a fuel system as above configured to supply the combustion chamber.

[0037] A second aspect of the invention relates to a method of operating a fuel system supplying the combustion chamber of an aircraft turbomachine, comprising the following steps: - circulating fuel through a supply line from a cryogenic fuel storage tank in liquid form to said combustion chamber, - to heat the cryogenic fuel, by means of a first heating element located on the supply pipe, to bring it to a temperature allowing its evaporation into fuel in a gaseous state, - to store the fuel in gaseous state in a fuel accumulator, and - to control the injection of the fuel in gaseous state from the accumulator into the combustion chamber.

[0038] According to the invention, the method also includes a step of heating the fuel in the gaseous state within the accumulator, by means of a heating element internal to the accumulator. This heating step can be triggered if a sudden increase in fuel flow in the supply line is detected, exceeding the first trigger threshold. Brief description of the drawings

[0039] The invention will be better understood upon a detailed study of two embodiments taken by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0040] [Fig.1] represents a known fuel system;

[0041] [Fig.2] represents an example of the realization of a structure of a turbomachine, here a double-flow, double-body turbomachine;

[0042] [Fig.3] represents a fuel system according to embodiments; and

[0043] [Fig.4] illustrates, using a flowchart, a method of controlling the internal heating element of the [Fig.3], as a function of fuel flow information.

[0044] For the sake of clarity, the same elements are designated by the same reference numerals in the different figures. Furthermore, the various figures are not drawn to scale, as is customary in schematic representations. Detailed description

[0045] Figure 2 schematically illustrates the structure of a double-flow turbomachine and dual-body.

[0046] The double-flow turbomachine 2 comprises successively, in the direction of air circulation, i.e. from upstream (left in the figure) to downstream (right in the figure), an air inlet 20 and a blower 21, which delivers air on the one hand into a primary channel 22 and on the other hand into a secondary channel 23. By "channel", we mean the volume through which an airflow circulates.

[0047] The airflow circulating in the primary channel 22 passes successively through a low-pressure compressor 24a, a high-pressure compressor 24b, a combustion chamber 25, a high-pressure turbine 26a and a low-pressure turbine 26b, before being ejected through a primary flow nozzle 220.

[0048] Furthermore, the secondary airflow which flows in the secondary vein 23 is ejected separately through a secondary flow nozzle 230, after passing through a series of guide vanes 231.

[0049] Fig. 3 schematically illustrates a fuel system 300 according to embodiments, typically for supplying injectors in the combustion chamber 25.

[0050] Just like the fuel system 100 of [Fig.1], that of [Fig.3] includes, in the direction of fuel flow, a fuel storage tank 110 connected to injectors 117 by a supply line 120, a pressurization member 111, a heating member 112, a gaseous fuel accumulator 310 and an injection system 114.

[0051] The tank 110 can be any type of tank for cryogenic fuel in liquid form, such as liquid natural gas (known by the acronym "LNG") or liquid hydrogen (known by the acronym "LH2"). Cryogenic fuel is typically stored at low pressure (2-3 bar) and low temperature (113K or -160°C for LNG, 20K or -253°C for LH2).

[0052] The pressurization member 111 allows the cryogenic fuel in liquid form to be pressurized in the supply line 120 so as to maintain an injection pressure higher than that of the combustion chamber 25 of the turbomachine 2. In particular, at a given injection flow rate, the difference between the pressure at the outlet of the pressurization member 111 and the pressure in the combustion chamber 25 is maintained greater than the sum of the pressure losses of the various equipment or components along the supply line 120 of the fuel system 300 up to the injectors 117.

[0053] By way of illustration only, the pressurization unit 111 can be one or more high-pressure pumps, for example centrifugal pumps in series, controlled by a controller 320, such as the electronic control unit or ECU (for "Engine Control Unit").

[0054] The pressure in the injection chamber for aeronautical applications can be several tens of bars for a maximum takeoff regime, typically between 30 and 50 bars for dihydrogen and a few bars for LPG.

[0055] The heating element 112 raises the cryogenic fuel to a temperature that allows its evaporation into gaseous fuel, in particular within a range of temperatures permissible for its injection into the combustion chamber 25 and therefore for its combustion.

[0056] By way of example, the range of permissible temperatures, and therefore targeted at the outlet of the heating element 112, can be set at 300K + / - 15K (27°C + / - 15°C) for dihydrogen and at 323K + / - 15K (50°C + / - 10°C) for LPG.

