Pressure variation control device for a turbomachine's hydrogen supply system

Abstract

The invention relates to a pressure control device for a hydrogen supply system (A) of a turbomachine comprising a combustion chamber, the hydrogen supply system (A) comprising, from upstream to downstream in the direction of hydrogen flow: a reservoir (1); a pressurization device (2) for the liquid hydrogen arriving from said reservoir (1); a heating device (3); an accumulator (4); a metering device (5) for metering the mass flow rate of gaseous hydrogen at the inlet of the combustion chamber, and a shut-off valve (6) configured to isolate the supply system from the rest of the turbomachine, characterized in that said control device further comprises a filtration control device (7). Figure 2.

Description

Title of the invention: Pressure variation control device for a turbomachine hydrogen supply system. Field of the invention

[0001] The present invention relates to the field of aeronautics, and more specifically, to the field of turbomachinery.

[0002] More particularly, the invention relates to a hydrogen supply system for a turbomachine and a pressure variation control device for this hydrogen supply system. Prior art

[0003] The propulsion sector, and in particular the aeronautical sector, faces major environmental challenges. The interest in using hydrogen combustion as an alternative to the use of fossil fuels is increasingly important because, unlike fossil fuels whose combustion generates carbon dioxide, the combustion of hydrogen generates only water vapor.

[0004] One of the main differences between a conventionally powered turbomachine and a hydrogen-powered turbomachine lies in the fuel supply system.

[0005] A hydrogen supply system for the turbomachine comprises, in series, according to a direction of hydrogen flow, from upstream to downstream:

[0006] - a liquid hydrogen reservoir;

[0007] - a liquid hydrogen pressurization device;

[0008] - a heating element intended to raise the temperature of the liquid hydrogen in order to allow its evaporation into hydrogen gas;

[0009] - an accumulator, otherwise called a capacitive element;

[0010] - a dosing device intended to dose the mass flow rate of gaseous hydrogen in combustion chamber inlet, and

[0011] - a shut-off valve allowing the supply system to be isolated from the rest of the turbomachine.

[0012] The hydrogen supply system also includes, in a conventional manner, a plurality of sensors, including temperature and pressure sensors located upstream of the dosing unit, and a mass flow meter located as close as possible to the injectors of the turbomachine.

[0013] Dosing devices are already commonly used to control the mass flow rate of gaseous hydrogen. For example, in the space sector, it is common to use dosing valves with gaseous dihydrogen.

[0014] However, these valves used in the space sector are not applicable to the aeronautical sector because the metering components of an aeronautical system require a metering accuracy that must be between 3% and 15% of the fuel flow of this aeronautical system and this with a response time that must be between 20ms and 500ms in order to guarantee the stability and acceleration or deceleration performance of the engine.

[0015] Furthermore, in the context of a conventional aircraft engine, the metering valves are based on a passage section whose pressure differential between the upstream and downstream of these valves is fixed thanks to the action of the recirculation valve which recirculates the additional fuel upstream of the pressurization devices.

[0016] However, in the case of an aircraft engine operating on hydrogen, with dihydrogen to be metered in gaseous form, the additional flow cannot be returned upstream of the pressurization unit because these operate with hydrogen in liquid form. Therefore, the pressure differential cannot, in this case, be achieved by recirculating excess dihydrogen.

[0017] Furthermore, other events such as the change of state of dihydrogen generate relatively significant pressure variations that also disrupt the operation of the metering device. Even if the accumulator helps to mitigate the pressure differential upstream of the metering device, its action will vary depending on the engine's operating point, and therefore its filtration capacity will vary over time, which does not guarantee adequate stability for an aircraft engine running on dihydrogen.

[0018] There is therefore a need to provide a solution to prevent or limit pressure variation problems within the hydrogen supply system of a turbomachine, and in particular a solution which would stabilize the pressure differential between the upstream and downstream of the metering device of this hydrogen supply system. Description of the invention

[0019] The invention aims to remedy at least in part the aforementioned drawbacks relating to prior art techniques.

[0020] To this end, the invention relates to a pressure regulation device for a hydrogen supply system of a turbomachine comprising a combustion chamber, the hydrogen supply system comprising, from upstream to downstream in the direction of hydrogen flow: - a liquid hydrogen storage and pressurization unit; - a heating element configured to raise the temperature of the liquid hydrogen to allow its evaporation into gaseous hydrogen, said heating element comprising a circulation circuit of a heat transfer fluid configured to exchange heat energy with said liquid hydrogen in order to heat it; - an accumulator; - a metering device designed to measure the mass flow rate of gaseous hydrogen entering the combustion chamber, and - a shut-off valve configured to isolate the fuel system from the rest of the turbomachine and configured to be connected to an inlet of the combustion chamber.

