High pressure two-phase surge tank arrangement

Abstract

The invention relates to a high-pressure two-phase buffer tank device (7) for distributing fuel gas from at least one liquefied gas source (2) to at least one gas-consuming component (3); the device comprises a container (27) and a shut-off component (28); wherein the container (27) comprises a structural wall with thermal insulation and gas tightness, and an inner layer (34) with a lower specific heat capacity than the structural wall and a seal against liquefied gas.

Description

[0001] This invention relates to the field of cryogenic engineering.

[0002] Cryogenic engineering provides solutions for maritime, rail, and road transport, as well as stationary gas storage.

[0003] Since the birth of aviation, high-octane gasoline engines have been used. After 1945, with the development of jet and turbine engines, aviation fuel shifted to kerosene; compared to gasoline, kerosene has a higher molecular weight, higher energy density, higher combustion efficiency, and lower flammability. These fuels are typically stored in tanks located inside the wings, at the fuselage-wing junction, or in the tail section.

[0004] With the rise of the trend to reduce carbon dioxide emissions, efforts are being made to develop engines with lower fuel consumption. However, as certain technologies mature, particularly turbine blade tip speed technology, the marginal benefits in reducing carbon dioxide emissions are gradually diminishing. Therefore, the introduction of a breakthrough change has become increasingly urgent.

[0005] This demand has driven the development of gas-fueled aircraft projects. Combustion of gases with short or no carbon chains (with the addition of oxygen if necessary) produces very little or no pollutants. On the other hand, the storage of hydrogen (H2), oxygen (O2), or gases containing one or two carbon atoms (C1 or C2) presents significant challenges due to their extremely small molecular size and are highly susceptible to leakage.

[0006] In ground-based applications, the storage of hydrogen, methane, ethane, ethylene, acetylene, or oxygen typically relies on pressure vessels; however, these vessels are often too heavy, too bulky, and contain excessively high potential pressure energy to be mounted on aircraft. Another storage method is the use of cryogenic storage tanks constructed by welding and / or bonding. Cryogenic storage methods have time limitations, with the storage duration directly proportional to the volume of the stored gas.

[0007] Furthermore, gases stored in liquid form cannot be directly used by internal combustion engines, external combustion engines, or fuel cells. To achieve final consumption and utilization, the gas must be conditioned to a specific temperature and pressure range specified by the end-use gas component manufacturer.

[0008] The fields of cryogenic engineering and aerospace engineering have significant differences in technical requirements, which makes the compatibility issues between the two particularly challenging.

[0009] There is currently a need to treat the gases inside the aircraft for use on board. WO2022263307 describes a fuel circuit including a buffer tank and multiple compression modules for supplying fuel to the buffer tank. Each compression module includes: a base tank of fixed volume, a primary heat source for increasing the fuel temperature in the base tank in an isochoric manner, an inlet valve connecting the base tank to an upstream section of the fuel circuit, an outlet valve connecting the base tank to the buffer tank, and a degassing valve connecting the base tank to a cryogenic tank via a circuit that allows airflow.

[0010] The present invention aims to improve the above situation.

[0011] This invention proposes a high-pressure two-phase buffer tank device.

[0012] This invention provides a high-pressure two-phase buffer tank device for distributing fuel gas from at least one liquefied gas source to at least one gas-using component. The device includes a container and a shut-off component; wherein the container includes a structural wall with thermal insulation and airtightness, and an inner layer with a lower specific heat capacity than the structural wall and a sealing effect on the liquefied gas. The inner layer with low specific heat capacity or low thermal inertia helps to reduce vaporization during the filling process of the buffer tank. This inner layer can reduce heat conduction. After filling is completed, the buffer tank is shut off again. Subsequently, a vaporization process is sought to allow fuel gas to be supplied downstream. Vaporization is considered a disadvantage during the brief filling phase; however, it is beneficial in subsequent phases. The gas can be used as fuel for both internal combustion engines and fuel cells. After vaporization is completed, the term "fuel gas" will be used consistently below.

[0013] In one embodiment, the structural wall comprises a first structural insulation layer (made of carbon fiber matrix composite) and at least one second layer (airtight and made of polymer); wherein the specific heat capacity of the inner layer is lower than that of the first and second layers. The first layer has the characteristics of high strength and lightweight.

[0014] In one embodiment, the structural wall includes a third layer with better insulation properties than the first and second layers; in this case, the specific heat capacity of the inner layer is lower than that of the third layer. Both the second and third layers have good insulation properties.

[0015] In one embodiment, the inner layer is made of a metallic material, specifically selected from aluminum, stainless steel, titanium, Inconel, and iron-nickel alloys with a nickel content between 30% and 40%; its thickness is between 10 micrometers and 300 micrometers. This inner layer has a low heat capacity. Therefore, during filling, when the inner layer temperature is higher than the liquefied gas temperature, it transfers very little energy to the liquefied gas.

[0016] In one embodiment, the inner layer is attached to the structural wall. This inner layer can have a relatively small thickness, ranging from 10 micrometers to 300 micrometers. The inner layer can be made of a lightweight and conductive material, such as aluminum.

[0017] In one embodiment, the inner layer is free relative to the structural wall and is breathable. Alternatively, the inner layer is free relative to the structural wall and has at least one gap on its upper portion. The inner layer defines a peripheral chamber filled with fuel gas, which is at least largely separated from the material inside the container and acts as a temporary insulator during filling.

