Removable aviation liquefied gas storage device

Abstract

A gaseous storage cryogenic tank device for aeronautics, comprising: an inner container (26) delimiting a liquefied gas storage chamber (28); an outer envelope (27) containing the inner container (26) and made of a plurality of removable parts for accessing the inner container (26), the outer envelope (27) being made of a material resistant to temperatures lower than -60°C to at least +80°C; an insulation chamber (29) delimited between the inner container (26) and the outer envelope (27), the reduced pressure insulation chamber (29) having a helium tightness equal to or better than 10 ‑9 millibar*liters / second; two connections, at least one of which is a sliding connection, supporting the inner container (26) and carried by the outer envelope (27); a removable collector (42) passing in a sealed manner through the outer envelope (27) and the inner container (26); and a flexible thermal insulation neck (42) forming a sealed interface between the collector and the inner container (26) on the one hand and between the outer envelope (27) and the inner container (26) on the other hand, the neck (42) being formed around a portion of the collector (38), the neck (42) passing through the insulation chamber (29) so as to allow the collector (38) to be removed independently of the pressure in the insulation chamber (29).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of aeronautics. BACKGROUND

[0002] The aeronautical industry has been using high-octane gasoline engines since its inception. After 1945, the development of jet engines and turbines led to the use of kerosene, whose molecular weight is higher than that of gasoline, with lower flammability. These fuels are stored in tanks located in the wings, in the body-wing junction or in the tail.

[0003] The trend to reduce carbon dioxide gas emissions leads to engines consuming less. However, as certain technologies mature, in particular the increase in blade tip speed, the gains in carbon dioxide gas emissions are decreasing, and it seems increasingly necessary to make a breakthrough.

[0004] Thus, gas-powered aircraft projects have emerged. The combustion of short carbon chain or non-existent carbon chain gases, if appropriate, pollutes little or not at all. On the contrary, due to the small size of the gas molecules, it is difficult to store H2, O2 or C1 or C2 gases and there is a risk of leakage.

[0005] On the ground, such gases are usually stored in pressurized shells, which have a large capacity and contain too much potential pressure energy to be carried on board an aircraft, or in cryogenic tanks welded and / or glued. The cryogenic preservation time of these gases is limited, in proportion to the volume stored.

[0006] In addition, hydrogen, methane, ethane, ethylene, acetylene or oxygen stored in liquid state cannot be used by internal combustion engines or external combustion engines or fuel cells. The end consumption requires a gaseous state.

[0007] It seems necessary to store propellant gases on board an aircraft for on-board consumption, while implementing aeronautical maintenance techniques and avoiding the development of new standards. Indeed, the development of new standards is a long and time-consuming process, which can therefore lead to a delay in the commercialization of gas aircraft. Obtaining new maintenance techniques is also a long process, costly and can even lead to silence. SUMMARY

[0008] The invention proposes an on-board aeronautical gas storage cryogenic tank device, which is spherical or elongated, comprising: an inner container delimiting a liquefied gas storage chamber; an outer envelope containing the inner container and made of a plurality of removable parts making it possible to access the inner container, the outer envelope being made of a material resistant to temperatures lower than -60°C to at least +80°C; an insulating chamber delimited between the inner container and the outer envelope, the reduced pressure insulating chamber having a thermal conductivity equal to or better than 10 -9Helium tightness of 10"5bar l / s; two connections, at least one of which is a sliding connection, supporting the inner container and carried by the outer envelope; a removable collector which passes through the outer envelope and the inner container in a sealed manner; and a flexible thermal neck which forms a sealed interface on the one hand between the collector and the inner container and on the other hand between the outer envelope and the inner container. The neck is formed around a portion of the collector. The neck passes through the insulated chamber so as to enable the collector to be removed independently of the pressure inside the insulated chamber. Thanks to the invention, the cryogenic tank meets the requirements of aeronautical practice, in particular thermal requirements, in particular in terms of mechanical deformation and pipe volume.

[0009] In one embodiment, the device comprises a thermal plug assembly removably mounted on the collector and accessible from the outside. The thermal effect is satisfactory.

[0010] In one embodiment, one of the connections comprises an axial recess in the outer envelope for receiving and supporting an axial protrusion of the inner container. The connection is adapted to the expansion that can occur.

[0011] In one embodiment, the outer envelope comprises a frame, sealing panels, a seal resistant to the pressure between the frame and the panels and / or between the panels. Maintenance is facilitated.

[0012] In one embodiment, the frame comprises ribs and spars, the structure being robust.

[0013] In one embodiment, the seal is housed in a groove and, in a free state, the height of the seal beyond the groove is less than 10% of the height of the seal. The leakproofness is high.

[0014] In one embodiment, the device comprises a shockproof member located inside the inner container. The mechanical properties, in particular the stability, of the device are improved.

[0015] In one embodiment, the device comprises a stiffener, preferably a bracket or a tie rod, located inside the inner container. The device, in particular the inner container, can be lightened.

[0016] In one embodiment, the device comprises at least one support ring mounted between the inner container and the outer envelope at a distance from the connection inside the insulated chamber. The rigidity is increased.

[0017] In one embodiment, a hydrogen-absorbing material is arranged inside the insulated chamber. A low pressure is maintained inside the insulated chamber.

[0018] In one embodiment, a hydrogen presence detector is mounted inside the insulated chamber. An alarm can be emitted if a threshold value is exceeded.

