Cryogenic liquid storage system, aircraft comprising cryogenic liquid storage system, method of accessing measurement probe of cryogenic liquid storage system, and aircraft comprising cryogenic fuel storage system

Abstract

The invention relates to a cryogenic liquid storage system, an aircraft comprising a cryogenic liquid storage system, a method of accessing a measurement probe of a cryogenic liquid storage system, and an aircraft comprising a cryogenic fuel storage system. The cryogenic liquid storage system includes: an outer tank; an inner tank inside the outer tank and configured to store a cryogenic liquid; an isolation valve; a collection chamber external to the outer tank and fluidly connected to the inner tank such that fluid can flow from the inner tank to the collection chamber via an isolation valve, where the isolation valve can be actuated to isolate the collection chamber from the inner tank; and a measurement probe movable between the inner tank and the collection chamber.

Description

Technical Field

[0001] This invention relates to cryogenic liquid storage systems, aircraft, and methods for accessing measurement probes in cryogenic liquid storage systems. Background Technology

[0002] Maintaining cryogenic liquid storage systems, particularly those within cryogenic storage tanks, is challenging due to the difficulty of accessing components housed within multi-walled storage containers. Accessing these components typically requires draining the liquid stored in the tank, removing any vacuum, and providing the user with direct access to the tank's interior to reach the components. This is especially time-consuming and labor-intensive in the case of tank-stored cryogenic liquids, as the equipment must be gradually acclimated to ambient temperature once emptied and before the required components can be accessed. Summary of the Invention

[0003] A first aspect of the present invention provides a cryogenic liquid storage system comprising: an outer tank; an inner tank located inside the outer tank and configured to store a cryogenic liquid; an isolation valve; a collection chamber located outside the outer tank and fluidly connected to the inner tank such that fluid can flow from the inner tank to the collection chamber via the isolation valve, wherein the isolation valve can be actuated to isolate the collection chamber from the inner tank; and a measuring probe movable between the inner tank and the collection chamber.

[0004] Placing the collection chamber outside the outer tank provides the user with access to the volume where the fluid is connected to the inner tank, without requiring direct contact with the inner tank, for example, through access ports in either the outer or inner tank. The ability of a measuring probe to move from the inner tank to the collection chamber (and from the collection chamber to the inner tank) thus allows for easier access, thereby improving the ease of maintenance of the measuring probe. An isolation valve between the collection chamber and the inner tank allows for selective prevention of fluid communication between the two. In this way, the collection chamber can be isolated from the inner tank, allowing it to be accessed, cleaned, or otherwise modified without affecting the conditions inside the inner tank.

[0005] Optionally, the measuring probe can move between the inner tank and the collection chamber via an isolation valve.

[0006] Cryogenic liquid storage systems may also include cryogenic liquids in an inner tank.

[0007] Cryogenic liquids can include hydrogen, helium, or any other cryogenic liquid. The term "cryogenic liquid" as used herein refers to a liquid with a temperature below -150 degrees Celsius.

[0008] Cryogenic liquids can include fuels, such as aircraft fuel.

[0009] The measuring probe can be at least partially immersed in a cryogenic liquid.

[0010] Providing a measuring probe immersed in cryogenic liquid within an inner tank allows for the measurement or other monitoring of a range of parameters of the cryogenic liquid. Examples of these parameters may include the liquid level or volume, or the liquid temperature.

[0011] The measuring probe can be configured to measure the amount of cryogenic liquid in the inner tank (e.g., the volume, mass, or level of the liquid).

[0012] Providing a measuring probe configured to measure the amount of liquid in the inner tank allows for monitoring of the liquid level over time. This data can then be used to determine the rate of change in the amount of cryogenic liquid when the level reaches a predetermined value or when the inner tank should be refilled.

[0013] The cryogenic liquid storage system may also include a guide rail device (which includes one or more guide rails) extending from the collection chamber into the inner tank. A measuring probe may be coupled to the guide rail device and configured to move along the guide rail device as the measuring probe moves between the inner tank and the collection chamber.

[0014] The measuring probe can be guided by a guide rail device and / or constrained by a guide rail device.

[0015] Optionally, the guide rail device has a gap at the isolation valve.

[0016] An isolation valve can define a valve orifice through which fluid can flow between the collection chamber and the inner tank, and a gate or other closure can extend across the valve orifice when actuated to prevent fluid from flowing through it. Thus, a guide rail device can extend through the valve orifice and therefore from the collection chamber to the inner tank via the isolation valve.