[0018] In one embodiment, the inner layer is free relative to the structural wall and is airtight, forming a cavity with the third layer that communicates with the outside; this cavity is filled with an insulating gas. The inner layer defines an outer cavity, which is filled with gas and isolated from the medium inside the container, and acts as an insulator.

[0019] In one embodiment, the insulation performance of the inner layer is lower than that of the first and second layers; and where applicable, its insulation performance is also lower than that of the third layer, while its heat capacity is lower than that of the third layer. The required characteristics of the inner layer are lightweight and low heat capacity.

[0020] In one embodiment, the layers of the structural wall are bonded together. The bonded layers of the wall provide extremely high strength.

[0021] In one embodiment, the shut-off component includes a plug and at least one channel for filling with liquefied gas and extracting fuel gas. This simplifies the inspection of the device.

[0022] In one embodiment, a gas distribution assembly disposed between at least one liquefied gas source and at least one gas-consuming component includes: at least one first valve, controllable to open and close, disposed at the outlet of each liquefied gas source; a cryogenic distributor connected to each first controllable valve and receiving liquid fluid; a plurality of second valves, controllable to open and close, connected in parallel to each other and connected to the cryogenic distributor; a plurality of buffer tank devices, each receiving liquid fluid through one of the aforementioned second controllable valves and discharging gas; a plurality of third controllable valves disposed at the outlet of each buffer tank device to discharge gas; a regulator disposed at the outlet of the third controllable valves; and a manifold supplied by the regulator to supply gas to the at least one gas-consuming component. This fuel gas distribution system utilizes liquefied gas stored in a cryogenic, low-pressure state for gas supply.

[0023] Further features and advantages of the present invention will become apparent upon review of the following detailed description and accompanying drawings, wherein: Figure 1 The distribution components according to one aspect of the invention are schematically shown in perspective view.

[0024] Figure 2 An apparatus according to one aspect of the invention is schematically shown in the form of an axial cross-sectional view.

[0025] Figure 3 This is a partial detailed view of the previous attached figure.

[0026] Figure 4 This is a variation of the previous attached figure.

[0027] Figure 5 An apparatus according to one aspect of the invention is schematically shown in the form of an axial cross-sectional view.

[0028] Figure 6 An apparatus according to one aspect of the invention is schematically shown in the form of an axial cross-sectional view.

[0029] Figure 7 The state of the device according to one aspect of the invention during the cooling phase is schematically shown in the form of an axial cross-sectional view.

[0030] Figure 8 The state of the device according to one aspect of the invention during the filling stage is schematically shown in the form of an axial cross-sectional view.

[0031] Figure 9 The state of the device according to one aspect of the invention during the pressurization stage is schematically shown in the form of an axial cross-sectional view.

[0032] Figure 10 The state of the apparatus according to one aspect of the invention during the evacuation step is schematically shown in the form of an axial cross-sectional view.

[0033] Figure 11 An apparatus according to one aspect of the invention is schematically shown in the form of an axial cross-sectional view, in the state of restoring to ambient pressure.

[0034] The accompanying drawings are not only used to supplement the description of the present invention, but also, if applicable, to help define the scope of the present invention.

[0035] The gas distribution assembly is designed to be fixed in place or carried by vehicles (especially aircraft: such as airplanes, drones, helicopters, etc.). This assembly supplies liquid and can deliver gas at a selected pressure. In other words, fuel or oxidizer is stored in a cryogenic tank in liquid form at low temperatures. According to one embodiment, the density of gaseous hydrogen at 0°C and 1 atmosphere is approximately 800 times lower than the density of liquid hydrogen at -253°C, and therefore its volume is approximately 800 times higher. Cryogenic tanks cannot withstand high pressures, especially pressures exceeding 10 bar.

[0036] The stored gases can be hydrogen, methane, ethane, ethylene, acetylene, and oxygen.

[0037] The applicant has recognized that gas distribution is required for aviation cryogenic storage tanks, regardless of whether they are connected to the aircraft structure, installed on the aircraft, or carried by the aircraft.

[0038] From another perspective, according to ETOPS certification, aircraft are currently subject to a maximum distance from alternate airports, measured in flight hours. This distance depends on the type of aircraft.

[0039] To ensure users have a high level of safety and develop a sense of security, the applicant recognizes that flight operations are still necessary even in the event of damage to the cryogenic storage tank and the need to release the contents into the atmosphere.

[0040] The applicant recognized that the buffer tank needed to be insulated from the outside environment, with a heat capacity far lower than that of the liquefied gas entering during filling, and required low mass and compact dimensions. It also needed to withstand a temperature range from -253°C to +50°C, resist temperature fluctuations, mechanical stress (especially acceleration and vibration), and withstand internal fuel gas pressures exceeding 500 bar or even 700 bar. The buffer tank required a highly robust construction.

[0041] The filling process uses liquefied gas. The pressure inside the buffer tank is lower than the pressure of the liquefied gas source, achieved through pumping or flow under pressure differential. The temperature of the buffer tank is close to room temperature, accurate to 10°C or 20°C, which ranges from -56°C at altitude to +50°C under ground heat conditions. However, the enthalpy of vaporization of the aforementioned liquefied gas is low. Introducing liquefied gas into a buffer tank at a temperature 50°C to 300°C higher than the liquefied gas temperature results in extremely rapid and very early vaporization. The pressure inside the buffer tank rises abruptly. Filling stops.