[0057] The heating element 112 can be of any type, and in particular those described in publication FR3110938A1. By way of illustration only, it is a closed-circuit heat exchanger with a heat transfer fluid which recovers heat from the exhaust gases at the outlet of the nozzle 220, to transfer it to the cryogenic fuel at the exchanger.

[0058] The heating element 112 is controlled by the controller 320, for example on the central value of the range in stabilized regime.

[0059] The accumulator 310 is any container suitable for storing a gas such as LPG or H2 in a gaseous state.

[0060] The accumulator 310 operates as a buffer zone for gaseous fuel, i.e. an intermediate reserve to ensure the supply of fuel to the injectors 117 under all circumstances - in particular during sudden fuel demands - without the pressure in the supply line 120 falling under the injection pressure.

[0061] The accumulated gas is stored in particular at the pressure fixed by the pressurization device 111, taking into account any pressure losses (from the heating device 112 and in the accumulator 310).

[0062] According to this disclosure, the accumulator 310 includes an internal component 311 for heating the fuel in the gaseous state, that stored within the accumulator.

[0063] In one embodiment, the internal heating element 311 is an electric heater. The electric heater can be any type of electrical equipment capable of heating a gas stored in a container. For example, a heating rod (electrical resistance) is disposed inside the accumulator. This heating rod can be insulated with metallic foam. In another example, heating wires are disposed on the internal walls (or alternatively within the internal walls) of the accumulator.

[0064] The electrical part of the internal heating element, which supplies the heating rod or heating wires, is preferably insulated from the gas to be heated in order to reduce any risk of sparking on contact with the gas.

[0065] The injection system 114 controls the injection of gaseous fuel from the accumulator 113 into the combustion chamber. It includes a metering unit 115, an optional shut-off valve 116, and the injector(s) 117 opening into the combustion chamber 25.

[0066] The metering device 115 is for example a regulator coupled to a sonic neck or a metering valve, configured to meter the mass flow of the gaseous fuel into the combustion chamber 25. It is notably controlled by the controller 320 according to control commands.

[0067] These different organs, typically the pressurization organ 111, the heating organ 112, the internal heating organ 113 and the injection system 114 (therefore its internal organs) are controlled by one or more controllers 320 (hereinafter "the controller") which receive measurements taken on the supply line 120.

[0068] In particular, a temperature sensor 130 provides temperature measurements of the fuel in the pipeline 120 to the controller 320.

[0069] In one embodiment, the temperature sensor 130, for example a temperature probe or thermocouple sensor, is positioned upstream of the dosing unit 115, after the accumulator 310. Alternatively, the temperature sensor 130 is an internal temperature sensor of the accumulator 310.

[0070] A pressure sensor 131 provides fuel pressure measurements in the line 120 to the controller 320. The pressure sensor 131 can also be positioned upstream of the metering unit 115, after the accumulator 300.

[0071] Thus, the state (temperature and pressure) of the gaseous fuel at the level of the inlet pipe of the injection system 114 is reported to controller 320.

[0072] Finally, a flow sensor 132 provides fuel flow measurements in the line 120 to the controller 320. For example, a mass flow meter is placed as close as possible to the injectors 117 opening into the combustion chamber 25.

[0073] The controller 320 can also receive external pilot commands, typically a fuel flow variation command to meet a need to modify the thrust of the turbomachine 2 (engine acceleration or deceleration).

[0074] A sensor acquisition frequency on the order of one hundredth to one tenth of a second allows dynamic control of all the organs.

[0075] For example, the pump or pressurizing device 111 is activated by the controller 320 when the pressure measured by the sensor of 131 falls below a low trigger threshold, higher than the pressure in the combustion chamber 25, and is deactivated by the controller when the measured pressure reaches a high stop threshold.

[0076] Furthermore, the heat exchanger or heating element 112 is temperature controlled by the controller 320, according to the temperature measured by the sensor 130. Since the gaseous fuel must remain within the range of temperatures permissible for its combustion, the controller 320 increases the thermal energy exchanged at the exchanger 112 (via, for example, an increase in the flow rate of the heat transfer fluid) when the measured temperature decreases, and conversely decreases the thermal energy exchanged when the measured temperature increases.