[0021] According to the invention, said regulation device further comprises a filtration control element located upstream of said accumulator and configured to control a pressure differential upstream of said accumulator as a function of a time setpoint and a pressure differential downstream of said accumulator.

[0022] Thus, the solution proposes an approach that makes it possible to resolve at least in part the disadvantages of the prior art.

[0023] In particular, the solution makes it possible to stabilize the pressure differential between the upstream and downstream of the dosing unit of the hydrogen supply system, and thus to guarantee filtration performance and ensure that the filtration is identical at all times.

[0024] According to a particular aspect of at least one embodiment of the invention, the filtration control device is provided downstream of said liquid hydrogen storage and pressurization assembly.

[0025] According to a particular aspect of at least one embodiment of the invention, said upstream pressure differential of said accumulator is a pressure differential between an outlet of the liquid hydrogen storage and pressurization assembly and an inlet of the accumulator.

[0026] According to a particular aspect of at least one embodiment of the invention, said pressure differential downstream of said accumulator is a pressure differential between an outlet of said accumulator and an outlet of the shut-off valve.

[0027] According to a particular aspect of at least one embodiment of the invention, the filtration control element comprises a valve.

[0028] According to a particular aspect of at least one embodiment of the invention, said liquid hydrogen storage and pressurization assembly comprises a tank and a pressurization device.

[0029] According to a particular aspect of at least one embodiment of the invention, the device includes a controller of a pressure differential across said filtration control element, and said filtration control element controls said pressure differential upstream of said accumulator as a function of said pressure differential across said filtration control element.

[0030] According to a particular aspect of at least one embodiment of the invention, the device includes a controller of a pressure differential between an outlet of said accumulator and an outlet of said shut-off valve, and said filtration control element controls said pressure differential upstream of said accumulator as a function of said pressure differential between said outlet of said accumulator and said outlet of said shut-off valve.

[0031] The invention also relates to a hydrogen supply system for a turbomachine, comprising a pressure regulation device according to one of the aforementioned embodiments.

[0032] The invention also relates to a turbomachine comprising a combustion chamber and a hydrogen supply system according to the aforementioned embodiment, said combustion chamber further comprising injectors configured to inject hydrogen from said hydrogen supply system into said combustion chamber.

[0033] The invention also relates to an aircraft, comprising a turbomachine according to the aforementioned embodiment.

[0034] The invention also relates to a method for regulating the pressure of a hydrogen supply system of a turbomachine comprising a combustion chamber, characterized in that it implements a pressure regulation device according to one of the aforementioned embodiments.

[0035] According to a particular aspect of at least one embodiment of the invention, the pressure regulation method comprises the following steps: - a step involving the command of a time instruction; - a step of measuring a pressure differential downstream of said accumulator; - a step of controlling a pressure differential upstream of said accumulator as a function of a step of controlling a time setpoint and of said step of measuring said pressure differential downstream of said accumulator. Presentation of the figures

[0036] The invention, as well as its various advantages, will be more easily understood in the light of the following description of illustrative and non-limiting embodiments thereof, and the accompanying drawings, among which:

[0037] [Fig-1] is a partial schematic view of a hydrogen supply system according to one embodiment of the invention;

[0038] [Fig.2] is another partial schematic view of a power supply system hydrogen according to the embodiment of [Fig.1];

[0039] [Fig.3] is a partial schematic view of an alternative pressure regulation device of a hydrogen supply system according to the embodiment of [Fig.1].

[0040] Detailed description of an embodiment of the invention

[0041] Fig. 1 schematically presents an embodiment of the invention of a hydrogen supply system A of a turbomachine comprising a combustion chamber and injectors 100 configured to inject hydrogen from the hydrogen supply system into the combustion chamber.

[0042] This hydrogen supply system A is capable of providing a controlled flow of hydrogen to injectors 100 located in a combustion chamber of the turbomachine.

[0043] Such a turbomachine can, for example, be mounted on an aircraft.

[0044] As illustrated in this [Fig.1], the hydrogen supply system A comprises, according to a direction of hydrogen flow from upstream to downstream, a hydrogen reservoir 1, in particular in which the hydrogen is in a cryogenic liquid state, in particular at low pressure, for example of an order of magnitude between 2 bar and 3 bar, and at low temperature, for example of an order of magnitude of 10K.

[0045] The hydrogen tank 1 is connected to a pressurization device 2 intended to raise the hydrogen, in particular liquid hydrogen, to a pressure.

[0046] At a given injected hydrogen flow rate, the difference between the pressure at the outlet of the pressurization device 2 and the pressure in the combustion chamber must therefore be greater than the sum of the pressure losses of the various equipment of the hydrogen supply system A.