[0042] It is necessary to make the filling process simpler, more repeatable, and more reliable. To this end, a buffer tank device and a gas distribution assembly were designed.

[0043] exist Figure 1 In the illustrated embodiment, the gas distribution assembly 1 is supplied with gas from a liquefied gas source 2 to supply gas to one or more gas-consuming components 3. Here, two gas-consuming components 3 are shown, such as two propulsion units, an electric power generator, or an air heater. A flow meter 22 is installed at the outlet of each liquefied gas source 2. The gas distribution assembly 1 can be installed on an aircraft.

[0044] In this configuration, the liquefied gas source 2 comprises two cryogenic storage tanks arranged side-by-side. Each cryogenic storage tank is equipped with an outlet pipeline 4. The terms upstream and downstream refer to the flow direction of the fluid (liquid then gas) during normal operation.

[0045] Each cryogenic tank is insulated to hold liquid gases, such as liquid hydrogen at -253°C. Each cryogenic tank can withstand a maximum operating pressure of approximately 6 to 10 bar.

[0046] The gas distribution assembly 1 includes a first valve 11 for each cryogenic storage tank. The first valve 11 is mounted on the outlet line 4. The first valve 11 is controlled to have open and closed positions. The intermediate positions of the first valve 11 are dynamic, meaning they are in motion as they pass through these intermediate positions. In other words, the first valve 11 is either open or closed. The first valve 11 may be arranged immediately downstream of the flow meter 22. Optionally, the flow meter 22 is located downstream of the first valve 11.

[0047] The first valve 11 leads to the cryogenic distributor 5. The cryogenic distributor 5 may include a common line 6 connecting to the outlet of the first valve 11. The distributor is cryogenic because it handles liquefied gases.

[0048] The cryogenic distributor 5 includes multiple outlets, three in this embodiment. A second valve 12 is mounted on each outlet. The second valve 12 is controlled by open and closed positions. The intermediate positions of the second valve 12 are dynamic, meaning they are in motion as they pass through these intermediate positions. In other words, all second valves 12 are either open or closed. In this case, there are three second valves 12 in total.

[0049] Unlike cryogenic valves used in the aerospace industry that are used once and do not need to be closed again, the first valve 11 and the second valve 12 are reclosable, such as solenoid valves.

[0050] A buffer tank device 7 is installed downstream of each second valve 12. In this embodiment, three buffer tanks 7 are provided. Each buffer tank device 7 also acts as a vaporizer. This avoids isolation. Each buffer tank device 7 receives liquid and supplies gas downstream. Between each filling and emptying, a pressure rise or vaporization process occurs in each buffer tank device 7. Each buffer tank device 7 is capable of withstanding a maximum operating pressure of approximately 300 to 1000 bar. Each buffer tank device 7 is designed to operate in a temperature range of -253°C to +60°C. The buffer tank 7 operates as a two-phase gas in some phases and as a single-phase gas in others. Each buffer tank device 7 may be equipped with a heating element 8, such as... Figure 1 The external form shown.

[0051] Downstream of each buffer tank assembly 7, a third valve 13 is installed for gas supply, and downstream of the third valve 13, a regulator 9 is installed. This regulator 9 limits the gas supply pressure to the operating pressure range set by the manufacturer of the gas-using component 3. The regulator 9 is activated when the pressure in the buffer tank assembly 7 is higher than the operating pressure; conversely, it is deactivated when the pressure is lower. The operating pressure is lower than the maximum pressure of the buffer tank assembly 7. The operating pressure is independent of the maximum pressure of the cryogenic storage tank. The third valve 13 can be opened or closed.

[0052] Downstream of each regulator 9, a fourth control valve 14 may be provided. The fourth valve 14 may also be opened or closed.

[0053] Depending on the selected option, the fourth valve 14 or regulator 9 is connected to manifold 10. Manifold 10 may include a line connecting to the outlet of the fourth valve 14 or regulator 9. Gas is transmitted through manifold 10. Manifold 10 supplies gas to gas-consuming components 3 via downstream supply lines 23. Typically, one supply line 23 is provided for each gas-consuming component 3. Each supply line 23 may be equipped with a control supply valve 24. The supply valve 24 is flow-adjustable.

[0054] The gas distribution assembly 1 may include at least one compressor 20 connected to the manifold 10. Generally, two compressors 20 are arranged in parallel for redundancy. The compressor 20 is electrically powered. The compressor 20 may be equipped with a controllable upstream valve. The compressor 20 delivers gas to the manifold 10. In particular, in the case of a single gas-consuming component 3, the manifold 10 consists of a single pipe.

[0055] Downstream of each buffer tank assembly 7, a fifth valve 15 is installed to supply gas, and a second manifold is installed downstream of the fifth valve 15. The second manifold is connected to the compressor 20. The fifth valve 15 isolates the buffer tank 7 from the compressor 20. The fifth valve 15 is controllable; it can be opened or closed.

[0056] Compressor 20 increases the pressure to supply gas at a pressure equal to the operating pressure set by the manufacturer of the gas-using component 3. The operating pressure is lower than the maximum pressure in the buffer tank assembly 7. Compressor 20 can extract gas from the buffer tank assembly 7, which is at a pressure lower than the operating pressure, and deliver it to the manifold 10 and the gas-using component 3. More thoroughly emptying the buffer tank assembly 7 allows for increased autonomy of the gas contained in the buffer tank assembly 7, or allows for a reduction in the volume of the buffer tank assembly 7.

