SYSTEM COMPLETING A CRYOPASTICAL AND A THERMAL SIPHON

Description

[0001] The invention relates to a system comprising a vehicle and a cryogenic container carried on the vehicle, i.e. mounted on the vehicle, with an inner tank and an outer tank vacuum-insulated from the inner tank, wherein the system further comprises a fluid conveying device located outside the inner tank and a pipeline which is led to extract cryogenic fluid from the inner tank and is connected to the fluid conveying device.

[0002] According to the state of the art, liquefied gases can be stored in containers ("cryogenic containers") for use as fuel, for example, in a vehicle engine. The cryogenic container is carried on the vehicle, for instance, by being mounted on the vehicle frame. Liquefied gases are gases that exist in the liquid state at their boiling point, which is pressure-dependent. When such a cryogenic liquid is filled into a cryogenic container, a pressure corresponding to the boiling point is established, apart from thermal interactions with the cryogenic container itself.

[0003] Since the fluid stored in the cryogenic container is at a significantly lower temperature than the ambient temperature of the container, the container must be designed accordingly to minimize heat transfer. Prior art has shown that cryogenic containers can be designed as double-walled tanks, comprising an inner and an outer tank. The inner tank is enclosed within the outer tank and thermally insulated from it, for example, by maintaining a vacuum between the two.

[0004] A primary general objective in the field of cryogenic containers is to minimize heat input into the container. Heat input is directly related to the cryogenic container's hold time, i.e., the period from the cessation of cryofluid withdrawal from the container until the pressure within the container reaches a predefined threshold.

[0005] It is known from the prior art to reduce the heat input from pipes leading into the cryogenic container by designing the pipe outside the inner tank as a thermal siphon. In cryogenic containers, a thermal siphon functions by heating the cryogenic fluid at the end of the pipe located outside the inner tank. This causes the cryogenic fluid to evaporate at this end of the pipe, but due to the buoyancy of the gas, it cannot flow back into the cryogenic container through the thermal siphon. This creates an insulating gas cushion at the warm end of the pipe, thus reducing the heat input into the overall system. Without the thermal siphon, the gas, and therefore the heat, would flow back into the cryogenic container after evaporation, continuously drawing liquid into the warm area where it would evaporate again, resulting in a constantly increasing heat input into the inner tank.

[0006] However, this thermal siphon solution is not suitable for all applications. In particular, an insulating gas cushion is a hindrance for pumps, as the pumps must operate at a temperature where the cryofluid does not evaporate in order to effectively pump the cryofluid. If the cryofluid were present in gaseous phase at the pump, the pump's efficiency would be extremely low, since the gas phase would first have to be compressed by the pump before it could be pumped. Only after a prolonged period of gas pumping could the suction line and pump cool down sufficiently to prevent liquid phase evaporation, thus allowing – after a long warm-up time – the liquid phase to be pumped with higher efficiency. This time is unacceptable for the user, and the invention aims to minimize this time and enable cooling, primarily by gravity, even without a running motor or pump.

[0007] For this reason, the prior art provides for the pump, in particular the piston of a piston pump, to protrude into the cryogenic container in order to continuously flush it with cold cryogenic fluid. This allows the pump to be started at any time, as the pump is always at a temperature at which the cryogenic fluid can exist in a liquid state. Therefore, a second general objective in the field of cryogenic containers is to provide a pump suitable for rapid motor starting.

[0008] It is evident that the two stated objectives, on the one hand low heat input and on the other hand a cold pump, are in contradiction to each other, since a cold pump means a high heat input into the cryogenic container.

[0009] Documents EP 3232111 A1, WO 9506188 A1, EP 1248032 A2 and US 5218827 A each describe stationary storage systems for refueling vehicles. However, the pumps shown therein are not designed to be carried on a vehicle and would also require too much installation space in such applications.

[0010] The object of the invention is to provide a system comprising a cryogenic container and a fluid conveying device in which the heat input into the cryogenic container is low on the one hand and the fluid conveying device can operate quickly with high efficiency on the other.

[0011] This problem is solved by a system comprising a cryogenic container with an inner tank and an outer container vacuum-insulated from the inner tank, wherein the system further comprises a fluid conveying device and a pipeline that is led to the inner tank for the extraction of cryogenic fluid and is connected to the fluid conveying device, wherein the fluid conveying device is arranged outside the inner tank, the pipeline is designed as a thermal siphon with at least one section rising towards the fluid conveying device, which is at least partially arranged in a region that is insulated from the cryogenic fluid located in the inner tank, wherein a vent line closable by a valve is located in the said region, preferably in an extraction plane of the fluid conveying device.is connected to the pipeline or directly to the fluid conveying device and is returned to the inner tank above the connection point to the pipeline or above the connection point to the fluid conveying device.

[0012] The solution according to the invention enables the heat input into the cryogenic container to be kept low, since a gas cushion can form between the fluid delivery inlet and the rising section when the valve of the vent line is closed. On the other hand, the intake area of ​​the fluid delivery device, or the fluid delivery device itself, can be cooled rapidly by opening the valve of the vent line, whereby the insulating gas cushion is carried into the cryogenic container by buoyancy via the vent line, and fluid phase can flow through the pipeline to the fluid delivery device.