[0019] In an embodiment, an assembly comprises: a device as described above; a temporary storage tank forming a gasification means for pressurizing the gas provided by the device; an upstream valve arranged to open for liquid flow during a filling phase of the temporary storage tank and to close outside the filling phase; a downstream valve arranged to open for gas flow during an emptying phase of the temporary storage tank and to close outside the emptying phase, the upstream and downstream valves being controlled all or nothing during a gasification phase; a compressor arranged downstream of the downstream valve, said compressor being activated at the end of the emptying phase to bring the pressure value in the temporary storage tank below the pressure value in the device; and a pressure reducer arranged downstream of the downstream valve, said pressure reducer being activated at the beginning of the emptying phase to bring the gas pressure value at the outlet below the pressure value in the temporary storage tank. The device ensures the necessary autonomy of the aircraft by the capacity in the temporary storage tank, regardless of the state of the device. The temporary storage tank can provide a gas pressure of several hundred bars, but the selected gas pressure is still supplied to the consumption means. The valves are reliable. The temporary storage tank can be sufficiently emptied to increase the amount of gas available to the consumption means and to bring the pressure of the temporary storage tank at the end of the emptying below the current pressure in the device. The filling of the temporary storage tank is done by manipulating the cryogenic valve under the effect of the pressure difference. Not using a cryogenic pump can increase the mass and reduce the risk of accidents.

[0020] In an embodiment, the working pressure of the temporary storage tank is greater than 500 bars.

[0021] In an embodiment, the working pressure of the device is less than 8 bars. BRIEF DESCRIPTION OF DRAWINGS

[0022] Other features and advantages of the present application will become apparent upon reading the detailed description hereinafter and upon examining the drawings, in which:

[0023] Figure 1 An axial section of a device according to an aspect of the application is schematically illustrated.

[0024] Figure 2 A transversal section of a device according to an aspect of the application is schematically illustrated.

[0025] Figure 3 A side view of a device according to an aspect of the application is schematically illustrated.

[0026] Figure 4 A side view of a device according to another aspect of the application is schematically illustrated.

[0027] Figure 5 A perspective view of a device according to another aspect of the application is schematically illustrated.

[0028] Figure 6 A cross-sectional view of a neck according to an aspect of the present invention is schematically shown.

[0029] Figure 7 Schematically shown is a cross-sectional view of a neck and collector according to an aspect of the present invention.

[0030] Figure 8 A perspective view of an assembly according to an aspect of the present invention is schematically shown. DETAILED DESCRIPTION

[0031] The accompanying drawings can be used not only to complete the invention but also to help define it if necessary.

[0032] Aviation gas storage units (AGSs) are designed to be carried on aircraft such as airplanes, drones, and helicopters. They contain liquid and provide gas. In other words, the gas is stored in liquid form in cryogenic tanks at extremely low temperatures. Cryogenic tanks are not suitable for withstanding high pressures, particularly those exceeding 10 bar.

[0033] The stored gas is selected from the group consisting of hydrogen, methane, ethane, ethylene, acetylene and oxygen.

[0034] Applicants also intend to consider that vaporization is a rapid phenomenon even in the ambient atmosphere of -55°C encountered at high altitudes. As an example, gaseous hydrogen at 0°C and 1 atmosphere pressure has a density approximately 800 times lower than liquid hydrogen at -253°C, and therefore has a volume approximately 800 times greater.

[0035] However, aviation maintenance regulations require that most aircraft components be removed and repaired or replaced. Therefore, an aircraft can land anywhere suitable for its weight and landing requirements—airfields for airplanes, landing zones for helicopters—but it is not necessary to have maintenance equipment specific to the aircraft type. If damage is discovered, the aircraft should be repaired permanently or temporarily, or disassembled to replace or repair the defective component, in accordance with the manufacturer's manual and documentation approved by the aviation safety authority. Ideally, the component should be easily accessible to maintenance personnel. If replacement is necessary, it is best to keep the component as small as possible for easy handling and transportation. If repairs are necessary, they should ideally be performed using current tools and methods proven in the aviation industry.

[0036] Aircraft are subject to daily, weekly, etc. inspection visits, and aircraft downtime is inversely proportional to the frequency of inspections.

[0037] However, gas tanks used in land-based industrial applications or in space are not subject to such requirements and are in particular not designed for such repairability.

[0038] The applicant has determined that it is necessary to store hydrogen, methane, ethane, ethylene, acetylene, or oxygen in cryogenic tanks carried on board the aircraft.

[0039] The applicant has identified a need for a removable, repairable, and removable cryogenic tank for aviation, which is inspectable according to the aircraft inspection model. Furthermore, a need exists for a tank that has a high ratio of useful volume to external volume, a high ratio of contained gas mass to total mass, and high reliability and safety.

[0040] As shown, the aviation gas storage device has a generally elongated shape with rounded ends. The aviation gas storage device may be annular about a longitudinal axis. The aviation gas storage device includes an outer envelope and an inner container. The inner container forms a liquefied gas storage chamber. The inner container is contained within the outer envelope. Typically, the inner container and outer envelope are spaced apart from each other.

[0041] In the embodiment shown, the aviation gas storage device has a cylindrical center of rotation and hemispherical ends. However, exceptional shapes having cylindrical, annular and / or hemispherical shapes can be manufactured.

[0042] Each cryogenic tank is insulated to hold liquid fuel or oxidizer at -253°C. Each cryogenic tank is capable of withstanding a maximum operating pressure of 6 to 10 bar.