[0057] The liquid in the buffer tank assembly 7 is fully drained, reducing the internal pressure of the buffer tank assembly 7 to a level lower than the pressure inside one of the cryogenic storage tanks. During the filling operation after draining, the pressure difference can be used to transfer liquid from the cryogenic storage tanks to the buffer tank assembly 7. Therefore, liquid drawn from the cryogenic storage tanks enters the buffer tank assembly 7 until pressure equilibrium is reached. No cryogenic pump is required, which reduces weight and energy consumption.

[0058] The gas distribution assembly 1 provides a respective state combination for each cryogenic tank, each buffer tank assembly 7, and each gas-consuming component 3. Multiple gas-consuming components 3 can be activated simultaneously. In normal mode, one cryogenic tank is being emptied, while other tanks are inactive and therefore shut down. However, in certain situations, such as to reduce the pressure within multiple cryogenic tanks, a specific mode can be provided in which multiple cryogenic tanks are being emptied. The buffer tank 7 has a filling mode, a vaporization mode, a gas storage mode, and an emptying mode.

[0059] When one of the cryogenic storage tanks is being emptied, the corresponding first valve 11 opens, while the other first valves 11 close. When one of the gas-using components 3 is being supplied, the corresponding supply valve 24 opens.

[0060] When one of the buffer tanks 7 is in filling mode, the second valve 12 connected to that buffer tank assembly 7 opens, and at least one of the first valves 11 opens. Except when both buffer tanks 7 are being filled simultaneously, the other second valves 12 are closed. The third valve 13 connected to that buffer tank assembly 7 closes. The fifth valve 15 connected to that buffer tank assembly 7 also closes.

[0061] When one of the buffer tanks 7 is in vaporization mode, the second valve 12, the third valve 13, and the fifth valve 15 connected to that buffer tank device 7 are all closed. The vaporization mode lasts for a short period of time, especially when the ambient temperature is high and / or the buffer tank device 7 is heated.

[0062] When one of the buffer tanks 7 is in venting mode, the second valve 12 connected to that buffer tank assembly 7 closes. During the first stage of the venting process, the pressure inside the buffer tank assembly 7 is higher than the operating pressure. The third valve 13 connected to that buffer tank assembly 7 opens, the corresponding fourth valve 14 opens, and the fifth valve connected to that buffer tank assembly 7 closes. The gas is depressurized in the regulator 9 and supplied to the manifold 10 at the operating pressure. Subsequently, the gas is consumed by the gas-consuming component 3.

[0063] At any given time, of the three buffer tank devices 7, one is in filling mode, another is in vaporization mode followed by storage mode, and the third is in venting mode. Because the durations of these modes differ, it is also possible that two buffer tank devices 7 are in filling mode while the third is in venting mode, or vice versa. It is also possible that two buffer tank devices 7 are in storage mode while the third is in venting mode, or vice versa.

[0064] In this embodiment, a flow meter 22 is installed at the outlet of each liquefied gas source 2. These flow meters 22 enable a sufficiently accurate determination of the amount of liquid supplied to the buffer tank device 7.

[0065] In one embodiment, the gas distribution assembly 1 includes a control unit 25 that receives external setpoints, such as from the gas-consuming component 3 or a central control unit, and liquid flow data from the flow meter 22. The control unit 25 generates and sends setpoints to the first, second, third, fourth, and fifth control valves and the control supply valve 24. These setpoints can be "on" or "off". The control unit 25 manages combinations of these various states.

[0066] Alternatively, the multiple first valves 11 can be replaced by at least one multi-way valve having multiple inlets and one outlet. In this case, it is useful to provide a multi-way valve with a mixing position, especially with at least one position for simultaneously discharging two or more liquefied gas sources 2 to reduce pressure and prevent leakage to the atmosphere.

[0067] Alternatively, the multiple second valves 12 can be replaced by at least one multi-port valve having one inlet and multiple outlets (one outlet for each buffer tank assembly 7). This multi-port valve forms a distributor.

[0068] Alternatively, multiple controllers 9 can be replaced by a single controller 9, to which the third valve 13 leads. In this case, the multiple third valves 13 can be replaced by at least one multi-way valve having multiple inlets and a path to the controller outlet. Then, the multiple fourth valves 14 can be replaced by a single fourth valve 14, which may be a non-control valve.

[0069] Alternatively, the multiple fifth valves 15 can be replaced by at least one multi-way valve having multiple inlets (one inlet for each buffer tank assembly 7) and one outlet (leading to compressor 20 or multiple compressors 20). The multi-way valve forms a manifold 10.

[0070] Buffer tank device 7 in Figures 2 to 11 A more detailed demonstration is available in the section.

[0071] The buffer tank unit 7 is a two-phase design, intended to contain substances that are essentially liquid at low temperatures and essentially gaseous under high pressure. The essentially liquid substance comprises 80% to 90% liquid with a gaseous upper space. The gaseous substance can reach pressures of several hundred bar. The buffer tank unit 7 can be carried by an aircraft, either internally (e.g., within the fuselage or, if the wing is thick enough), or externally (e.g., under the wing).

