Hydrogen propulsion system including an inert gas injection device; aircraft comprising at least one such propulsion system

Abstract

Hydrogen propulsion assembly including an inert gas injection device, aircraft comprising at least one such propulsion assembly. The invention relates to a propulsion assembly comprising a fairing (34) delimiting an internal zone (ZI), a hydrogen-powered engine (32), a hydrogen conduit (38.1) connected to the engine (32) and positioned in the internal zone (ZI), a debris ejection zone (36) and an inert gas container (46) positioned around or near the hydrogen conduit (38.1) and configured to puncture or break when impacted by debris from the engine (32).Thus, in the event of a hydrogen leak due to debris impact, the inert gas exiting the inert gas container and injected into the interior area dilutes the hydrogen within that area, preventing the hydrogen and / or oxygen concentration from reaching a critical threshold. The invention also relates to an aircraft comprising at least one such propulsion system. Figure 4.

Description

Title of the invention: Hydrogen propulsion system comprising an inert gas injection device, aircraft comprising at least one such propulsion system

[0001] The present application relates to a hydrogen propulsion system comprising an inert gas injection device and to an aircraft comprising at least one such propulsion system.

[0002] According to an embodiment shown in [Fig. 1], an aircraft propulsion system comprises an engine 10 and a nacelle 12 in which the engine 10 is positioned. The latter comprises a combustion chamber 10.1, a turbine 10.2 and an exhaust 10.3. The propulsion system comprises at least one hydrogen supply circuit 14 configured to deliver hydrogen from a tank to the combustion chamber 10.1. The propulsion system may also include at least one hot air intake circuit 16, 16' configured to draw hot air from the engine 10, for example to preheat the air used in the aircraft's air conditioning and de-icing systems, and an oil circuit 18 configured to cool the oil of the engine 10.

[0003] The propulsion system includes at least one debris ejection zone 20, which corresponds to a volume in which parts and / or debris ejected from the engine 10 in the event of an incident may impact the aircraft. These parts and / or debris, of varying sizes, may originate from different stages of the engine 10.

[0004] The hydrogen supply circuit 14 includes at least one hydrogen conduit 22 passing through the debris ejection zone 20.

[0005] To limit the risks of hydrogen leakage, the hydrogen conduit 22 passing through the debris ejection zone 20 is a double-walled conduit.

[0006] To limit the risk of damage to the hydrogen conduit 22, the propulsion assembly includes at least one shield 24 positioned between the engine 10 and the hydrogen conduit 22. This shield 24 is designed to retain debris with energy levels below a given threshold. However, due to limitations related to its size and mass, this shield 24 cannot retain debris with high energy levels. Consequently, such debris can impact the hydrogen conduit 22, which can generate a hydrogen leak inside the nacelle 12 and lead to an increase in hydrogen concentration and pressure within the nacelle 12.

[0007] The propulsion assembly may also include at least one system fire extinguishing device 26 allowing for the rapid extinguishing of a fire outbreak.

[0008] To limit the increase in pressure inside the nacelle 12, the propulsion assembly includes at least one decompression door 26 configured to open automatically as soon as the pressure inside the nacelle 12 exceeds a trigger threshold and to communicate the inside and outside of the nacelle 12. The propulsion assembly may include two decompression doors 26, 26' allowing ventilation inside the nacelle 12, which helps to reduce the concentration of hydrogen inside the nacelle 12.

[0009] The ventilation of the inside of the nacelle is not optimal because its triggering is delayed and only occurs when the pressure inside the nacelle exceeds the triggering threshold.

[0010] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0011] To this end, the invention relates to a propulsion assembly comprising a fairing separating an inner zone and an outer zone, a motor positioned in the inner zone, a debris ejection zone positioned at least partially in the inner zone and into which debris from the motor can be ejected, and a hydrogen supply system comprising at least one hydrogen conduit passing through the debris ejection zone.

[0012] According to the invention, the propulsion assembly includes an inert gas injection device comprising an inert gas container which contains at least one pressurized inert gas, said inert gas container being positioned at least partly in the debris ejection zone, around or near the hydrogen conduit, and being configured to puncture or break when the inert gas container is impacted by debris from the engine.

[0013] According to the invention, when debris ejected from the engine causes a leak in the hydrogen line, it also simultaneously causes a leak in the inert gas container. The inert gas exiting the inert gas container and injected into the interior area dilutes the hydrogen in that area and prevents the concentration of hydrogen and / or oxygen in the interior area from reaching a critical threshold.