[0043] exist Figures 1 to 3 In the embodiment shown, the cryogenic tank 2 has an elongated shape, in particular an elongated shape about an axis. The cryogenic tank 2 has dome-shaped ends and a generally cylindrical center of rotation. In an alternative embodiment, the cryogenic tank 2 has a spherical shape.

[0044] The cryogenic storage tank 2 includes an inner container 26 and an outer envelope 27. The inner container 26 defines a liquefied gas storage chamber 28 to accommodate the gas load at the liquefaction temperature and the upper limit of the boil-off gas. The inner container 26 is sealed. The inner container 26 can withstand the liquefaction temperature, for example, -253°C for hydrogen. The outer envelope 27 houses the inner container 26. The outer envelope 27 is made of a plurality of detachable parts, so that the inner container 26 can be accessed. The outer envelope 27 protects the inner container 26 from impact. The outer envelope 27 ensures the structural strength of the aviation gas storage device. The outer envelope 27 is made of a material with a temperature resistance of from below -60°C to at least +80°C.

[0045] An insulating chamber 29 is defined between the inner container 26 and the outer envelope 27. Insulation in the insulating chamber 29 is ensured by a pressure reduced compared to atmospheric pressure. In addition, a solid insulating material may be arranged in the insulating chamber 29. The reduced pressure insulating chamber 29 has a pressure equal to or better than 10°C defined between the inner container 26 and the outer envelope 27. -9 Helium tightness at mbar*L / s. The tightness of the insulating chamber 29 includes tightness relative to the interior of the inner container 26 and tightness relative to the external atmosphere.

[0046] Inner container 26 can be made of a welded metal alloy. Examples of metal alloys include Al-Cu-Li (particularly 2050 or 2099), Al-Cu (particularly 2219), and stainless steel (particularly 304, 304L, 316, or 316L). Inner container 26 has an elongated shape with two domed ends surrounding a main body. The main body can be cylindrical. The main body can be a rotating body.

[0047] The outer envelope 27 comprises a frame 30, sealing panels 31, and seals resistant to pressure between the frame 30 and the panels 31 and / or between the panels 31. The panels 31 may be assembled to the frame 30 by screws.

[0048] The frame 30 comprises ribs 32 and spars 33. The ribs 32 may have a closed profile, for example a ring. The spars 33 extend longitudinally. The spars 33 are connected together at the ends of the outer envelope 27.

[0049] Panel 31 is made of a welded metal alloy or composite material. Examples of composite materials include epoxy resin and carbon fiber, Kevlar fiber, and / or glass fiber. Examples of metal alloys include Al-Mg (particularly 5086), Al-Mg-Si (particularly 6061), and Al-Cu-Li (particularly 2195).

[0050] A seal is provided between the panel 31 and the frame 30. The seal can be metal or a synthetic material, such as an elastomer. For synthetic seals, a groove is formed in the panel 31 or frame 30 to accommodate the seal. In its free state, the seal extends beyond the groove by less than 10% of the seal's height. The height refers to the diameter of the O-ring.

[0051] The cryogenic tank 2 comprises two connections between the outer envelope 27 and the inner container 26 to support the inner container 26. The connections are configured for very low thermal conductivity.

[0052] At least one of the connectors is a sliding connector, allowing for differential expansion of the outer envelope 27 and the inner container 26 to be accommodated. The connector is carried by the outer envelope 27. The first connector is an extreme connector. Extreme connector 34 may include a central protrusion at one end of the inner container 26, which mates with an axially concave surface of the outer envelope 27 to form a housing for the protrusion. The protrusion slides axially over a travel of a few millimeters, allowing for the contraction of the inner container 26 during filling with liquefied gas and the expansion of the inner container 26 after emptying. Extreme connector 34 is configured to have a long heat conduction path.

[0053] The second connector is located at a distance from the opposite end of the first connector. The second connector surrounds inner container 26. The second connector is mounted in insulating chamber 29. The second connector includes a support ring 35. Support ring 35 is mounted between inner container 26 and outer envelope 27. Support ring 35 is mounted at a distance from the connector in insulating chamber 29.

[0054] The support ring 35 comprises outer sectors 36 that project radially outwards. The outer sectors 36 are three in number. The outer sectors 36 have a peripheral surface that is in contact with the bore of the outer envelope 27. The outer sectors 36 occupy an angle of approximately 15° to 40°.

[0055] The support ring 35 includes inner sectors 37 that protrude radially inward. There are three inner sectors 37. Each inner sector 37 has a convex surface that contacts the periphery of the inner container 26. The inner sectors 37 occupy an angle of approximately 15° to 40°. The outer sectors 36 and inner sectors 37 alternate. The outer sectors 36 and inner sectors 37 are angularly spaced apart from each other. Preferably, three inner sectors 37 and three outer sectors 36 alternate, spaced approximately 20° to 30° apart, separated by non-protruding areas, and each occupying an angle of approximately 40° to 30°. The support ring 35 is retained by sufficient friction or permanent fastening to the inner container 26.

[0056] The support ring 35 is made of a composite material having low thermal conductivity and high mechanical strength.