[0072] exist Figure 2 and 3 In the illustrated embodiment, the buffer tank device 7 includes a container 27 and a shut-off member 28. The container 27 is rigid. The container 27 is thermally insulated. The container 27 is airtight. The container 27 can withstand low temperatures internally. The container 27 can withstand rapid temperature changes. In the illustrated embodiment, the container 27 has a multi-layered structure.

[0073] The container 27 has an opening 29. A stop member 28 is installed in the opening 29 to ensure that the internal material is retained and to allow the material to be filled and emptied into the downstream member.

[0074] Container 27 includes a wall and an inner layer 34. The wall is structural, insulating, and airtight. From the outside in, the wall consists of a first layer 31, a second layer 32, and a third layer 33, as follows: Figure 3 As shown. Alternatively, from the outside in, the wall consists of a first layer 31 and a second layer 32, as shown. Figure 4 As shown.

[0075] The first layer 31 is structural, giving the container 27 its shape, rigidity, and external mechanical connection to the support of the container 27. The first layer 31 may be thermally insulating. The specific heat capacity of the inner layer 34 is lower than that of the third layer 33. The first layer 31, the second layer 32, and the third layer 33 form a mechanical, thermal, and sealing assembly. The inner layer 34 is located inside.

[0076] The container 27 has a rotationally symmetrical shape, comprising a cylindrical central portion, a circularly arcuate bottom (e.g., hemispherical), and a circularly arcuate top (e.g., hemispherical). The top is covered by a neck 30, which defines an opening. The thickness of the neck 30 may be greater than that of the central portion and the bottom to absorb mechanical forces transmitted by the stop member 28. The neck 30 consists of at least a first layer 31, and optionally also includes a second layer 32 and a third layer 33.

[0077] The first layer 31 is made of a composite material. The first layer 31 comprises fibers (e.g., carbon fibers or aramid fibers) and a matrix. The first layer 31 is resistant to low temperatures and rapid temperature changes. The first layer 31 has a first thickness. This first thickness is designed according to the volume and shape of the container, as well as external and internal pressures. The first layer 31 is continuous except for the opening 29. In this case, the first layer 31 extends over the entire height of the container 27.

[0078] The second layer 32 is airtight. The second layer 32 provides a seal for container 27 (preventing the passage of small molecules such as hydrogen, if applicable). The second layer 32 is more effective at sealing helium than layer 10. -10 Pa.m 3 / s. The second layer 32 has a second thickness. The second thickness is less than the first thickness. The second layer 32 is made of a polymer. The second thickness may be between 0.1 and 10 mm. The first layer 31 and the second layer 32 are usually bonded to each other. The second layer 32 is continuous except for the opening 29. In this case, the second layer 32 extends to the height of the container 27 minus the height of the neck 30.

[0079] The third layer 33 provides better insulation than the first and second layers. The third layer 33 provides insulation for the container 27. The thermal conductivity of the third layer 33 is less than 100 mW·m. -1 .K -1 The third layer 33 can be made of a polymer, such as fiber-reinforced polyurethane foam. Alternatively, the third layer 33 can be made of mineral wool. The third layer 33 has a third thickness. The third thickness is greater than the first thickness. The third thickness may be between 1 and 100 mm. The second layer 32 and the third layer 33 are typically bonded together. The third layer 33 is continuous except for the opening 29. In this case, the third layer 33 extends upward from the bottom of the container 27 to the container height minus the height of the neck 30.

[0080] The inner layer 34 has a lower heat capacity than any of the first, second, and third layers. The inner layer 34 is sealable to prevent the ingress of liquefied gases. Airtightness is optional. The inner layer 34 reduces the amount of gas released from the container 27 during filling. The inner layer 34 is less insulating than any of the first, second, and third layers.

[0081] The inner layer 34 is made of metal, such as aluminum or an aluminum alloy. More broadly, the inner layer 34 is made of metal. The metal used for the inner layer 34 can be: aluminum, stainless steel, titanium, Inconel, and iron-nickel alloy. For iron-nickel alloys, the nickel content is between 30% and 40%. Therefore, this material used for the intended application is characterized by low heat capacity, low temperature resistance, and low surface quality.

[0082] The inner layer 34 has a fourth thickness. This fourth thickness is less than the first, second, and third thicknesses. The fourth thickness may be between 10 and 300 micrometers.

[0083] exist Figure 3 In the illustrated embodiment, the inner layer 34 is adhered to the wall. The inner layer 34, for example, covers the entire inner surface of the third layer 33. The inner layer 34 can have a relatively thin thickness, specifically ranging from 10 to 300 micrometers.

[0084] exist Figure 4 In the illustrated embodiment, the inner layer 34 is separate from the wall. The inner layer 34 may be permeable to fuel gases. The inner layer 34 may be impermeable to liquids (especially liquefied gases). The second layer 32 and the inner layer 34 may form a chamber 35. This chamber 35 may have a variable volume. The thickness of the inner layer 34 may be between 0.01 and 1 mm.

[0085] Additionally, see Figure 6 The inner layer 34 may have at least one gap 36 in its upper part. This gap 36 allows gas to pass between the inner layer 34 and the wall, i.e., to enter the chamber 35. This gap 36 may be located high enough to be in the upper gaseous space at the end of filling and after filling. The upper gaseous space is the portion of the container filled with gas and located above the liquid phase. The volume of the upper gaseous space is minimized at the end of filling and after filling.