[0014] According to another characteristic, the inert gas container has a lower resistance to perforation or rupture than the hydrogen conduit.

[0015] According to another characteristic, the inert gas contained in the inert gas container has a temperature below 20°C.

[0016] According to another feature, the inert gas container includes at least one inert gas conduit which has a section juxtaposed to the hydrogen conduit.

[0017] According to another feature, the section of the inert gas conduit is positioned between the engine and the hydrogen conduit.

[0018] According to another feature, the inert gas container includes at least one inert gas conduit which has a section in which the hydrogen conduit is inserted at least partially.

[0019] According to another feature, the propulsion assembly includes at least one shield positioned between the engine on the one hand and the hydrogen duct and the section of the inert gas duct on the other hand.

[0020] According to another feature, the hydrogen supply system includes a shut-off valve configured to occupy open and closed states, the propulsion assembly including a control for controlling the state of the shut-off valve and at least one first leak detection system configured to inform the control in order to control the state of the shut-off valve.

[0021] According to another feature, the first leak detection system includes at least one element selected from at least one pressure sensor configured to measure the pressure in the internal area, at least one pressure sensor configured to measure the pressure of the inert gas in the inert gas container and at least one wire break detector positioned along the hydrogen conduit.

[0022] According to another feature, the first wire break detector includes a wire running along the hydrogen conduit, the propulsion assembly including a shield positioned between the motor and the wire of the first wire break detector.

[0023] According to another feature, the inert gas container includes a trigger valve configured to be in a first state in which the trigger valve allows injection of inert gas into the internal area and a second state in which the trigger valve prevents any flow of inert gas into the internal area. In addition, the inert gas injection device includes a control for monitoring the state of the trigger valve and a second leak detection system configured to detect a leak in the motor and provide information to the trigger valve control to monitor its state.

[0024] According to another feature, the propulsion assembly includes a shield. In addition, the second leak detection system includes at least one second wire break detector having at least one wire positioned between the motor and the shield.

[0025] The invention also relates to an aircraft comprising at least one propulsion assembly according to one of the preceding characteristics.

[0026] Other features and advantages will become apparent from the following description of the invention, given by way of example only, with reference to the drawings attached, including:

[0027] [Fig. 1] is a schematic longitudinal section of a propulsion assembly illustrating an embodiment of the prior art,

[0028] [Fig.2] is a schematic longitudinal section of a propulsion assembly illustrating one embodiment of the invention,

[0029] [Fig.3] is a schematic longitudinal section of a propulsion assembly illustrating another embodiment of the invention,

[0030] [Fig.4] is a schematic longitudinal section of a propulsion assembly illustrating another embodiment of the invention.

[0031] According to one configuration, an aircraft includes at least one hydrogen-powered propulsion system 30.

[0032] According to embodiments visible in figures 2 to 4, a propulsion assembly 30 comprises a hydrogen-powered engine 32 and a nacelle 34 in which the engine 32 is positioned.

[0033] According to one configuration, the engine 32 comprises a combustion chamber 32.1, a turbine 32.2, an exhaust 32.3 and a casing 32.4 forming an enclosure in which the majority of the engine 32 elements are positioned. The nacelle 34 comprises a fairing 34.1 separating an inner zone ZI in which the engine 32 is positioned and an outer zone ZE.

[0034] The propulsion assembly 30 includes at least one debris ejection zone 36, positioned at least partially within the inner zone ZI, into which debris from the engine 32 can be ejected in the event of incidents. In one arrangement, this debris ejection zone 36 is positioned around the turbine 32.2. It extends between a forward boundary 36.1 and a rear boundary 36.2, the terms forward and rear referring to the direction of gas flow in the engine 32. Of course, the invention is not limited to this arrangement for the debris ejection zone 36.

[0035] The propulsion assembly 30 includes at least one hydrogen supply system 38 configured to deliver hydrogen from at least one tank to the propulsion unit 32. This hydrogen supply system 38 includes at least one hydrogen conduit 38.1, through which hydrogen flows, passing through the debris ejection zone 36. In one configuration, the hydrogen conduit 38.1 is a double-walled conduit. In one arrangement, the hydrogen conduit 38.1 passes through the front and rear boundaries 36.1, 36.2 of the debris ejection zone 36.

[0036] The motor 32, the nacelle 34 and the hydrogen supply system 38 are not described further as they may be identical to those of the prior art.