[0057] The cryogenic storage tank 2 includes a removable collector 38 that passes through the outer envelope 27 and the inner container 26 in a sealed manner. The collector 38 includes a straight rod 39 for extracting the liquefied gas from the inner container 26. The rod 39 is made of an insulating material. The collector 38 includes a first open end located inside the inner container 26. The collector 38 includes a second open end located outside the outer envelope 27. The second end is used to connect to a pipeline, such as the outlet pipeline 4, see Figure 6 . The first end and the second end are connected by a port. In the installed state, the first end is located near the lower part of the inner container 26. The first end is free. Therefore, the collector 38 extracts the liquefied gas. When the liquid level is low, the extraction stops. In other words, in operation, the inner container 26 contains a gas phase and a liquid phase. At the end of filling, the liquid phase is the largest and the gas phase is the smallest. At the end of extraction, the liquid phase is the smallest or even does not exist, and the gas phase is the largest. The liquid phase is extracted. The extraction of the liquid phase makes the diameter of the pipeline significantly smaller than that of the gas phase. The compactness of the downstream components of the cryogenic storage tank 2 is improved. The rod 39 is also used to fill the liquefied gas.

[0058] At its second end, collector 38 includes a plug 41 surrounding rod 39. Plug 41 is made of an insulating material. Plug 41 protrudes outward from outer envelope 27. Plug 41 may have a gripping area for removal, such as for maintenance. The outer diameter of plug 41 is greater than the diameter of rod 39. Plug 41 forms a sealing head that is removable from cryogenic storage tank 2.

[0059] The plug assembly includes a plug 41 and a plug cap 45. In the case of an aircraft or unmanned aerial vehicle, the cryogenic storage tank 2 can be mounted with the plug assembly facing the front of the aircraft type, with the free end of the rod 39 facing the rear of the aircraft type, to take advantage of the general inclination of the aircraft type, thereby enabling more complete filling and extraction of the liquefied gas. The cryogenic storage tank 2 can also be mounted at an angle, particularly by having support members at different heights between the front and rear of the cryogenic storage tank 2.

[0060] In addition, the collector 38 includes a level gauge 40. The level gauge 40 extends along the rod 39. The level gauge 40 is connected to the outside of the tank by wired communication through a plug 41. The level gauge 40 provides a signal representing the liquid level as an output. The level gauge can be capacitive. The accuracy of the level gauge is higher when the collector 38 has a smaller angle with respect to the horizontal plane. In fact, for a level gauge with a given resolution and an inner container 26 with a given height, an increase in the length of the inner container 26 causes the length of the level gauge to increase, thereby improving the accuracy. For example, a level gauge at an angle of 30° with respect to the horizontal plane has twice the accuracy of a vertical level gauge.

[0061] The collector 38 includes a vent 53 for rapid venting of gas in the event of overpressure. Vent 53 is also used to vent gas during filling to avoid overpressure. Vent 53 is used to repressurize the container by introducing gas (if necessary) during extraction. Vent 53 is provided in the plug 41 and emerges from the inner container 26 near the plug 41. Vent 53 is provided with a liquid check valve.

[0062] A vent 53 is provided in plug 41 and emerges from inner container 26 near plug 41. Thus, vent 53 is connected to the gaseous top plate of inner container 26. Vent 53 is connected to a pipeline that passes through plug 41. A bypass valve having an opening pressure lower than the permissible pressure in cryogenic storage tank 2 can be connected to the pipeline. A rupture disk having a rupture pressure lower than the permissible pressure in cryogenic storage tank 2 can also be connected to the pipeline. The bypass valve and rupture disk are installed in parallel.

[0063] The collector 38 includes a temperature sensor provided at the lower inner portion of the plug 41. The temperature sensor provides information on the temperature measured in the inner container 26.

[0064] The cryogenic tank 26 includes an insulated neck 42. The neck 42 has a bore. The neck 42 can be made of metal. The metal chosen has the properties of weak thermal conductivity, mechanical resistance, flexibility and impermeability to hydrogen. The neck 42 is welded or screwed with a seal to the inner vessel 26. The neck 42 is welded or screwed with a seal to the outer envelope 27. The neck 42 has sufficient flexibility to accommodate the difference in expansion between the inner vessel 26 and the outer envelope 27. The neck 42 comprises an outer wall fixed to the inner vessel 26 and to the outer envelope 27. The neck 42 comprises an inner wall remote from the inner vessel 26 and from the outer envelope 27. The inner wall can be fixed to the outer wall at the end of the neck 42.

[0065] The outer wall is tubular. The inner wall is in the shape of a tubular bellows. The inner wall can be made of a sheet metal of a thickness less than the outer wall sheet metal to increase the capacity of elastic deformation. The inner wall can have the shape of a bellows which increases the capacity of elastic deformation. The bellows shape, for example a wave shape, reduces the contact surface between the inner wall and the plug 41 and therefore the thermal conductivity.

[0066] Advantageously, the bellows inner wall comprises two concentric sheets. These sheets are assembled together and connected at the ends. A double wall is thus formed, which makes it possible to reduce the risk of leakage. In the event of a puncture in one of the two sheets, detection can be carried out by applying a gas pressure between the two sheets, greater than the pressure inside the insulated chamber and lower than atmospheric pressure, and by monitoring the variation in the applied pressure. If said applied pressure decreases, the large-diameter sheet leaks with the insulated chamber. If said applied pressure increases, the small-diameter sheet leaks with the bore of the neck 42. The neck can then be replaced. Furthermore, if only one sheet leaks, the insulated chamber will remain at its low pressure to ensure weak thermal conduction, and the cryogenic tank 2 can be operated until the next maintenance operation. If a single sheet loses its leakproofness, the insulated chamber will lose its weak thermal conduction, and the cryogenic tank 2 will be emptied urgently, its contents being lost.