[0086] In one embodiment, container 27 includes an intermediate layer disposed between the third layer 33 and the inner layer 34. This intermediate layer forms an additional insulator. The intermediate layer comprises a porous material capable of absorbing or adsorbing fuel gases.

[0087] Container 27 includes an insert 37. The insert 37 is sealed. The insert 37 is pressure-resistant. During high-pressure phases, the insert 37 is capable of transmitting axial forces to container 27.

[0088] The insert 37 is generally annular. The insert 37 may be made of metal. The insert 37 includes a downwardly widening lower portion 38 and a cylindrical upper portion 39. The lower portion 38 contacts the inner surface of the top of the container 27. The upper portion 39 contacts the opening in the neck 30. The height of the insert 37 is greater than the height of the neck 30, but less than the sum of the heights of the neck 30 and the top of the container 27. The insert 37 is fixed in position by shape fitting. The insert 37 may be attached to the neck 30 and the top of the container 27 by adhesive bonding. The insert 37 is made as a single, integral component. The insert 37 has a central gap forming an opening 29.

[0089] Opening 29 is axial. Opening 29 has a ribbed or helical peripheral surface. Here, the grooves or helixes are dovetail-shaped to extend the heat conduction path. Opening 29 may be covered with a coating different from that of insert 37.

[0090] The stop member 28 is sealed. The stop member 28 is pressure-resistant. The stop member 28 is removable. The stop member 28 includes a body forming a plug. The body includes a lower portion 40 located within an opening 29 and an upper portion 41 projecting from the opening 29. The upper portion 41 contacts the upper surface of the neck 30.

[0091] The shut-off member 28 includes a filling line 42 that passes through the body between the exterior and interior of the container 27.

[0092] The shut-off member 28 includes an extraction line 43 that passes through the body between the exterior and interior of the container 27. The extraction line 43 serves as an exhaust port. The extraction line 43 is configured to capture gas and transport it downstream. Within the body, the extraction line 43 and the filling line 42 are parallel and spaced apart from each other.

[0093] exist Figure 2 In the illustrated embodiment, the shut-off member 28 includes at least one additional channel. An internal heating member 44 is mounted in this additional channel. Here, the heating member 44 passes through two additional channels. The heating member 44 is used to accelerate vaporization after filling, and to be used when the second and third valves are closed, or at least the second valve 12 is closed. The heating member 44 is located in the high region of the container, such as at the top of the container and, where applicable, in the central portion of the cylinder. The heating member 44 may be positioned above the maximum liquid level of the liquefied gas. The heating member 44 extends into the upper gaseous space.

[0094] The heating element 44 can be electrically powered; one additional channel is sufficient.

[0095] The heating element 44 can exchange heat with a heat transfer fluid flowing through a conduit. The conduit is spiral-shaped. The heating element 44 can consist of two to five coils. The heat transfer fluid can be a gas, fuel, or combustion fluid. Two additional channels are also provided for the inlet of the heat transfer fluid and the outlet of the cooled heat transfer fluid. Alternatively, the inlet and outlet share a single additional channel.

[0096] exist Figure 1 In the illustrated embodiment, the heating element 8 is mounted outside the container 27. Figure 5 and Figure 6 In the embodiments shown, the heating element is missing or external (not shown).

[0097] exist Figure 5In the illustrated embodiment, the inner layer 34 is replaced by an outer layer 45. The outer layer 45 forms a heat insulation sleeve surrounding the first layer 31. The outer layer 45 surrounds the upper portion 41 of the body of the stop member 28. The outer layer 45 may be made of a foam material, such as EPS. The outer layer 45 may consist of at least two removable parts.

[0098] exist Figure 6 In the illustrated embodiment, the inner layer 34 is free relative to the third layer 33 and is airtight. The inner layer 34, together with the wall, forms a chamber 35 communicating with the outside. This communication with the outside serves to fill and refill the chamber. The chamber 35 is typically filled with an insulating gas, such as argon. After filling, the chamber 35 is sealed. The heating level is very low when the liquefied gas is introduced into the container. The outer layer 45 enhances the insulation effect. The outer layer 45 forms a heat-insulating sleeve surrounding the first layer 31. The outer layer 45 surrounds the upper portion 41 of the body of the stop member 28.

[0099] Figures 7 to 11 The steps of implementing the buffer tank device 7 are illustrated. The buffer tank device 7 is in operation, with the shut-off member 28 fixedly connected to the container 27. A first cooling step is performed starting from an empty tank at ambient temperature (typically between -56°C and +50°C). This step is accomplished by introducing liquefied gas into the container 27 and then degassing it. The liquefied gas can be the same as that used in subsequent steps, or it can be a neutral gas, such as nitrogen. While the liquefied gas is being supplied through the filling line 42, the evacuation line 43 is open. The release of the liquefied gas causes rapid evaporation and cooling of the container interior (starting from the inner layer 34, then the third layer 33). The duration of the first step is kept as short as possible. This invention enables the shortening of the first step's duration. At the end of the first step, the pressure inside the container is equal to the ambient pressure (e.g., the ambient pressure around an aircraft).

