Detachable aviation liquefied gas storage device

Abstract

An aviation gas storage cryogenic tank arrangement comprising: an inner container (26) defining a liquefied gas storage chamber (28); an outer envelope (27) housing the inner container (26) and made of a plurality of detachable parts for accessing the inner container (26), the outer envelope (27) being made of a material resistant to a temperature of less than-60 DEG C to at least + 80 DEG C; an insulating chamber (29) defined between the inner container (26) and the outer envelope (27), the reduced-pressure insulating chamber (29) having a helium gas tightness defined between the inner container (26) and the outer envelope (27) equal to or superior to 10-9 mbar * L / sec; two connectors, at least one of which is a sliding connector supporting the inner container (26) and carried by the outer envelope (27); a removable collector (42) 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 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 insulating chamber (29) so as to allow the collector (38) to be detached independently of the pressure in the insulating chamber (29).

Description

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

[0002] Aviation has used high-octane gasoline engines since its inception. After 1945, the development of jet engines and turbines led to the use of kerosene, which has a higher molecular weight than gasoline and is less flammable. These fuels are stored in tanks located in the wings, at the fuselage-wing junction, or in the tail.

[0003] The trend towards reducing CO2 emissions has resulted in engines that consume less fuel. However, as certain technologies mature, particularly increasing blade tip speeds, the gains in CO2 emissions are diminishing and a breakthrough seems increasingly needed.

[0004] Hence the emergence of gas powered aircraft projects. Combustion of gases with short or absent carbon chains (if appropriate) with oxygen produces little or no pollution. On the contrary, storage of H2, O2 or C1 or C2 gases is difficult due to the small size of gas molecules and there is a risk of leakage.

[0005] On the ground, these gases are usually stored in pressurized containers that are large and contain too much potential pressure energy to be carried on an aircraft, or in welded and / or bonded cryogenic tanks. The gases can be kept cold for a limited time, proportional to the volume stored.

[0006] Furthermore, hydrogen, methane, ethane, ethylene, acetylene or oxygen stored in liquid form cannot be used by internal or external combustion engines or fuel cells. Final consumption requires the gaseous state.

[0007] It seems that there is a need to store propellant gas inside the aircraft for onboard consumption, while implementing aviation maintenance technology and avoiding the development of new standards. In fact, the development of new standards is a long and time-consuming process, so there is a risk of delaying the commercialization of gas-fired aircraft. Acquiring new maintenance technology is also a long process, costly, and may even cause silence.

[0008] The present invention proposes an onboard aviation gas storage cryogenic storage tank device, which is spherical or elongated, comprising: an inner container defining a liquefied gas storage chamber; an outer envelope containing the inner container and made of a plurality of detachable parts so as to enable access to the inner container, the outer envelope being made of a material resistant to temperatures from below -60°C to at least +80°C; an insulating chamber defined between the inner container and the outer envelope, the decompression insulating chamber having a pressure of equal to or better than 10°C defined between the inner container and the outer envelope -9mbar*l / s helium tightness; two connections, at least one of which is a sliding connection, which support the inner container and are 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 insulating neck, which forms a sealing interface between the collector and the inner container on the one hand and between the outer envelope and the inner container on the other hand. The neck is formed around a part of the collector. The neck passes through the insulating chamber so as to be able to remove the collector independently of the pressure in the insulating chamber. Thanks to the invention, the cryogenic tank meets the requirements of aviation practice, especially thermal requirements, especially in terms of mechanical deformations and pipe volume.

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

[0010] In one embodiment, one of the connections comprises an axial concave surface in the outer envelope for receiving and supporting an axial protrusion of the inner container. The connection is adapted for possible expansion.

[0011] In one embodiment, the outer envelope comprises a frame, a sealing panel, and a seal capable of withstanding pressure between the frame and the panel and / or between the panels.

[0012] In one embodiment, the frame includes ribs and spars, and is structurally strong.

[0013] In one embodiment, the sealing member is arranged in the groove, and in a free state, the height beyond the groove is less than 10% of the height of the sealing member.