[0013] The system can thus assume two operating states, wherein in a first operating state the valve is closed in order to maintain an insulating gas cushion between the said section and the valve on the fluid conveying device after heating, and wherein in a second operating state the valve is open in order to allow a flow of cryofluid to the fluid conveying device and a simultaneous discharge of cryofluid in gas phase through the vent line.

[0014] The invention achieves both of the initial objectives. On the one hand, it reduces the heat input into the overall system because the cryogenic fluid located in the connection area to the fluid delivery system evaporates after the vehicle is switched off and does not flow back into the cryogenic container via the thermal siphon. After the initial evaporation of the cryogenic fluid, the heat input via the pipeline is reduced to a minimum. On the other hand, an engine start can be performed as quickly as possible because the pipeline and the intake area of ​​the fluid delivery system can be rapidly cooled by opening the valve – even without a running engine or pump, and primarily by gravity. After the valve is opened, the liquid phase passes through the pipeline, which previously acted as a thermal siphon, thereby cooling the pipeline and the fluid delivery system.

[0015] According to the invention, the pipeline leading to the fluid conveying device can also be cooled as quickly as possible. The cooling of the pipeline depends on the mass of the pipeline, the temperature difference that needs to be cooled, and the incoming heat, i.e., the insulation efficiency. The invention provides for the pipeline to be as short as possible while still allowing for the formation of the gas cushion. To achieve this, the fluid conveying device can be positioned as close as possible to the inner tank, so that in thermal equilibrium—i.e., after the liquid phase in the fluid conveying device or in the pipeline in this area has evaporated—a temperature is established that is just warmer than the temperature of the liquid phase to generate the insulating gas cushion.According to the invention, it can be achieved that the pipelines in the area of ​​the fluid conveying device only heat up by 1 °C to 5 °C compared to the temperature in the inner tank.

[0016] Cryogenic containers are typically formed by a cylindrical shell wall and two adjoining end caps, i.e., end walls. In the prior art, fittings are provided at the end caps, as routing lines through them is easier. The solution according to the invention now makes it possible, for the first time, to provide a fluid conveying device directly on the shell wall. This creates, for the first time, a lateral arrangement that simultaneously enables very low heat input and rapid start-up of the fluid conveying device.

[0017] Particularly in automotive engineering, available space is extremely limited, so the fluid conveying device is positioned directly next to the casing. For example, the fluid conveying device can be essentially rod-shaped and arranged parallel to a longitudinal axis of the cryogenic container along the casing surface or perpendicular to the longitudinal axis of the cryogenic container next to the end cap.

[0018] In a preferred embodiment, the vent line is routed at least partially between the inner and outer tanks in the circumferential direction of the cryogenic container, and the valve preferably comprises a closure element located in the vent line between the inner and outer tanks and an actuating element located outside the outer tank. Routing the vent line back into the vacuum chamber reduces the overall heat input into the cryogenic container when changing the operating state, i.e., from standstill to operation and vice versa. The vent line can also be located entirely between the inner and outer tanks, for example, if the valve is divided into two parts as described above. The connection between the closure element and the actuating element can be mechanical or via a control line or wireless control.

[0019] In further preferred embodiments, the vent line is routed back into the inner tank in the upper third, preferably at the very top. This prevents any liquid from entering the vent line. Alternatively, the line could also be routed back into the container below a maximum liquid phase level, with the valve being located directly on the inner tank. The vent line could also have a thermal siphon, for example, at its upper end.

[0020] The thermal siphon can be designed in a variety of ways. For example, the pipeline can have two essentially horizontal sections, between which a loop is formed to create the thermal siphon, encompassing the section rising towards the fluid conveying device. This design is advantageous because the loop can be easily integrated into the pipeline without requiring a separate pipe penetration module that projects into the inner tank.

[0021] In the latter embodiment, the pipeline can connect directly to the inner tank without protruding into it. However, it could also be generally provided that the pipeline is routed into the inner tank of the cryogenic container, i.e., protrudes into it, and is surrounded within the inner tank by a sheathing tube that insulates the pipeline from any fluid located in the inner tank.

[0022] In these embodiments with a sheathing tube, it is usually provided that the vacuum-insulated space located between the outer container and the inner tank also extends between the pipeline and the sheathing tube.

[0023] In the embodiment with a casing pipe, it is particularly preferred if the section rising towards the fluid conveying device is at least partially arranged inside the casing pipe. This allows the length of the pipeline outside the inner tank to be reduced and the thermal siphon to be relocated inside the inner tank.

[0024] In principle, the pipeline may consist of only the aforementioned rising section, or only additional horizontal or vertical sections. Particularly preferably, the pipeline has a descending section located within the casing between the rising section and the fluid conveying device. This allows the pipeline to have a kink within the casing, which provides particularly favorable compensation for thermal expansion and contraction.

