Aircraft Tank Device for Hydrogen Storage at Cryogenic Temperatures for Transport by Aircraft

Abstract

The present invention provides a removable aviation tank system 30 with cryogenic storage capability for transportation by aircraft. The aviation tank system 30 according to the present invention comprises a forward cryogenic tank 36, an aft cryogenic tank 37 and at least one temporary storage central tank 7 for pressurization of gas supplied by the forward cryogenic tank 36 and the aft cryogenic tank 37.

Description

Technical Field

[0001] The present invention relates to the aviation industry.

Background Art

[0002] In the aviation industry, initially, high-octane gasoline engines have been used. Since 1945, with the development of jet engines and turbines, kerosene has come to be used. Kerosene has a higher molecular weight, higher energy density, higher efficiency, and lower flammability than gasoline. These fuels are usually stored in tanks located in the wings, the connection between the fuselage and the wings, or the tail fins.

[0003] Due to the trend of reducing carbon dioxide emissions, engines with low fuel consumption have been developed. However, with the development of certain technologies (especially the speed at the blade tip), the effect of reducing carbon dioxide emissions has been decreasing. Such a break from the past is increasingly desired.

[0004] This has led to the development of gas-powered aircraft. Gases with short or no carbon chains produce little or no pollution even when burned with oxygen as needed. On the other hand, gases such as H2, O2, C1, and C2 are difficult to store and prone to leakage because the gas molecules are small.

[0005] Such gases are usually stored on the ground in a pressure case (this type of case is too heavy, voluminous, and has too much pressure energy to be mounted on an aircraft) or in a cryogenic tank that is welded or adhered. The cryogenic storage of such gases has a storage period limited in proportion to the storage amount.

[0006] Furthermore, hydrogen, methane, ethane, ethylene, acetylene, and oxygen stored in a liquid state cannot be used in internal combustion engines, external combustion engines, or fuel cells. For final consumption, it is necessary to be in a gaseous state.

[0007] Therefore, while applying the know-how of aircraft maintenance and avoiding the need for new standardization, there is a need to store the propulsion gas for consumption inside the aircraft within the aircraft. In fact, establishing new standardization is a long and time-consuming process, and there is a risk of delaying the market entry of gas-powered aircraft. Since it also takes time and cost to acquire new maintenance know-how, it can lead to a sense of resistance.

Summary of the Invention

[0008] The present invention proposes a detachable aircraft tank device having cryogenic storage performance for transportation by aircraft. The aircraft tank device according to the present invention includes a front cryogenic tank, a rear cryogenic tank, and at least one central tank for temporarily storing for increasing the pressure of the gas supplied by the front cryogenic tank and the rear cryogenic tank. According to the present invention, the aircraft tank device can be made into an elongated shape so that it can be mounted on an aircraft with a high ratio of stored energy to the size of the aircraft tank device. Storage and gasification are performed individually and close to each other. The above "detachable" means that on the taxiway of an airport, the aircraft tank device can be very quickly attached to or detached from the aircraft regardless of the presence or absence of tools. It is advantageous that the attachment of the aircraft tank device is of the "plug and play" type.

[0009] Unlike the aerospace industry where parts are used for only a few seconds or dozens of seconds, the aviation industry requires parts with a long service life of tens of thousands of hours and tens of thousands of cycles.

[0010] In one embodiment, each of the front cryogenic tank and the rear cryogenic tank has a convex outer shape. Each of the front cryogenic tank and the rear cryogenic tank includes an inner casing that defines a storage chamber, an outer casing that houses the inner casing, a heat insulation chamber defined between the inner casing and the outer casing, a detachable manifold that penetrates the outer casing and the inner casing in a sealed state, and a pipe through which gas is supplied by the manifold. The central tank for temporary storage has a quasi (substantially) toroidal or quasi (substantially) annular shape. Thereby, the utilization of available space is promoted.

[0011] In one embodiment, each of the front cryogenic tank and the rear cryogenic tank is insulated under vacuum against conduction, convection, and radiation. Thereby, natural evaporation is reduced.