[0100] Once the selected temperature is reached inside container 27, the second step of filling the fuel gas with liquefied precursor gas begins. This filling is performed by filling line 42. During the second step, evacuation line 43 may be opened and then closed, or it may remain closed from the beginning of the second step. A gaseous upper layer, occupying approximately a few percent of the container's volume, will remain inside container 27. At the end of the second step, filling line 42 will be closed. The duration of the second step should be as short as possible. The brevity of the second step is less important than that of the first step. This invention allows for a shorter duration of the second step. Pressure will increase during the second step. The pressure at the end of the second step will be equal to or lower than the pressure of the cryogenic storage tank supplying the liquefied gas. The pressure at the end of the second step is between 6 and 10 bar. The use of cryogenic pumps should be avoided.

[0101] Once container 27 is filled with the required amount of liquefied gas, the third step of pressurization begins. Pressurization can be assisted by heating element 44. Heating element 44 is continuously energized for a sufficient time to bring the pressure inside container 27 to the minimum pressure required to supply fuel gas downstream. In other steps, heating element 44 is not energized. In the third step, evacuation line 43 and filling line 42 are closed. The duration of the third step is as short as possible to allow the buffer tank to begin supplying fuel gas. The brevity of the third step is less important than that of the first step. The pressure at the end of the third step is higher than the pressure of the cryogenic container supplying the liquefied gas. The pressure at the end of the third step is between 100 and 700 bar. Pressurization and temperature rise occur simultaneously.

[0102] Filling line 42 is closed. Once pressurization is complete, the fourth evacuation step begins. Evacuation line 43 is opened. The duration of the fourth step varies depending on the fuel gas demand downstream of buffer tank unit 7. The pressure at the end of the fourth step depends on whether there is a compressor 20 downstream of buffer tank unit 7. If a compressor 20 is provided (e.g., ... Figure 1 As shown), the pressure at the end of the fourth step will depend on the characteristics of compressor 20 and may be lower than the ambient pressure. If compressor 20 is not equipped, the pressure at the end of the fourth step will depend on the characteristics of the gas-using component 3. The pressure at the end of the fourth step can range from 1 to 50 bar.

[0103] Once pressurization is achieved, the fourth evacuation step begins. Evacuation line 43 opens, and filling line 42 closes. The duration of the fourth step varies depending on downstream fuel gas demand. Temperature gradually increases with the evacuation flow rate. A higher flow rate results in a slower temperature rise, while a lower flow rate results in a faster temperature rise. The pressure at the end of the fourth step depends on whether a compressor 20 is located below the buffer tank assembly 7. If a compressor 20 is present (e.g., ...), ... Figure 1 As shown), the pressure at the end of the fourth step depends on the characteristics of the compressor and may be lower than the ambient pressure.

[0104] Without a compressor, the pressure at the end of the fourth step depends on the characteristics of gas-using component 3. The pressure at the end of the fourth step can be between 1 and 50 bar. The pressure at the end of the fourth step reaches the level at which fuel gas extraction ceases.

[0105] Once the pressure at the end of step four is reached, step five, the step of restoring to ambient pressure, begins. Step five is optional. If the pressure at the end of step four is greater than ambient pressure, degassing will be performed through the open evacuation line 43. Simultaneously, the filling line 42 will be closed. Step five is shorter in duration. The temperature inside container 27 will decrease. The pressure at the end of step five is equal to ambient pressure, for example, 1013 hPa at ground level or 265 hPa at an altitude of 10,000 meters. Step five is performed in the absence of a compressor or if compressor 20 cannot provide sufficient flow or efficiency to provide the required fuel gas flow at the end of step four.

[0106] After completing step 5, either container 27 will be sufficiently cooled, at which point the process will proceed directly to step 2, or it will continue to step 1.

[0107] In one embodiment, a high-pressure two-phase buffer tank aircraft device 7 is installed on an aircraft for distributing fuel gas to at least one gas-using component 3 on the aircraft, supplied from at least one liquefied gas source 2 on the aircraft. The buffer tank device 7 includes a container 27 and a shut-off component 28. The container 27 comprises a set of structural, insulating, and airtight layers, and an inner layer that is airtight to the liquefied gas and has a lower heat capacity than each of the layers in the set. The inner layer may be thermally conductive.