[0025] Particularly if the pipeline has a kink within the outer casing that forms the highest point of the thermal siphon, the vent line can be connected to the pipeline inside the casing, routed out of the casing within the inner tank, and exited the inner tank via its own vent casing. In this case, the vent line can, for example, be connected directly at the kink, thus allowing for particularly effective gas release from the pipeline. As in the other embodiments, routing the vent line out of the cryogenic container serves the purpose of providing access to the valve outside the cryogenic container.

[0026] In other preferred embodiments, however, the vent line is connected to the pipeline outside the inner tank, as it is easier to insulate in this configuration. This embodiment is typically used when the highest point of the pipeline is located at the fluid conveying device, for example, when it runs horizontally away from it.

[0027] To achieve a particularly compact design, the fluid conveying device, and preferably also the section rising towards the fluid conveying device, are arranged on a shell wall of the inner or outer tank. The fluid conveying device is preferably located at least partially, and more preferably completely, within one of the gussets formed by a smallest imaginary cuboid extending over the inner or outer tank. This gusset arrangement allows the fluid conveying device to be positioned on the cryogenic container without protruding significantly laterally, below, or above it, for example, when the cryogenic container is mounted laterally on a motor vehicle. Typically, the fluid conveying device is arranged in the gusset located at the bottom on the side facing away from the motor vehicle.Particularly preferably, the fluid conveying device is designed in a rod shape and lies parallel to the cryogenic container, e.g. parallel to a longitudinal axis of the cryogenic container.

[0028] Alternatively, the fluid conveying device, and preferably also the section rising towards the fluid conveying device, can be arranged on an end wall of the inner tank or the outer container, wherein the fluid conveying device is preferably located at least partially, and particularly preferably completely, in one of the gussets formed by a smallest imaginary cuboid over the inner tank or the outer container. The gusset on the end wall is formed if the end wall is convex. In this case, the fluid conveying device can preferably be arranged vertically or horizontally, particularly transversely to the longitudinal axis of the tank, for example, in a gusset formed between one of the convex end caps and the aforementioned smallest imaginary cuboid. Particularly preferably, the fluid conveying device is rod-shaped and lies perpendicular to the cryogenic container, e.g.horizontal or vertical and normal to a longitudinal axis of the cryocontainer.

[0029] The two aforementioned designs are particularly advantageous because very little installation space is available on a vehicle, especially for the fluid transfer system. These two designs allow for a particularly compact system, and the cryogenic container and the fluid transfer system can be arranged together in the smallest possible imaginary cuboid, for example, the installation space available on the vehicle frame.

[0030] To enable the liquid phase of the cryofluid to be extracted down to the last drop, the pipeline can be connected at the lowest point of the inner tank without protruding into it, and from there lead to the fluid conveying device. This maximizes the extraction volume from the cryogenic tank, which was not previously possible with the prior art. Alternatively, to achieve this goal, the pipeline could also protrude into the inner tank, even uninsulated, and be led out with a downward-sloping section towards the fluid conveying device, with the upward-sloping section located between this downward-sloping section and the fluid conveying device.

[0031] Preferably, the fluid transfer system is located in the vacuum-insulated space between the inner tank and the outer tank. The outer tank can thus be pulled over the fluid transfer system, allowing it to be positioned within the vacuum-insulated area. This results in particularly efficient use of the available installation space on the vehicle, as the insulated space between the inner and outer tanks simultaneously serves as the mounting space for the fluid transfer system. In alternative embodiments, the fluid transfer system can also be located outside the outer tank and be separately insulated there.

[0032] In all the aforementioned embodiments, but especially in the one in which the fluid conveying device is located in the vacuum-insulated space between the inner tank and the outer tank, both the cryogenic container and the fluid conveying device are rod-shaped (meaning that they each have a longitudinal axis and preferably have a greater length in the longitudinal direction than in the other directions normal to the longitudinal direction), wherein the longitudinal axis of the cryogenic container and the fluid conveying device lies in a vertical plane that is in the normal direction of travel of the vehicle. This allows both the cryogenic container and the fluid conveying device to be arranged compactly on the vehicle.Preferably, the longitudinal axis of the cryogenic container lies in a horizontal plane and the longitudinal axis of the fluid conveying device lies in a horizontal plane or is inclined by 0.1° to 20° with respect to a horizontal plane, thereby still achieving the compact arrangement.

[0033] Furthermore, the fluid conveying device is preferably rod-shaped, and one longitudinal axis of the fluid conveying device is inclined with respect to a horizontal plane, with the end at which the fluid conveying device is connected to the pipeline and / or the vent line being higher than the end that is not connected to the pipeline and / or the vent line. This allows cryogenic fluid that has evaporated in or on the fluid conveying device to be more easily returned to the cryogenic container via the extraction line.

[0034] Furthermore, it is preferred if the section rising towards the fluid conveying device increases by a height that is at least twice the diameter of the pipeline at the connection point to the fluid conveying device. This ensures a sufficient height for the presence of the gas cushion and thus the effectiveness of the thermal siphon. The height is defined as the difference between the highest point of the top of the pipe in the rising section and the lowest point of the underside of the pipe in the rising section. This ensures that the siphon effect is maintained even when the vehicle is parked at an angle.