[0067] The neck 42 forms a sealed interface on the one hand between the collectors 38 and on the other hand between the outer envelope 27 and the inner vessel 26. The neck 42 can maintain the airtightness between the outer envelope 27 and the inner vessel 26 whatever the position of the collectors 38, even their absence. The neck 42 is fixed in a sealed manner in a perforation on the outer envelope 27. The neck 42 is fixed in a sealed manner in a perforation on the inner vessel 26. The perforation on the outer envelope 27 and the perforation on the inner vessel 26 are located in the circular end of the cryogenic tank 2 close to the circular end of the outer diameter of the upper cryogenic tank 2. The outer end of the collectors 38 extends outward beyond the neck 42. The collectors 38 extend inside the cryogenic tank 2 beyond the neck 42, downward to the other circular end of the cryogenic tank 2.

[0068] Neck 42 is shaped to surround a portion of collector 38. It extends through insulating chamber 29, allowing collector 38 to be removed independently of the pressure within the insulating chamber 29. Neck 42 is provided with a through-hole 43, into which plug 41 of collector 38 is removably mounted. The contact surface between neck 42 and plug 41 may be provided with female annular teeth 44 to increase the length of the leakage path and facilitate mechanical retention of collector 38 in the neck. Here, teeth 44 have a V-shaped pattern. Plug 41 has a smooth, rotating outer surface in its free state. Plug 41 fits snugly into neck 42. A slight gap may be provided between the bellows and plug 41. A liquid deflector is provided inside the neck, near the storage chamber 28. Plug 41 is made of a thermally insulating material. Plug 41 may include a corrosion-resistant shell and insulating synthetic foam within the shell.

[0069] exist Figure 6 and Figure 7 In the embodiment of the present invention, the neck portion 42 is welded around its outer wall to the inner container 26. The neck portion 42 has a flange that overlies the flange of the inner container 26. The flange can be welded using an electron beam. The neck portion 42 is welded around its outer wall to the outer envelope 27 at a distance from the weld point to the inner container 26. The outer wall of the neck portion 42 comprises two distinct and separate portions, one portion being connected to the inner container 26 and the other portion being connected to the outer envelope 27.

[0070] The inner wall connects the two parts of the outer wall. The inner wall consists of two concentric thin sheets with a thickness between 0.1 mm and 0.2 mm. Seen from the outside, the neck 42 includes a collar 54 pointing toward the inner wall. The collar 54 seals the inner and outer walls. A seal 55 is fastened to the collar 54, typically by a threaded connection. The seal 55 contacts the stopper 41 of the collector 38. There is no level gauge.

[0071] The cryogenic tank 2 comprises a cover 45 permanently mounted on the collector 38 and accessible from the outside. The cover 45 is fastened to the rod 39 by screws or bolts. The cover 45 is arranged outside the outer envelope 27. The cover 45 is arranged at the outer end of the collector 38. The cover 45 is sealed.

[0072] The cryogenic storage tank 2 provides a working pressure lower than 8 bar, in particular 6 bar.

[0073] Advantageously, the cryogenic storage tank 2 includes an anti-vibration structure mounted within the inner container 26. The anti-vibration structure comprises one or more perforated plates that divide the interior volume of the inner container 26 into several zones. The surface area of ​​the openings of the perforated plates may be 1% to 5% of the surface area of ​​the perforated plates. The perforated plates may be longitudinal or transverse. The perforated plates reduce the displacement rate of the liquefied gas in the inner container 26 during acceleration (e.g., during takeoff, landing, or atmospheric turbulence).

[0074] Advantageously, the cryogenic tank 2 comprises a reinforcement element located inside the inner container 26. The reinforcement element comprises at least one bracket or tie rod connecting opposite areas of the inner container 26. The reinforcement element makes it possible to lighten the remaining structure of the inner container 26.

[0075] A hydrogen absorbing material 46, such as a nanoporous material, is installed in the insulating chamber 29. In the event of a minor leak, the insulation loss associated with the pressure increase in the insulating chamber 29 is reduced. After such a leak occurs, the outer envelope 27 is removed to open the insulating chamber 29, and the hydrogen absorbing material 46 is removed to desorb the hydrogen, for example, by heating.

[0076] A hydrogen presence detector 47 is installed in the insulating chamber 29. It monitors the presence of hydrogen. If a major leak occurs, an emergency evacuation of the inner container 26 may be ordered. If a minor leak occurs, maintenance operations may be anticipated. Maintenance operations may include repairing the inner container 26 to remedy the leak, replacing or desorbing the hydrogen absorbing material (if appropriate), and evacuating the insulating chamber 29.

[0077] exist Figures 1 to 3 In the embodiment shown, the outer envelope 27 comprises two separable parts 48 and 49. The first part 48 comprises an end and a body. The second part 49 comprises an opposite end. The first and second parts are connected in a sealing manner and can be separated by two sealing rings 50 and 51, which provide metal / metal sealing surfaces by an interference fit. The interference fit can be cone-to-cone, ring-to-cone or plane-to-plane, and if appropriate, a shrink-fit metal O-ring (in particular a copper alloy) or an elastomer can be used. The interference fit is ensured by axial tightening (in particular bolts). The sealing rings 50 and 51 are annular.