[0012] In one embodiment, the aircraft tank device includes a front cryogenic tank and a rear cryogenic tank having an elongated shape along a common axis. Thereby, an elongated outer shape of the aircraft tank device is obtained.

[0013] In one embodiment, the aircraft tank device includes at least two spherical front cryogenic tanks and at least two spherical rear cryogenic tanks. Thereby, the utilization of available space with respect to the contained weight is promoted.

[0014] In one embodiment, the aircraft tank device includes a plurality of temporary storage tanks respectively disposed between two cryogenic tanks (between two front cryogenic tanks and between two rear cryogenic tanks). Thereby, the capacity of temporary storage is increased.

[0015] In one embodiment, the central tank for temporary storage forms a gasification member, and an upstream valve and a downstream valve are provided for the central tank for temporary storage. The upstream valve is provided to open so that liquid flows during the filling stage of the central tank for temporary storage and to close at other times than the filling stage. The downstream valve is provided to open so that gas flows during the discharge stage of the central tank for temporary storage and to close at other times than the discharge stage. The upstream valve and the downstream valve are closed during the gasification stage. With such a system, regardless of the state of the cryogenic tank, it is guaranteed that the volume of the temporary storage tank gives the aircraft the required autonomy. The temporary storage tank may be configured to adapt to a gas pressure of several hundred bar, but the desired gas pressure is supplied to the gas consumption section.

[0016] In one embodiment, the upstream valve and the downstream valve are controlled in an on-off manner. Such valves are highly reliable.

[0017] In one embodiment, the aircraft tank device includes a compressor disposed downstream of the downstream valve and a pressure regulator disposed downstream of the downstream valve. The compressor operates at the end of the discharge stage to make the pressure in the central tank for temporary storage lower than the minimum value of the pressure in the front cryogenic tank and the pressure in the rear cryogenic tank. The pressure regulator operates at the start of the discharge stage to make the pressure of the gas at the outlet of the central tank for temporary storage lower than the pressure in the central tank for temporary storage. Discharge from the temporary storage tank can be sufficiently performed so as to increase the amount of gas available at the gas consumption section and to make the pressure in the temporary storage tank at the end of discharge lower than the pressure in the cryogenic tank at the current time designated for filling. Filling of the temporary storage tank is performed by the operation of the cryogenic valve under the influence of the pressure difference. Omission of the cryogenic pump reduces the weight and the risk of accidents.

[0018] In one embodiment, each of the front cryogenic tank and the rear cryogenic tank is configured to adapt to a working pressure of less than 8 bar, and the central tank for temporary storage is configured to adapt to a working pressure exceeding 500 bar. Thereby, the empty weight of the cryogenic tank is reduced.

[0019] Other features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings below.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0021] The accompanying drawings not only supplement the present invention but may also contribute to the definition of the present invention if necessary.

Embodiments for Carrying Out the Invention

[0022] An aviation gas storage device is configured to be transportable by an aircraft (e.g., an airplane, a drone, a helicopter, etc.). The aviation gas storage device stores a liquid and supplies a gas. In other words, the gas is stored in a cryogenic tank in a liquid state at a very low temperature. The cryogenic tank cannot withstand a high pressure exceeding 10 bar, in particular.

[0023] Furthermore, the gas stored in a liquid state cannot be used in an internal combustion engine, an external combustion engine, or a fuel cell. For final consumption, gas within the temperature range and pressure range specified by the manufacturer of the consumer parts is required.

[0024] The gas to be stored is selected from hydrogen, methane, ethane, ethylene, acetylene, and oxygen.

[0025] The applicant of the present application also takes into account the phenomenon that gasification occurs rapidly even in the ambient air at -55 °C at high altitudes. For example, gaseous hydrogen at 0 °C and 1 atmosphere has a density about 800 times lower, that is, a volume about 800 times larger, than liquid hydrogen at -253 °C.