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

[0015] In one embodiment, the device comprises a reinforcement member, preferably a bracket or a tie rod, located inside the inner container. The device, in particular the inner container, can reduce weight.

[0016] In one embodiment, the device comprises at least one supporting ring mounted between the inner container and the outer envelope at a distance from the connection element in the insulating chamber. Increased rigidity.

[0017] In one embodiment, the hydrogen absorbing material is arranged in an insulating chamber. A low pressure is maintained in the insulating chamber.

[0018] In one embodiment, the hydrogen presence detector is mounted in an insulated chamber. Exceeding a limit value may cause an alarm to sound.

[0019] In one embodiment, an assembly comprises: a device as described above; a temporary storage tank forming a gasification component for pressurizing the gas provided by the device; an upstream valve, which is set to open for liquid flow during the filling phase of the temporary storage tank and closed outside the filling phase; a downstream valve, which is set to open for gas flow during the emptying phase of the temporary storage tank and closed outside the emptying phase, the upstream valve and the downstream valve are closed during the gasification phase, and the upstream valve and the downstream valve are controlled by all or nothing; a compressor arranged downstream of the downstream valve, the compressor is started at the end of the emptying phase to make the pressure value in the temporary storage tank lower than the pressure value in the device; and a pressure reducer arranged downstream of the downstream valve, the pressure reducer is started at the beginning of the emptying phase to make the gas pressure value at the outlet lower than the pressure value in the temporary storage tank. The device ensures that the aircraft has the necessary autonomy independent of the state of the device through the capacity in the temporary storage tank. The temporary storage tank can provide a gas pressure of several hundred bars, but the selected gas pressure is still supplied to the consumable component. The valve is reliable. The temporary storage tank can be emptied sufficiently to increase the amount of gas available to the consumable components and to make the pressure of the temporary storage tank lower than the current pressure in the device at the end of the emptying. The filling of the temporary storage tank is done by operating the cryogenic valve under the effect of the pressure difference. Not using a cryogenic pump increases quality and reduces the risk of accidents.

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

[0021] In one embodiment, the operating pressure of the device is less than 8 bar.

[0022] Other features and advantages of the present invention will become apparent from a reading of the following detailed description and the accompanying drawings, in which:

[0023] Figure 1 An axial cross section of a device according to an aspect of the invention is schematically shown.

[0024] Figure 2 A transverse cross section of a device according to an aspect of the invention is schematically shown.

[0025] Figure 3 A side view of a disassembled device according to an aspect of the invention is schematically shown.

[0026] Figure 4 A side view of a disassembled device according to another aspect of the invention is schematically shown.

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

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

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

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

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

[0032] Aviation gas storage units are designed to be carried on board aircraft such as airplanes, drones, helicopters, etc. Aviation gas storage units 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, especially pressures greater than 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 is approximately 800 times less dense than liquid hydrogen at -253°C, and therefore approximately 800 times more voluminous.

[0035] However, aviation maintenance rules require the ability to remove and repair or replace most parts of an aircraft. Thus, an aircraft can land anywhere that is suitable for its weight and landing requirements - an airport for airplanes, a landing zone for helicopters, but it does not have to be equipped with maintenance equipment specific to the aircraft type. If damage is found, the aircraft should be repaired permanently or temporarily, or disassembled to replace or repair the defective part, in accordance with the manufacturer's manual and documents approved by the aviation safety authority. It is best to make the part easily accessible to maintenance personnel. If replacement is required, it is best to make the part as small as possible to facilitate handling and transportation. If repair is required, it is best to repair the part using current tools and methods that have been proven in the aviation field.

[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 the terrestrial industrial sector or in the space sector 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] Applicants have identified a need for a removable aerospace cryogenic tank that is inspectable in accordance with aircraft inspection mode and is repairable. In addition, a tank is needed that has a high useful volume / external volume ratio, a high contained gas mass / total mass ratio, high reliability and high 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 the 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 contain liquid fuel or oxidant at -253°C. Each cryogenic tank is capable of withstanding a maximum operating pressure of 6 bar 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, the cryogenic tank 2 has a spherical shape.