[0017] A guide rail device can provide a convenient structure for defining the path followed by the measuring probe as it moves between the inner tank and the collection chamber. In this way, the guide rail device can be used to control the position of the measuring probe in the inner tank and the collection chamber, or the movement of the measuring probe between the inner tank and the collection chamber.

[0018] The first part of the guide rail device can extend downward within the inner tank. The second part of the guide rail device can extend laterally within the collection chamber. The second part of the guide rail device can be substantially perpendicular to the first part of the guide rail device. A curved portion of the guide rail device can connect the first part of the guide rail device to the second part of the guide rail device.

[0019] The first portion of the guide rail device, extending downward within the inner tank, allows the measuring probe to extend downward along the guide rail device within the inner tank, optionally from the top of the inner tank. This allows the measuring probe to function as a level sensor. Compared to a guide rail device that extends upward within, for example, the collection chamber, a second portion of the guide rail device, extending laterally within the collection tube, allows for a reduction in the height of the cryogenic liquid storage system. The curved portion of the guide rail device provides a path along which the measuring probe can move between the inner tank and the collection chamber.

[0020] The isolation valve may include: a housing defining an orifice through which the isolation valve passes; and a closure for blocking the orifice. The guide rail assembly may include a gap through which the closure can move.

[0021] An isolation valve that includes a physical closure capable of moving to block the valve orifice provides a convenient method for isolating the collection chamber from the inner tank. With the closure extending across the entire valve orifice to block fluid flow through it, clearance in the guide rails allows the closure to be actuated without obstruction by the guide rail mechanism.

[0022] The guide rail device may include end stops in the inner tank for limiting the movement of the measuring probe along the guide rail device.

[0023] End stops can provide a convenient method for limiting the movement of a measuring probe beyond a target position within the inner can and / or for controlling tension within the probe, for example, when the probe is suspended downwards from the top of the inner can under its own weight.

[0024] The guide rail device may have at least one curved section located within the collection chamber. The guide rail device may follow a U-shaped path within the collection chamber.

[0025] Providing a guide rail device with a curved section in the collection chamber can reduce the length of the collection chamber required to accommodate the measuring probe when the probe is located in the collection chamber.

[0026] The cryogenic liquid storage system may also include a tubular bellows located between the inner and outer tanks. The bellows connects the fluid in the inner tank to the collection chamber.

[0027] Tubular corrugated pipes can provide a convenient way to connect an inner tank and an outer tank to accommodate movement of the inner tank relative to the outer tank (e.g., due to temperature changes).

[0028] Optionally, the measuring probe also includes a chain, and the system further includes a drive mechanism, such as a pinion, arranged to engage the chain to move the measuring probe between the inner tank and the collection chamber. The chain is capable of moving between the inner tank and the collection chamber.

[0029] Optionally, when the measuring probe is in the inner tank, the chain extends from the collection chamber into the inner tank via an isolation valve.

[0030] Optionally, the measurement probe includes one or more cables, such as fiber optic cables or electrical cables. Optionally, when the measurement probe is located in the inner tank, the cables (or each cable) extend from the collection chamber into the inner tank via an isolation valve.

[0031] The chain may include a series of flexible links, each of which may optionally be rotatable relative to its adjacent links.

[0032] The chain can provide convenient components for engagement with a drive mechanism (such as a pinion) to enable the measuring probe to move in a linear motion, optionally along a guide rail device.

[0033] The drive mechanism may include a clutch for selectively disengaging the drive mechanism from the chain.

[0034] A device for selectively disengaging the drive mechanism from the chain is provided to facilitate the removal of the chain from the drive mechanism and / or collection chamber for optional maintenance.

[0035] A vacuum space can be provided between the inner tank and the outer tank.

[0036] Setting up an evacuated space between the inner and outer tanks can improve the insulation of the cryogenic liquid storage system and, in particular, reduce heat transfer from and / or to the inner tank.

[0037] The collection chamber may include a port for connecting to a pump to clean the collection chamber.

[0038] Cleaning the collection chamber can be defined as removing fluid from the collection chamber. A device for cleaning the collection chamber allows fluid to be removed from the collection chamber, for example, before the collection chamber is opened to provide access to the user.

[0039] Cryogenic liquid storage systems may also include pressure sensors located in the collection chamber.

[0040] Placing the pressure sensor in the collection chamber outside the outer tank allows for monitoring of the pressure inside the inner tank when the inner tank and collection chamber are fluidly connected, without requiring direct access to the inner tank. This improves the ease of maintenance of the pressure sensor, as it is more accessible than a pressure sensor located inside the inner tank.

