SYSTEM AND METHOD FOR CONDITIONING FUEL FOR AN AIR-BREATHING HYDROGEN ENGINE

Description

Technical Field

[0001] This presentation concerns a fuel conditioning system and method for an aerobic hydrogen engine, particularly for aircraft. Previous technique

[0002] Today, aircraft engine designs are perfectly adapted to run on kerosene, the standard aircraft fuel. These engines, which include turbojets and sometimes turboprops, are called air-breathing engines because they use oxygen from the air to perform the chemical reactions necessary for thrust. Unlike the anaerobic engines of launch vehicles and spacecraft, which are capable of producing thrust outside of an atmosphere, these air-breathing engines can only be used in the atmosphere. The latter can use liquid hydrogen as fuel combined with liquid oxygen as an oxidizer to ensure the thrust performance required for this type of application in an oxygen-deprived environment.

[0003] Hydrogen aircraft engines exist but cannot accommodate liquid hydrogen in the combustion chamber of these engines due to its cryogenic nature, namely a particularly low temperature of around 20 to 30K.

[0004] One of the challenges in designing a hydrogen fuel system for an aircraft engine concerns the transformation of liquid hydrogen at very low temperatures (around 20 to 30 K) and low pressures (around 1 bar) into hydrogen at high temperatures (300 K) and high pressures (several tens of bars). These high temperature and high pressure conditions are required for injecting hydrogen into the aircraft engine's combustion chamber to meet the performance, energy efficiency, and operational safety requirements of such an aeronautical system.

[0005] Furthermore, for a commercial aircraft, particularly short-, medium-, or long-haul aircraft, an additional challenge lies in ensuring that the hydrogen reaches the required temperature at the engine's combustion chamber inlet is independent of heat sources originating from the engine itself, especially those generated by the combustion gases in the chamber or nozzle. Indeed, the use of these heat sources: can lead to a decrease in the performance of the aircraft's propulsion system, generally does not offer sufficient range in fuel flow and pressure to manage all phases of flight while meeting the performance and fuel consumption requirements for that type of aircraft, and can create a risk to operational safety due to the risk of uncontrolled hydrogen combustion in the vicinity of pressurized air present in the aircraft engine's combustion chamber. US 2021 / 310442 A1 describes an engine module.

[0006] In view of the above, it would therefore be useful to design a hydrogen fuel system for an aircraft engine that addresses at least one of the problems mentioned above. Description of the invention

[0007] One embodiment relates to a fuel conditioning system for an aerobic hydrogen engine, the system comprising: at least one hydrogen pump configured to increase the pressure of liquid hydrogen from a reservoir, one or more heat exchangers configured to increase the temperature of the pressurized hydrogen, an air supply circuit, the system being characterized in that it also includes at least one combustion device configured to provide partial combustion of the hydrogen with air from the air supply circuit in order to produce a fuel comprising a gas mixture including gaseous hydrogen and which is devoid of oxygen.

[0008] This conditioning system is designed to operate independently of the combustion chamber of an air-breathing hydrogen engine. This means it does not rely on the engine's combustion chamber capacity and, in particular, does not use the hot gases from the combustion chamber to heat the hydrogen. Furthermore, this system efficiently transforms liquid hydrogen at very low temperatures (around 20-30 K) and low pressures (around 1 bar) into high-temperature, high-pressure hydrogen (e.g., 550 K and 40 bar) at the inlet of the air-breathing engine's combustion chamber. In addition, this system does not require an intermediate heat transfer fluid (e.g., helium) to isolate or seal the hydrogen from the air and prevent fire hazards.The system, on the contrary, plans to achieve a partial combustion of hydrogen by consuming all the oxygen available at the time of combustion so that the gaseous mixture produced by the partial combustion no longer contains oxygen, thus eliminating any risk of fire, or even explosion, and therefore offering a high level of operational safety.

[0009] Depending on other possible characteristics: said at least one hydrogen pump is disposed upstream of the heat exchanger(s) in the direction of hydrogen flow from said at least one hydrogen pump; the heat exchanger(s) are configured to increase the temperature of hydrogen at least in part by cooling one or more fluids; the system includes a hydrogen circuit downstream of said at least one hydrogen pump in the direction of hydrogen flow from said at least one hydrogen pump and a fuel circuit downstream of said at least one combustion device, the heat exchanger(s) being fluidically connected between the two circuits in order to increase the temperature of the hydrogen in the hydrogen circuit from the heat of the fuel produced by said at least one combustion device in the fuel circuit;Thus, the heat from this combustion contributes primarily to increasing the temperature of the hydrogen; the system includes, downstream of said at least one hydrogen pump in the direction of flow of hydrogen from said at least one hydrogen pump, a turbine configured to provide a partial expansion of the hydrogen under pressure in order to supply said at least one hydrogen pump, in mechanical form via a drive shaft connecting the turbine to said at least one hydrogen pump, at least a part of the power required for the operation of said at least one hydrogen pump;the system includes, downstream of said at least one combustion device in the direction of fuel flow from said at least one combustion device, a turbine configured to provide partial expansion of the fuel produced by said at least one combustion device in order to supply said at least one hydrogen pump, in mechanical form via a drive shaft connecting the turbine to said at least one hydrogen pump, at least a portion of the power required for the operation of said at least one hydrogen pump; the system includes a turbine bypass circuit equipped with a valve that connects an upstream point located between said at least one combustion device and the turbine and a downstream point located downstream of the turbine, the valve being configured to control the passage of the flow of fuel produced by said at least one combustion device into the turbine and / or the turbine bypass circuit;said at least one hydrogen pump and the turbine together form a turbopump; the system includes a flow separator disposed upstream of said at least one combustion device in the direction of flow of hydrogen from said at least one hydrogen pump and which is configured to separate the hydrogen into a first flow supplied to said at least one combustion device and a second flow which joins the fuel produced by said at least one combustion device downstream of the latter; said at least one hydrogen pump is an electrically powered pump and the system includes at least one electric motor configured to supply the electrically powered pump with all the power required for the operation of the electrically powered pump;The air supply circuit is configured to carry air taken from a hydrogen engine to at least one combustion device and includes a pressure boosting device configured to increase the pressure of this air for introduction into said at least one combustion device; the system includes a compression device configured to increase the pressure of the fuel produced by said at least one combustion device; the compression device is disposed in the fuel circuit downstream of the heat exchanger(s) which are fluidically connected between the fuel circuit, downstream of said at least one combustion device, and the hydrogen circuit, downstream of said at least one hydrogen pump.

[0010] Another embodiment relates to an aerial, maritime or land locomotion device, characterized in that it comprises an aerobic hydrogen engine and a conditioning system such as briefly described above for the conditioning of fuel for an aerobic hydrogen engine.

[0011] Another embodiment relates to a fuel supply system for a combustion chamber of an aerobic hydrogen engine, characterized in that the fuel supply system comprises: at least one fuel conditioning system as briefly described above, at least one liquid hydrogen tank configured to deliver liquid hydrogen to said at least one hydrogen pump of said at least one fuel conditioning system, and an injection device configured to inject the fuel produced by said at least one combustion device of said at least one fuel conditioning system into a combustion chamber of an aerobic hydrogen engine.