[0078] exist Figure 4 In the embodiment shown, the outer envelope 27 is composed of multiple sections. As described above, the two sections are connected in a sealing manner by sealing rings 50 and 51. The sections can be standardized to accommodate different capacities of inner containers 26, having one end section, one or more central sections, and an end section free of neck perforations. Multiple support rings 35 can be provided.

[0079] exist Figure 5 In the illustrated embodiment, the frame 30 of the outer envelope 27 comprises annular ribs 32, spars 33 extending parallel to the longitudinal axis, and diagonal braces. The outer envelope 27 comprises generally triangular panels 31, each mounted between the ribs, spars, and braces, and terminated with domed panels. The triangular panels 31 provide visibility to the frame 30. The domed panels cover the frame 30 beyond the ribs 32.

[0080] exist Figure 6In the illustrated embodiment, the distribution circuit 1 includes a first valve 11 for each cryogenic storage tank 2. The first valve 11 is mounted on the outlet pipe 4. The first valve 11 is controlled using an open position and a closed position. The intermediate position of the first valve 11 is dynamic, as the first valve 11 is in motion when entering the intermediate position. In other words, the first valve 11 is an all-or-nothing valve. The first valve 11 can be positioned downstream of the flow meter 22.

[0081] The first valve is present in a cryogenic distributor 5. The cryogenic distributor 5 may comprise a common conduit 6 connected to the outlet of the first valve 11. The distributor is cryogenic because liquid fuel / oxidant passes through it.

[0082] The cryogenic distributor 5 includes multiple outlets, three in this example. Two second valves 12 are installed at each outlet. The second valves 12 are controlled by an open position and a closed position. The intermediate position between the two valves 12 is dynamic; that is, the second valves 12 are in a moving state when in this intermediate position. In other words, the second valves 12 are all-or-nothing valves. Here, there are three second valves 12.

[0083] A central tank 7 is installed downstream of each second valve 12. In this embodiment, three central tanks 7 are provided. Each central tank 7 also serves as a vaporizer. Insulation can be provided. Each central tank 7 receives liquid and supplies gas downstream. Between filling and emptying, a pressure increase or vaporization step occurs in each central tank 7. Each central tank 7 can withstand a maximum operating pressure of 300 bar to 1000 bar. The operating temperature range of each central tank 7 is designed to be -253°C to +60°C. The central tank 7 is biphasic in one operating step and gaseous single-phase in another operating step. Each central tank 7 can be equipped with a heating element 8.

[0084] A third valve 13 is installed downstream of each central tank 7 to supply gas, and a pressure reducer 9 is installed downstream of the third valve 13. The pressure reducer 9 limits the pressure to the consumption pressure set by the manufacturer of the consumable component 3 to supply gas. The pressure reducer 9 is active when the pressure in the central tank 7 exceeds the consumption pressure; otherwise, it is inactive. The consumption pressure is lower than the maximum pressure of the central tank 7. The consumption pressure is independent of the maximum pressure of the cryogenic storage tank. The third valve 13 is an all-or-nothing valve.

[0085] A fourth controlled valve 14 may be provided downstream of each pressure reducer 9. The fourth valve 14 is an all-or-nothing valve.

[0086] Depending on the selected option, a fourth valve 14 or a pressure reducer 9 is present in the collector 10. The collector 10 may include a pipe connected to the outlet of the fourth valve 14 or the pressure reducer 9. Gas passes through the collector 10. Downstream of the collector 10, a supply pipe 23 is connected to the consumable components 3. Typically, a supply pipe 23 is provided for each consumable component 3. Each supply pipe 23 may be equipped with a controlled supply valve 24. The supply valves 24 are variable flow.

[0087] The distribution circuit includes at least one compressor 20 connected to a collector 10. Typically, two compressors 20 are provided in parallel for redundancy. The compressors 20 are electrically powered and can be equipped with controlled upstream valves. The compressors 20 deliver gas to the collector 10. Specifically, in the case of a single consumer component 3, the collector 10 is formed by a pipeline.

[0088] A fifth valve 15 is installed downstream of each central tank 7 to supply gas, and a second collector 38 is installed downstream of the fifth valve 15. The second collector 38 is connected to the compressor 20. The fifth valve 15 allows isolation between the central tank 7 and the compressor 20. The fifth valve 15 is controlled and is an all-or-nothing valve.

[0089] The compressor 20 increases the pressure, supplying gas at a pressure equal to the consumption pressure set by the manufacturer of the consumable components 3. The consumption pressure is lower than the maximum pressure in the central tank 7. The compressor 20 allows gas in the central tank 7 at a pressure lower than the consumption pressure to be extracted to supply the collector 10 and the consumable components 3. More complete emptying of the central tank 7 makes it possible to increase the autonomy of the gas contained in the central tank 7 or reduce the volume of the central tank 7.

[0090] The central tank 7 is evacuated sufficiently so that the internal pressure of the central tank 7 is lower than the pressure in one of the cryogenic storage tanks, so that during filling after evacuation, liquid can be transferred from the cryogenic storage tank to the central tank 7 due to the pressure difference. Thus, the liquid in the cryogenic storage tank is sucked into the central tank 7 until the pressure is balanced. A cryogenic pump can be omitted, thereby increasing mass and energy consumption.