[0037] According to an embodiment shown in [Fig. 4], to limit the risk of damage to the hydrogen conduit 38.1, the propulsion assembly 30 includes at least one shield 40 positioned between the propulsion unit 32 and the hydrogen conduit 38.1 and configured to retain at least one piece of debris with an energy level below a given threshold. This shield 40 is not further described as it may be identical to those of the prior art.

[0038] According to an embodiment visible in [Fig.4], the propulsion assembly 30 includes at least one fire extinguishing system 42. This fire extinguishing system 42 is not further described as it may be identical to those of the prior art.

[0039] According to a configuration shown in [Fig. 4], the propulsion assembly 30 includes at least one decompression gate 44 configured to open automatically as soon as the pressure in the inner zone ZI of the nacelle 34 exceeds a trigger threshold, thus connecting the inner zone ZI and the outer zone ZE of the nacelle. In the event of a rupture or perforation of the hydrogen conduit 38.1, each decompression gate 44 prevents the pressure in the inner zone ZI of the nacelle 34 from exceeding a given threshold, thereby limiting the risks of overpressure and bursting of the nacelle 34.

[0040] According to one arrangement, the propulsion assembly 30 includes at least first and second decompression doors 44, 44' positioned on either side of the debris ejection zone 36. Thus, the first decompression door 44 is positioned in front of the debris ejection zone 36 and the second decompression door 44' is positioned behind the debris ejection zone 36. This arrangement promotes ventilation of the internal zone ZI, in particular the part of the internal zone ZI in which the debris ejection zone 36 is located. Upon opening, the first and second decompression doors 44, 44' limit the pressure and hydrogen concentration in the internal zone ZI.

[0041] The propulsion assembly 30 includes an inert gas injection device 45 which has an inert gas container 46 which contains at least one inert gas, positioned at least partly in the debris ejection zone 36 and near the hydrogen conduit 38.1, the inert gas container 46 being configured to puncture or break when impacted by debris from the engine 32. According to one configuration, the inert gas container 46 has a lower resistance to puncture or breakage than the hydrogen conduit 38.1.

[0042] Consequently, when debris causes a leak in the hydrogen conduit 38.1, it also simultaneously causes a leak in the inert gas container 46 positioned next to the hydrogen conduit 38.1. The hydrogen and inert gas contained respectively in the hydrogen conduit 38.1 and the inert gas container 46 then spread into the internal zone ZI. The inert gas exiting the inert gas container 46 and injected into the internal zone ZI dilutes the hydrogen in the internal zone ZI and prevents the hydrogen concentration from in the inner industrial zone does not reach a critical threshold.

[0043] The inert gas container 46 contains at least one inert gas under pressure. For the remainder of this description, "one" or "the" inert gas refers to a single inert gas or a mixture of inert gases.

[0044] The inert gas can be nitrogen or helium. Of course, the invention is not limited to these gases for the inert gas.

[0045] The inert gas contained in the inert gas container 46 has a temperature below 20°C.

[0046] According to embodiments visible in Figures 2 and 4, the inert gas container 46 comprises at least one inert gas conduit 48 having a section 48.1 juxtaposed to the hydrogen conduit 38.1. In one arrangement, the section 48.1 of the inert gas conduit 48 is positioned between the drive unit 32 and the hydrogen conduit 38.1. In the presence of a shield 40, the section 48.1 of the inert gas conduit 48 is positioned between the shield 40 and the hydrogen conduit 38.1. In one arrangement, the section 48.1 of the inert gas conduit 48 extends approximately from the front boundary 36.1 to the rear boundary 36.2 of the debris ejection zone 36 and is positioned in the same angular sector as the hydrogen conduit 38.1.

[0047] According to another embodiment shown in [Fig. 3], the inert gas conduit 48 has a section 48.2 positioned around the hydrogen conduit 38.1, which is consequently inserted at least partially into the section 48.2. According to this embodiment, the annular section 48.2 and the hydrogen conduit 38.1 are substantially coaxial. During operation, debris impacts the annular section 48.2 before impacting the hydrogen conduit 38.1.

[0048] According to a configuration visible in [Fig.4], the inert gas container 46 comprises at least one pressurized inert gas reservoir 50 connected to the inert gas conduit 48. This configuration allows a large volume of inert gas to be injected in the event of a leak.