[0012] According to one possible feature, the system includes a pump, for example submerged in the tank, which is configured to deliver hydrogen under pressure.

[0013] Another embodiment relates to a fuel conditioning process for an aerobic hydrogen engine, the process comprising: a pressure increase of liquid hydrogen, a temperature increase of the hydrogen under pressure, the process being characterized in that it also includes a partial combustion of hydrogen with air in order to produce a fuel comprising a mixture of gases including gaseous hydrogen and which is devoid of oxygen.

[0014] Depending on other possible characteristics: The hydrogen temperature rise is achieved at least in part by cooling one or more fluids; the hydrogen temperature rise is achieved at least in part by cooling the fuel from the partial combustion; the process includes a partial expansion of the hydrogen to provide, in mechanical form, at least part of the power required to raise the pressure of liquid hydrogen before the partial combustion of the hydrogen; the process includes a partial expansion of the fuel produced by the partial combustion of the hydrogen to provide, in mechanical form, at least part of the power required to raise the pressure of liquid hydrogen before the partial combustion of the hydrogen; at least part of the power required to raise the pressure of liquid hydrogen is provided in electrical form;The process comprises separating a hydrogen stream that has been subjected to a pressure and temperature increase into a first stream subjected to partial combustion and a second stream that rejoins the fuel produced by the partial combustion before its injection into a combustion chamber of an engine; the hydrogen that has been subjected to a pressure and temperature increase is directly subjected to partial combustion; the process comprises increasing the pressure of the fuel produced by the partial combustion of hydrogen with air; the increase in the pressure of the fuel produced by the partial combustion of hydrogen with air is carried out after the cooling of the fuel resulting from the partial combustion. Brief description of the drawings

[0015] 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: [ Fig. 1 ] There figure 1 represents a first possible architecture of a circuit of a fuel conditioning system SC1 integrated into a fuel supply system 10 of a combustion chamber of an aircraft hydrogen-powered air-breathing engine according to the invention; [ Fig. 2 ] There figure 2 represents a second possible architecture of a circuit of an SC2 fuel conditioning system integrated into a 110 fuel supply system for a combustion chamber of an aircraft hydrogen-powered air-breathing engine according to the invention; [ Fig. 3 ] There figure 3 represents a third possible architecture of a circuit of an SC3 fuel conditioning system integrated into a 1110 fuel supply system for a combustion chamber of an aircraft hydrogen-powered air-breathing engine according to the invention; [ Fig. 4 ] There figure 4 represents a fourth possible architecture of a circuit of an SC4 fuel conditioning system integrated into a 210 fuel supply system for a combustion chamber of an aircraft hydrogen-powered air-breathing engine according to the invention; [ Fig. 5 ] There figure 5 represents a flowchart illustrating the main steps of a fuel conditioning process for a combustion chamber of an aircraft hydrogen-powered air-breathing engine according to the invention in relation to each of the different architectures of the figures 1 à 4 , and more generally, a method for supplying fuel to this combustion chamber of an aerobic hydrogen engine. Description of the implementation methods

[0016] There figure 1 represents a first possible architecture of a fuel conditioning system SC1 for an aircraft hydrogen aerobic engine M according to the invention (engine comprising at least one air inlet) or of a gas turbine of a hydrogen engine and, more particularly, for a combustion chamber CC of such an engine M.

[0017] The SC1 fuel conditioning system of the figure 1 uses, as input, on the one hand, liquid hydrogen supplied by one or more liquid hydrogen sources present on board the aircraft, here at least one liquid hydrogen tank 12 (several tanks may be present, in particular for redundancy or distribution of centers of mass in the aircraft) and, on the other hand, air supplied by at least one air source present on board the aircraft in order to produce fuel which will be supplied, at the output of the SC1 system, to a fuel injection device DI in the combustion chamber CC of the engine M, as will be described later.

[0018] As depicted on the figure 1 , the SC1 fuel conditioning system is here part of a more general fuel supply system 10 which includes elements or components external to the SC1 conditioning system, such as said at least one liquid hydrogen tank 12 and the fuel injection device DI described below.

[0019] Said at least one liquid hydrogen tank 12 (here only one tank is shown and described, but this does not exclude the presence of other tanks, and the following description also applies to a fuel supply system comprising several tanks) contains liquid hydrogen at a low temperature and low pressure, for example, on the order of 20 to 25 K and on the order of 1 bar, respectively. It should be noted that the tank 12 is designed, in a known manner, to have sufficient thermal insulation to control, or even eliminate, the vaporization of the liquid hydrogen contained in the tank (a phenomenon known in Anglo-Saxon terminology as "boil-off"). The system described below with reference to the figure 1 and in particular its components, as well as the other possible system architectures described below with reference to the following figures, do not exploit this phenomenon.

[0020] As depicted on the figure 1 , a boost pump 14 (according to Anglo-Saxon terminology) can be immersed in the tank 12 and has the function of pressurizing the liquid hydrogen present in the tank, for example to a pressure of 4 bars, in order to deliver, at the outlet of the tank, pressurized liquid hydrogen.

[0021] The SC1 fuel conditioning system includes, at the inlet, at least one liquid hydrogen pump 16 which is connected to the tank by a portion of circuit 10A. Said at least one liquid hydrogen pump 16 is disposed downstream of the tank 12 (the downstream direction being indicated with respect to the direction of flow of hydrogen in the circuit from the tank 12).

[0022] Pump 16, supplied with pressurized liquid hydrogen delivered from tank 12 and circulating in circuit section 10A, progressively increases the pressure of the liquid hydrogen to a pressure within a first range, for example, from 10 to 200 bar, more specifically within a second range, for example, from 10 to 120 bar, or even within a third range, for example, from 10 to 80 bar, and for example, approximately 50 bar in one embodiment. The pressure differences depend on the requirements of the combustion chamber of the aircraft's hydrogen-powered air-breathing engine. Pump 16 is connected to a turbine 18 via a mechanical drive shaft 20 and thus, together with the turbine, forms a turbopump. The fuel conditioning system SC1 includes at least one turbopump.It should be noted that the feed pump 14 is immersed in the reservoir 12 forming a cryogenic bath, which makes it possible to overcome the problems of net positive suction pressure at the inlet of the liquid hydrogen pump 16 (a phenomenon known in Anglo-Saxon terminology as "Net Positive Suction Pressure" and which is related to the problem of cavitation), while respecting the temperature and pressure requirements at the inlet of this pump.

[0023] The SC1 fuel conditioning system circuit includes, downstream of the hydrogen turbopump 16 (in the direction of hydrogen flow in the circuit), a circuit portion 10B comprising a control valve 22 followed by one or more heat exchangers which are configured to increase the temperature of the pressurized hydrogen delivered by the turbopump 16.