[0041] A second aspect of the present invention provides an aircraft that includes the cryogenic liquid storage system of the first aspect of the present invention. The cryogenic liquid storage system may include an aircraft fuel storage system.

[0042] A third aspect of the invention provides a method for accessing a measuring probe in a cryogenic liquid storage system, the cryogenic liquid storage system comprising: an outer tank; an inner tank located inside the outer tank; a cryogenic liquid located in the inner tank; an isolation valve; a collection chamber located outside the outer tank and fluidly connected to the inner tank such that fluid can flow from the inner tank to the collection chamber via the isolation valve; and a measuring probe located in the inner tank, the method comprising: retracting the measuring probe from the tank to the collection chamber via the isolation valve; actuating the isolation valve to isolate the collection chamber from the inner tank, thereby preventing fluid from flowing from the inner tank to the collection chamber via the isolation valve; opening the collection chamber; and accessing the measuring probe in the opened collection chamber.

[0043] The method may also include cleaning the collection chamber once the isolation valve is actuated to isolate the collection chamber from the inner tank.

[0044] Once the isolation valve is activated, flushing the collection chamber allows for the removal of fluid from the collection chamber without affecting the conditions and / or fluid in the inner tank.

[0045] A fourth aspect of the invention provides an aircraft including a cryogenic fuel storage system, the cryogenic fuel storage system comprising: an outer tank; an inner tank located inside the outer tank; cryogenic fuel located in the inner tank; an isolation valve; a collection chamber located outside the outer tank and fluidly connected to the inner tank such that fluid can flow from the inner tank to the collection chamber via the isolation valve; a measuring probe movable between the inner tank and the collection chamber, the measuring probe including a chain, wherein the measuring probe is immersed in cryogenic fuel when located in the inner tank; a guide rail device extending from the collection chamber into the inner tank and along which the measuring probe is movable, the guide rail device including a first portion extending downward from the top of the inner tank in the inner tank and a second portion extending substantially perpendicular to the first portion of the guide rail device in the collection chamber. Attached Figure Description

[0046] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0047] Figure 1 The aircraft was shown;

[0048] Figure 2 It shows Figure 1 Part of the aircraft;

[0049] Figure 3 A cryogenic liquid storage system is shown;

[0050] Figure 4 It shows Figure 3 It is part of a cryogenic liquid storage system, in which the probe is in a deployment position within the inner tank;

[0051] Figure 5 It shows Figure 4 A detailed view of a portion of a cryogenic liquid storage system, showing the measurement probe in its deployment position within the inner tank;

[0052] Figure 6 It shows Figure 3 It is part of a cryogenic liquid storage system, in which the measuring probe is in the retracted position in the collection chamber;

[0053] Figure 7 It shows Figure 6 Detailed view of a part of a cryogenic liquid storage system;

[0054] Figure 8a The bent portion of the measuring probe is shown;

[0055] Figure 8b It is a schematic cross-sectional view showing the connection between the chain and the guide rail device; and

[0056] Figure 9 A method according to an embodiment of the present invention is shown. Detailed Implementation

[0057] Figure 1 An aircraft 10 is shown. The aircraft 10 has a fuselage 12, a starboard fixed wing 13, and a port fixed wing 14. Each wing 13, 14 is equipped with an engine 15. The aircraft 10 is a typical jet-powered passenger aircraft; however, the invention is applicable to a wide variety of fixed-wing aircraft types, including commercial, military, passenger, cargo, jet, propeller, and general aviation, wherein any number of engines are attached to the wings or fuselage. This aircraft is a fixed-wing aircraft with cantilevered wings.

[0058] The aircraft 10 includes a cryogenic liquid storage system 20, such as in Figure 2 The liquid storage system 20 is shown schematically. Although it is shown as being within the fuselage 12 of the aircraft 10, it will be understood that the liquid storage system 20 may be housed anywhere within the aircraft 10, such as within the wings 13 and 14. It will also be understood that the aircraft 10 may include any number of liquid storage systems 20, for example, two separate liquid storage systems 20 housed within the fuselage 12. The liquid storage system 20 may be a cryogenic fuel tank configured to store cryogenic fuel, such as liquid hydrogen, to be supplied to the engine 15.