[0049] According to embodiments visible in Figures 3 and 4, the hydrogen supply system 38 includes a shut-off valve 52, referred to as the FSOV (for Fuel Shut-off Valve), configured to occupy a passing state in which the shut-off valve 52 allows a flow of hydrogen towards the engine 32 and a blocked state in which the shut-off valve 52 prevents any flow of hydrogen towards the engine 32. This shut-off valve 52 is positioned in the outer zone ZE of the nacelle 34 (outside the nacelle 34) to block any flow of hydrogen towards the inner zone ZI in the blocked state.In addition, the propulsion assembly 30 includes a control 54 configured to control the state of the shut-off valve 52 and at least a first leak detection system 56 comprising at least one element selected from at least one pressure sensor configured to measure the pressure in the zone in. exterior ZI and positioned near the hydrogen conduit 38.1, at least one pressure sensor 58 configured to measure the pressure of the inert gas in the inert gas container 46 and at least one wire break detector 60, the first leak detection system 56 being configured to detect a hydrogen leak and inform the control 54 in order to control the status of the shut-off valve 52.

[0050] According to an embodiment visible in [Fig.3], the first leak detection system 56 includes a first wire break detector 60 which has a wire positioned along the hydrogen conduit 38.1. The wire of the first wire break detector 60 extends at least from the front boundary 36.1 to the rear boundary 36.2 of the debris ejection zone 36.

[0051] According to another embodiment visible in [Fig.4], the first leak detection system 56 includes a first wire break detector 60 which has a wire positioned along the hydrogen conduit 38.1 and a pressure sensor 58 configured to measure the pressure of the inert gas in the reservoir 50 of the inert gas container 46.

[0052] According to these two embodiments, the wire of the first wire break detector 60, running along the hydrogen conduit 38.1, is further away from the motor 32 than the shield 40. Thus, the latter is positioned between the motor 32 and the wire of the first wire break detector 60.

[0053] Of course, the invention is not limited to these embodiments for the first leak detection system. Thus, other sensors or other combinations of sensors are conceivable.

[0054] According to an embodiment shown in [Fig. 4], the inert gas container 46 comprises at least one exhaust 46.1 and a trigger valve 46.2 configured to occupy a first state in which the trigger valve 46.2 allows the injection of inert gas via the exhaust 46.1 into the internal zone ZI and a second state in which the trigger valve 46.2 prevents any flow of inert gas into the internal zone ZI via the exhaust 46.1. In addition, the inert gas injection device 45 comprises a control for monitoring the state of the trigger valve 46.2 and a second leak detection system 62 configured to detect a leak at the level of the crankcase 32.4 of the motor 32 and to inform the control of the trigger valve 46.2 in order to monitor its state.

[0055] According to one configuration, the second leak detection system 62 comprises at least one second wire break detector 64 which has at least one wire positioned in the debris ejection zone 36. According to one arrangement, the wire of the second wire break detector 64 extends at least from the front boundary 36.1 to the rear boundary 36.2 of the debris ejection zone 36. According to one embodiment, The wire of the second wire break detector 64 is positioned between the motor 32 and the shield 40.

[0056] Thus, according to the embodiment visible in [Fig.4], the propulsion assembly 30 includes a first wire break detector 60 to control the state of the shut-off valve 52 of the hydrogen supply system 38 and a second wire break detector 64 to control the state of the trigger valve 46.2 of the inert gas injection device 45.

[0057] During operation, when debris with low energy levels punctures the housing 32.4 of the motor 32, it is retained by the shield 40 and does not puncture the hydrogen conduit 38.1. However, hot gases may escape from the motor 32. The debris ejected from the motor 32, having punctured its housing 32.4, cuts the wire of the second wire break detector 64, causing the opening of the trigger valve 46.2 and the injection of cold inert gas into the internal zone ZI, thus limiting the temperature increase of the gas mixture in this internal zone ZI.

[0058] If debris with high energy levels is ejected from the engine 32, it can pass through the shield 40, impact the hydrogen conduit 38.1 and possibly puncture the fairing 34.1 of the nacelle 34.

[0059] Regardless of the flight phase, the hydrogen flow rate in the hydrogen conduit 38.1 is such that it theoretically leads to a rapid filling of the internal zone ZI in the event of a leak at the hydrogen conduit 38.1. Given its position near the hydrogen conduit 38.1, the inert gas container 46 is punctured or broken simultaneously with the hydrogen conduit 38.1, which leads to the injection of an inert gas into the internal zone ZI.

[0060] The injection of cold inert gas limits the increase in temperature of the gas mixture present in the internal zone ZI and the hydrogen concentration in the internal zone ZI, which does not reach a critical concentration. Thanks to this inert gas injection, the internal zone ZI is saturated with inert gas and contains a gaseous environment rich in hydrogen and inert gas with a low oxygen content, which greatly reduces the risk of explosion.