[0024] In the example shown on the figure 1 Circuit segment 10B may include several successive heat exchangers, including a first heat exchanger 24 that uses a heat source available on board the aircraft to achieve an initial temperature increase for the hydrogen. This first heat exchanger 24 uses a heat source produced in another segment (10E) of the conditioning system circuit, which will be described later and where, more specifically, hot combustion gases (fuel) are generated. In the architecture described here, the first heat exchanger 24 is configured to ensure the greatest temperature increase for the hydrogen compared to the other heat exchangers described below (auxiliary exchangers) and is therefore designated as the primary exchanger. The fuel conditioning system SC1 may include several exchangers of the type of exchanger 24.

[0025] The first heat exchanger 24 can be followed by a second heat exchanger 26 which performs a second temperature increase of the hydrogen, here by cooling a heat transfer fluid from another circuit present on board the aircraft, such as for example an aircraft oil circuit.

[0026] A third heat exchanger 28, which can be placed downstream of the second exchanger 26, carries out a third temperature increase of the hydrogen, here by cooling another heat fluid from another circuit present on board the aircraft such as, for example, an air circuit, and more particularly a cabin air circuit from an environmental control system called ECS (according to the Anglo-Saxon terminology "Environmental Control System").

[0027] By heating the hydrogen in the SC1 conditioning system circuit of the figure 1 Other circuits on board the aircraft are therefore cooled, which reduces energy requirements and thus improves the aircraft's energy balance by using the available enthalpies of the on-board circuits.

[0028] As an example, liquid hydrogen, which has a temperature of approximately 25K at the control valve 22, increases in temperature at the outlet of the first exchanger 24 to a temperature of approximately 240K, then increases to a temperature of approximately 280K at the outlet of the second exchanger 26 and finally to a temperature of approximately 310K at the outlet of the third exchanger 28.

[0029] Note that the desired temperature of the hydrogen at the outlet of the last exchanger is, for example, between 240K and 310K.

[0030] For example, the heat exchanged in the main heat exchanger can be around 1.3 MW, while it is closer to 200 kW and 50 kW respectively in the other two exchangers. Since these latter two exchangers have little impact on the air conditioning system circuit, they are easier to design and control than the main heat exchanger 24.

[0031] The order in which the heat exchangers in the circuit are configured can of course vary, in particular depending on the temperature ranges required by each of the fluids used to heat the hydrogen.

[0032] Any heat exchanger that is configured to heat a fluid from an inlet temperature of around 200K to an outlet temperature between 240K and 310K can be suitable, in addition to the temperature increase provided by the first exchanger.

[0033] The number and type of heat exchangers, as well as the aircraft circuits (including the heat transfer fluid(s) used) from which heat is extracted to heat hydrogen, can of course vary from the description just given.

[0034] The portion of circuit 10B is connected, downstream, to the turbine 18 of the hydrogen turbopump which thus receives hydrogen under pressure, for example at a temperature of 310K and at a pressure of 50 bar, from the exchanger 28.

[0035] The partial expansion of pressurized hydrogen in the turbine 18 provides the turbopump with the power required for the remainder of the fuel cycle. Specifically, mechanical power is thus transmitted to the hydrogen pump 16 via the mechanical drive shaft 20 connecting the turbine 18 to the pump 16 for the operation of this pump.

[0036] The control valve 22 contributes to regulating the appropriate hydrogen flow rate injected into the turbine 18 and to achieving optimal turbine performance. According to an alternative embodiment (not shown), the control valve can be arranged in parallel with the turbine to form a bypass. This configuration is justified for reasons of ease of valve design, ease of regulation, and instability at the pump's lowest operating point.

[0037] The hydrogen exiting turbine 18 is, for example, at a pressure of around 30 bars and at a temperature of around 260K.

[0038] The SC1 fuel conditioning system circuit includes, downstream of the turbine 18, a portion of circuit 10C connecting the latter to a flow separator 30.

[0039] The flow separator 30 is connected, via a circuit segment 10D, to at least one combustion device, also called a pre-combustion chamber 32 (or "pre-burner" in Anglo-Saxon terminology), which produces hydrogen-rich, oxygen-free combustion gases. These gases constitute, in particular, a fuel for the combustion chamber CC of the aircraft's air-breathing engine M (e.g., a gas turbine). For example, the molar composition of the gases exiting the pre-combustion chamber 32 could be as follows: between 5 and 10% N2, between 3 and 5% H2O, and between 85 and 92% H2. For example, the pre-combustion chamber 32 could be a gas generator similar to that used in the Ariane 6 launcher or a gas generator similar to that of the Vulcain engine.In general, the components used in this system can be similar to those of a space engine, such as those used in the Ariane 6 upper stage auxiliary power unit system, provided they are appropriately sized, particularly to replace liquid oxygen with air and adapt it to the resulting thermomechanical characteristics. For example, the first heat exchanger 24 can be a heat exchanger from the Ariane 6 upper stage auxiliary power unit system, which can be resized according to the thermal power requirements. The pump can be similar to a motor-driven pump from the Ariane 6 upper stage auxiliary power unit, adapted to the flow and pressure requirements of this conditioning circuit.

[0040] The fuel conditioning system circuit SC1 includes, downstream of the pre-combustion chamber 32, the circuit portion 10E already mentioned above in relation to the main exchanger 24 and which connects the latter to the DI injection device of the CC combustion chamber of the aerobic engine.

[0041] The flow separator 30 is connected, by a portion of circuit 10F, to the portion of circuit 10E downstream of the pre-combustion chamber 32, in an area of ​​this portion located downstream of the pre-combustion chamber and upstream of the DI injection device of the combustion chamber.

[0042] The flow separator is thus configured to separate the hydrogen delivered by the turbine 18, on the one hand, into a first flow supplied to the pre-combustion chamber 32 by the portion of circuit 10D and, on the other hand, into a second flow which joins the fuel produced by the pre-combustion chamber 32 upstream of the DI combustion injection device.

[0043] The flow ratio between the two flows can, for example, be 50 / 50 or, depending on the needs of the equipment located downstream of the flow separator in the different sections of the circuit concerned, the ratio can adopt another distribution.

[0044] Note that the optional circuit segment 10F comprises one or more successive heat exchangers, only one of which, 34, is shown. In this example, heat exchanger 34 can be configured to increase the temperature of the second hydrogen stream before it enters the engine's combustion chamber. The nature of the heat exchanger(s) used in this circuit segment or branch is the same as that of heat exchangers 26 and 28 in the circuit segment or branch 10B described above; namely, they are configured, for example, to cool an oil circuit and / or an air circuit and / or a cabin air circuit (CAC) of the aircraft. In this example, heat exchanger 34 is configured to cool the aircraft's cabin air circuit.The circuit portion 10F may also include, downstream of the exchanger 34, an injector 36 located upstream of the connection point with the circuit portion 10E, a point which is located upstream of the DI injection device of the CC combustion chamber of the engine.

[0045] As an example, the hydrogen exiting exchanger 34 can be at a temperature of around 280K and at a pressure of 4 bars.