[0044] The cryogenic tank 2 comprises an inner container 26 and an outer envelope 27. The inner container 26 defines a liquefied gas storage chamber 28 to accommodate a gas load at a liquefaction temperature and an upper limit of boil-off gas. The inner container 26 is sealed. The inner container 26 can withstand a liquefaction temperature, for example -253°C for hydrogen. The outer envelope 27 accommodates 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 impacts. The outer envelope 27 ensures the structural strength of the aviation gas storage device. The outer envelope 27 is made of a material having a temperature tolerance 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. The insulation in the insulating chamber 29 is ensured by a pressure reduced compared to the 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 of mbar*L / s. The tightness of the insulating chamber 29 includes the tightness relative to the inside of the inner container 26 and the tightness relative to the external atmosphere.

[0046] The inner container 26 may be made of a welded metal alloy. An example of a metal alloy may be Al-Cu-Li (particularly 2050 or 2099), Al-Cu (particularly 2219), stainless steel (particularly 304, 304L, 316, 316L). The inner container 26 has an elongated shape with two domed ends surrounding a body. The body may be cylindrical. The body may be a body of rotation.

[0047] The outer envelope 27 comprises a frame 30, a sealing panel 31, and a seal resistant to pressure between the frame 30 and the panel 31 and / or between the panels 31. The panel 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] The panel 31 is made of a welded metal alloy or a composite material. Examples of composite materials may be epoxy resin with carbon fiber, Kevlar fiber and / or glass fiber. Examples of metal alloys may be Al-Mg (especially 5086), Al-Mg-Si (especially 6061), Al-Cu-Li (especially 2195).

[0050] A seal is provided between the panel 31 and the frame 30. The seal may be metal / metal or a synthetic material, such as an elastomer. For a seal of synthetic material, a groove is formed in the panel 31 or the frame 30 to accommodate the seal. In a free state, the height of the seal beyond the groove is less than 10% of the height of the seal. 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 connections is a sliding connection, making it possible to accommodate differential expansion of the outer envelope 27 and the inner container 26. The connection is carried by the outer envelope 27. The first connection is an extreme connection. The extreme connection 34 may comprise a central protrusion at one end of the inner container 26, cooperating with an axial concave surface of the outer envelope 27, forming a housing for the protrusion, which slides axially over a travel of a few millimeters, so that the contraction of the inner container 26 when filled with liquefied gas and the expansion of the inner container 26 after emptying of liquefied gas are free. The extreme connection 34 is configured to have a heat conduction path of a long length.

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

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

[0055] The support ring 35 comprises inner sectors 37 protruding radially inwards. The number of inner sectors 37 is three. The inner sectors 37 have a convex surface in contact with the periphery of the inner container 26. The inner sectors 37 occupy an angle of about 15° to 40°. The outer sectors 36 and the inner sectors 37 are alternating. The outer sectors 36 and the inner sectors 37 are angularly spaced from each other. Preferably, three inner sectors 37 and three outer sectors 36 are alternately distributed, spaced about 20° to 30°, separated by non-protruding areas, and respectively occupy an angle of about 40° to 30°. The support ring 35 is retained by sufficient friction or permanent fastening with 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 in 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 an 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 relative to 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] The collector 38 comprises, at a second end side, a plug 41 surrounding the rod 39. The plug 41 is made of an insulating material. The plug 41 protrudes outward from the outer envelope 27. The plug 41 may have a gripping area for removal, for example for maintenance. The outer diameter of the plug 41 is greater than the diameter of the rod 39. The plug 41 forms a sealing head that can be removed from the cryogenic storage tank 2.

