Pressure regulation device for a heat transfer loop in a turbomachine hydrogen supply system

Abstract

The invention relates to a control device comprising an auxiliary reservoir (91) fluidly connected to said circulation circuit of a heat transfer fluid (30) and containing an auxiliary volume (92) of heat transfer fluid, and in that said control device further comprises means for regulating the temperature of said auxiliary volume of heat transfer fluid configured to vary the temperature of said auxiliary volume (92) of heat transfer fluid as a function of a target pressure within said circulation circuit of a heat transfer fluid (30) and of an actual pressure within the circulation circuit of a heat transfer fluid (30), said means for regulating the temperature of said auxiliary volume (92) of heat transfer fluid being controlled by control means (900) configured to: determine said target pressure within said circulation circuit of a heat transfer fluid (30);determine said current pressure within the circulation circuit of a heat transfer fluid (30); control said temperature control means of said ancillary volume (92) of heat transfer fluid to adjust said current pressure within the circulation circuit of a heat transfer fluid (30) on the basis of said target pressure within said circulation circuit of a heat transfer fluid (30).;

Description

Title of the invention: Pressure regulation device for a heat transfer loop in 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 regulation device for a heat transfer loop 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;

[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 conventionally includes 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] The heating element comprises, or is constituted in a known manner, a circulation circuit of a heat transfer fluid in which a quantity of heat transfer fluid exchanges heat energy with the outside of the circuit without exchanging matter.

[0014] However, the pressure in such a heat transfer fluid circulation circuit, or heat transfer fluid circulation loop, is relative to the average temperature of the heat transfer fluid circulating in that circuit. In hydrogen turbomachine applications, this average circuit temperature will depend, in particular, on the operating conditions of the turbomachine, for example, the flight regime or external conditions. Consequently, there is a significant difference between the minimum and maximum pressures that can be exerted within this circuit, which is problematic for the pressure resistance of the equipment and operational safety constraints (for example, leaks).

[0015] There is therefore a need to provide a solution to prevent or limit pressure variation problems within a heat transfer fluid circulation circuit in the hydrogen supply systems of a turbomachine. Description of the invention

[0016] The invention aims to remedy at least in part the aforementioned drawbacks relating to prior art techniques.

[0017] To this end, the invention relates to a pressure regulation device for a heat transfer loop of a hydrogen supply system for a turbomachine comprising a combustion chamber, the hydrogen supply system comprising: - a reservoir; - a pressurization device for the liquid hydrogen arriving from said reservoir; - 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 feed system from the rest of the turbomachine.

[0018] According to the invention, said control device comprises an auxiliary reservoir fluidly connected to said heat transfer fluid circulation circuit and containing an auxiliary volume of heat transfer fluid, and said control device comprises in addition to temperature control means for said auxiliary volume of heat transfer fluid configured to vary the temperature of said auxiliary volume of heat transfer fluid as a function of a target pressure within said heat transfer fluid circulation circuit and an actual pressure within the heat transfer fluid circulation circuit, said temperature control means for said auxiliary volume of heat transfer fluid being controlled by control means configured to: - determine said target pressure within said heat transfer fluid circulation circuit; - determine the current pressure within the circulation circuit of a heat transfer fluid; - to control said means of regulating the temperature of said ancillary volume of heat transfer fluid in order to adjust said current pressure within the circulation circuit of a heat transfer fluid on the basis of said target pressure within said circulation circuit of a heat transfer fluid.

[0019] Thus, the solution presented proposes a new and inventive approach that makes it possible to resolve at least in part some of the drawbacks of the prior art.

[0020] In particular, by implementing an auxiliary reservoir fluidly connected to the circulation circuit of a heat transfer fluid and containing an auxiliary volume of heat transfer fluid, the quantity of heat transfer fluid circulating in the heat transfer fluid circulation circuit can be varied, and therefore the pressure can be varied, which is linked to the quantity of fluid by the real gas equation, or even by the ideal gas equation in the case of ideal gases.

[0021] Furthermore, by implementing temperature control means for the auxiliary volume of heat transfer fluid configured to vary the temperature of the auxiliary volume of heat transfer fluid as a function of a target pressure within the circulation circuit of a heat transfer fluid and an actual pressure within the circulation circuit of a heat transfer fluid, it is also possible to vary the quantity of heat transfer fluid circulating in the heat transfer fluid circulation circuit, and therefore the variation of the pressure which is related to the quantity of fluid by the ideal gas equation.

[0022] According to a particular aspect of at least one embodiment of the invention, said means for regulating the temperature of said auxiliary volume of heat transfer fluid include means for heating said auxiliary volume of heat transfer fluid and means for cooling said auxiliary volume of heat transfer fluid.