[0046] The fuel conditioning system circuit SC1 also includes an air supply circuit, which here takes the form of a circuit segment 10G. Generally, circuit segment 10G supplies the combustion pre-chamber 32 with air (from an air source available on board the aircraft and external to the fuel conditioning system SC1) at a pressure that meets the required inlet pressure of the combustion pre-chamber 32, which is, for example, on the order of 50 bar. Circuit segment 10G may also include a pressure booster or booster 38, which is configured to increase the pressure of the air supplied by the air source if this air does not have the required pressure. Circuit segment 10G may also include an injector 39 to ensure combustion stability by controlling the pressure and flow rate of the incoming air. In the embodiment illustrated on the figure 1 Circuit segment 10G connects the high-pressure compressor (HPC) of the aircraft's hydrogen engine M to the pre-combustion chamber 32. This circuit segment 10G forms an air supply circuit to transport air drawn from the hydrogen engine to the pre-combustion chamber 32. Circuit segment 10G may further include one or more heat exchangers to cool the air drawn from the engine, if necessary. In another embodiment not shown, the air source on board the aircraft that can supply air to the pre-combustion chamber 32 may be a pressurized air cylinder or tank.

[0047] The first hydrogen stream supplied through circuit section 10D by the flow separator 30, originating from the stream delivered by the turbine 18, is introduced into the pre-combustion chamber 32 where it is mixed with air from the air supply circuit 10G. It should be noted that the hydrogen present in the circuit upstream of the pre-combustion chamber 32, and particularly at the inlet of this pre-combustion chamber, is not necessarily in gaseous form. Hydrogen can be in a subcritical state, i.e., gaseous, if its pressure is below the critical pressure (around 13 bar for hydrogen), and in a supercritical state if its pressure is above the critical pressure.Hydrogen is partially burned in the pre-combustion chamber 32 (for example, 4% by volume of the hydrogen may be burned), and the partial combustion is controlled (by a control device not shown) to consume all the oxygen supplied by the feed air. This partial combustion produces a gas mixture including hydrogen gas, nitrogen, and water vapor, forming the fuel for the aircraft's hydrogen engine, for example, with the molar composition mentioned above. The absence of oxygen in the gas mixture (fuel) supplied to the engine's combustion chamber provides a high degree of safety to the fuel system configured in this way.

[0048] It should be noted that the need to heat the hydrogen before it enters the pre-combustion chamber 32 (via the upstream heat exchanger(s) 24, 26, 28) is necessary to avoid problems of hydrogen combustion instability in the pre-chamber and to avoid icing phenomena that may occur in the pre-chamber with low-temperature hydrogen.

[0049] The pre-combustion chamber 32 is present in particular to increase the temperature of the hydrogen. As an example, the gaseous mixture produced by the pre-combustion chamber 32 reaches a temperature of around 750K and a pressure of approximately 40 bar.

[0050] The section of circuit 10E located downstream of the pre-combustion chamber 32 is connected to the heat exchanger 24 described above and thus allows the hydrogen circulating in the section of circuit 10B described above upstream of the turbine 18 to be heated. This has been shown on the figure 1 The two parts of the heat exchanger, 24a and 24b, each carry one of two fluids: hydrogen to be heated and the hot combustion gas mixture (fuel) to be cooled. This configuration allows the enthalpy requirements of the two circuit sections, 10E and 10B, to be shared. It should be noted that the temperature of the hydrogen upstream of the turbine 18 must be increased, and that the temperature of the combustion gases from the pre-combustion chamber 32 is too high to be used directly in the engine's combustion chamber.

[0051] As an example, the temperature of the gas mixture produced by the pre-combustion chamber 32 and cooled in the exchanger 24 is between 400K and 600K and is, for example, about 550K.

[0052] The second flow transported by the portion of circuit 10F joins the portion of circuit 10E downstream of the exchanger 24 in order to mix with the cooled gaseous (fuel) mixture.

[0053] The gaseous mixture (fuel) transported by the 10E circuit segment and enriched by the second flow is thus routed to the DI injection device of the CC combustion chamber of the air-breathing engine to be injected into it in a known manner. This gaseous mixture is, for example, at a temperature of approximately 550 K and a pressure of approximately 40 bar.

[0054] It should be noted, however, that the flow separator 30 and the associated circuit portion 10F can be omitted in one embodiment, and thus the conditioning system comprises only a single circuit portion at the outlet of the turbine 18 for supplying hydrogen to the downstream part of the system, which includes the pre-combustion chamber 32. In such an embodiment, the CC combustion chamber is thus supplied from only one circuit portion and a single gas mixture directly from the pre-combustion chamber 32.

[0055] The configuration of the SC1 fuel conditioning system just described (including the aforementioned variant), and in particular the fuel supply system 10 which incorporates the SC1 system, improves the aircraft engine's energy performance compared to an open-cycle configuration, while minimizing fluid losses in the system. Here, the entire hydrogen flow is reinjected into the engine, unlike in an open cycle where some of the fuel is used for other functions and is released into the atmosphere without contributing to engine operation.

[0056] Although this is not shown on the figure 1 , several components or subsystems of the same type may be present in the system concerned such as, for example, the tank 12 of the fuel supply system 10 and, in the fuel conditioning system SC1: the turbopump (16, 18), the main heat exchanger 24 and the pre-combustion chamber 32. For example, the main heat exchanger 24 and the pre-combustion chamber 32 may be made in the form of a single component or block.

[0057] The operation of the aforementioned SC1 fuel conditioning system of the figure 1 and the operation of the fuel supply system 10, of which it forms part in this embodiment, is illustrated on the figure 5 in the form of a flowchart describing the main steps of the fuel conditioning process for the M engine and, more generally, of the fuel supply process for this engine.

[0058] More specifically, the process of the figure 5 The process comprises the respective steps S1 to S4 of supplying liquid hydrogen, increasing the pressure of the liquid hydrogen, and increasing the temperature of the hydrogen, notably by cooling a fluid (in this case, the fuel from the pre-combustion chamber 32). This process then includes a step S5 of partially expanding the hydrogen whose pressure and temperature have been increased in the preceding steps, followed by an (optional) step S6 of separating the stream from the partial expansion of the preceding step, and a step S7 of partially combusting the hydrogen with air to produce a fuel comprising a gas mixture including gaseous hydrogen and which is devoid of oxygen. In the subsequent step S8, the fuel thus produced is cooled by heat exchange with the pressurized hydrogen, as described above, which is itself heated.The cooled fuel is then injected into the combustion chamber CC of the aerobic hydrogen engine M during a step S9. Steps S2-S8 are carried out by the fuel conditioning process for an aerobic hydrogen engine and steps S1 and S9 are carried out only by the fuel supply process of the aerobic hydrogen engine.