[0059] The plug assembly comprises a plug 41 and a plug cover 45. In the case of an aircraft or unmanned aerial vehicle, the cryogenic tank 2 can be mounted with the plug assembly towards the front of the aircraft type, with the free end of the rod 39 towards the rear of the aircraft type, to take advantage of the general inclination of the aircraft type, thereby enabling more complete filling with liquefied gas and more complete extraction of liquefied gas. The cryogenic tank 2 can also be mounted at an inclination, in particular by means of a support member of unequal height between the front and rear of the cryogenic 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 relative 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, the accuracy of a level gauge at an angle of 30° relative to the horizontal plane is twice that of a vertical level gauge.

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

[0062] The exhaust port 53 is provided in the plug 41 and emerges in the inner container 26 near the plug 41. Thus, the exhaust port 53 is connected to the gaseous head plate of the inner container 26. The exhaust port 53 is connected to a pipe passing through the plug 41. A bypass valve having a lower opening pressure than the allowable pressure in the cryogenic storage tank 2 may be connected to the pipe. A rupture disk having a lower rupture pressure than the allowable pressure in the cryogenic storage tank 2 may be connected to the pipe. The bypass valve and the rupture disk are installed in parallel.

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

[0064] The cryogenic tank 26 includes an insulating neck 42. The neck 42 has a bore. The neck 42 can be made of metal. The selected metal has the characteristics of poor thermal conductivity, mechanical resistance, flexibility and no leakage to hydrogen. The neck 42 is welded or screwed to the inner container 26 with a seal. The neck 42 is welded or screwed to the outer envelope 27 with a seal. The neck 42 has sufficient flexibility to accommodate the expansion difference between the inner container 26 and the outer envelope 27. The neck 42 includes an outer wall fixed to the inner container 26 and the outer envelope 27. The neck 42 includes an inner wall away from the inner container 26 and 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 tubular bellows shape. The inner wall may be made of a metal sheet having a thickness less than that of the outer wall metal sheet to increase elastic deformation capability. The inner wall may have a bellows shape, which increases elastic deformation capability. The bellows shape, such as a wave shape, reduces the contact surface between the inner wall and the plug 41, and thus the thermal conductivity is low.

[0066] Advantageously, the inner wall of the bellows comprises two concentric sheets. These sheets are assembled together and connected at the ends. A double wall is thus formed, which can reduce the risk of leakage. In the event that one of the two sheets is pierced, it can be detected by applying a gas pressure greater than the pressure in the insulating chamber and lower than the atmospheric pressure between the two sheets and monitoring the change in the applied pressure. If the applied pressure decreases, the sheet with a large diameter leaks with the insulating chamber. If the applied pressure increases, the sheet with a small diameter leaks with the drilled hole in the neck 42. The neck can then be replaced. In addition, if only one sheet leaks, the insulating chamber will maintain its low pressure to ensure weak thermal conduction, and the cryogenic storage tank 2 can be operated until the next maintenance operation. If a single sheet loses its leakproofness, the insulating chamber will lose its weak thermal conductivity, and the cryogenic storage tank 2 will be urgently emptied and its contents will be lost.

[0067] The neck 42 forms a sealing interface between the collector 38 on the one hand and the outer envelope 27 and the inner container 26 on the other hand. The neck 42 maintains the airtightness between the outer envelope 27 and the inner container 26 regardless of the position of the collector 38 or even the absence of the collector. The neck 42 is fixed in a sealing manner in the perforation of the outer envelope 27. The neck 42 is fixed in a sealing manner in the perforation of the inner container 26. The perforation of the outer envelope 27 and the perforation of the inner container 26 are located in the circular end of the cryogenic storage tank 2 near the circular end of the outer diameter of the upper cryogenic storage tank 2. The outer end of the collector 38 extends outwardly beyond the neck 42. The collector 38 extends inwardly beyond the neck 42 to the interior of the cryogenic storage tank 2 and extends downwardly to the other circular end of the cryogenic storage tank 2.