[0035] It is particularly preferred if the pipeline is more flexible over at least one functional section than outside of that section. Alternatively or additionally, the pipeline can have a thinner wall thickness over at least one functional section than outside of that section, with the functional section preferably being located at least partially within a sheathing tube. Alternatively or additionally, the pipeline can be designed as a bellows tube over at least one functional section, with the functional section preferably being located at least partially within the sheathing tube. Depending on the embodiment, the functional section can also be located entirely within the sheathing tube or cryogenic container, or entirely outside of the sheathing tube or cryogenic container.

[0036] These designs with a functional section have the advantage that, due to their flexible construction, thinned pipe wall thickness, and / or bellows-like design, no or fewer vehicle-induced vibrations are transmitted to the fluid handling system. This is therefore a vehicle-specific advantage. The functional section is usually provided for the pipeline because it has a large diameter over its length and is therefore rigid. The vent line, due to its typically greater length and smaller diameter, is less rigid, thus transmitting fewer vibrations to the fluid handling system. However, in general, all the aforementioned variants of the functional section could also be provided for the vent line; that is, the vent line can have a functional section as described above for the pipeline.

[0037] Advantageous and non-restrictive embodiments of the invention are explained in more detail below with reference to the drawings. Figure 1 Figure 1 shows a system according to the invention comprising a cryogenic container and a pipeline designed as a thermal siphon in a first embodiment. Figure 2 The system according to the invention is shown in a second embodiment. Figure 3 The system according to the invention is shown in a third embodiment variant. Figure 4 The system according to the invention is shown in a fourth embodiment. Figure 5 The system according to the invention is shown in a fifth embodiment variant. Figure 6 Figure 1 shows the system according to the invention in a sixth embodiment variant. Figure 7 Figure 1 shows the system according to the invention in a seventh embodiment variant. Figure 8 shows a vehicle with cryogenic container and fluid conveying device in the arrangement according to the invention.

[0038] Figure 1Figure 1 shows a cryogenic container 1 comprising an inner tank 2 and an outer tank 3 that is vacuum-insulated from the inner tank 2. The cryogenic fluid 4 stored in the cryogenic container 1 is, for example, liquefied natural gas, also known to those skilled in the art as LNG ("Liquid Natural Gas"). In the illustrated example, the cryogenic fluid 4 exists in liquid phase 5 up to a fill level F, and in gas phase 6 above this level. The cryogenic container 1 is carried on a motor vehicle, in which case the cryogenic fluid 4 serves, for example, as fuel for the vehicle's engine. For this purpose, a discharge line from the cryogenic container can be connected to the engine. The cryogenic container 1 is typically mounted on the vehicle frame, with one longitudinal axis of the cryogenic container 1 being substantially horizontal and parallel to the vehicle frame, i.e., parallel to the vehicle's normal direction of travel.

[0039] The cryocontainer 1 can, for example, have a cylindrical shape, i.e., comprise a cylindrical shell closed by two flat or convex end caps. Thus, the cryocontainer 1 typically has a longitudinal axis that may coincide with the cylinder axis of the cryocontainer 1. However, in general, the cryocontainer 1, or its shell, need not have a circular cross-section in section perpendicular to the longitudinal axis.

[0040] To introduce cryofluid 4 into or remove cryocontainer 1, a pipeline 7 is provided between inner tank 2 and outer tank 3. Further pipelines for introducing or removing cryofluid from the tank are not shown for clarity.

[0041] To convey cryofluid 4, a fluid conveying device 8, preferably a pump such as a piston pump or centrifugal pump, or its inlet or suction area, is connected to the pipeline 7. The cryogenic container 1, the pipeline 7, and the fluid conveying device 8 are collectively referred to, optionally with further components, as system 9. The fluid conveying device 8 is preferably arranged directly on a surface of the cryogenic container 1, so that the pipeline 7 can also be connected directly to the fluid conveying device 8, i.e., without an intermediate system. In this embodiment, the fluid conveying device 8 is, for example, parallel to the longitudinal axis of the cryogenic container 1. In other embodiments, the fluid conveying device 8 can also be arranged on an end face of the cryogenic container 1, e.g., vertically or horizontally.In this variant, the fluid conveying device 8 is, for example, perpendicular to the longitudinal axis of the cryogenic container 1. The fluid conveying device 8 can convey at least a liquid phase 5, e.g., by pumping. If the fluid conveying device 8 can also convey a gas phase 6, it will, for example, have a higher efficiency for conveying the liquid phase 5 than for conveying the gas phase 6.

[0042] As is known to those skilled in the art, the cryofluid 4 is stored in the inner tank 2 at very low temperatures. The temperature inside the inner tank 2 is therefore lower than outside the inner tank 2. During operation, the fluid conveying device 8 is cooled by the liquid cryofluid 4 flowing through it. When the fluid conveying device 8 is in operation, its temperature is therefore essentially the same as the temperature of the liquid phase 5. However, when the fluid conveying device 8 is not in operation, it heats up due to external heat input, causing the cryofluid 4 in the fluid conveying device 8 or in the pipeline 7 to evaporate near the fluid conveying device 8, forming a gas phase 6.If the pipeline 7 were not designed as a thermal siphon as described below, the cryogenic fluid 4 would constantly convert into gas phase 6 near the fluid conveying device 8 and flow back into the inner tank 2, resulting in a significant heat input. Although the fluid conveying device 8 can also be arranged between the inner tank 2 and the outer container 3 or within insulation 10 to enclose the fluid conveying device 8 between the outer container 3 and insulation 10, for example in a vacuum, this does not completely prevent the heat input into the fluid conveying device 8.