[0059] Figure 3A schematic cross-sectional view of a liquid storage system 20 is shown. The liquid storage system 20 includes an outer tank 22 and an inner tank 24 supported within the outer tank 22. It will be understood that the inner tank 24 can be supported using any suitable support structure (not shown), and the inner tank 22 is spaced apart from the outer tank 22. The inner tank 24 is configured to store a cryogenic liquid 21. The evacuated space 23 between the outer tank 24 and the inner tank 22 reduces heat transfer with the inner tank 22. The outer tank 22 and the inner tank 24 may include ports (not shown) for filling the inner tank 24 with the cryogenic liquid 21 and / or for removing the cryogenic liquid 21 from the inner tank 24.

[0060] The liquid storage system 20 also includes a collection chamber 26 located outside the outer tank 22. The collection chamber 26 may be referred to as the outer collection chamber 26, where "outer" is defined herein as the exterior of the outer tank 22. The collection chamber 26 may be formed as a separate component from the outer tank 22, or alternatively, the collection chamber 26 may be integrally manufactured with the outer tank 22, for example, formed as a "bubble" on the outer surface of the outer tank 22. Preferably, the collection chamber 26 is configured as a separate component connected to the outer tank 22, such that a shared collection chamber 26 can be fitted into a series of liquid storage systems 20.

[0061] The collection chamber 26 is fluidly connected to the inner tank 24. A fluid connection between components is defined here as a connection that allows fluid (i.e., liquid or gas) to flow between those components. In this way, fluid can flow between the inner tank 24 and the collection chamber 26. Figure 3 In the illustrated liquid storage system 20, a collection chamber 26 is fluidly connected to an inner tank 24 via a tubular bellows 30. The tubular bellows 30 extends between the outer tank 22 and the inner tank 24 and provides a sealed passage between the collection chamber 26 and the inner tank 24. The tubular bellows 30 may include a flexible-walled pipe, for example, a pipe comprising sidewalls formed of corrugated rubber material. This arrangement allows movement of the inner tank 24 relative to the outer tank 22 while still maintaining a passage for fluid flow between the inner tank 24 and the collection chamber 26. By a non-limiting example, the inner tank 24 may be supported by a support assembly (not shown) that allows the inner tank 24 to move relative to the outer tank 22 in the horizontal direction (i.e., in...). Figure 3 (Move left and right in the view). This movement can be caused by the expansion and / or contraction of the inner tank 24 due to temperature changes within the inner tank 24.

[0062] As in Figure 4As shown, the collection chamber 26 includes a cylindrical housing 26a having a fitting 26b at one end and an isolation valve 40 at the other end. The isolation valve 40 is arranged between the inner tank 24 and the collection chamber 26, allowing fluid to flow between the inner tank 24 and the collection chamber 26 via the isolation valve 40. The isolation valve 40 may include any valve adapted to selectively isolate the collection chamber 26 from the inner tank 24, i.e., by preventing fluid flow through the isolation valve 40. Examples of such an isolation valve 40 include gate valves, butterfly valves, or ball valves. The isolation valve 40 may include... Figure 7 The housing 42 shown defines a valve orifice 43 through which fluid can flow. The isolation valve 40 also includes a closure 44 (in... Figure 6 and Figure 7 As shown in the figure, the closure 44 is arranged to selectively block the valve orifice 43 and prevent fluid from flowing through it, thereby isolating the collection chamber 26 from the inner tank 24.

[0063] The liquid storage system 20 also includes a measuring probe 50 movable between the inner tank 24 and the collection chamber 26. The measuring probe 50 is configured to measure one or more parameters within the inner tank 24, optionally the cryogenic liquid 21 within the inner tank 24. By way of non-limiting example, the measuring probe 50 may include a temperature sensor configured to determine the temperature of the cryogenic liquid 21 in the inner tank 24 or a level sensor configured to determine the level of the cryogenic liquid 21. The measuring probe 50 may include one or more fiber optic cables 52 and a chain 70 carrying the fiber optic cables 52, as shown in... Figure 8a The most clearly shown is shown below. Each fiber optic cable 52 may have one or more fiber Bragg gratings and is configured to determine the level of cryogenic liquid 21 in the inner tank 24. The use of fiber Bragg gratings to determine the amount of cryogenic liquid in a tank of known size is known in the art and will not be described in detail here. In other embodiments, the measuring probe may include a different type of sensor (e.g., a temperature sensor) coupled to a flexible cable, which extends between the inner tank 24 and the collection chamber 26 when the measuring probe is located in the inner tank.

[0064] The measuring probe 50 can be connected via a flexible connecting cable 54 (for clarity, from...) Figure 3 Omitted in and Figure 4 and Figure 6 (Most clearly shown) connects to an external system (not shown). The connection cable 54 may, for example, include a continuation of the fiber optic cable 52 housed within a flexible protective sleeve.