[0068] The neck 42 is formed to surround a portion of the collector 38. The neck 42 passes through the insulating chamber 29 so that the collector 38 can be removed independently of the pressure in the insulating chamber 29. The neck 42 is provided with a through hole 43, in which the plug 41 of the collector 38 is removably mounted. The contact surface between the neck 42 and the plug 41 can be provided with female annular teeth 44 to increase the length of the leakage path and promote the mechanical retention of the collector 38 in the neck. Here, the teeth 44 have a V-shaped pattern. The plug 41 has a smooth rotating outer surface in a free state. The plug 41 is adapted to the neck 42. A slight gap can be set between the bellows and the plug 41. A liquid guide plate is provided inside the neck near the storage chamber 28. The plug 41 is made of a heat-insulating material. The plug 41 may include a corrosion-resistant shell and an insulating synthetic foam inside the shell.

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

[0070] The inner wall connects the two parts of the outer wall. The inner wall comprises two concentric sheets with a thickness between 0.1 mm and 0.2 mm. Seen from the outside, the neck 42 comprises a collar 54 pointing towards the inner wall. The collar 54 connects the inner wall and the outer wall in a sealed manner. A seal 55 is fastened to the collar 54, in particular by a threaded connection. The seal 55 is in contact with the plug 41 of the collector 38. There is no level gauge here.

[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 said outer end of the collector 38. The cover 45 is sealed.

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

[0073] Advantageously, the cryogenic tank 2 comprises an anti-vibration member mounted within the inner container 26. The anti-vibration member comprises one or more perforated plates, dividing the inner volume of the inner container 26 into several regions. 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 located inside the inner container 26. The reinforcement comprises at least one bracket or tie rod connecting opposite areas of the inner container 26. The reinforcement 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, such as by heating.

[0076] A hydrogen presence detector 47 is installed in the insulating chamber 29. The presence of hydrogen is monitored. 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 expected. 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 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 (especially copper alloy) or elastomer can be used. The interference fit is ensured by axial tightening (especially 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 parts. As mentioned above, the two parts are connected in a sealed manner by sealing rings 50 and 51. The parts can be standardized to adapt to different capacities of inner containers 26, with one end part, one or more central parts and an end part free of neck perforations. Multiple support rings 35 can be provided.

[0079] exist Figure 5 In the embodiment shown, the frame 30 of the outer envelope 27 comprises annular ribs 32, spars 33 parallel to the longitudinal axis and diagonal braces. The outer envelope 27 comprises generally triangular panels 31, each of which is mounted between the ribs, spars and braces and has a dome panel at the end. The triangular panels 31 make the frame 30 visible. The dome panel covers the frame 30 outside the ribs 32.

[0080] exist Figure 6In the embodiment shown, the distribution circuit 1 comprises 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 with an open position and a closed position. The intermediate position of the first valve 11 is dynamic, because 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 arranged 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 connecting the outlets of the first valve 11. The distributor is cryogenic because liquid fuel / oxidant passes through it.

[0082] The cryogenic distributor 5 comprises a plurality of outlets, three in this case. Two second valves 12 are mounted on each of the outlets. The second valves 12 are controlled with an open position and a closed position. The intermediate position between the two valves 12 is dynamic, i.e. the second valves 12 are in a moving state when entering the intermediate position. In other words, the second valves 12 are all-or-nothing valves. Here, the number of the second valves 12 is three.

[0083] A central tank 7 is installed downstream of each second valve 12. Three central tanks 7 are provided in this embodiment. 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 is capable of withstanding 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 part of the operating steps and gaseous single-phase in another part of the operating steps. Each central tank 7 can be equipped with a heating member 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 consumption component 3 to supply gas. When the pressure in the central tank 7 is greater than the consumption pressure, the pressure reducer 9 is active, otherwise it is inactive. The consumption pressure is lower than the maximum pressure of the central tank 7. The consumption pressure has nothing to do with 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 connecting the outlet of the fourth valve 14 or the pressure reducer 9. The gas passes through the collector 10. The collector 10 is connected downstream to a supply pipe 23 to the consumer member 3. Typically, a supply pipe 23 is provided for each consumer member 3. Each supply pipe 23 can be equipped with a controlled supply valve 24. The supply valve 24 is variable flow.