[0059] The fuel conditioning system circuit of the figure 1 It may also include, according to one embodiment, a compression device 40, also called a compressor, which is configured to increase the pressure of the fuel produced by the pre-combustion chamber 32. In this embodiment, the air booster 38 of the circuit portion 10G is omitted. The compressor 40 is located in the fuel circuit portion 10E situated downstream of the heat exchanger(s) 24 (part 24b of the exchanger on the fuel circuit). This heat exchanger(s) is / are fluidically connected between the fuel circuit, downstream of the pre-combustion chamber 32, and the hydrogen circuit, downstream of the hydrogen pump 16. In the example shown in the figure 1 The compressor 40 is positioned in circuit SC1, just upstream of the DI injection device and, more specifically, downstream of the connection point between section 10E and the optional section 10F. Compressor 40 is thus located here at the outlet of the conditioning circuit SC1. However, compressor 40 can alternatively be located upstream of this connection point. Of course, in the embodiment described here, section 10F of circuit can also be omitted. It should be noted that compressor 40 can be a centrifugal compressor driven by an air turbine or a compressor driven by an electric motor.

[0060] By using a compressor 40 downstream of the pre-combustion chamber 32 and removing the air booster 38 from the air circuit, the pressure at the inlet of the pre-combustion chamber 32 is reduced, thus decreasing the pressure requirements on the hydrogen circuit and consequently the associated stresses. Furthermore, this variant simplifies the design of part 10G of the air supply circuit (particularly the booster 38), where the airflow temperature and mass flow rate are limiting factors in the embodiment where the air is drawn from the engine's combustion chamber. The compressor 40 compensates for the pressure losses occurring upstream of the circuit and thus supplies the DI injection system with fuel at an increased pressure, for example, around 50 bar.As an example, the pressure at the inlet of the pre-combustion chamber 32 can be around 50 bar, the hydrogen pressure at the outlet of the pump 16 can be around 100 bar and 50 bar downstream of the turbine 18.

[0061] There figure 2 represents a second possible architecture of a circuit of a fuel conditioning system SC2 for a combustion chamber CC of an aircraft hydrogen aerobic engine M according to the invention.

[0062] The SC2 fuel conditioning system of the figure 2 uses, as input, on the one hand, liquid hydrogen supplied by one or more liquid hydrogen sources present on board the aircraft, here at least one liquid hydrogen tank 112 (several tanks may be present) and, on the other hand, air supplied by at least one air source present on board the aircraft in order to produce fuel which will be supplied, at the output of the SC2 system, to a fuel injection device DI in the combustion chamber CC of the engine M, as will be described later.

[0063] As depicted on the figure 2 , the SC2 fuel conditioning system is here part of a more general fuel supply system 110 which includes elements or components external to the SC2 conditioning system, such as said at least one liquid hydrogen tank 112 and the fuel injection device DI described below.

[0064] As with the first architecture of the figure 1 The liquid hydrogen tank 112, in which a feed pump 114 can be immersed, is configured to supply pressurized liquid hydrogen, via a circuit segment 110A, to a hydrogen pump 116 of the fuel conditioning system SC2 (inlet of the SC2 system), via a mechanical drive shaft 120 to a turbine 118. The pump 116 is connected, via a mechanical drive shaft 120, to a turbine 118 and together they form a turbopump. The fuel conditioning system SC2 also includes, downstream of the pump 116 used to pressurize the liquid hydrogen, a circuit segment 110B comprising a control valve 122 and, downstream of this valve, one or more heat exchangers to ensure the temperature of the pressurized hydrogen is raised.In this architecture, system 110 can include heat exchangers 124, 126 and 128 corresponding respectively to heat exchangers 24, 26 and 28 of the . figure 1 (or at least the main exchanger 124).

[0065] The portion of circuit 110 B may also include, downstream of the heat exchanger(s), another control valve 123 which, like the control valve 122, also allows the hydrogen flow rate in the circuit to be adjusted.

[0066] Unlike the architecture of the figure 1 , in the architecture of the figure 2 : The portion of circuit 10B which includes the heat exchanger(s) is not connected to the turbine 118 of the turbopump but to the pre-combustion chamber 132, and the hydrogen heated by this heat exchanger(s) is thus directly admitted into the pre-combustion chamber 132 to be partially burned using air from the air supply circuit 110E, which is identical to circuit 10G of the figure 1 ; the combustion gas (fuel) mixture generated by the pre-combustion chamber 132 (as for the architecture of the figure 1 , this mixture comprises partially burned gaseous hydrogen, nitrogen, water vapor and is free of oxygen; it may comprise the same molar composition as indicated above) is transported by a portion of circuit 110C which directly connects the outlet of the pre-combustion chamber 132 to the inlet of the turbine 118 of the turbopump and is thus injected directly into this turbine where it undergoes a partial expansion.

[0067] The SC2 fuel conditioning system includes, downstream of the turbine 118, a portion of circuit 110D which connects the outlet of the turbine 118 to the DI injection device of the engine combustion chamber (the DI injection device is, in turn, part of the fuel supply system 110).

[0068] As with the architecture of the figure 1 , the circuit segment 110D passes through the heat exchanger 124 (same configuration as for the circuit segment 10E with the heat exchanger 24 of the figure 1 ) in which the combustion gas mixture (fuel) from the pre-combustion chamber 132 is cooled, while the hydrogen circulating in the portion of circuit 110B is heated.

[0069] It should be noted that turbine 118 is a hot gas turbine which has superior operating and performance characteristics compared to turbine 18 of the architecture of the figure 1 The power delivered by turbine 118, which operates with hot gases, also allows, as with the architecture of the figure 1 , to reduce the operating constraints of the hydrogen pump 116 (for example, a centrifugal pump) via the drive shaft 120 connecting the turbine to the pump 116.

[0070] Insofar as the specifications of the components used in the circuit of the figure 2 are less demanding than those of the circuit components figure 1 (hydrogen turbopump 16 and turbine 18) which must operate at low temperature, the system performance of the figure 2 and the production cost of this system are improved compared to the system of the figure 1 .

[0071] Everything that has been described in relation to the architecture of the figure 1 remains applicable to the architecture of the figure 2 with the exception, however, of the differences presented above.

[0072] The circuit of the figure 2 downstream of turbine 118, it comprises a single circuit connected to the DI injection device of the CC combustion chamber of the air-breathing engine to supply the latter with fuel. This arrangement simplifies the system architecture compared to an architecture where the flow from the turbine is split into two flows by a flow separator, with a second circuit segment (analogous to segment 10F of the figure 1 ) which reinjects part of the flow downstream of the combustion gases from the pre-combustion chamber, after their passage through the main heat exchanger, in particular for their cooling.

[0073] However, according to an alternative embodiment not shown, the architecture of the figure 2 may include a configuration with a stream separator as on the figure 1 .

[0074] As an example, the hydrogen temperatures in circuit section 110B are 180K, 210K, and 250K at the outlets of heat exchangers 124, 126, and 128, respectively. At the outlet of the pre-combustion chamber 132, the combustion gas mixture (fuel) is, for example, at a temperature of approximately 630K and a pressure of 60 bar, which is higher than at the outlet of the pre-combustion chamber 32 of the figure 1 . At the outlet of the turbine 118, the combustion gas mixture which has been partially expanded, for example to a pressure of around 50 bar, is cooled in the exchanger 124 for example to a temperature of around 470K.