[0026] Furthermore, aircraft maintenance regulations require that most parts of an aircraft can be removed for repair or replacement. As a result, even without maintenance equipment specific to the aircraft model, an aircraft can land anywhere as long as it is a location (airport for airplanes and landing site for helicopters) that meets the aircraft's weight and landing requirements. When damage is detected, the aircraft is configured to be repaired permanently or temporarily, or disassembled to replace or repair faulty parts, in accordance with the manufacturer's manual and documents approved by the aviation safety authority. It is desirable that the parts of the aircraft can be easily accessed by maintenance personnel. The parts to be replaced are preferably configured to be as small as possible to facilitate handling and transportation. The parts to be repaired are preferably repairable by proven tools and methods commonly used in the aviation industry.

[0027] Since an aircraft undergoes inspections, for example, daily or weekly, the aircraft will stay on the ground for a period inversely proportional to that frequency.

[0028] The applicant of the present application has confirmed the need for storage using an aircraft-mounted cryogenic tank, particularly for the storage of hydrogen, methane, ethane, ethylene, acetylene, or oxygen.

[0029] From another perspective, currently, airplanes are subject to rules that define the maximum distance from the runway according to ETOPS certification. This distance varies depending on the type of airplane.

[0030] For the purpose of providing a high level of safety and having this safety recognized by users, the applicant of the present application has recognized the need to fly even if the cryogenic tank is damaged and the internal gas is released into the atmosphere.

[0031] The aircraft tank device (aircraft fuel tank device) 30 aims to meet the complex requirements analyzed as above by the applicant of the present application.

[0032] The aircraft tank device 30 with a cryogenic storage function is configured to be transported by an aircraft. The aircraft tank device 30 is filled with a liquid and supplies gas under a selected pressure. In other words, the fuel or oxidizer is stored in a liquid state at a very low temperature inside the cryogenic tank. The cryogenic tank cannot withstand high pressures, particularly exceeding 10 bar.

[0033] The aircraft tank device 30 has the shape of a fuel tank. The aircraft tank device 30 is provided with an attachment mechanism 31 for quickly attaching to the wing of an aircraft.

[0034] In the embodiment shown in FIGS. 1 to 3, the aircraft tank device 30 has an elongated shape. The aircraft tank device 30 includes a central body 32, a front end portion 33, and a rear end portion 34. The front end portion 33 and the rear end portion 34 each include a shell (outer contour structure) to ensure an aerodynamic shape. The central body 32 includes one or more generally cylindrical sections (compartment structures). In the present embodiment, three sections, namely a central section 35, a front section, and a rear section, are provided. The shells of the front end portion 33 and the rear end portion 34 and the sections of the central body 32 are detachable. The shells of the front end portion 33 and the rear end portion 34 and the sections of the central body 32 provide mechanical protection against impacts (particularly, bird collisions at the front end and impacts during handling).

[0035] The mounting mechanism 31 is configured to enable quick assembly and disassembly. This allows the aircraft tank device 30 to be attached to the aircraft in a short time (particularly, a few minutes or several tens of minutes) simultaneously with other operations performed on the taxiway. Here, the short time is shorter than the minimum transfer time. The mounting mechanism 31 is provided at approximately the center in the longitudinal direction of the aircraft tank device 30, or at the position of the center of gravity of the aircraft tank device 30 in the longitudinal direction or in the vicinity thereof. In the present embodiment, the mounting mechanism 31 is integrated with the central section 35 of the central body 32. The mounting mechanism 31 includes a quick connector for the gas line. The central section 35 supports the front section and the rear section. The front section supports the front end portion 33, and the rear section supports the rear end portion 34.

[0036] As shown in FIG. 1, the central body 32, the front end portion 33, and the rear end portion 34 each have an outer surface (particularly, an aerodynamic surface (airfoil surface)) adapted to the air flow at the moving speed of the aircraft. These outer surfaces form a fairing (streamlined cover). A coupling portion (joint) may be provided between the central body 32 and the front end portion 33 and between the central body 32 and the rear end portion 34. Vent holes are provided in the central body 32, the front end portion 33, and / or the rear end portion 34 for pressure balance and ventilation (ventilation). This prevents condensation and frost.