[0087] The distribution circuit comprises at least one compressor 20 connected to the collector 10. Typically, two compressors 20 are provided in parallel for redundancy. The compressor 20 is electric. The compressor 20 may be equipped with a controlled upstream valve. The compressor 20 delivers the gas into the collector 10. Specifically, in the case of a single consumer component 3, the collector 10 is constituted 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 enables isolation of the central tank 7 and the compressor 20. The fifth valve 15 is controlled. The fifth valve 15 is an all-or-nothing valve.

[0089] The compressor 20 increases the pressure to supply gas at a pressure equal to the consumption pressure set by the manufacturer of the consumable member 3. The consumption pressure is lower than the maximum pressure in the central tank 7. The compressor 20 makes it possible to extract gas at a pressure lower than the consumption pressure in the central tank 7 to supply the collector 10 and the consumable member 3. A 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 to reduce the volume of the central tank 7.

[0090] The central tank 7 is emptied sufficiently to make the internal pressure of the central tank 7 lower than the pressure in one of the cryogenic tanks, so that during filling after the evacuation, liquid can be transferred from the cryogenic tank to the central tank 7 by the pressure difference. Therefore, the liquid of the cryogenic tank is sucked into the central tank 7 until the pressure is balanced. A cryogenic pump may not be used, so the mass and energy consumption may be increased.

[0091] The distribution circuit 1 provides a combination of individual states of each cryogenic storage tank, each central tank 7 and each consumable member 3. Multiple consumable members 3 can be active at the same time. In normal mode, a cryogenic storage tank is in the process of emptying, while other cryogenic storage tanks are inactive and therefore closed. However, in some cases, for example in order to reduce the pressure in multiple cryogenic storage tanks, a specific mode can be provided in which multiple cryogenic storage tanks are in the process of emptying. The central tank 7 has a filling mode, a gasification mode, a gas storage mode and an emptying mode.

[0092] When one of the cryogenic tanks is in the emptying mode, the corresponding first valve 11 is opened, while the other first valves 11 are closed. When one of the consumable components 3 is in the supply process, the corresponding supply valve 24 is opened.

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

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

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

[0096] At a given moment, of the three central tanks 7, one is in filling mode, another in vaporization and storage mode and the third in emptying mode. Since the duration of these modes is different, it is possible that two central tanks 7 are in filling mode and the third in emptying mode, or vice versa. It is also possible that two central tanks 7 are in storage mode and the third in emptying mode, or vice versa.

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

[0098] In one embodiment, the distribution circuit 1 comprises a control unit 25 which receives external commands (e.g. from a consumer 3 outside the aircraft storage device or a central control unit of the aircraft) and liquid flow rate data from the flow meter 22. The control unit 25 generates and sends commands to the first, second, third, fourth and fifth control valves and the control supply valve 24. The command can be "open" or "closed". The control unit 25 manages the combination of the various states.

[0099] In an alternative, the first valve 11 can be replaced by at least one multi-way valve with a plurality of inlets and one outlet. In this case, it makes sense to provide a multi-way valve with mixed positions, in particular at least one position for simultaneously emptying two or more cryogenic tanks 2 to reduce the pressure therein while avoiding losses to the atmosphere.

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

[0101] In an alternative, the plurality of pressure reducers 9 are replaced by a single pressure reducer 9, in which the third valve 13 is present. In this case, the third valve 13 can be replaced by at least one multi-way valve having a plurality of inlets and outlets leading to the pressure reducer. The plurality of fourth valves 14 are then replaced by a single fourth valve 14, which is not controlled if appropriate.

[0102] In an alternative, the fifth valve 15 may be replaced by at least one multi-way valve having a plurality of inlets (one for each central tank 7 ) and an outlet leading to the compressor 20 or compressors 20 . The multi-way valve forms the collector 10 .