[0075] Although this is not shown on the figure 2 , several components or subsystems of the same type may be present in the system concerned such as, for example, the tank 112 of the fuel supply system 110 and, in the fuel conditioning system SC2: the turbopump (116, 118), the main heat exchanger 124 and the pre-combustion chamber 132.

[0076] The operation of the aforementioned SC2 fuel conditioning system of the figure 2 and the operation of the fuel supply system 110, of which it forms part in this embodiment, is illustrated on the figure 5 in the form of a flowchart describing the main steps of the fuel conditioning process for the M engine and, more generally, of the fuel supply process for this engine.

[0077] More specifically, the process of the figure 5 The process comprises the respective steps S1 to S4 of supplying liquid hydrogen, pressurizing the liquid hydrogen, and heating the hydrogen, notably by cooling a fluid (in this case, the fuel from the pre-combustion chamber 132). This process then includes a step S10 of partially combusting the hydrogen with air to produce a fuel comprising a gas mixture including gaseous hydrogen and devoid of oxygen, followed by a step S11 of partially expanding the fuel thus produced. In the subsequent step S12, the fuel thus produced is cooled by heat exchange with the pressurized hydrogen, as described above, which is itself heated. The cooled fuel is then injected into the combustion chamber CC of the hydrogen-powered air-cooled engine M in a step S9.Steps S2-S4 and S10-S12 are carried out using the fuel conditioning process for an aerobic hydrogen engine. Steps S1 and S9 are carried out only using the fuel supply process for the aerobic hydrogen engine.

[0078] The fuel conditioning system circuit of the figure 2 It may also include, according to one embodiment, a compressor 140 configured to increase the pressure of the fuel produced by the pre-combustion chamber 132. In this embodiment, the air booster 138 of the circuit portion 110E is omitted. The compressor 140 is located in the fuel circuit portion 110D downstream of the heat exchanger(s) 124. This heat exchanger(s) are fluidically connected between the fuel circuit, downstream of the pre-combustion chamber 132, and the hydrogen circuit, downstream of the hydrogen pump 116. In the example shown in the figure 2 , the compressor 140 is positioned, in the SC2 circuit, between the heat exchanger(s) 124 and the DI injection device, i.e. at the outlet of the SC2 conditioning circuit.

[0079] There figure 3 represents a third possible architecture of a circuit of a fuel conditioning system SC3 for a combustion chamber CC of an aircraft hydrogen aerobic engine M according to the invention.

[0080] The architecture of the figure 3 is very similar to that of the figure 2 and the corresponding elements of the figure 2 which are included in the figure 3 are preceded by the number "1" in the latter.

[0081] As depicted on the figure 3 , the SC3 fuel conditioning system is here part of a more general 1110 fuel supply system which includes elements or components external to the SC3 conditioning system, such as said at least one liquid hydrogen tank 1112 and the DI fuel injection device.

[0082] The system architecture of the figure 3 differs from that of the figure 2 , primarily because: The heat exchanger 1124, which at least partially heats the hydrogen circulating in the circuit section 1110B, is placed directly at the outlet of the pre-combustion chamber 1132 on the circuit section 110C' connecting the pre-combustion chamber to the turbine 1118, and not downstream of the turbine (as on the figure 2 where the heat exchanger is located downstream of turbine 118). A bypass circuit section 110F of turbine 1118 is provided between an upstream point Pam located on circuit section 110C', upstream of the turbine and downstream of heat exchanger 1124, and a downstream point Pav located on circuit section 110D' which connects the turbine to the DI injection device. This circuit section 110F is equipped with a bypass-type control valve Vbp configured to control the flow of the combustion gas (fuel) mixture through turbine 1118 and / or through circuit section 110F. When the control valve is fully open, the flow circulating in circuit section 110C' flows entirely into bypass circuit section 110F, thus stopping the turbine's operation. The Vbp control valve is thus controlled by the aircraft's thrust regime.

[0083] It should be noted that, unlike the architecture of the figure 2 , the circuit portion 1110B comprises a single heat exchanger 1124 corresponding to the exchanger 124 of the figure 2 and not several heat exchangers. However, according to an unshown variant, exchangers similar to the other exchangers 126 and 128 of the figure 2 can be added.

[0084] In an alternative embodiment not shown, the heat exchanger 1124 can be placed after the downstream point Pav of the bypass circuit portion 110F on the circuit portion 110D', i.e. downstream of the turbine as in the architecture of the figure 2 .

[0085] Although this is not shown on the figure 3 , several components or subsystems of the same type may be present in the system concerned such as, for example, the tank 1112 of the fuel supply system 1110 and, in the fuel conditioning system SC3: the turbopump (1116, 1118), the main heat exchanger 1124 and the pre-combustion chamber 1132.

[0086] The operation of the aforementioned SC3 fuel conditioning system of the figure 3 and the operation of the fuel supply system 1110, of which it is a part in this embodiment, is illustrated on the figure 5 in the form of a flowchart describing the main steps of the fuel conditioning process for the M engine and, more generally, of the fuel supply process for this engine.

[0087] More specifically, the process of the figure 5 The process comprises the respective steps S1 to S4 of supplying liquid hydrogen, pressurizing the liquid hydrogen, and heating the hydrogen, notably by cooling a fluid (in this case, the fuel from the pre-combustion chamber 1132). This process then includes a step S10 of partially combusting the hydrogen with air to produce a fuel comprising a gas mixture including gaseous hydrogen and devoid of oxygen. In the following step S13, the fuel thus produced is cooled by heat exchange with the pressurized hydrogen, as described above, which is itself heated. The process then includes either a step S11 of partially expanding the fuel thus produced and cooled, or a bypass step S14 that avoids the partial expansion step.The cooled fuel, partially or fully expanded, is then injected into the combustion chamber CC of the aerobic hydrogen engine M during step S9. Steps S2-S4, S10, S13, S11, and S14 are carried out using the fuel conditioning process for an aerobic hydrogen engine. Steps S1 and S9 are carried out only using the fuel supply process for the aerobic hydrogen engine.

[0088] The fuel conditioning system circuit of the figure 3 It may also include, according to one embodiment, a compressor 1140 configured to increase the pressure of the fuel produced by the pre-combustion chamber 1132. In this embodiment, the air booster 1138 of the circuit portion 1110E is omitted. The compressor 1140 may be located in the fuel circuit portion 110D' situated downstream of the heat exchanger(s) 1124. This heat exchanger(s) are fluidically connected between the fuel circuit, downstream of the pre-combustion chamber 1132, and the hydrogen circuit, downstream of the hydrogen pump 1116. In the example shown in the figure 3 The compressor 1140 is positioned in the SC3 circuit between the heat exchanger(s) 1124 and the DI injection device, i.e., at the outlet of the SC3 conditioning circuit. More specifically, the compressor 1140 is located downstream of the turbine 1118 and point Pav of the bypass section 110F.