[0077] Continuous, stepped, or binary control based on the center temperature of the range can be considered. Continuous control constantly modifies the heat energy exchanged over time according to a lookup table, for example, a table linking the measured temperature to a flow rate setpoint for the heat transfer fluid to bring the fuel back to the center temperature of the range. The table can be a function of the flow rate measured by sensor 132, or even a function of the dynamics of the flow rate thus measured (typically a function of the rate of change of the measured flow rate). Stepped control uses several triggering steps, varying the flow rate setpoint of the heat transfer fluid from one step to the next, to modify the heat energy exchanged. Similar to the lookup table, the steps can depend on the measured flow rate, or even on the dynamics of the flow rate.A binary control system, for example, involves triggering the heating (activating the heat transfer fluid) or deactivating it based on a trigger threshold.

[0078] The heating element 112 has a thermal inertia which does not allow, during sudden variations in flow (or rapid transients), the fuel circulating in the pipe 120 to be brought to the desired temperature.

[0079] The internal heating element 311 of the accumulator 310 is used to provide additional thermal power in the case of rapid flow transients. Its Positioning in the accumulator 310, which stores a larger quantity of gaseous fuel than at the level of the component 112, imposes reduced constraints in terms of thermal inertia and power.

[0080] The internal heating element 311 is thus controlled by the controller 140 according to the temperature measured by the temperature sensor 130 and / or according to information on fuel flow in the pipe 120.

[0081] Temperature-dependent control allows the fuel temperature to be finely adjusted to be as close as possible to the desired temperature for injection, since the pressure losses are lower than when the temperature is regulated by the heating element 112 alone.

[0082] A flow-dependent control system allows for responding to transients, rapid or not, in fuel flow in the pipeline 120.

[0083] Figure 4 illustrates, using a flowchart, a method 400 for controlling the internal heating element 311 based on fuel flow information. These steps are implemented by the controller 320 and begin when the internal heating element 311 is switched off.

[0084] At step 410, the controller receives information about the fuel flow in the line 120. This information can be a measurement, by the flow meter 132, of the fuel flow in the supply line 120 downstream of the accumulator 300, or it can be a fuel flow command, typically a command generated by the aircraft throttle (or equivalent) to control the power of the turbomachine 2.

[0085] This information is compared, in step 420, to the historical flow data to determine or calculate the current flow dynamics. In particular, a calculation of the second derivative (acceleration) of the flow rate can be performed to determine the suddenness of a flow rate variation.

[0086] Indeed, as explained above, the internal heating element 311 serves to provide additional heat in the event of rapid transitions, in particular a sudden increase in fuel flow.

[0087] The calculation of the second derivative can be carried out on a limited number of the last measurements / information received.

[0088] Thus, the flow dynamics obtained, such as the flow acceleration - i.e., a variation of the flow in a given time period - is compared to an SI trigger threshold value in step 430. This value can be determined empirically and / or according to the thermal characteristics of the exchanger 112, to correspond to the increase in thermal power that the exchanger 112 is not able to provide in a predetermined time period taking into account its thermal inertia.

[0089] In the negative of comparison 430 (no sudden increase in fuel flow), the process returns to step 410 for the acquisition of new flow information.

[0090] In the affirmative of comparison 430 (sudden increase in fuel flow), the internal heating element 311 is activated at step 440 by the controller 320.

[0091] This may simply involve supplying electrical power to the electric heater that is part of this component.

[0092] The thermal energy required to maintain the gaseous fuel at a given temperature within the accumulator 300 depends on the amount of newly introduced gaseous fuel. Therefore, the intensity of the electric current (and thus the thermal power delivered) to the internal heating element 311 is preferentially a function of the flow rate information to maintain the target mid-range temperature: the greater the flow rate acceleration, the greater the electrical power supplied to the electric heater. Of course, a single electrical power can be used as an alternative regardless of the flow rate acceleration.

[0093] In one embodiment, the intensity of the electric current (and therefore the thermal power delivered) can also be a function of the fuel temperature, measured by the sensor 130. This makes it possible, in particular, to adjust the temperature of the fuel stored in the accumulator 310 to be as close as possible to the injection temperature (taking into account the pressure losses in the subsequent fuel system 300). To this end, a preferred embodiment provides that the temperature sensor 130 is internal to the accumulator 310, in order to offer increased accuracy and responsiveness.