[0043] For this reason, the pipeline 7 is designed as a thermal siphon 11. The thermal siphon 11 has at least one section 12 rising towards the fluid conveying device, which is located at least partially in a region B that is insulated from the cryofluid 4 in the inner tank 2, i.e., it is not directly exposed to the cryofluid 4. Region B is thus located outside the inner tank 2 or, optionally, inside the inner tank 2 if the latter has an insulated recess such as a sheathing tube 19 as described in more detail below.

[0044] When heat is applied from the outside, area B, and therefore also the part of section 12 or pipe 7 located within area B, will reach a higher temperature than the cryofluid 4 in the inner tank 2. The cryofluid 4, which is in liquid phase 5 there, will therefore evaporate first due to the external heat input. Because of the buoyancy of the gas phase 6 compared to the liquid phase 5, an insulating gas cushion will form at the fluid conveying device 8 along the rising section 12, typically extending up to the rising section 12.

[0045] However, if the fluid pumping device 8 has not been in operation for a certain period of time, i.e., has become warm, and an insulating gas cushion is present at the fluid pumping device 8, it will not be able to pump cryogenic fluid 1 or will only be able to do so with poor efficiency. According to the invention, a vent line 14 is therefore provided, which is connected in the aforementioned area B, preferably in a discharge level of the fluid pumping device 8, to the pipeline 7 or directly to the fluid pumping device 8 and is routed back into the cryogenic container 1. If the vent line 14 is connected to the pipeline 7, then preferably directly adjacent to the fluid pumping device 8, e.g., to a section of the pipeline 7 that leads horizontally away from the fluid pumping device 8, or, if the section 12 is directly adjacent to the fluid pumping device 8, at the uppermost point of the section 12.

[0046] The vent line 14 has a valve 15, i.e., a shut-off valve, by means of which the vent line 14 can be selectively closed and opened. When the valve 15 in the vent line 14 is closed, the thermal siphon 11 can perform its insulating function as described above. However, when the valve 15 is opened, the gas phase 6 flows from the pipe 7 back into the inner tank 2 via the vent line 14, i.e., the thermal siphon 11 can no longer perform its function. As a result, fluid phase 5 flows from the inner tank 2 into the pipe 7 towards the fluid pumping device 8. Due to the inflow of liquid phase 5, the fluid pumping device 8 cools down particularly quickly, so that after sufficient cooling, the liquid phase 5 can be pumped.

[0047] The vent line 14 is routed back into the inner tank 2, for example above the connection point of the vent line 14 to the pipeline 7, above the section 12 rising towards the fluid conveying device 8, in the upper third of the cryogenic container 1 or at the highest point of the cryogenic container 1. Preferably, the vent line 14 is designed to rise continuously from the connection point to the pipeline 7, at least up to a height at which the connection point to the inner tank 2 is located, in order to reduce the risk of forming a siphon itself.

[0048] As in Figure 1As shown, the vent line 14 can be routed at least partially within the vacuum-insulated area between the inner tank 2 and the outer container 3 to provide the best possible insulation for the vent line 14. Preferably, the vent line 14 is located outside the outer container 3 and / or the insulation 10 only in the area of ​​the valve 15. Alternatively, only the valve 15 can be located outside the outer container 3 and / or the insulation 10. In other embodiments, the entire vent line 14 and also the valve 15 can be located within the vacuum-insulated area between the inner tank 2 and the outer container 3 and / or within the insulation 10. In this case, the valve 15 can have a control line that leads out of the outer container 3 or the insulation 10, so that the valve 15 can be closed mechanically, pneumatically, or electrically from the outside.

[0049] Based on the Figures 1 to 5Different types of thermal siphons 10 that can be used for the system according to the invention will now be explained. However, the invention is not limited to these embodiments; other thermal siphons not shown can also be used.

[0050] Figure 1Figure 11 shows a classic thermal siphon with two essentially horizontal sections 16 and 17 with a crossover 18. The portion of the crossover 18 facing the fluid conveying device 8 forms the upward-sloping section 12, which prevents the fluid phase 5 from flowing towards the fluid conveying device 8. If a gas phase 6 forms at the fluid conveying device 8, it will first accumulate at the upper end of the crossover 18 and fill it, thereby forming a buffer between the liquid phases 5 in the two horizontal sections 16 and 17. Subsequently, the remaining liquid phase 5 in the horizontal section 17 facing the fluid conveying device 8 will transform into gas phase 6 and, if applicable, escape from the thermal siphon 11 towards the cryogenic container 1.