[0089] According to another embodiment illustrated on the figure 3 , the compressor 1140' is positioned downstream of the interchange(s) 1124, in the portion 110C' and upstream of point Pam of the bypass portion 110F and, therefore, upstream of the turbine 1138. The same characteristics and advantages as those of the previous variant of the compressor 1140 also apply here and will not be repeated.

[0090] There figure 4 represents a fourth possible architecture of a circuit of an SC4 fuel conditioning system for a CC combustion chamber of an aircraft hydrogen aerobic engine M according to the invention.

[0091] The architecture of the figure 4 is similar in terms of cycle and power supply circuit to that of the figure 1 and the corresponding elements of the figure 1 which are included in the figure 4 are preceded by the number "2" in the latter.

[0092] As depicted on the figure 4 , the SC4 fuel conditioning system is here part of a more general 210 fuel supply system which includes elements or components external to the SC4 conditioning system, such as said at least one liquid hydrogen tank 212 and the DI fuel injection device.

[0093] Unlike the architecture of the figure 1 , the SC4 fuel conditioning system of the figure 4 includes an MP motor pump which includes an electrically powered Pae pump, for example centrifugal, replacing the pump 16 of the figure 1 and an ME electric motor replacing the turbine 18 of the figure 1 The electric motor is configured to supply the Pae pump with the power required for its operation and is connected to it via a 20' mechanical transmission shaft. This arrangement eliminates the design requirements of the turbine 18 of the figure 1 .

[0094] As with the architecture of the figure 1 , the SC4 fuel conditioning system of the figure 4 is also configured to ensure a temperature rise of the hydrogen at the outlet of the Pae pump by means of one or more heat exchangers 224, 226 and 228, to produce a mixture of combustion gas (fuel) using a gas generator 232 and to carry out a heat exchange between these hot gases (in order to cool them) and the hydrogen (to allow the temperature of the hydrogen to increase) by means of the heat exchanger(s) 224-228.

[0095] Unlike the architecture of the figure 1 The hydrogen heated in circuit section 210B is directly injected into the pre-combustion chamber 232, via circuit section 210C', instead of being supplied to a turbine as in the architecture figure 1 .

[0096] A Pu circuit purge system is provided for example immediately downstream of the exchanger 228 by means of a shut-off valve Va.

[0097] The use of a mechanically coupled electric motor (ME) coupled to a hydrogen pump (motor pump), in this case a centrifugal pump, reduces the pressure at the pump outlet and therefore decreases the mechanical stresses to which the entire hydrogen circuit is subjected. This arrangement also simplifies the pump's installation.

[0098] Although this is not shown on the figure 4 , several components or subsystems of the same type may be present in the system concerned such as, for example, the tank 212 of the fuel supply system 210 and, in the fuel conditioning system SC4: the Pae pump and the ME motor, the main heat exchanger 224 and the pre-combustion chamber 232.

[0099] The operation of the aforementioned SC4 fuel conditioning system of the figure 4 and the operation of the fuel supply system 210, of which it forms part in this embodiment, is illustrated on the figure 5 in the form of a flowchart describing the main steps of the fuel conditioning process for the M engine and, more generally, of the fuel supply process for this engine.

[0100] More specifically, the process of the figure 5 This process includes the respective steps S1 to S4 of supplying liquid hydrogen, pressurizing the liquid hydrogen, and heating the hydrogen, notably by cooling a fluid (in this case, the fuel from the pre-combustion chamber 232). The process then includes a step S7 of partially combusting the hydrogen with air to produce a fuel comprising a gas mixture including gaseous hydrogen and devoid of oxygen. In the following step S8, the fuel thus produced is cooled by heat exchange with the pressurized hydrogen, as described above, which is itself heated. The cooled fuel is then injected into the combustion chamber CC of the aerobic hydrogen engine M in a step S9. Steps S2-S4, S7, and S8 are carried out by the fuel conditioning process for an aerobic hydrogen engine.Steps S1 and S9 are only carried out by the process of supplying fuel to the aerobic hydrogen engine.

[0101] The fuel conditioning system circuit of the figure 4 It may also include, according to one embodiment, a compressor 240 configured to increase the pressure of the fuel produced by the pre-combustion chamber 232. In this embodiment, the air booster 238 of the circuit portion 210G is omitted. The compressor 240 is located in the fuel circuit portion 210E downstream of the heat exchanger(s) 224. This heat exchanger(s) are fluidically connected between the fuel circuit, downstream of the pre-combustion chamber 232, and the hydrogen circuit, downstream of the hydrogen pump Pae. In the example shown in the figure 4 , the compressor 240 is positioned, in the SC3 circuit, between the heat exchanger(s) 224 and the DI injection device, i.e. at the outlet of the SC3 conditioning circuit.

[0102] The different architectures described above have in common the fact that they restrict / confine the cryogenic part of the circuit as close as possible to the hydrogen tank, which prevents the engine from being in immediate contact with a cryogenic environment.

[0103] The risks of hydrogen leakage in the heat exchangers, particularly in the main heat exchanger 24 of the figure 1 Risks are reduced because, in the event of a leak, hydrogen could, at worst, come into contact with the hydrogen-rich, oxygen-free gaseous mixture (fuel), thus eliminating the risks of fire or explosion. The simplification of the design and therefore its construction is an advantage stemming from the limitation of the aforementioned risk.

[0104] The conditioning systems described above (SC1 to SC4) do not use the capabilities of the aerobic engine's combustion chamber to raise the temperature and pressure of hydrogen and, in particular, do not draw hot gases from it for this purpose, thus avoiding a decrease in the performance of the aircraft engine's propulsion system.

[0105] The conditioning systems described above (SC1 to SC4) are designed autonomously (i.e. without interaction) with respect to the combustion chamber and engine subsystems, namely the HP (high pressure) and LP (low pressure) turbines of the engine.

[0106] The invention described above can also be applied to other engines such as train, boat or land locomotion engine engines or to fixed installations using gas turbines.

[0107] 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.

[0108] It is also evident that all the characteristics described with reference to a system are transposable, alone or in combination, to a process, and conversely, all the characteristics described with reference to a process are transposable, alone or in combination, to a system.

Claims

1. A fuel conditioning system (SC1; SC2; SC3; SC4) for an aerobic hydrogen engine (M), the system comprising: - at least one hydrogen pump (16; 116; 1116; Pae) configured to increase the liquid hydrogen pressure coming from a tank, - one or several heat exchanger(s) (24, 26, 28; 124, 126, 128; 1124; 224, 226, 228) configured to increase the temperature of the pressurized hydrogen, - an air supply circuit (10G; 110E; 1110E; 210G), the system being characterized in that it further comprises - at least one combustion device (32; 132; 1132; 232) configured to ensure a partial combustion of the hydrogen with air coming from the air supply circuit in order to produce a fuel comprising a gas mixture including gaseous hydrogen and which is devoid of oxygen.