[0061] The injection of inert gas into the internal zone ZI simultaneously with that of hydrogen leads to a more rapid increase in pressure in the internal zone ZI and therefore to a more rapid opening of the decompression door(s) 44, 44', leading to ventilation of said internal zone ZI.

[0062] In addition to the rupture of the hydrogen conduit 38.1 and the inert gas conduit 48, the debris ejected by the motor 32 breaks the wire of the first wire break detector 60, causing the shut-off valve 52 to close. Simultaneously, the pressure sensor 58 detects the pressure drop of the inert gas and also causes the closing of the shut-off valve 52. This redundancy enhances safety.

Claims

Demands

1. Propulsion assembly comprising a fairing (34.1) separating an inner zone (ZI) and an outer zone (ZE), a drive unit (32) positioned in the inner zone (ZI), a debris ejection zone (36) positioned at least partially in the inner zone (ZI) and into which debris from the drive unit (32) can be ejected, and a hydrogen supply system (38) comprising at least one hydrogen conduit (38.1) which passes through the debris ejection zone (36); characterized in that the propulsion assembly comprises an inert gas injection device (45) comprising an inert gas container (46) which contains at least one pressurized inert gas, said inert gas container (46) being positioned at least partially in the debris ejection zone (36), around or near the hydrogen conduit (38.1), and being configured to puncture or break when the inert gas container (46) is impacted by debris from the engine (32).

2. Propulsion assembly according to the preceding claim, characterized in that the inert gas container (46) has a lower resistance to perforation or rupture than the hydrogen conduit (38.1).

3. Propulsion assembly according to any one of the preceding claims, characterized in that the inert gas contained in the inert gas container (46) has a temperature below 20°C.

4. Propulsion assembly according to any one of the preceding claims, characterized in that the inert gas container (46) comprises at least one inert gas conduit (48) which has a section (48.1) juxtaposed to the hydrogen conduit (38.1).

5. Propulsion assembly according to the preceding claim, characterized in that the section (48.1) of the inert gas conduit (48) is positioned between the motorization (32) and the hydrogen conduit (38.1).

6. Propulsion assembly according to any one of claims 1 to 3, characterized in that the inert gas container (46) comprises at least one inert gas conduit (48) which has a section (48.2) in which the hydrogen conduit (38.1) is inserted at least in part.

7. Propulsion assembly according to any one of claims 4 to 6, characterized in that the propulsion assembly comprises at least one shield (40) positioned between, on the one hand, the motor (32) and, on the other hand, the duct hydrogen (38.1) and the section (48.1) of the inert gas conduit (48).

8. Propulsion assembly according to any one of the preceding claims, characterized in that the hydrogen supply system (38) includes a shut-off valve (52) configured to occupy open and blocked states and in that the propulsion assembly (30) includes a control (54) for controlling the state of the shut-off valve (52) and at least a first leak detection system (56) configured to detect a hydrogen leak and inform the control (54) in order to control the state of the shut-off valve (52).

9. Propulsion assembly according to the preceding claim, characterized in that the first leak detection system (56) comprises at least one element selected from at least one pressure sensor configured to measure the pressure in the inner zone (IZ), at least one pressure sensor configured to measure the pressure of the inert gas in the inert gas container (46) and at least one wire break detector (64) positioned along the hydrogen conduit (38.1).

10. Propulsion assembly according to the preceding claim, characterized in that the first wire break detector (60) comprises a wire running along the hydrogen conduit (38.1) and in that the propulsion assembly comprises a shield (40) positioned between the motor (32) and the wire of the first wire break detector (60).

11. Propulsion assembly according to any one of the preceding claims, characterized in that the inert gas container (46) includes a trip valve (46.2) configured to occupy a first state in which the trip valve (46.2) permits an injection of inert gas into the inner zone (IZ) and a second state in which the trip valve (46.2) prevents any flow of inert gas into the inner zone (IZ), and in that the inert gas injection device (45) includes a control for controlling the state of the trip valve (46.2) and a second leak detection system (62) configured to detect a leak at the motorization (32) and inform the control of the trip valve (46.2) in order to control its state.

12. Propulsion assembly according to the preceding claim, characterized in that the propulsion assembly includes a shield (40) and in that the second leak detection system (62) includes at least one second wire break detector (64) having at least one wire positioned between the motor (32) and the shield (40).

13. Aircraft comprising at least one propulsion assembly according to one of the preceding claims.

Images