[0051] In the embodiment of Figure 1Pipeline 7 connects to the inner tank 2 but does not enter it. However, it can be provided that pipeline 7 enters the inner tank 2, in which case it is surrounded by a sheathing tube 19, as shown in the Figures 2 to 5 The sheathing tube 19 insulates the pipe 7 from a fluid located in the inner tank 2, i.e., cryofluid 4, when the cryogenic container 1 is filled. For example, the inner tank 2 is perforated at the point where the sheathing tube 19 is attached, so that the vacuum-insulated area between the inner tank 2 and the outer container 3 also extends to the area between pipe 7 and sheathing tube 19. Alternatively, the area between pipe 7 and sheathing tube 19 could also be insulated in another way.

[0052] Figure 2Figure 1 shows an embodiment in which the pipeline comprises a substantially horizontal section facing the fluid conveying device 8 and a substantially vertical section facing away from the fluid conveying device 8, forming the section 12 that rises towards the fluid conveying device 8. Since the vertical section 12, rising towards the fluid conveying device 8, is surrounded by the sheathing tube 19, it is located in region B, which is insulated from the cryofluid 4 in the inner tank 2. As shown in Figure 1, the pipe has a substantially horizontal section facing the fluid conveying device 8 and forms the section 12 that rises towards the fluid conveying device 8. Figure 1 The vent line 14 connects to the fluid conveying device 8 and is essentially entirely located in the vacuum-insulated area between the inner tank 2 and the outer tank 3, except for a section where the valve 15 is located.

[0053] Figure 3Figure 1 shows an embodiment in which the pipeline 7 within the inner tank 2 is straight, but rises from the inner tank 2 towards the fluid conveying device 8. The vent line 14 connects to the highest point of the descending pipeline 7, i.e., at a suction level of the fluid conveying device 8. The insulation of the vent line 14 is not shown for clarity.

[0054] Furthermore, in Figure 3A functional section 28 of the pipeline is shown, in which the pipeline 7 is more flexible than outside of the functional section 28. In the illustrated example, the functional section 28 is designed as a bellows tube. However, the bellows tube could also be designed such that it is not necessarily more flexible, but allows compression or expansion in the longitudinal direction of the pipeline 7. Alternatively, the functional section 28 could be formed by a local thinning of the pipeline 7, thereby creating a flexible section. This can prevent or reduce the transmission of vibrations from the vehicle and thus from the cryogenic container 1 to the fluid conveying device 8. The functional section is not required for the embodiment of Figure 3specific, but can be combined with all other embodiments described herein. Furthermore, the functional section 28 can be located wholly or partially inside or wholly outside the cryocontainer 1 (i.e., the cylindrical contour of the cryocontainer 1).

[0055] The Figures 4 and 5Figure 1 shows embodiments of the thermal siphon 10 that are particularly relevant in practice. In these embodiments, the pipe 7 has a bend 20 located inside the outer casing 19. Since the pipe 7 is not connected to the inner tank 2, but to the outer casing 19 on the side facing away from the fluid conveying device 8, temperature-related thermal expansion can be accommodated particularly well by the pipe 7. In both illustrated embodiments, the pipe 7 has a section 12 rising towards the fluid conveying device 8 and a section 21 descending towards the fluid conveying device 8. The bend 20 is formed between the two sections 12 and 21. The descending section 21 towards the fluid conveying device 8 is arranged between the fluid conveying device 8 and the descending section 12 towards the fluid conveying device 8.

[0056] In the embodiment of Figure 4 The vent line 14 connects to the pipeline 7 at a point located outside the inner tank 2 at a suction level of the fluid pumping device 8. Generally, it is preferred that the vent line 14 connects to a point in the pipeline 7 that lies at or above the suction level of the fluid pumping device 8, i.e., between the fluid pumping device 8 and the highest point of a section 21 descending towards the fluid pumping device 8. The insulation of the vent line 14 can be carried out as in the embodiments described above.

[0057] In Figure 5The vent line 14 is connected to the pipe 7, which lies inside the inner tank 2, at a certain point. Furthermore, the vent line 14 does not exit the inner tank 2 within the outer casing 18, but rather exits the outer casing 14 within the inner tank 2. To isolate the vent line 14 from the cryogenic fluid 1 in the inner tank 2, the vent line 14 exits the inner tank 2 via its own vent casing 23. After exiting the inner tank 2 and passing through the outer tank 3, the vent line 14 features a valve 15, which is thus accessible. The vent line 14 is then routed back into the inner tank 2 in a known manner.

[0058] Figure 6Figure 1 shows an embodiment in which as much cryofluid 4 as possible can be extracted from the inner tank 2 and the pipeline 7 is designed to be as short as possible. Here, the extraction level of the fluid conveying device 8 is essentially flush with the lowest point of the inner tank 2. The end of the pipeline 7 facing away from the fluid conveying device 8 preferably connects to the lowest point of the inner tank 2.

[0059] The fluid conveying device 8 is arranged entirely within one of the gussets 24 formed by a smallest imaginary cuboid 25 above the inner tank 2 or the outer container 3, for example, in a gusset 24 next to the shell wall, as shown, or in a gusset at a convex end cap. This is particularly advantageous if the fluid conveying device 8 has a rod shape and is no longer than the shell surface when the fluid conveying device 8 is arranged in a gusset 24 next to the shell surface, or no longer than the diameter of the inner tank 2 or the outer container 3 when the fluid conveying device 8 is arranged in a gusset 24 next to the end cap.