[0037] The central body 32 supports the members arranged inside and at the ends thereof. The central body 32 may comprise at least one layer of material that absorbs shock and vibration. The central body 32 functions as a shock absorber that limits the stress applied to the mounting mechanism 31 and other members of the device described later. The central body 32 forms a self-supporting fairing.

[0038] The aircraft tank device 30 includes a front cryogenic tank 36 and a rear cryogenic tank 37. The central section 35 supports the front cryogenic tank 36 and the rear cryogenic tank 37.

[0039] The front cryogenic tank 36 and the rear cryogenic tank 37 are attached inside the section of the central body 32. The front cryogenic tank 36 and the rear cryogenic tank 37 have generally the same configuration, but may have slightly different shapes in order to make the most of the available space. The front cryogenic tank 36 and the rear cryogenic tank 37 are attached over the entire length of the aircraft tank device 30 (from one end to the other end in the length direction). In the illustrated example, the front cryogenic tank 36 and the rear cryogenic tank 37 are arranged side by side along the longitudinal axis, but this feature is optional.

[0040] The front cryogenic tank 36 and the rear cryogenic tank 37 may have an elongated shape along a common axis or two axes. The front cryogenic tank 36 and the rear cryogenic tank 37 may each have a convexly curved front portion, a convexly curved rear portion, and a rotating cylindrical central portion.

[0041] The front section of the central body 32 covers substantially the entire front cryogenic tank 36. The rear section of the central body 32 covers substantially the entire rear cryogenic tank 37. The central section 35 of the central body 32 substantially covers the rear end of the front cryogenic tank 36, the front end of the rear cryogenic tank 37, and the central space 38. The central space 38 has a generally annular shape. The central space 38 is at atmospheric pressure. The central space 38 is configured to be ventilated.

[0042] The aircraft tank device 30 includes at least one central tank 7 for temporary storage. In the illustrated example, two central tanks 7 are shown. These central tanks 7 are installed in parallel. The central tank 7 is managed by the distribution circuit (regulation circuit) 1 shown in FIG. 6. The central tank 7 is alternately filled with liquid from at least one of the front cryogenic tank 36 and the rear cryogenic tank 37, and after gasification, gas is discharged from the central tank 7. The two central tanks 7 operate alternately such that one is filled and the other is empty during most of the operating time. However, the two central tanks 7 may be set to take off in a full state.

[0043] Each central tank 7 forms a gasification device (gasification means). Each central tank 7 forms a heat exchanger. Each central tank 7 includes at least one inlet for cryogenic liquid and at least one outlet for gas. No heat insulating material is provided in the central tank 7. The central tank 7 is composed of a simple casing. The central tank 7 is made of metal and / or composite materials. The central tank 7 is entirely or partially made of a conductive material. The central tank 7 has resistance to cryogenic temperatures. The central tank 7 has resistance to higher operating pressures compared to the front cryogenic tank 36 and the rear cryogenic tank 37 which are at low pressure. The central tank 7 has a shorter storage life compared to the front cryogenic tank 36 and the rear cryogenic tank 37 which have a long storage life.

[0044] The central tank 7 is attached to the central space 38, for example, on the side opposite to the attachment mechanism 31. In the embodiment of FIG. 2, the central tank 7 has a cylindrical shape with a vertical axis and rounded ends.

[0045] Since the central space 38 is compact, the lengths of the liquid line (liquid pipe) and the gas line (gas pipe) are limited. Also, the weight of the device is optimized.