[0091] The distribution circuit 1 provides a combination of individual states for each cryogenic tank, each central tank 7, and each consumable component 3. Multiple consumable components 3 can be active simultaneously. In normal mode, one cryogenic tank is in the process of being emptied, while the others are inactive and therefore shut down. However, in certain situations, for example to reduce the pressure in multiple cryogenic tanks, a special mode can be provided in which multiple cryogenic tanks are in the process of being emptied. The central tank 7 has a filling mode, a vaporization mode, a gas storage mode, and an emptying mode.

[0092] When one of the low-temperature tanks is in the emptying mode, the corresponding first valve 11 is open, and the other first valves 11 are closed. When one of the consuming members 3 is in the supply process, the corresponding supply valve 24 is open.

[0093] When one of the central tanks 7 is in the filling mode, the second valve 12 connected to said central tank 7 is open, and at least one first valve 11 is open. The other second valves 12 are closed, except in the case of filling two central tanks 7 simultaneously. The third valve 13 connected to said central tank 7 is closed. The fifth valve connected to said central tank 7 is closed.

[0094] When one of the central tanks 7 is in the vaporization mode, the second valve 12 connected to said central tank 7, the third valve 13 connected to said central tank 7, and the fifth valve 15 connected to said central tank 7 are closed. The vaporization mode lasts a short time, in particular in the case of a high ambient temperature and / or heating of the central tank 7.

[0095] When one of the central tanks 7 is in the emptying mode, the second valve 12 connected to said central tank 7 is closed. In the first emptying part, the pressure in the central tank 7 is greater than the consumption pressure. The third valve 13 connected to said central tank 7 is open, the corresponding fourth valve 14 is open, and the fifth valve connected to said central tank 7 is closed. The gas undergoes a pressure drop in the pressure reducer 9 and is supplied to the collector 10 at the consumption pressure. Next, the gas is consumed by the consuming member 3.

[0096] At a given instant, among the three central tanks 7, one is in the filling mode, another is in the vaporization then storage mode, and the third is in the emptying mode. Since the duration of these modes is different, it is possible for two central tanks 7 to be in the filling mode and the third to be in the emptying mode, and vice versa. It is also possible for two central tanks 7 to be in the storage mode and the third to be in the emptying mode, and vice versa.

[0097] In this embodiment, a flow meter 22 is arranged at the outlet of each source 2 of liquid fuel / oxidizer. The flow meter 22 makes it possible to know the quantity of liquid supplied to such a central tank 7 with sufficient precision.

[0098] In an embodiment, the distribution circuit 1 comprises a control unit 25 that receives external commands (for example from the consuming member 3 outside the aircraft storage device or from a central control unit of the aircraft) and liquid flow rate data from the flow meters 22. The control unit 25 generates and sends commands to said first, second, third, fourth, and fifth control valves and to the control supply valve 24. The commands can be “open” or “closed”. The control unit 25 manages the combinations of said various states.

[0099] In an alternative, the first valve 11 can be replaced by at least one multi-way valve having multiple inlets and one outlet. In this case, it is meaningful to provide the multi-way valve with a mixing position, in particular at least one position in which two or more cryogenic tanks 2 are simultaneously emptied, in order to reduce the pressure therein, while avoiding losses into the atmosphere.

[0100] In an alternative, the second valve 12 can be replaced by at least one multi-way valve having one inlet and multiple outlets, one for each central tank 7. Said multi-way valve forms the distributor.

[0101] In an alternative, the multiple pressure reducers 9 are replaced by a single pressure reducer 9, the third valve 13 appearing in the single pressure reducer 9. In this case, the third valve 13 can be replaced by at least one multi-way valve having multiple inlets and an outlet leading to the pressure reducer. Then, the multiple fourth valves 14 are replaced by a single fourth valve 14, if appropriate, not controlled.

[0102] In an alternative, the fifth valve 15 can be replaced by at least one multi-way valve having multiple inlets, one for each central tank 7, and an outlet leading to the compressor 20 or multiple compressors 20. Said multi-way valve forms the collector 10.

[0103] The cryogenic tank 2 is subject to liquid evaporation, so a gas collection circuit can be provided at the upper part of the cryogenic tank 2. The collection circuit can be active above a threshold pressure by means of a calibrated pressure bypass valve. The collection circuit comprises an injector for reinjecting the gas downstream, for example between the fifth valve 15 and the compressor 20.

[0104] Optionally, an additional flowmeter is arranged at the inlet of each buffer tank. Redundancy of the liquid flow measurement is ensured.

[0105] The capacity of the cryogenic tank installation is between 10 kg and 10,000 kg of gas, preferably between 100 kg and 10,000 kg of gas.

[0106] A temporary storage vaporization tank 7 is provided for pressurizing the gas provided by the apparatus. An upstream valve 12 is provided for opening during the filling phase of the temporary storage tank 7 to allow liquid flow, and for closing during the emptying phase. At least one downstream valve 13, 15 is provided for opening during the emptying phase of the temporary storage tank 7 to allow gas flow, and for closing outside of the emptying phase. The upstream valve and the downstream valve are closed during the vaporization phase. The upstream valve and the downstream valve are controlled in an all-or-nothing manner. At least one compressor 20 is arranged downstream of the downstream valve 15. The compressor 20 is activated at the end of the emptying phase to reduce the pressure in the temporary storage tank 7 to a lower value than the pressure in the apparatus. A pressure reducer 9 is arranged downstream of the downstream valve. The pressure reducer 9 is activated at the beginning of the emptying phase to reduce the gas pressure at the outlet to a lower value than the pressure in the temporary storage tank 7.