[0060] The fluid conveying device 8 could also be located only partially in one of the indentations 24 and thus protrude beyond the side or underside of the cryogenic container 1. In the embodiment of Figure 6It has been shown that the pipeline 7 can also be partially routed outside the cuboid 25, although this can also be avoided by having the pipeline 7 enter the space between the outer tank 3 and the inner tank 2 laterally, for example.

[0061] In general, it is preferred that the fluid conveying device 8 be arranged as low as possible in order to convey as much cryofluid 4 as possible. Preferably, the fluid conveying device 8 or its inlet opening is located below a plane bounded by the lowest third or the lowest fifth of the cryogenic container 1 and / or the end of the pipe 7 facing away from the fluid conveying device 8 preferably connects to a point on the inner tank 1 that is below a plane bounded by the lowest third or the lowest fifth of the cryogenic container 1.

[0062] Also Figure 7Figure 1 shows an embodiment in which as much cryofluid 4 as possible can be extracted from the inner tank 2. For this purpose, a pipe 7 is used, which projects into the inner tank 2 and has a vertical section 26 located inside the inner tank 2, or a section 26 rising towards the fluid conveying device 8, the end of which faces away from the fluid conveying device 8 being located at the lowest point of the inner tank 2. A section 27 descending towards the fluid conveying device 8 is connected to the section 26 and extends to a depth that essentially corresponds to the lowest point of the inner tank 2. A section 12, rising towards the fluid conveying device 8, is provided between the section 27 and the fluid conveying device 8.Since the section 12 rising towards the fluid conveying device 8 is located completely outside the inner tank 2, the part of the pipeline 7 located inside the inner tank 2 can also be designed without a casing pipe.

[0063] Figure 8Figure 1 shows an exemplary arrangement of the cryogenic container 1 on a vehicle 29. The vehicle 29 has a driver's cab 30, a semi-trailer 31, a front wheel 32, and a rear wheel 33. The cryogenic container 1 is mounted laterally on a vehicle frame (not shown), so that, for example, one cryogenic container 1 can be mounted on one side of the vehicle 29 (e.g., the driver's side) and another cryogenic container 1 on the other side of the vehicle 29 (e.g., the passenger side). The cryogenic container 1 is usually mounted between the front wheel 32 and the rear wheel 33. However, the cryogenic container 1 could also be mounted centrally on the vehicle directly behind the driver's cab or on a vehicle roof. The invention is not limited to this specific arrangement and could also be combined with other vehicle types, e.g., without a semi-trailer 31 or on a bus.

[0064] Out of Figure 8The preferred embodiment is shown in which both the cryogenic container 1 and the fluid conveying device 8 are rod-shaped, i.e., have a longitudinal axis. The fluid conveying device 8 is arranged on the side of the cryogenic container 1 facing away from or towards the vehicle frame. The longitudinal axis of the cryogenic container 1 is essentially parallel to a normal direction of travel of the vehicle 29, i.e., a direction of travel when the vehicle 29 is traveling straight ahead. Particularly preferably, the longitudinal axis of the fluid conveying device 8 is also parallel to the normal direction of travel and thus parallel to the longitudinal axis of the cryogenic container 1. This allows for a particularly compact arrangement, since the fluid conveying device 8 effectively occupies no additional space on the vehicle 1, as can be seen, for example, in the combined view of the Figure 7 and 8This is evident because the fluid conveying device 8 does not protrude laterally, forwards, backwards, above, or below the cryogenic container 1. In the example of the Figure 8 The fluid conveying device 8 and also the section 12 rising towards the fluid conveying device 8 are arranged on a shell wall of the outer container 3, wherein the fluid conveying device 8 is located completely in one of the wedges 24 formed by a smallest imaginary cuboid 25 above the outer container 3. The fluid conveying device 8 could also be arranged as in Figure 7 shown in the isolated space between inner container 2 and outer container 3, as shown in Figure 7 shown that, in addition to improved insulation, there is a further gain in space.

[0065] In Figure 8Furthermore, an alternative arrangement of a fluid conveying device 8' is shown by the dashed lines, which is inclined with respect to a horizontal plane. This fluid conveying device 8' is again rod-shaped and therefore has a longitudinal axis. The longitudinal axis of the fluid conveying device 8' lies in a vertical plane, which also contains the longitudinal axis of the cryogenic container 1 or the normal direction of travel of the vehicle 29. However, the longitudinal axis of the fluid conveying device 8' is inclined with respect to a horizontal plane such that the end at which the fluid conveying device 8' is connected to the pipeline 7 and / or to the vent line 14 is higher than the end that is not connected to the pipeline 7 and / or to the vent line 14. The higher end can be located in or against the normal direction of travel of the vehicle 29.The inclination of the fluid conveying device 8' facilitates the removal of evaporated cryofluid via the vent line 14. This inclination could also be used in embodiments other than the one shown. Figure 8 to be used. In order to achieve compact designs, the inclination is preferably a maximum of 30°, a maximum of 20°, a maximum of 10°, a maximum of 5°, a maximum of 3° or a maximum of 1° with respect to the horizontal plane.