[0103] The cryogenic storage tank 2 is affected by the evaporation of the liquid, so a gas collection loop can be provided on the upper part of the cryogenic storage tank 2. The collection loop can function above a threshold pressure through a calibrated pressure bypass valve. The collection loop includes an injector for re-injecting the gas downstream, for example, between the fifth valve 15 and the compressor 20.

[0104] Optionally, an additional flow meter is arranged at the inlet of each buffer tank. This ensures redundancy of the liquid flow measurement.

[0105] The capacity of the cryogenic storage tank means is from 10 kg to 10,000 kg of gas, preferably from 100 kg to 10,000 kg of gas.

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

[0107] A cryogenic tank device for the storage of gases 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 removable parts, allowing 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 between the inner container and the outer envelope an insulating chamber 29, the reduced pressure insulating chamber 29 having a pressure limit 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 supported by the outer envelope, a support ring is installed between the inner container and the outer envelope and is spaced 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, the device comprising an inner container defining a liquefied gas storage chamber, an outer envelope accommodating the inner container, a sealed insulating chamber defined between the inner container and the outer envelope, a detachable liquefied gas collector passing through the outer envelope and the inner container in a sealed manner, the collector extending on a diameter or diagonal of the inner container and having a free end close to the bottom of the inner container, a liquefied gas pipeline supplied by the collector, a temporary storage tank forming a gasification member for pressurizing the gas supplied by the device, an upstream valve provided for opening for liquid flow during a filling phase of the temporary storage tank and for closing during an emptying phase, a downstream valve provided for opening for gas flow during an emptying phase of the temporary storage tank and for 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, the pressure reducer acting at the beginning of the emptying phase to reduce the gas pressure at the outlet to a value lower than the pressure in the temporary storage tank.

Claims

1. An onboard cryogenic storage tank device for storing aviation gas, which is 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 removable parts to enable access to the inner container (26), the outer envelope (27) being made of a material resistant to temperatures from below -60°C to at least +80°C; an insulating chamber (29) defined between the inner container (26) and the outer envelope (27), the reduced pressure insulating chamber (29) having a pressure of equal to or better than 10°C defined between the inner container (26) and the outer envelope (27). -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 another envelope (27); a removable collector (38) passing through the outer envelope (27) and the inner container (26) in a sealed manner; and a flexible insulating neck (42), the neck 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), the neck (42) passing through the insulating chamber (29) so as to allow the collector (38) to be removed independently of the pressure in the 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 protrusion of the inner container (26).

4. The device according to any one of the preceding claims, 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 the preceding claim, wherein The frame (30) comprises ribs (32) and spars (33).

6. The device according to claim 4 or 5, wherein: The seal is received in the groove and, in a free state, its height beyond the groove is less than 10% of the height of the seal.

7. The device according to any of the preceding claims, comprising shock-absorbing elements in the inner container (26) and reinforcing elements in the inner container (26), preferably brackets or tie rods.

8. Device according to one of the preceding claims, comprising at least one supporting ring (35) mounted between the inner container (26) and the outer envelope (27) at a distance from the connection in the insulating chamber (29).

9. The device according to any one of the preceding claims, wherein A hydrogen absorbing material is arranged in the insulating chamber (29), and a hydrogen presence detector is installed in the insulating chamber (29).

10. A component comprising: Device according to one of the preceding claims; a temporary storage tank (7), which forms a gasification member for pressurizing the gas supplied by the device; an upstream valve (12), which is arranged to open during the filling phase of the temporary storage tank (7) to allow the flow of liquid and is closed outside the filling phase; a downstream valve (13, 15), which is arranged to open during the emptying phase of the temporary storage tank (7) to allow the flow of gas and is closed outside the emptying phase, the upstream valve and the downstream valve being closed during the gasification phase, the upstream valve and the downstream valve being controlled all or nothing; a compressor (20) arranged downstream of the downstream valve (15), which compressor (20) is started at the end of the emptying phase to make the pressure value in the temporary storage tank (7) lower than the pressure value in the device; and a pressure reducer (9) arranged downstream of the downstream valve, which pressure reducer (9) is started at the beginning of the emptying phase 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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