[0023] According to a particular aspect of at least one embodiment of the invention, said heat transfer fluid circulation circuit includes means for heating the heat transfer fluid. The heat transfer fluid circulation circuit may also include an exchange element between the heated heat transfer fluid and hydrogen.

[0024] According to a particular aspect of at least one embodiment of the invention, said means for heating said ancillary volume of heat transfer fluid belong to a list comprising: - an electric heater; - a heat exchanger connected to a heat source; - a heat exchanger connected to engine oil of said turbomachine; - a heat exchanger connected to an airflow circulating in said turbomachine.

[0025] According to a particular aspect of at least one embodiment of the invention, said cooling means for said ancillary volume of heat transfer fluid belong to a list comprising: - a heat exchanger connected to said tank; - a heat exchanger connected to a cold source; - a heat exchanger connected to an airflow circulating in said turbomachine.

[0026] According to a particular aspect of at least one embodiment of the invention, if the current pressure is lower than said target pressure within said heat transfer fluid circulation circuit, said control means control said heating means to heat said auxiliary volume of heat transfer fluid so that a portion of said auxiliary volume of heat transfer fluid is injected into said heat transfer fluid circulation circuit and said current pressure within the heat transfer fluid circulation circuit increases until it reaches said target pressure within said heat transfer fluid circulation circuit.

[0027] According to a particular aspect of at least one embodiment of the invention, if the current pressure is greater than said target pressure within said heat transfer fluid circulation circuit, said control means control said cooling means to cool said auxiliary volume of heat transfer fluid so that a portion of said heat transfer fluid from said heat transfer fluid circulation circuit is taken from said heat transfer fluid circulation circuit to said auxiliary reservoir and so that said current pressure within the heat transfer fluid circulation circuit decreases until said target pressure is reached within said heat transfer fluid circulation circuit.

[0028] According to a particular aspect of at least one embodiment of the invention, said ancillary volume of heat transfer fluid is between 0 and 200% of a volume of heat transfer fluid included in said heat transfer fluid circulation circuit.

[0029] The invention also relates to a hydrogen supply system for a turbomachine comprising a pressure regulation device according to any one of the aforementioned embodiments.

[0030] According to a particular aspect of at least one embodiment of the invention, said heat transfer fluid is a liquid, gaseous or supercritical fluid.

[0031] The invention also relates to a turbomachine comprising a combustion chamber and a hydrogen supply system according to the aforementioned embodiment, said turbomachine further comprising injectors configured to inject hydrogen from said hydrogen supply system into said combustion chamber. Presentation of the figures

[0032] 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:

[0033] [Fig-1] is a partial schematic view of a hydrogen supply system according to one embodiment of the invention;

[0034] [Fig.2] is another partial schematic view of a power supply system hydrogen according to the embodiment of [Fig.1];

[0035] [Fig.3] is a partial schematic view of a pressure regulation device of a hydrogen supply system according to the embodiment of [Fig.1].

[0036] Detailed description of an embodiment of the invention

[0037] 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.

[0038] 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.

[0039] 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 20K.

[0040] The hydrogen tank 1 is connected to a pressurization device 2 intended to raise the hydrogen, in particular liquid hydrogen, to a pressure.

[0041] 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 or equal to the sum of the pressure losses of the various equipment of the hydrogen supply system A.

[0042] 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.

[0043] 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.

[0044] In this embodiment, the heating element 3 comprises a circulation circuit for a heat transfer fluid 30, as shown in [Fig. 2], which is configured to exchange heat energy with said liquid hydrogen so as to heat it. Such a circuit may, in particular, include, as shown in [Fig. 2], a flow generator 31.

[0045] Such a circuit may also include means for heating the heat transfer fluid and / or an exchange element between the heated heat transfer fluid and hydrogen.

[0046] The heat transfer fluid may, in particular, be a gaseous or supercritical fluid. It may, in particular, be nitrogen or helium.

[0047] 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.

[0048] 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.

[0049] The metering element 5 can, for example, be a variable area metering valve or a pressure regulator coupled to a sonic neck.

[0050] 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.

[0051] The shut-off element 6 can, for example, be an "on or off" type shut-off valve.

[0052] The shut-off device 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.