Claims

1. System (9) comprising a cryogenic container (1) with an inner tank (2) and an outer container (3) vacuum-insulated from the inner tank, wherein the system (9) further comprises a fluid conveying device (8) and a pipe (7) which is guided for the removal of cryogenic fluid (4) from the inner tank (2) and connected to the fluid delivery device (8), wherein the fluid conveying device (8) is arranged outside the inner tank (2), the pipe (7) is designed as a thermal siphon (10) with at least one section (12) rising in the direction of the fluid conveying device (8), which is at least partially arranged in an area (B) that is insulated from the cryogenic fluid (4) located in the inner tank (2), wherein a vent line (14) closable by a valve (15) is connected in said area (B), preferably in a withdrawal plane of the fluid conveying device (8), connected to the pipe (7) or directly to the fluid conveying device (8) and returning to the inner tank (2) above the connection point to the pipe (7) or above the connection point to the fluid conveying device (8), characterised in that the system further comprises a vehicle (29) on which the cryogenic container (1) is carried, and the fluid conveying device (8) is arranged on a jacket wall of the inner tank (2) or of the outer container (3).

2. System (9) according to claim 1, wherein the vent line (14) is at least partially guided between the inner tank (2) and the outer tank (3) and the valve (15) preferably comprises a closure part arranged in the vent line (14) between the inner tank (2) and the outer tank (3) and an actuating part arranged outside the outer container (3).

3. System (9) according to claim 1 or 2, wherein the vent line (14) is returned to the inner tank (2) in the upper third of the inner tank (2), preferably at the uppermost point of the inner tank (2).

4. System (9) according to any one of claims 1 to 3, wherein the pipe (7) has two substantially horizontal sections (16, 17) between which, to form the thermal siphon (10), a U-bend (18) is formed which comprises the section (12) rising in the direction of the fluid conveying device (8).

5. System (9) according to any one of claims 1 to 4, wherein the pipe (7) is led into the inner tank (2) and is at least partially surrounded within the inner tank (2) by a casing pipe (19) which insulates the pipe (7) from a fluid located in the inner tank (2), wherein the vacuum-insulated space between the outer container (3) and the inner tank (2) preferably also extends between the pipe (7) and the casing pipe (19), wherein preferably the section (12) rising in the direction of the fluid conveying device (8) is at least partially arranged within the casing pipe (19), wherein further preferably the pipe (7) has a section (21) located within the casing tube (19) and sloping in the direction of the fluid conveying device (8) between the section (12) rising in the direction of the fluid conveying device (8) and the fluid conveying device (8).

6. System (9) according to claim 5, wherein the vent line (14) is connected to the pipe (7) within the casing tube (19), is led out of the casing tube (19) within the inner tank (2) and is led out of the inner tank (2) with its own vent casing tube (23).

7. System (9) according to any one of claims 1 to 6, wherein the vent line (14) is connected to the pipe (7) outside the inner tank (2).

8. System (9) according to any one of claims 1 to 9, wherein also the section (12) rising in the direction of the fluid conveying device (8) is arranged on a jacket wall of the inner tank (2) or of the outer container (3).

9. System (9) according to any one of claims 1 to 8, wherein the fluid conveying device (8) is located at least partially, preferably completely, in one of the gussets (24) formed by a smallest imaginary cuboid (25) over the inner tank (2) or the outer container (3).

10. System (9) according to any one of claims 1 to 9, wherein the pipe is connected to the lowest point of the inner tank (2) and is led from there to the fluid conveying device (8).

11. System (9) according to any one of claims 1 to 10, wherein the fluid conveying device (8) is located in the vacuum-insulated space between the inner tank (2) and the outer container (3).

12. System (9) according to any one of claims 1 to 11, wherein both the cryogenic container (1) and the fluid delivery device (8) are rod-shaped and the cryogenic container (1) and the fluid conveying device (8) have a longitudinal axis which is contained in a vertical plane which lies in the normal direction of travel of the vehicle (29).

13. System according to any one of claims 1 to 12, wherein the fluid conveying device (8') is rod-shaped and a longitudinal axis of the fluid conveying device (8') is inclined with respect to a horizontal plane, wherein the end at which the fluid conveying device (8') is connected to the pipe (7) and / or to the vent line (14) is higher than the end which is not connected to the pipe (7) and / or to the vent line (14).

14. System (9) according to any one of claims 1 to 13, wherein the section (12) rising in the direction of the fluid conveying device (8) rises within the area (B) by a height which corresponds to at least twice the diameter of the pipe (7) at the connection point to the fluid conveying device (8).

15. System (9) according to any one of claims 1 to 14, wherein the pipe (7) is more flexible over at least one functional section (28) than outside the functional section (28) and / or wherein the pipe (7) has a thinner wall thickness over at least one functional section (28) than outside the functional section (28) or wherein the pipe (7) is designed as a bellows pipe over at least one functional section (28).