[0046] In the embodiment shown in FIG. 4, the aircraft tank device 30 includes two front cryogenic tanks 36 and two rear cryogenic tanks 37. The front cryogenic tanks 36 and the rear cryogenic tanks 37 are each spherical. In the illustrated example, the front cryogenic tanks 36 and the rear cryogenic tanks 37 are arranged in a line, but this feature is optional. The shape of the central tank 7 for temporary storage is annular, particularly toroidal. Further, between the two front cryogenic tanks 36 and between the two rear cryogenic tanks 37, cryogenic tanks 39 for temporary storage (buffer tanks) are respectively arranged as additional temporary storage tanks. The shape of the cryogenic tank 39 for temporary storage is annular, particularly toroidal.

[0047] Each cryogenic tank (front cryogenic tank 36, rear cryogenic tank 37, and cryogenic tank 39 for temporary storage) is insulated so as to be able to contain liquid fuel or oxidant at -253°C. Each cryogenic tank (front cryogenic tank 36, rear cryogenic tank 37, and cryogenic tank 39 for temporary storage) can withstand a maximum operating pressure of about 6 to 10 bar.

[0048] In the embodiment shown in FIG. 5, between the two front cryogenic tanks 36, a plurality of cryogenic tanks 39 for temporary storage (additional buffer tanks) are arranged in a regular polygon shape. Each cryogenic tank 39 for temporary storage has a cylindrical body and rounded ends. The axes of the bodies of the plurality of cryogenic tanks 39 for temporary storage are arranged, for example, so as to define a hexagon.

[0049] Between the two rear cryogenic tanks 37, a plurality of cryogenic tanks 39 for temporary storage (additional buffer tanks) are arranged parallel to each other. Each cryogenic tank 39 for temporary storage has a cylindrical body and rounded ends. The longitudinal axis of the aircraft tank device 30 and the axis of the cryogenic tank 39 for temporary storage are arranged parallel to each other. In a cross-sectional view, the axes of the bodies of the plurality of cryogenic tanks 39 for temporary storage are arranged so as to define the vertices of a regular polygon. The plurality of cryogenic tanks 39 for temporary storage are arranged like the chambers of a cask.

[0050] FIG. 5 shows two embodiments simultaneously for the purpose of simplification. Specifically, it shows a polygonal embodiment at the front of the aircraft tank device 30 and a parallel embodiment at the rear of the aircraft tank device 30. In reality, the aircraft tank device 30 has only one of these embodiments (the embodiment in which all the cryogenic tanks 39 for temporary storage are arranged in a polygonal shape, or the embodiment in which all the cryogenic tanks 39 for temporary storage are arranged parallel to each other). In any of the embodiments, the configuration of the cryogenic tanks 39 for temporary storage is very robust due to its shape being adapted to high pressure and manufacturing constraints.

[0051] In one embodiment, at least one cryogenic tank 39 for temporary storage is provided with a cylindrical body and rounded ends.

[0052] [Gas Distribution Circuit]

[0053] Referring to FIG. 6, the distribution circuit 1 is described.

[0054] In the distribution circuit 1 for an aircraft, fuel is supplied by the cryogenic tanks 36, 37 to one or more gas-consuming parts of the aircraft. A flow meter 22 is arranged at the outlet of each cryogenic tank 36, 37.

[0055] An outlet pipe 4 is attached to each cryogenic tank 36, 37. The terms "upstream" and "downstream" refer to the direction of the flow of fluid, liquid, or gas during normal operation.

[0056] The distribution circuit 1 is provided with a first valve 11 for each of the cryogenic tanks 36, 37. The first valve 11 is attached to the outlet pipe 4. The first valve 11 is controllably switched between an open position and a closed position. The intermediate position of the first valve 11 is dynamic in the sense that the first valve 11 passes through the intermediate position during movement. In other words, the first valve 11 is configured to be on-off controlled. The first valve 11 may be arranged immediately downstream of the flow meter 22.

[0057] The first valve 11 can communicate with the cryogenic distributor 5. The cryogenic distributor 5 may be provided with a common pipe 6 connecting the outlets of the plurality of first valves 11. The cryogenic distributor 5 is cryogenic in the sense that liquid fuel and / or oxidant passes through it.