[0065] The external system may include a light source for supplying light to the fiber optic cable 52, a light receiver for receiving light from the fiber optic cable 52, and a computer storage device or similar device for real-time monitoring and storage of parameter values. The measuring probe 50 may be part of the fuel quantity measurement system.

[0066] The measuring probe 50 is capable of moving between a deployed position and a retracted position. Figure 4 In the deployment location shown, most or all of the measuring probe 50 is located within the inner tank 24. When cryogenic fluid 21 is present in the inner tank 24, the measuring probe 50 can be at least partially immersed in the cryogenic fluid 21. Figure 6 In the retracted position shown, the measuring probe 50 has passed the isolation valve 40 and is fully within the collection chamber 26. Therefore, in the retracted position, the measuring probe 50 does not extend into the inner tank 24. When moving between the inner tank 24 and the collection chamber 26, the measuring probe 50 can move through the isolation valve 40, optionally via the previously described valve orifice 43.

[0067] The liquid storage system 20 may also include Figure 3 and Figure 4 The guide rail devices 64 to 68 shown extend from the collection chamber 26 into the inner tank 24 via the isolation valve 40, and optionally via the previously described tubular bellows 30.

[0068] like Figure 3 As shown, the guide rail device may include a first portion 64 extending vertically downward within the inner tank 24. A second portion 65 of the guide rail device extends laterally within the collection chamber 26, as shown... Figure 4 As shown in the figure. Figure 3 and Figure 6 The curved portion 68 of the guide rail device shown connects the first portion 64 and the second portion 65.

[0069] The third part 66 of the guide rail device extends laterally in the collection chamber 26, as... Figure 4 As shown, the curved portion 67 of the guide rail device connects the second portion 65 and the third portion 66 of the guide rail device. The curved portion 67 of the guide rail can be removed from the second portion 65 and the third portion 66 in the collection chamber so that it can be removed from the collection chamber together with the probe 50.

[0070] The measuring probe 50 is connected to the guide rail devices 64 to 68 and is able to move along the guide rail devices 64 to 68.

[0071] The guide rail devices 64 to 68 and the tubular bellows 30 can be arranged such that if the inner tank 24 moves relative to the outer tank 22 as previously described, the guide rail devices do not contact the tubular bellows 30 and / or the inner tank 24. It will be understood that the guide rail devices 64 to 68 may include multiple guide rails, such as... Figure 5 and Figure 7 A pair of parallel guide rails are shown. The measuring probe 50 can move along the guide rail arrangement, which guides the measuring probe 50 as it moves into and out of the inner tank 24. Therefore, the guide rail arrangement can define the path followed by the measuring probe 50 as it moves between the inner tank 24 and the collection chamber 26. The guide rail arrangement may include end stops (not shown) in the inner tank 24 to limit the movement of the measuring probe 50; however, it will be understood that in other embodiments, the end stops may be omitted. The guide rail arrangement can be rigidly fixed to the inner tank 24 and / or the collection chamber 26. In this way, the guide rail arrangement and / or the end stops can define a target position of the measuring probe 50 within the inner tank 24.

[0072] When the guide rail device provides an end stop, the tip 50a of the measuring probe 50 can contact the end stop when the measuring probe 50 is in its deployment position. Figure 6 It is shown in its retracted position in the collection chamber 26.

[0073] The first portion 64 of the guide rail device, extending vertically within the inner tank 24, ensures the vertical orientation of the measuring probe 50, allowing it to operate accurately as a level sensor. An end stop (not shown) is located at the bottom end of the first (vertical) portion 64 of the guide rail device.

[0074] The second and third sections 65 and 66 of the guide rail device extend laterally within the collection chamber 26 (in this case, they extend horizontally and substantially perpendicular to the first section 64). This reduces the overall height of the liquid storage system 20 while still allowing the measuring probe 50 to extend downwards from the top of the inner tank 24. This reduction in height can be particularly beneficial when the liquid storage system 20 is housed within the aircraft 10 with strict dimensional constraints. The curved portion 68 of the guide rail device provides a smooth path for the measuring probe 50 as it moves between the inner tank 24 and the collection chamber 26, taking into account the minimum bending radius of the cable 52.