[0053] The hydrogen supply system A further comprises several sensors. In particular, the hydrogen supply system A comprises:

[0054] - a hydrogen temperature sensor 7, in particular arranged upstream of the organ dosing 5, in particular between the hydrogen accumulator 4 and the dosing unit 5;

[0055] - a hydrogen pressure sensor 8, in particular arranged upstream of the organ of dosing 5, in particular between the hydrogen accumulator 4 and the dosing unit 5; and / or

[0056] - a hydrogen flow sensor 9, advantageously located as close as possible to the injectors 100 of the turbomachine, notably arranged downstream of the shut-off device 6.

[0057] The hydrogen flow sensor 9 is, for example, a mass flow meter or any other type of sensor enabling the acquisition of information on the flow circulating in the hydrogen supply system A. The hydrogen flow sensor 9 therefore makes it possible to measure a flow of hydrogen supplied to the injectors 100.

[0058] In order to prevent or limit pressure variation problems within the heat transfer fluid circulation circuit, the supply system includes a pressure regulation device for the supply system.

[0059] According to the invention, and as more particularly illustrated in [Fig.2], the device regulation includes an auxiliary reservoir 91 fluidly connected to the circulation circuit of a heat transfer fluid 30 and containing an auxiliary volume 92 of heat transfer fluid.

[0060] It should be noted that the auxiliary tank 91 has a volume which is greater than the auxiliary tank 92 of heat transfer fluid which is contained in this auxiliary tank 91 so that the auxiliary tank 91 can also contain heat transfer fluid from the heat transfer fluid circulation circuit.

[0061] According to different embodiments, the additional volume of heat transfer fluid is between 0 and 200% of a volume of heat transfer fluid included in the circulation circuit of a heat transfer fluid 30.

[0062] The control device according to the invention further includes means for regulating the temperature of the auxiliary volume of heat transfer fluid configured to vary the temperature of the auxiliary volume 92 of heat transfer fluid as a function of a target pressure within the circulation circuit of a heat transfer fluid 30 and of an actual pressure within the circulation circuit of a heat transfer fluid 30.

[0063] These temperature regulation means for the auxiliary volume 92 of heat transfer fluid are controlled by control means 900 configured to: - determine the target pressure within the circulation circuit of a heat transfer fluid 30; - determine the current pressure within the circulation circuit of a heat transfer fluid 30; - control the temperature regulation means of the annex volume 92 of heat transfer fluid to adjust the current pressure within the circulation circuit of a heat transfer fluid 30 on the basis of the target pressure within the circulation circuit of a heat transfer fluid 30.

[0064] This target pressure within the circulation circuit of a heat transfer fluid 30 can in particular be defined by the manufacturer of the supply system according to foreseen cases of flight regime of the turbomachine and of external conditions.

[0065] This target pressure can also be defined or calculated by the control means 900 according to an observed case of flight regime of the turbomachine, for example in communication with the FADEC system, and observed external conditions, for example through sensors.

[0066] The current pressure within the circulation circuit of a heat transfer fluid 30 can be measured either in real time, or measured at predefined time intervals, or randomly. For example, it can be measured by pressure sensors implemented within the circulation circuit of a heat transfer fluid.

[0067] The control means 900 may include in particular a microprocessor, a memory, and means of communication with the power supply system.

[0068] In order to regulate the temperature in order to influence the volume of heat transfer fluid in the circulation circuit of a heat transfer fluid and therefore the pressure within this circulation circuit of a heat transfer fluid, the means for regulating the temperature of the auxiliary volume of heat transfer fluid include means for heating 93 of the auxiliary volume 92 of heat transfer fluid and means for cooling 94 of the auxiliary volume 92 of heat transfer fluid.

[0069] These means for regulating the temperature of the auxiliary volume of heat transfer fluid are controlled by the control means in order to vary the pressure of the heat transfer fluid circulation circuit.

[0070] More specifically, if the current pressure is lower than the target pressure within the circulation circuit of a heat transfer fluid 30, the control means 900 control the heating means 93 to heat the auxiliary volume 92 of heat transfer fluid so that a portion of the auxiliary volume 92 of heat transfer fluid is injected into the circulation circuit of a heat transfer fluid 30 and so that the current pressure within the circulation circuit of a heat transfer fluid 30 increases until the target pressure is reached within the circulation circuit of a heat transfer fluid.

[0071] Furthermore, if the current pressure is greater than the target pressure within the circulation circuit of a heat transfer fluid 30, the control means 900 control the cooling means 94 to cool the auxiliary volume 92 of heat transfer fluid so that a portion of said heat transfer fluid from the circulation circuit of a heat transfer fluid 30 is taken from the circulation circuit of a heat transfer fluid 30 to the auxiliary reservoir 91 and so that the current pressure within the circulation circuit of a heat transfer fluid 30 decreases until it reaches the target pressure within the circulation circuit of a heat transfer fluid 30.