[0058] The cryogenic distributor 5 is provided with a plurality of outlets, specifically, for example, three outlets. A second valve 12 is attached to each outlet of the cryogenic distributor 5. The second valve 12 is controllably switched between an open position and a closed position. The intermediate position of the second valve 12 is dynamic in the sense that the second valve 12 passes through the intermediate position during movement. In other words, the second valve 12 is configured to be on-off controlled. In the illustrated example, three second valves 12 are provided.

[0059] The central tank 7 is attached downstream of each second valve 12. In this embodiment, three central tanks 7 are provided. Each central tank 7 also functions as a gasifier (gasification means). Insulation is not required. Each central tank 7 receives liquid and supplies gas downstream. Inside each central tank 7, a pressure increase stage, that is, a gasification stage, occurs between filling and discharging. Each central tank 7 can withstand a maximum operating pressure of about 300 to 1000 bar. Each central tank 7 is configured to operate in a temperature range of -253°C to +60°C. Inside the central tank 7, it is in a gas-liquid two-phase state in some operating stages and in a gas single-phase state in other operating stages. A heating member (heater) 8 may be attached to each central tank 7.

[0060] Downstream of each central tank 7, a third valve 13 for supplying gas is provided, and a pressure regulator 9 is provided downstream of the third valve 13. The pressure regulator 9 reduces the pressure to supply gas at a consumption pressure defined by the manufacturer of the gas consumption unit 3. The pressure regulator 9 operates when the pressure in the central tank 7 is higher than the consumption pressure and does not operate otherwise. The consumption pressure is lower than the maximum pressure of the central tank 7. The consumption pressure is independent of the maximum pressures of the cryogenic tanks 36, 37. The third valve 13 is configured to be on-off controlled.

[0061] A controllable fourth valve 14 may be provided downstream of each pressure regulator 9. The fourth valve 14 is configured to be on-off controlled.

[0062] The fourth valve 14 (i.e., the pressure regulator 9) is communicable with the manifold 10 according to a selected option. The manifold 10 may be composed of a single conduit connecting the outlets of a plurality of fourth valves 14 (i.e., pressure regulators 9). Gas flows through the manifold 10. The manifold 10 is connected downstream to a supply line (supply pipe) 23 to the gas consumption unit 3. Generally, one supply line 23 is provided for each gas consumption unit 3. A controllable supply valve 24 may be provided in each supply line 23. The supply valve 24 has a variable flow rate.

[0063] The distribution circuit 1 includes at least one compressor 20 connected to the manifold 10. Usually, two compressors 20 are provided in parallel for redundancy. The compressor 20 is electric. A controllable upstream valve may be provided for the compressor 20. The compressor 20 feeds gas into the manifold 10. In particular, when there is one gas consumption unit 3, the manifold 10 is composed of a single pipe (conduit).

[0064] Downstream of each central tank 7, a fifth valve 15 for supplying gas is provided, and downstream of the fifth valve 15, a second manifold is provided. The second manifold is connected to the compressor 20. The fifth valve 15 can separate the central tank 7 from the compressor 20. The fifth valve 15 is controllable. The fifth valve 15 is configured to be on-off controlled.

[0065] The compressor 20 raises the pressure so as to supply gas at a pressure equal to the consumption pressure defined by the manufacturer of the gas consumption unit 3. The consumption pressure is lower than the maximum pressure of the central tank 7. The compressor 20 can take out gas at a pressure lower than the consumption pressure from the central tank 7 and supply it to the manifold 10 and the gas consumption unit 3. As the central tank 7 becomes more completely empty, an increase in the self-regulation (supply range) brought about by the gas contained in the central tank 7, or a decrease in the volume of the central tank 7 is brought about.

[0066] When the central tank 7 becomes sufficiently empty so that the internal pressure of the central tank 7 becomes lower than the pressure in one of the plurality of cryogenic tanks, due to the pressure difference during filling after it becomes empty, liquid can be transferred from the cryogenic tank to the central tank 7. Thereby, the liquid in the cryogenic tank is drawn into the central tank 7 until pressure equilibrium is reached. Since the omission of the cryogenic pump becomes possible, the weight is reduced and the energy consumption is reduced.