[0107] A cryogenic tank device for the storage of gas by rail, road or sea, having a spherical or elongated shape (particularly about a longitudinal axis), comprising an inner container defining a liquefied gas storage chamber 28, an outer envelope 27 containing the inner container and made of a plurality of detachable parts, enabling access to the inner container, the outer envelope 27 being made of a material resistant to temperatures from below -60°C to at least +80°C, defining an insulating chamber 29 between the inner container and the outer envelope, the reduced pressure insulating chamber 29 having a pressure of equal to or better than 10°C defined between the inner container and the outer envelope -9 mbar*L / s helium tightness, at least one of the two connections is a sliding connection, supporting the inner container and being supported by the outer envelope, a support ring is installed between the inner container and the outer envelope and is spaced apart from the connection in the insulating chamber, a removable collector 38 passes through the outer envelope and the inner container in a sealed manner, and a flexible insulating neck 42 forms a sealed interface between the collector 38 and the outer envelope and the inner container, the neck 42 is formed around a portion of the collector 38, and the neck 42 passes through the insulating chamber to allow the collector 38 to be removed independently of the pressure in the insulating chamber.

[0108] The storage and distribution assembly comprises a hydrogen storage cryogenic tank device comprising an inner container defining a liquefied gas storage chamber, an outer envelope containing the inner container, a sealed and insulated chamber defined between the inner container and the outer envelope, a removable liquefied gas collector passing in a sealed manner through the outer envelope and the inner container, the collector extending over the diameter or the diagonal of the inner container and having a free end close to the bottom of the inner container, a liquefied gas pipe supplied by the collector, a temporary storage tank forming a vaporization means for pressurizing the gas supplied by the device, an upstream valve provided for opening for liquid flow during the filling phase of the temporary storage tank and closing during the emptying phase, a downstream valve provided for opening for gas flow during the emptying phase of the temporary storage tank and closing outside the emptying phase, the upstream valve and the downstream valve being controlled all or nothing, and a pressure reducer arranged downstream of the downstream valve, said pressure reducer acting at the beginning of the emptying phase to reduce the gas pressure value at the outlet to below the pressure inside the temporary storage tank.

Claims

1. An onboard cryogenic storage tank device for aviation gas storage, spherical or elongated, comprising: an inner container (26) defining a liquefied gas storage chamber (28); an outer envelope (27) containing the inner container (26) and made of a plurality of detachable parts to enable access to the inner container (26), the outer envelope (27) being made of a material resistant to temperatures below -60°C to at least +80°C; A reduced pressure insulating chamber (29) defined between the inner container (26) and the outer envelope (27), the reduced pressure insulating chamber (29) having a pressure difference between the inner container (26) and the outer envelope (27) equal to or better than 10 -9 mbar*L / s helium tightness; two connections, at least one of which is a sliding connection, supporting the inner container (26) and carried by the outer envelope (27); a removable collector (38) passing through the outer envelope (27) and the inner container (26) in a sealed manner; and a flexible, thermally insulating neck (42) forming a sealing interface between the collector (38) and the inner container (26) on the one hand and between the outer envelope (27) and the inner container (26) on the other hand, the neck (42) being formed around a portion of the collector (38) and passing through the reduced-pressure insulating chamber (29) so as to allow the collector (38) to be disassembled independently of the pressure in the reduced-pressure insulating chamber (29).

2. The apparatus of claim 1, comprising a thermal plug assembly removably mounted on the collector (38) and accessible from the outside.

3. The device according to claim 1, wherein One of the connecting members comprises an axial recess in the outer envelope (27) for receiving and supporting an axial projection of the inner container (26).

4. The device according to claim 1, wherein The outer envelope (27) comprises a frame (30), sealed panels (31), and seals resistant to pressure between the frame (30) and the panels (31) and / or between the panels (31).

5. The device according to claim 4, wherein The frame (30) includes ribs (32) and spars (33).

6. The device according to claim 4, wherein The sealing member is accommodated in the groove and, in a free state, has a height exceeding the groove that is less than 10% of the height of the sealing member.

7. The device according to claim 1, comprising a shock-absorbing member in the inner container (26) and a reinforcement member in the inner container (26), preferably a bracket or a tie rod.

8. The device according to claim 1, comprising at least one support ring (35) mounted between the inner container (26) and the outer envelope (27) at a distance from the connection in the reduced pressure insulating chamber (29).

9. The device according to claim 1, wherein A hydrogen absorbing material is arranged in the reduced-pressure insulating chamber (29), and a hydrogen presence detector is installed in the reduced-pressure insulating chamber (29).

10. An assembly comprising:

1. The device according to claim 1 , wherein the at least one valve is arranged to open during the filling phase of the temporary storage tank (7) so as to allow the flow of liquid and to close outside the filling phase; the at least one valve is arranged to open during the emptying phase of the temporary storage tank (7) so as to allow the flow of gas and to close outside the emptying phase, the at least one valve being closed during the emptying phase, the at least one valve being controlled in an all-or-nothing manner; a compressor (20) arranged downstream of the downstream valve (15) and being started at the end of the emptying phase so as to reduce the pressure in the temporary storage tank (7) to a lower value than the pressure in the device; and a pressure reducer (9) arranged downstream of the downstream valve and being started at the beginning of the emptying phase so as to reduce the gas pressure at the outlet to a value lower than the pressure in the temporary storage tank (7).

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