[0075] exist Figure 4In the example shown, portions 65 to 67 of the guide rail device within the collection chamber 26 form a U-shape. More generally, the guide rail device may have one or more curved portions within the collection chamber 26. Providing a guide rail device that follows a curved or meandering path within the collection chamber 26 reduces the length of the collection chamber 26 required to accommodate the measurement probe 50 in its retracted position, particularly when the measurement probe 50 includes a long, flexible component such as an optical fiber cable 52.

[0076] The measuring probe 50 includes a chain 70 carrying the optical fiber 52, such as Figure 8a The most clearly shown is shown in the diagram. The chain 70 includes a series of links 71, each of which is rotatably connected to an adjacent link. Each fiber optic cable 52 passes through a pair of apertures in each link 71, thereby connecting the fiber optic cable 52 to the chain 70.

[0077] Alternatively, fiber optic cable 52 can be connected to different types of chains, such as corrugated flexible tubes.

[0078] Chain 70 is mounted to guide rail devices 64 to 68 such that the curved portions 67, 68 of the guide rail devices force the measuring probe 50 to follow a curved path as it is driven in and out of the collection chamber 26.

[0079] Figure 8b This is a schematic cross-sectional view illustrating an example of a suitable connection between the chain 70 and the guide rail assembly 68. Each segment of the guide rail assembly includes a pair of U-shaped rails. Figure 8b The curved portion 68 of the guide rail assembly is shown, but the other portions 64 to 67 are similar. As illustrated, the chain 70 is constrained between the U-shaped guide rails, such that the guide rail assembly can constrain and guide the measuring probe 50 as it moves between the inner tank 24 and the collection chamber 26. The measuring probe 50 slides along the guide rail assembly 64 to 68 during its movement.

[0080] The isolation valve 40 is connected to the bellows 30 via fittings having a pair of windows 27a, 27b, such as Figure 4 and Figure 6 The window 27a is shown most clearly in the diagram. Window 27a allows the user to observe the interior of the collection chamber 26, for example, to confirm when the measuring probe 50 is in the retracted position inside the collection chamber 26. Window 27b allows the user to observe the interior of the inner tank 24. This can, for example, allow the user to confirm when the measuring probe 50 is fully deployed inside the collection chamber 26.

[0081] The fitting 26b at the end of the collection chamber 26 may also include a port 28 for connection to a pump or similar device (not shown) for cleaning the collection chamber 26. Cleaning is defined here as removing fluid from the collection chamber 26 while maintaining a fluid seal with the inner tank 24. The collection chamber 26 can be cleaned before opening. In this way, the user can remove fluid from the collection chamber 26 before touching the measuring probe 50 within it. This can be particularly advantageous when the collection chamber 26 stores cryogenic fluids.

[0082] exist Figure 3 In the example shown, the liquid storage system 20 also includes a pressure sensor 29 in the collection chamber 26. Since the collection chamber 26 and the inner tank 24 are fluidly connected via an isolation valve 40, the pressure in the inner tank 24 and the pressure in the collection chamber 26 will be equal. Therefore, positioning the pressure sensor 29 in the collection chamber 26 provides a convenient method for monitoring the pressure within the inner tank 24 without direct access. This improves the ease of maintenance for the pressure sensor 29 and / or the liquid storage system 20.

[0083] Figure 4 and Figure 5 An example of a measuring probe 50 in its deployment position is shown. In the deployment position, the isolation valve 40 is open and the tip 50a of the measuring probe 50 is located inside the inner tank 24. A chain 70 extends from the collection chamber 26 into the inner tank 24 via the isolation valve 40, wherein a portion of the chain 70 remains in the collection chamber 26, as shown. Figure 4 As shown in the diagram, a connecting cable 54 extends from a connection point 55 on accessory 26b, which, as previously described, is capable of connecting to an external system (not shown).

[0084] Figure 5 This is a cross-sectional view showing the chain 70 and fiber optic cable 52 extending from the tubular corrugated pipe 30 into the inner tank 24. As previously discussed... Figure 3 The measurement probe is forced to follow a curved path via the curved portion 68 of the guide rail device.

[0085] Figure 6 and Figure 7 The measuring probe 50 is shown in the retracted position. In the retracted position, the measuring probe 50 (including its tip 50a) is completely stored within the collection chamber 26 and does not extend into the inner tank 24. The isolation valve 40 is closed, thereby fluidly isolating the collection chamber 26 from the inner tank 24.