[0108] The presence of this high-pressure two-stage buffer tank device reduces liquefied gas evaporation due to the low heat capacity of the inner layer, thereby minimizing pressure rise during filling. This results in reduced losses, shorter filling time, and a lower likelihood of incomplete filling. The ratio of active service time (i.e., the duration of the fourth step) to the buffer tank cycle duration is improved. Claims (as amended under Article 19 of the Treaty) 1. A high-pressure two-phase buffer tank device (7) for distributing fuel gas from at least one liquefied gas source (2) to at least one gas-using component (3), the device comprising a container (27) and a shut-off component (28); the container (27) comprising a structural wall having thermal insulation and airtightness, and an inner layer (34) having a lower specific heat capacity than the structural wall and having a sealing effect on the liquefied gas; the structural wall comprising a first structural thermal insulation layer (31) made of carbon fiber-based composite material, and at least one second layer (32) made of polymer and having airtightness; the specific heat capacity of the inner layer (34) being lower than that of the first layer (31) and the second layer (32); the layers of the structural wall being bonded together. 2. The device according to claim 1, wherein the structural wall includes a third layer (33) having stronger thermal insulation than the first layer and the second layer; in this case, the specific heat capacity of the inner layer (34) is lower than that of the third layer. 3. The device according to any of the preceding claims, wherein the inner layer (34) is made of a metallic material, specifically selected from: aluminum, stainless steel, titanium, Inconel alloy and iron-nickel alloy with a nickel content of 30% to 40%; and its thickness is between 10 and 300 micrometers. 4. The device according to any of the preceding claims, wherein the inner layer (34) is bonded to the structural wall. 5. The device according to any one of claims 1-4, wherein the inner layer (34) is in a free state relative to the structural wall. 6. The device according to claim 5, wherein the inner layer (34) is breathable while maintaining a seal against liquefied gas. 7. The apparatus according to claim 5 or 6, wherein the inner layer (34) is provided with a gap (36) that allows gas to flow between the inner layer (34) and the structural wall, and the gap (36) is positioned high enough that it is located in the upper gaseous space at the end of filling and after filling. 8. The device according to any one of claims 1 to 4, wherein the structural wall comprises a third layer (33) having better thermal insulation than the first layer and the second layer; and the inner layer (34) is free relative to the structural wall, has airtightness, and together with the third layer (33) forms a chamber (35) communicating with the outside, the chamber (35) being filled with insulating gas. 9. The device according to any one of the preceding claims, wherein the inner layer (34) has lower thermal insulation than each of the first layer and the second layer. 10. The device according to any one of the preceding claims, wherein the structural wall includes a third layer (33) having better thermal insulation than the first layer and the second layer; and the inner layer (34) has lower thermal insulation than the third layer, and the specific heat capacity of the inner layer (34) is also lower than that of the third layer. 11. The apparatus according to any of the preceding claims, wherein the shut-off member (28) comprises a plug and at least one channel for filling liquefied gas and extracting fuel gas. 12. A gas distribution assembly (1) located between at least one liquefied gas source (2) and at least one gas-using component (3), comprising: At least one first valve (11), controlled to open and close, is located at the outlet of each liquefied gas source (2); A cryogenic distributor (5) is connected to each of the first controlled valves (11) and receives the liquid supply; Multiple second valves (12) are controlled to open and close and are connected in parallel to the cryogenic distributor (5). According to any one of the preceding claims, a plurality of buffer tank devices (7) each receive a liquid supply through one of the second controlled valves (12) and is used to supply gas; Multiple third controlled valves (13) are installed at the outlet of each buffer tank device (7) to supply gas; Regulator (9), installed at the outlet of the plurality of third controlled valves (13); and The manifold (10), supplied by the regulator (9), is used to supply gas to the at least one gas-using component (3).

Claims

1. A high-pressure two-phase buffer tank device (7) for distributing fuel gas from at least one liquefied gas source (2) to at least one gas-using component (3), the device comprising a container (27) and a shut-off component (28); the container (27) comprising a structural wall having thermal insulation and airtightness, and an inner layer (34) having a lower specific heat capacity than the structural wall and having a sealing effect on the liquefied gas; the structural wall comprising a first structural thermal insulation layer (31) made of carbon fiber-based composite material, and at least one second layer (32) made of polymer and having airtightness; the specific heat capacity of the inner layer (34) being lower than that of the first layer (31) and the second layer (32); the layers of the structural wall being bonded together.

2. The apparatus according to claim 1, wherein, The structural wall includes a third layer (33) that has stronger thermal insulation than the first and second layers; in this case, the specific heat capacity of the inner layer (34) is lower than that of the third layer.

3. The apparatus according to any one of the preceding claims, wherein, The inner layer (34) is made of a metallic material, specifically selected from: aluminum, stainless steel, titanium, Inconel alloy and iron-nickel alloy with a nickel content of 30% to 40%; and its thickness is between 10 and 300 micrometers.

4. The apparatus according to any one of the preceding claims, wherein, The inner layer (34) is bonded to the structural wall.

5. The apparatus according to any one of claims 1-4, wherein, The inner layer (34) is in a free state relative to the structural wall and is breathable, and / or has at least one gap (36) in the upper part.

6. The apparatus according to any one of claims 1-4, wherein, The inner layer (34) is free and airtight relative to the structural wall, and together with the third layer (33) forms a chamber (35) that communicates with the outside; the chamber (35) is filled with insulating gas.

7. The apparatus according to any one of the preceding claims, wherein, The inner layer (34) has lower thermal insulation than each of the first and second layers, and where applicable, the inner layer (34) also has lower thermal insulation than the third layer; and the inner layer (34) has lower specific heat capacity than the third layer.

8. The apparatus according to any one of the preceding claims, wherein, The shut-off member (28) includes a plug and at least one channel for filling liquefied gas and extracting fuel gas.

9. A gas distribution assembly (1) located between at least one liquefied gas source (2) and at least one gas-using component (3), comprising: At least one first valve (11), controlled to open and close, is located at the outlet of each liquefied gas source (2); A cryogenic distributor (5) is connected to each of the first controlled valves (11) and receives the liquid supply; Multiple second valves (12) are controlled to open and close and are connected in parallel to the cryogenic distributor (5). According to any one of the preceding claims, a plurality of buffer tank devices (7) each receive a liquid supply through one of the second controlled valves (12) and is used to supply gas; Multiple third controlled valves (13) are installed at the outlet of each buffer tank device (7) to supply gas; Regulator (9), installed at the outlet of the plurality of third controlled valves (13); and The manifold (10), supplied by the regulator (9), is used to supply gas to the at least one gas-using component (3).

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