[0094] Then at step 450, controller 320 receives new fuel flow information, similarly to step 410.

[0095] This information is compared, in step 460, with the flow information history, similarly to step 420, to determine or calculate the current flow dynamics.

[0096] This dynamic is then compared to a stopping threshold value S2 at step 470, in a manner analogous to step 430. In one embodiment, S2 = S1. Of course, these two values ​​can be different, in particular S2 > S1, so as to deactivate the internal heater 311 in advance of a reduction in dynamics under SI. Indeed, the inertia of the heater 311 may be sufficient to provide the necessary thermal energy during this phase of dynamic reduction.

[0097] In the negative of comparison 470 (the sudden increase in fuel flow persists), the process returns to step 450 for the acquisition of new flow information.

[0098] In the affirmative of comparison 470, the internal heating element 311 is deactivated at step 480 by the controller 320.

[0099] In one embodiment, the deactivation 480 is immediate in response to the comparison 470. Alternatively, the deactivation 480 is timed (for example by a few tenths of a second) in response to the comparison 470, in order to avoid cooling of the fuel in the accumulator 310 by the fuel circulating between the heating element 112 and the accumulator when the comparison 470 is carried out.

[0100] Following step 480, the process returns to step 410.

[0101] The injection system 114, and in particular the metering unit 115, is controlled according to the throttle control. For example, the metering unit 115 is controlled so that the fuel flow measured by the sensor 132 equals that corresponding to the throttle control.

[0102] It follows from the preceding operations that a method of operating a fuel system 300 supplying the combustion chamber 25 of an aircraft turbomachine 2 can comprise the following steps: - to circulate fuel in the supply line 120 from the storage tank 110 of cryogenic fuel in liquid state, to the combustion chamber 25, - to heat the cryogenic fuel, using the heating element 112, to bring it to a temperature allowing its evaporation into fuel in a gaseous state, - to store the fuel in a gaseous state in the accumulator 310, - to heat the fuel in the accumulator, by means of a heating element 311 internal to the accumulator, during transients in fuel flow in the line 120. In particular, heating can be triggered if a sudden increase in fuel flow is detected in the supply line, exceeding a trigger threshold, and - control the injection of fuel in gaseous state from the accumulator into the combustion chamber 25.

[0103] Of course, the present invention is not limited to the embodiments described above by way of example; it extends to other variants.

Claims

Demands

1. Fuel system (300) supplying the combustion chamber (25) of an aircraft turbomachine (2), the fuel system comprising: - a storage tank (110) of cryogenic fuel in liquid form, connected by a supply line (120) to said combustion chamber (25), - a first heating element (112) on the supply line, for bringing the cryogenic fuel to a temperature enabling its evaporation into fuel in gaseous form, - an accumulator (310) of fuel in gaseous form, and - an injection system (114) configured to control the injection of fuel in gaseous form from the accumulator into the combustion chamber, fuel system in which the fuel accumulator (310) includes an internal heating element (311) for the fuel in gaseous form.

2. Fuel system according to claim 1, wherein the internal heating element (311) is controlled as a function of fuel flow information in the supply line.

3. Fuel system according to claim 2, wherein the internal heating element (311) is configured to be activated when an increase in fuel flow in the supply line exceeds a first threshold value (SI) in a given time period.

4. Fuel system according to claim 3, wherein the internal heating element (311) is configured to be deactivated when an increase in fuel flow in the supply line falls below a second threshold value (S2) in a given time period.

5. Fuel system according to any one of claims 1 to 4, wherein the internal heating element (311) is controlled based on temperature measurements of the fuel in the gaseous state.

6. Fuel system according to claim 5, comprising a temperature sensor (130) internal to the accumulator (311), configured to provide temperature measurements.

7. Fuel system according to any one of claims 1 to 6, wherein the internal heating element (311) is an electric heater.

8. Fuel system according to claim 7, wherein the electric heater comprises a heating rod disposed inside the accumulator or one or more heating wires disposed on an internal wall of the accumulator.

9. Fuel system according to any one of claims 1 to 8, wherein the cryogenic fuel in the liquid state is liquid dihydrogen.

10. Aircraft turbomachine (2), comprising a combustion chamber (25) and a fuel system (300) according to any one of claims 1 to 9 configured to supply the combustion chamber.

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