[0086] like Figure 7As shown, the isolation valve 40 includes a closure 44 that closes one end of the collection chamber 26. To allow the closure 44 to extend across the entire width of the collection chamber 26, a gap 69 is provided in the guide rail assembly 65 through which the closure 44 can move, as shown in… Figure 7 The gap 69 is shown most clearly in the diagram. It can be large enough that the closure 44 does not contact the guide rail assembly 65 when closed. The gap 69 can be smaller than the smallest link 71 of the chain 70 to reduce the likelihood that the chain 70 will disengage from the guide rail assembly as it moves through the gap 69.

[0087] The liquid storage system 20 may also include a drive mechanism 80, such as Figure 7 As shown, the drive mechanism 80 is arranged to engage the chain 70 to move the measuring probe 50 between the inner tank 24 and the collection chamber 26. By way of a non-limiting example, the drive mechanism 80 may include a motor 82 arranged to rotate a pinion 84, which is arranged to engage subsequent links 71 of the chain 70 to move the chain 70 as the pinion 84 rotates. In this way, the drive mechanism 80 can deploy and retract the measuring probe 50 by rotating the pinion 84 in the opposite direction. It will be understood that alternative drive mechanisms 80 may be used, such as linear actuators (not shown). The arrangement of the motor 82 and the pinion 84 may be preferred for providing a compact arrangement for moving the measuring probe 50. The drive mechanism 80 may also include a clutch 86 for selectively disengaging the pinion 84 from the chain 70. This may allow the chain 70 to be removed from the drive mechanism 80 and optionally from the collection chamber 26, for example, for maintenance.

[0088] Fiber optic cable 52 and chain 70 can be supplied as pre-assembled components before being assembled into the liquid storage system 20. Figure 8a A portion of an example of such a pre-assembled component is shown. The measurement probe 50 includes three fiber optic cables 52, but it will be understood that the measurement probe 50 may include any number of fiber optic cables 52. Setting the measurement probe 50 as a single pre-assembled component improves ease of maintenance because the measurement probe 50 can be removed more easily by handling the support chain 70 rather than by directly handling the fiber optic cables 52.

[0089] Figure 9 A method 100 for accessing a measuring probe 50 within a liquid storage system 20 is shown. At step 110, the measuring probe 50 retracts from the inner tank 24 into the collection chamber 26. The measuring probe 50 can be moved by driving a chain 70, as previously referenced. Figures 4 to 7As described. At step 120, isolation valve 40 is actuated to fluidly isolate collection chamber 26 from inner tank 24. At step 130, once collection chamber 26 is isolated from inner tank 24, collection chamber 26 is cleaned, as described in reference... Figure 4 As described. It will be understood that in some cases, cleaning of the collection chamber 26 (i.e., step 130) can be omitted. At step 140, the collection chamber 26 is opened to provide the user with access to the measurement probe 50. The collection chamber 26 can be opened by removing the cover 35 at one end of the accessory 26b. Finally, at step 150, the user accesses the measurement probe 50 in the collection chamber 26. The user can then visually inspect, repair, or remove the measurement probe 50 from the collection chamber 26 so that the measurement probe 50 can be repaired or replaced. For example, the measurement probe 50 (including the chain and fiber optic cable 52) and the connecting cable 54 can be removed from the collection chamber 26 as a single unit.

[0090] As mentioned above, the curved portion 67 of the guide rail device can be removed from the second portion 65 and the third portion 66 of the guide rail device. This allows the measuring probe 50 and the connecting cable 54 to be removed from the collection chamber 26 along with the curved portion 67 of the guide rail device. This allows the chain 70 to slide out of the straight portions 65 and 66 of the guide rail device, which remain in the collection chamber 26.

[0091] Optionally, a tray (not shown) is provided. The measuring probe 50, connecting cable 54, and bend 67 are pre-assembled on the tray, which is then... Figure 9 During the maintenance process, slide in and out of the collection chamber 26.

[0092] Once the new measuring probe 50 has been installed in the collection chamber 26, the collection chamber 26 is closed, the isolation valve 40 is opened, and the new measuring probe is driven to its deployment position in the inner tank 24.

[0093] exist Figure 9 During the process, the evacuated space 23 between the outer tank 24 and the inner tank 22 remains evacuated.

[0094] When the word "or" appears, it will be interpreted as meaning "and / or", meaning that the items referred to are not necessarily mutually exclusive and can be used in any appropriate combination.

[0095] Although the invention has been described above with reference to one or more preferred embodiments, it will be understood that various modifications or variations may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A cryogenic liquid storage system, comprising: Outer can; An inner tank, located inside the outer tank and configured to store cryogenic liquids; Isolation valve; A collection chamber located outside the outer tank and fluidly connected to the inner tank, such that fluid can flow from the inner tank to the collection chamber via the isolation valve, wherein the isolation valve can be actuated to isolate the collection chamber from the inner tank; as well as A measuring probe that can move between the inner tank and the collection chamber.