2. The system according to the preceding claim, characterized in that said at least one hydrogen pump (16; 116; 1116; Pae) is disposed upstream of the heat exchanger(s) in the direction of circulation of the hydrogen from said at least one hydrogen pump.

3. The system according to claim 1 or 2, characterized in that the heat exchanger(s) (24, 26, 28; 124, 126, 128; 1124; 224, 226, 228) is / are configured to increase the hydrogen temperature at least partly by cooling one or several fluid(s).

4. The system according to any of claims 1 to 3, characterized in that it comprises a hydrogen circuit downstream of said at least one hydrogen pump (16; 116; 1116; Pae) in the direction of circulation of the hydrogen from said at least one hydrogen pump and a fuel circuit downstream of said at least one combustion device, the heat exchanger(s) (24, 26, 28; 124,126,128; 1124; 224, 226, 228) being fluidly connected between the two circuits in order to increase the temperature of the hydrogen in the hydrogen circuit from the heat of the fuel produced by said at least one combustion device (32; 132; 1132; 232) in the fuel circuit.

5. The system according to any of claims 1 to 4, characterized in that it comprises, downstream of said at least one hydrogen pump (16) in the direction of circulation of the hydrogen from said at least one hydrogen pump, a turbine (18) configured to ensure partial expansion of the pressurized hydrogen in order to provide to said at least one hydrogen pump (16), in mechanical form via a transmission shaft (20) connecting the turbine to said at least one hydrogen pump, at least part of the power necessary for the operation of said at least one hydrogen pump.

6. The system according to any of claims 1 to 4, characterized in that the system comprises, downstream of said at least one combustion device (1132) in the direction of circulation of the fuel from said at least one combustion device, a turbine (1118) configured to ensure partial expansion of the fuel produced by said at least one combustion device in order to provide to said at least one hydrogen pump (1116), in mechanical form via a transmission shaft (1120) connecting the turbine to said at least one hydrogen pump, at least part of the power necessary for the operation of said at least one hydrogen pump.

7. The system according to claim 6, characterized in that the system includes a circuit (110F) for bypassing the turbine, provided with a valve (Vbp) which connects an upstream point (Pam) located between said at least one combustion device and the turbine and a downstream point (Pav) located downstream of the turbine, the valve (Vbp) being configured to control the passage of the flow of fuel produced by said at least one combustion device (1132) into the turbine and / or the turbine bypass circuit (110F).

8. The system according to any of claims 5 to 7, characterized in that said at least one hydrogen pump and the turbine together form a turbopump.

9. The system according to any of claims 1 to 5, characterized in that it comprises a flow separator (30) disposed upstream of said at least one combustion device (32) in the direction of circulation of the hydrogen from said at least one hydrogen pump (16) and which is configured to separate the hydrogen into a first flow provided to said at least one combustion device (32) and a second flow which joins the fuel produced by said at least one combustion device (32) downstream of the latter.

10. The system according to any of claims 1 to 4, characterized in that said at least one hydrogen pump (Pae) is an electrically-powered pump and the system comprises at least one electric motor (ME) configured to provide to the electrically-powered pump all of the power necessary for the operation of the electrically-powered pump.

11. The system according to any of the preceding claims, characterized in that the air supply circuit (10G; 110E; 1110E; 210G) is configured to transport air taken from an aerobic hydrogen engine to said at least one combustion device and comprises a pressure relief device (38; 138; 1138; 238) configured to ensure a rise in the pressure of this air with a view to introducing it into said at least one combustion device.

12. The system according to any of claims 1 to 10, characterized in that the system comprises a compression device (40; 140; 1140; 240) configured to increase the pressure of the fuel produced by said at least one combustion device (32; 132; 1132; 232).

13. The system according to claims 4 and 12, characterized in that the compression device (40; 140; 1140; 240) is disposed in the fuel circuit downstream of the heat exchanger(s) (24; 124; 1124; 224) which are fluidly connected between the fuel circuit, downstream of said at least one combustion device, and the hydrogen circuit, downstream of said at least one hydrogen pump (16; 116; 1116; Pae).

14. A system (10; 110; 1110; 210) for supplying fuel to a combustion chamber (CC) of an aerobic hydrogen engine (M), characterized in that the fuel supply system comprises: - at least one fuel conditioning system (SC1; SC2; SC3; SC4) according to any of the preceding claims, - at least one liquid hydrogen tank (12; 112; 1112; 212) configured to deliver liquid hydrogen to said at least one hydrogen pump (16; 116; 1116; 216) of said at least one fuel conditioning system (SC1; SC2; SC3; SC4), and - an injection device (DI) configured to inject the fuel produced by said at least one combustion device of said at least one fuel conditioning system into a combustion chamber (CC) of an aerobic hydrogen engine (M).

15. The fuel supply system according to the preceding claim, characterized in that it comprises a pump (14; 114; 1114; 214) which is configured to deliver pressurized hydrogen to said at least one fuel conditioning system.

16. A fuel conditioning method for an aerobic hydrogen engine (M), the method comprising: - a rise in the pressure of liquid hydrogen (S2), - a rise in the temperature of the pressurized hydrogen (S3), the method being characterized in that it further comprises - a partial combustion (S7; S10) of the hydrogen with air in order to produce a fuel comprising a gas mixture including gaseous hydrogen and which is devoid of oxygen.

17. The method according to the preceding claim, characterized in that the hydrogen temperature rise is obtained at least partly by cooling (S4) one or several fluid(s).

18. The method according to claim 16 or 17, characterized in that the hydrogen temperature rise is obtained at least partly by cooling (S8; S12; S13) the fuel resulting from the partial combustion.

19. The method according to any of claims 16 to 18, characterized in that it comprises a partial expansion (S5) of the hydrogen to provide in mechanical form at least part of the power necessary for the rise in the liquid hydrogen pressure before the partial combustion of the hydrogen.

20. The method according to any of claims 16 to 18, characterized in that it comprises a partial expansion (S11) of the fuel produced by the partial combustion of hydrogen to provide in mechanical form at least part of the power necessary for the rise in the liquid hydrogen pressure before the partial combustion of the hydrogen.

21. The method according to any of claims 16 to 18, 20, characterized in that at least part of the power necessary for the liquid hydrogen pressure rise is provided in electrical form.

22. The method according to any of claims 16 to 19, characterized in that it comprises the separation (S6) of a hydrogen flow that has been subjected to a pressure and temperature rise into a first flow subjected to the partial combustion and a second flow which joins the fuel produced by the partial combustion before its injection into a combustion chamber of an engine.

23. The method according to any of claims 16 to 18, 20, 21, characterized in that the hydrogen that has been subjected to a pressure and temperature rise is directly subjected to the partial combustion.

24. The method according to any of the preceding claims, characterized in that it comprises an increase in the pressure of the fuel produced by the partial combustion of the hydrogen with air.

25. The method according to claims 18 and 24, characterized in that the increase in the pressure of the fuel produced by the partial combustion of the hydrogen with air is carried out after the cooling of the fuel resulting from the partial combustion.