[0047] The pressurization device 2 can, for example, be a pump, in particular a centrifugal pump, or several pumps, in particular several centrifugal pumps, in series.

[0048] According to a generic embodiment, the hydrogen supply system includes a liquid hydrogen storage and pressurization unit, which in this embodiment includes the tank 1 and the pressurization unit 2.

[0049] According to an alternative, the liquid hydrogen storage and pressurization assembly could also be a high-pressure tank.

[0050] The pressurization element 2 is connected to a heating element 3, designed to raise the temperature of the hydrogen, particularly liquid hydrogen. This temperature increase ensures the evaporation of the hydrogen entering the heating element 3 into gaseous hydrogen, while maintaining a temperature range suitable for hydrogen combustion.

[0051] The heating element 3 is connected to a hydrogen accumulator 4, in particular a hydrogen accumulator in the gaseous state, intended to provide a "buffer" function between an upstream part of the hydrogen supply system A arranged upstream of the hydrogen accumulator 4 and a downstream part of the hydrogen supply system A arranged downstream of the hydrogen accumulator 4.

[0052] The hydrogen accumulator 4 is connected to a dosing device 5 intended to dose a mass flow rate of hydrogen, in particular gaseous hydrogen, into the combustion chamber.

[0053] The metering element 5 can, for example, be a variable area metering valve or a pressure regulator coupled to a sonic neck.

[0054] The metering device 5 is connected to a shut-off device 6 intended to allow isolation between the hydrogen supply system A and the combustion chamber of the turbomachine.

[0055] The shut-off element 6 may more particularly be an "on or off" type shut-off valve.

[0056] The shut-off valve 6 is connected to a supply line connected to the injectors 100 located in the combustion chamber of the turbomachine. The injectors 100 and the combustion chamber are conventional and are not detailed here.

[0057] The hydrogen supply system A further comprises several sensors. In particular, the hydrogen supply system A comprises:

[0058] - a hydrogen temperature sensor 80, in particular arranged upstream of the dosing unit 5, in particular between the hydrogen accumulator 4 and the dosing unit 5;

[0059] - a hydrogen pressure sensor 81, in particular arranged upstream of the organ of dosing 5, in particular between the hydrogen accumulator 4 and the dosing unit 5; and / or

[0060] - a hydrogen flow sensor 82, advantageously located as close as possible to the injectors 100 of the turbomachine, notably arranged downstream of the shut-off valve 6.

[0061] The hydrogen flow sensor 82 is, for example, a mass flow meter or any other type of sensor enabling the acquisition of information on the flow rate circulating in the hydrogen supply system A. The hydrogen flow sensor 9 therefore allows the measurement of a flow of hydrogen supplied to the injectors 100.

[0062] The hydrogen supply system of a turbomachine further comprises, according to the invention, a pressure regulation device.

[0063] Such a pressure regulation device for a turbomachine hydrogen supply system is configured to implement a pressure regulation method.

[0064] The regulation device here includes a filtration control element 7 located upstream of the accumulator 4 and configured to control a pressure differential APamont upstream of the accumulator 4 as a function of a cut-off frequency setpoint equivalent to a time constant Tcibie and a pressure differential APavai downstream of the accumulator 4.

[0065] Therefore, the pressure regulation process may include the following steps: - a step involving the command of a time instruction; - a step of measuring a pressure differential downstream of said accumulator; - a step of controlling a pressure differential upstream of said accumulator as a function of a step of controlling a time setpoint and of said step of measuring said pressure differential downstream of said accumulator.

[0066] Thus, the principle of controlling this filtration control element 7 is to control the pressure drop upstream of the accumulator. Since the variation of the time constant depends on the flow rate of fluid circulating in the system, the time setpoint Tcibie can therefore depend on a flow rate of fluid circulating in the system.

[0067] As illustrated in the figures, in this embodiment, the filtration control element 7 is provided downstream of the liquid hydrogen storage and pressurization assembly.

[0068] More specifically, the filtration control element 7 is provided downstream of the pressurization element 2.

[0069] Thus, in the illustrated embodiment, the upstream pressure differential AP^m of the accumulator 4 is a pressure differential between an outlet of the liquid hydrogen storage and pressurization assembly and an inlet of the accumulator 4.

[0070] More specifically, in this embodiment, the upstream pressure differential APamont of the accumulator 4 is a pressure differential between an outlet of the pressurization member 2 and an inlet of the accumulator 4.

[0071] Furthermore, in this embodiment, the downstream pressure differential APavai of the accumulator 4 is a pressure differential between an outlet of the accumulator 4 and the outlet of the shut-off valve 6.