2. The cryogenic liquid storage system according to claim 1 further includes cryogenic liquid located in the inner tank, wherein, The measuring probe is at least partially immersed in the cryogenic liquid.

3. The cryogenic liquid storage system according to claim 2, wherein, The measuring probe is configured to measure the amount of cryogenic liquid in the inner tank.

4. The cryogenic liquid storage system according to any of the preceding claims further includes a guide rail device extending from the collection chamber into the inner tank, wherein, The measuring probe is coupled to the guide rail device and configured to move along the guide rail device as the measuring probe moves between the inner tank and the collection chamber.

5. The cryogenic liquid storage system according to claim 4, wherein, The first part of the guide rail device extends downward inside the inner tank, the second part of the guide rail device extends laterally inside the collection chamber, and the curved portion of the guide rail device connects the first part of the guide rail device to the second part of the guide rail device.

6. The cryogenic liquid storage system according to claim 4 or 5, wherein, The isolation valve includes: a housing defining a valve orifice through which the isolation valve passes; and a closure for blocking the valve orifice, wherein the guide rail device includes a gap through which the closure is movable.

7. The cryogenic liquid storage system according to any one of claims 4 to 6, wherein, The guide rail device has at least one curved section located within the collection chamber.

8. The cryogenic liquid storage system according to any of the preceding claims further includes a tubular corrugated pipe located between the inner tank and the outer tank, wherein, The bellows connects the fluid in the inner tank to the collection chamber.

9. The cryogenic liquid storage system according to any of the preceding claims, wherein, The measuring probe also includes a chain, and the system also includes a drive mechanism arranged to engage the chain to move the measuring probe between the inner tank and the collection chamber.

10. The cryogenic liquid storage system according to claim 9, wherein, When the measuring probe is located in the inner tank, the chain extends from the collection chamber into the inner tank via the isolation valve.

11. The cryogenic liquid storage system according to any of the preceding claims further includes a evacuated space located between the inner tank and the outer tank.

12. The cryogenic liquid storage system according to any of the preceding claims further includes a pressure sensor located in the collection chamber.

13. The cryogenic liquid storage system according to any of the preceding claims, wherein, The measuring probe includes one or more cables; and when the measuring probe is located in the inner tank, the cables (or each cable) extend from the collection chamber through the isolation valve into the inner tank.

14. The cryogenic liquid storage system according to any of the preceding claims, wherein, The measuring probe can move between the inner tank and the collection chamber via the isolation valve.

15. An aircraft comprising a cryogenic liquid storage system according to any of the preceding claims.

16. A method for accessing a measurement probe in a cryogenic liquid storage system, the cryogenic liquid storage system comprising: Outer can; An inner tank, located inside the outer tank; A cryogenic liquid, wherein the cryogenic liquid is located in the inner tank; Isolation valve; A collection chamber located outside the outer tank and fluidly connected to the inner tank, allowing fluid to flow from the inner tank to the collection chamber via the isolation valve; The method includes: and a measuring probe located within the inner tank. The measuring probe is retracted from the inner tank through the isolation valve back into the collection chamber; The isolation valve is actuated to isolate the collection chamber from the inner tank, thereby preventing fluid from flowing from the inner tank to the collection chamber via the isolation valve; Open the collection chamber; and Touch the measuring probe in the opened collection chamber.

17. The method of claim 16, further comprising cleaning the collection chamber once the isolation valve is actuated to isolate the collection chamber from the inner tank.

18. An aircraft including a cryogenic fuel storage system, the cryogenic fuel storage system comprising: Outer can; An inner tank, located inside the outer tank; Cryogenic fuel, wherein the cryogenic fuel is located in the inner tank; Isolation valve; A collection chamber located outside the outer tank and fluidly connected to the inner tank, allowing fluid to flow from the inner tank to the collection chamber via the isolation valve; A measuring probe, movable between the inner tank and the collection chamber, the measuring probe including a chain, wherein the measuring probe is immersed in the cryogenic fuel when located in the inner tank; A guide rail device extending from the collection chamber into the inner tank, and the measuring probe being movable along the guide rail device, the guide rail device comprising: The first part extends downward from the top of the inner tank; and The second part extends substantially perpendicular to the first part of the guide rail device within the collection chamber.

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