[0067] The distribution circuit 1 provides a combination of individual states for each cryogenic tank, each central tank 7, and each gas consumption unit 3. A plurality of gas consumption units 3 can operate simultaneously. In the normal mode, discharge from one cryogenic tank is performed and the other tanks are closed without operating. However, in a specific situation, for example, a specific mode in which discharge from a plurality of cryogenic tanks is performed can be provided to lower the pressure of the plurality of cryogenic tanks. The central tank 7 has a filling mode, a gasification mode, a gas storage mode, and a discharge mode.

[0068] When the discharge from one cryogenic tank is in progress, the corresponding first valve 11 is open and the other first valves 11 are closed. When gas is being supplied to one gas consumption unit 3, the corresponding supply valve 24 is open.

[0069] When one central tank 7 is in the filling mode, the second valve 12 connected to the central tank 7 is open and at least one first valve 11 is open. The other second valves 12 are closed except when two central tanks 7 are filled simultaneously. The third valve 13 connected to the central tank 7 is closed. The fifth valve connected to the central tank 7 is closed.

[0070] When one central tank 7 is in the gasification 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 gasification mode ends in a short time especially when the ambient atmosphere is warm and / or when the central tank 7 is heated.

[0071] When one central tank 7 is in the discharge mode, the second valve 12 connected to the central tank 7 is closed. At the initial stage of the discharge mode, the pressure in the central tank 7 is higher than the consumption pressure. The third valve 13 connected to the central tank 7 is open, the corresponding fourth valve 14 is open, and the fifth valve connected to the central tank 7 is closed. The gas is depressurized in the pressure regulator 9 and supplied to the manifold 10 at the consumption pressure. Then, the gas is consumed by the gas consumption unit 3.

[0072] At any given time, out of the three central tanks 7, one central tank 7 is in the filling mode, another central tank 7 is in the gasification mode and then the storage mode, and the remaining central tank 7 is in the discharge mode. Due to the different durations of the modes, there may be a situation where two central tanks 7 are in the filling mode and the remaining central tank 7 is in the discharge mode, and a situation where two central tanks 7 are in the discharge mode and the remaining central tank 7 is in the filling mode. Also, there may be a situation where two central tanks 7 are in the storage mode and the remaining central tank 7 is in the discharge mode, and a situation where two central tanks 7 are in the discharge mode and the remaining central tank 7 is in the storage mode.

[0073] In this embodiment, a flow meter 22 is arranged at the outlet of each liquid fuel source (oxidant source). The flow meter 22 provides sufficiently accurate information regarding the amount of liquid supplied to the central tank 7 as described above.

[0074] In this embodiment, the distribution circuit 1 includes a control unit 25 that receives, for example, an external command from the gas consumption unit 3 outside the aircraft tank device 30 or the central control unit of the aircraft, and liquid flow rate data from the flow meter 22. The control unit 25 generates and transmits commands to the above-described controllable valves (the first, second, third, fourth, and fifth valves, and the supply valve 24). The command may be a command to "open" or a command to "close". The control unit 25 manages combinations of individual states.

[0075] Alternatively, the first valve 11 may be replaced with at least one multi-way valve having a plurality of inlets and one outlet. In this case, it is advantageous to provide a multi-way valve with a mixing position (in particular, at least one position for simultaneously discharging from two or more cryogenic tanks so as to reduce the pressure while preventing loss to the atmosphere).

[0076] Alternatively, the second valve 12 may be replaced with 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.

[0077] Alternatively, the plurality of pressure regulators 9 may be replaced by a single pressure regulator 9 with which the third valve 13 can communicate. In this case, the third valve 13 may be replaced by at least one multi-way valve having a plurality of inlets and one outlet to the pressure regulator 9. Accordingly, the plurality of fourth valves 14 are replaced by a single fourth valve 14 that is not controlled, if appropriate.