[0072] According to various embodiments, the heating means 93 for the ancillary volume 92 of heat transfer fluid belong to a list comprising: - an electric heater; - a heat exchanger connected to a heat source; - a heat exchanger connected to the turbomachine's engine oil; - a heat exchanger connected to an airflow circulating in the turbomachine.

[0073] As for the cooling means 94 of the annex volume 92 of heat transfer fluid, they belong, according to different embodiments, to a list comprising: - a heat exchanger connected to tank 1; - a heat exchanger connected to a cold source; a heat exchanger heat connected to an airflow circulating in the turbomachine.

[0074] The means for cooling the auxiliary volume of heat transfer fluid may also include a heat exchanger connected to an additional tank dedicated to this function.

Claims

1. Demands Pressure regulation device for a heat transfer loop of a hydrogen supply system (A) of a turbomachine comprising a combustion chamber, the hydrogen supply system (A) comprising: - a reservoir (1); - a pressurization device (2) for the liquid hydrogen arriving from said reservoir (1); - a heating element (3) configured to raise the liquid hydrogen to a temperature so as to allow its evaporation into gaseous hydrogen, 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 feed system from the rest of the turbomachine, characterized in that said control device comprises an auxiliary reservoir (91) fluidly connected to said heat transfer fluid circulation circuit (30) and containing an auxiliary volume (92) of heat transfer fluid, and in that said control device further comprises temperature control means for said auxiliary volume of heat transfer fluid configured to vary the temperature of said auxiliary volume (92) of heat transfer fluid as a function of a target pressure within said heat transfer fluid circulation circuit (30) and an actual pressure within the heat transfer fluid circulation circuit (30), said temperature control means for said auxiliary volume (92) of heat transfer fluid being controlled by control means (900) configured to: - determine said target pressure within said heat transfer fluid circulation circuit (30); - determine said current pressure within the circulation circuit of a heat transfer fluid (30); - control said temperature control means of said ancillary volume (92) of heat transfer fluid to adjust said current pressure within the circulation circuit of a heat transfer fluid (30) on the basis of said target pressure within said circulation circuit of a heat transfer fluid (30).

2. Device according to claim 1, characterized in that said means for regulating the temperature of said auxiliary volume of heat transfer fluid include means for heating (93) said auxiliary volume (92) of heat transfer fluid and means for cooling (94) said auxiliary volume (92) of heat transfer fluid.

3. Device according to claim 2, characterized in that said heating means (93) of said ancillary volume (92) of heat transfer fluid belong to a list comprising: - an electric heater; - a heat exchanger connected to a heat source; - a heat exchanger connected to engine oil of said turbomachine; - a heat exchanger connected to an airflow circulating in said turbomachine.

4. Device according to any one of claims 2 or 3, characterized in that said cooling means (94) of said ancillary volume (92) of heat transfer fluid belong to a list comprising: - a heat exchanger connected to said reservoir (1); - a heat exchanger connected to a cold source; - a heat exchanger connected to an airflow circulating in said turbomachine.

5. A pressure regulating device according to any one of claims 2 to 4, characterized in that if the actual pressure is lower than said target pressure within said heat transfer fluid circulation circuit (30), said control means (900) control said heating means (93) to heat said auxiliary volume (92) of heat transfer fluid so that a portion of said auxiliary volume (92) of heat transfer fluid is injected into said heat transfer fluid circulation circuit (30) and that said current pressure within the circulation circuit of a heat transfer fluid (30) increases until said target pressure is reached within said circulation circuit of a heat transfer fluid (30).

6. Pressure regulation device according to any one of claims 2 to 5, characterized in that if the actual pressure is greater than said target pressure within said heat transfer fluid circulation circuit (30), said control means (900) control said cooling means (94) to cool said auxiliary volume (92) of heat transfer fluid so that a portion of said heat transfer fluid from said heat transfer fluid circulation circuit (30) is taken from said heat transfer fluid circulation circuit (30) to said auxiliary reservoir (91) and said actual pressure within the heat transfer fluid circulation circuit (30) decreases until said target pressure is reached within said heat transfer fluid circulation circuit (30).

7. Pressure regulation device according to any one of the preceding claims, said ancillary volume (92) of heat transfer fluid being between 0 and 200% of a volume of heat transfer fluid included in said heat transfer fluid circulation circuit (30).

8. Hydrogen supply system for a turbomachine, characterized in that it comprises a pressure regulation device according to any one of claims 1 to 7.

9. Hydrogen supply system (A) according to claim 8, characterized in that said heat transfer fluid is a liquid, gaseous or supercritical fluid.

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

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