[0072] It should be noted that the pressure between the outlet of the shut-off valve 6 is substantially equal to the pressure at the inlet of the combustion chamber.

[0073] This filtration control element 7 can, for example, be a valve which allows a pressure drop to be provided at a given flow rate.

[0074] Such a given flow rate can in particular be defined as a function of a target upstream pressure differential APamont.

[0075] As illustrated in [Fig.2], the device according to the embodiment presented further includes a controller 70 of a differential pressure APvalne at the terminals of said filtration control element 7.

[0076] Such a pressure differential controller APvanne at the terminals of the filtration control element 7 allows measurement of a differential between the pressure PVannc.mi<)rilcn upstream of the filtration control element 7 and the pressure PVannea vai downstream of the filtration control element 7.

[0077] As a result, the filtration control unit 7 controls the pressure differential APamont upstream of the accumulator 4 as a function of the pressure differential APvanne across the terminals of the filtration control unit 7.

[0078] In one variant, illustrated in [Fig.3], the device according to the embodiment presented further includes a controller 71 of a differential pressure APdosage between an outlet of the accumulator 4 and an outlet of the shut-off valve 6.

[0079] Such a controller of a differential pressure APdosage at the terminals of the dosing element 5 makes it possible to measure a differential between the pressure PDosageamont upstream of the dosing element 5 and the pressure PDosagea vaien outlet of the shut-off valve 6.

[0080] As a result, the filtration control unit 7 controls the pressure differential APamont upstream of the accumulator 4 as a function of the pressure differential APdosage between the outlet of the accumulator 4 and the outlet of the shut-off valve 6.

Claims

Demands

1. Pressure control device of a hydrogen supply system (A) of a turbomachine comprising a combustion chamber, the hydrogen supply system (A) comprising, from upstream to downstream in the direction of hydrogen flow: - a liquid hydrogen storage and pressurization unit; - a heating element (3) configured to raise the liquid hydrogen to a temperature so as to allow its evaporation into hydrogen gas, said heating element (3) comprising a circulation circuit of a heat transfer fluid (30) configured to exchange heat energy with said liquid hydrogen so as to heat it; - an accumulator (4);- a metering device (5) intended to meter the mass flow rate of gaseous hydrogen at the inlet of the combustion chamber, and - a shut-off valve (6) configured to isolate the supply system from the rest of the turbomachine and configured to be connected to an inlet of the combustion chamber, characterized in that said control device comprises a filtration control device (7) provided upstream of said accumulator (4) and configured to control a pressure differential (APamont) upstream of said accumulator (4) as a function of a time setpoint (rcibie) and a pressure differential (APavai) downstream of said accumulator (4).;

2. Device according to claim 1, characterized in that said filtration control element (7) is provided downstream of said liquid hydrogen storage and pressurization assembly.

3. Device according to claim 2, characterized in that said upstream pressure differential (APamont) of said accumulator (4) is a pressure differential between an outlet of the assembly of liquid hydrogen storage and pressurization and an accumulator inlet (4).

4. Device according to any one of claims 1 to 3, characterized in that said downstream pressure differential (APavai) of said accumulator (4) is a pressure differential between an outlet of said accumulator (4) and an outlet of said shut-off valve (6).

5. Device according to any one of the preceding claims, characterized in that the filtration control element (7) comprises a valve.

6. Device according to any one of the preceding claims, characterized in that said liquid hydrogen storage and pressurization assembly comprises a reservoir (1) and a pressurization member (2).

7. Device according to any one of the preceding claims, characterized in that it comprises a controller (70) of a pressure differential (APvalne) across said filtration control member (7), and in that said filtration control member (7) controls said pressure differential (APamont) upstream of said accumulator (4) as a function of said pressure differential (APvalne) across said filtration control member (7).

8. Device according to any one of the preceding claims, characterized in that it comprises a controller (71) of a pressure differential (APdosage) between an outlet of said accumulator (4) and an outlet of said shut-off valve (6), and in that said filtration control element (7) controls said pressure differential (AP^m) upstream of said accumulator (4) as a function of said pressure differential (APdosage) between said outlet of said accumulator (4) and said outlet of said shut-off valve (6).

9. Hydrogen supply system for a turbomachine, characterized in that it comprises a pressure regulation device according to any one of claims 1 to 8.

10. Turbomachine comprising a combustion chamber and a hydrogen supply system (A) according to claim 9, said combustion chamber further comprising injectors (100) configured to inject hydrogen from said hydrogen supply system (A) into said combustion chamber.

11.

12. Aircraft, comprising a turbomachine according to claim 10. Method for regulating the pressure of a hydrogen supply system (A) of a turbomachine comprising a chamber of combustion, characterized in that it implements a pressure regulation device according to any one of claims 1 to 8.

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