[0078] Alternatively, the fifth valve 15 may be replaced by at least one multi-way valve having a plurality of inlets (one inlet for each central tank 7) and one outlet to one or more compressors 20. The multi-way valve forms the manifold 10.

[0079] Since the cryogenic tank is exposed to the evaporation of the liquid, a gas collection circuit may be provided at the upper part of the cryogenic tank. The gas collection circuit may be operated when the threshold pressure is exceeded via a calibration pressure valve. The gas collection circuit includes a compressor for re-injecting the gas downstream (for example, between the fifth valve 15 and the compressor 20).

[0080] Optionally, additional flow meters may be arranged at the inlets of the respective temporary storage tanks (buffer tanks). Thereby, redundancy of the liquid flow measurement is ensured.

Claims

1. A detachable aircraft tank device (30) having cryogenic storage performance for transportation by aircraft, comprising: a front cryogenic tank (36); a rear cryogenic tank (37); at least one central tank (7) for temporary storage for increasing the pressure of the gas supplied by the front cryogenic tank (36) and the rear cryogenic tank (37); An aircraft tank device comprising:

2. Each of the front cryogenic tank (36) and the rear cryogenic tank (37) has a convex outer shape, Each of the front cryogenic tank (36) and the rear cryogenic tank (37) an inner casing defining a storage chamber; an outer casing housing the inner casing; a heat insulation chamber defined between the inner casing and the outer casing; a detachable manifold penetrating the outer casing and the inner casing in a sealed state; a pipe through which gas is supplied by the manifold, and comprising: The central tank (7) for temporary storage has a quasi-annular or quasi-circular shape, The aircraft tank device according to claim 1.

3. Each of the front cryogenic tank (36) and the rear cryogenic tank (37) is thermally insulated under vacuum against conduction, convection, and radiation, The aircraft tank device according to claim 1.

4. The front cryogenic tank (36) and the rear cryogenic tank (37) have an elongated shape along a common axis, The aircraft tank device according to claim 1.

5. Comprising at least two spherical front cryogenic tanks (36) and at least two spherical rear cryogenic tanks (37), The aircraft tank device according to claim 1.

6. Comprising a plurality of temporary storage tanks (39) respectively arranged between the two front cryogenic tanks (36) and between the two rear cryogenic tanks (37), The aircraft tank device according to claim 1.

7. The central tank (7) for temporary storage constitutes gasification means, With respect to the central tank (7) for temporary storage, an upstream valve (12) provided to open so that liquid flows during the filling stage of the central tank (7) for temporary storage and to close at other times than the filling stage; downstream valves (13, 15) provided to open so that gas flows during the discharge stage of the central tank (7) for temporary storage and to close at times other than the discharge stage, the upstream valve (12) and the downstream valves (13, 15) are provided to be closed during the gasification stage, The aircraft tank device according to claim 1.

8. the upstream valve (12) and the downstream valves (13, 15) are on-off controlled, The aircraft tank device according to claim 7.

9. a compressor (20) disposed downstream of the downstream valve (15) and a pressure regulator (9) disposed downstream of the downstream valve (13), at the end of the discharge stage, the compressor (20) is configured to operate so that the pressure in the central tank (7) for temporary storage becomes lower than the minimum value of the pressure in the front cryogenic tank (36) and the pressure in the rear cryogenic tank (37), at the start of the discharge stage, the pressure regulator (9) is configured to operate so that the pressure of the gas at the outlet of the central tank (7) for temporary storage becomes lower than the pressure in the central tank (7) for temporary storage, The aircraft tank device according to claim 7 or claim 8.

10. each of the front cryogenic tank (36) and the rear cryogenic tank (37) is configured to adapt to an operating pressure of less than 8 bar, the central tank (7) for temporary storage is configured to adapt to an operating pressure exceeding 500 bar, The aircraft tank device according to claim 1.

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