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EP-4402399-B1 - CRYOGENIC CONTAINER COMPRISING A THERMAL BRIDGE SWITCH

EP4402399B1EP 4402399 B1EP4402399 B1EP 4402399B1EP-4402399-B1

Inventors

  • REBERNIK, MATTHIAS

Dates

Publication Date
20260513
Application Date
20220915

Claims (10)

  1. A device (1) comprising a cryogenic container (2), in particular a hydrogen container, comprising an inner container (5) and an outer container (6) enclosing the inner container (5), with a cooling layer (7) being arranged between the inner container (5) and the outer container (6), the cooling layer enveloping the inner container (5) at least partially and being insulated with respect to both the inner container (5) and the outer container (6), with a removal line (10) being routed through the inner container (5) as well as through the cooling layer (7) and the outer container (6), thereby passing through them, characterized in that the device (1) comprises a thermal bridge switch (11) designed for establishing a contact between the cooling layer (7) and the removal line (10) in a closed position so as to form a thermal bridge and for separating the cooling layer (7) from the removal line (10) in an opened position so as to eliminate the thermal bridge.
  2. A device (1) according to claim 1, wherein the cooling layer (7) is a rigid metal shield, preferably an aluminium shield, or a single-layer or multi-layer metal foil and preferably has a greater thickness at end caps (8) of the cryogenic container (2) than at an area between the end caps (8).
  3. A device (1) according to claim 1 or 2, furthermore comprising a control unit (12) which is designed for closing the thermal bridge switch (11) when cryogenic fluid is removed from the cryogenic container (2) via the removal line (10) and for opening the thermal bridge switch (11) as soon as the removal of cryogenic fluid from the cryogenic container (2) via the removal line (10) is stopped, wherein the control unit (12) preferably closes the thermal bridge switch (11) not only when an active removal of cryogenic fluid from the removal line (10) exists, but also when boil-off gas escapes through the removal line (10).
  4. A device (1) according to claim 3, wherein the control unit (12) is designed for closing the thermal bridge switch (11) after a predetermined period of time upon completion of the removal, and/or wherein the control unit (12) is designed for determining a hold time of the cryogenic container (2), the hold time being the time span from the end of the removal until the point in time at which the pressure in the cryogenic container (2) reaches a predefined threshold, with the control unit (12) being designed for closing the thermal bridge switch (11) when the hold time is reached upon completion of the removal.
  5. A device according to claim 3 or 4, wherein a pressure relief valve (14, 19) is provided in the removal line (10) or in a boil-off line (18) connected to the removal line (10) or routed into the cryogenic container (2), and a control line is routed from the pressure relief valve (14, 19) to the control unit (10) via which the triggering of the pressure relief valve (14, 19) can be indicated, and the control unit (10) is designed for closing the thermal bridge switch (10) when the pressure relief valve (14, 19) is opened.
  6. A device (1) according to any one of claims 1 to 5, wherein the thermal bridge switch (11) comprises at least one connecting element made of metal, which particularly preferably comprises a copper mesh (16) surrounding the removal line (10) in the closed state of the thermal bridge switch (11), wherein the connecting element is connected only to the cooling layer (7) in the opened state of the thermal bridge switch (11) and is connected to both the cooling layer (7) and the removal line (10) in the closed state, or vice versa.
  7. A device (1) according to any one of claims 1 to 6, furthermore comprising a boil-off line (18) comprising a valve (19) that opens at a predetermined overpressure, wherein the boil-off line (18) is in a heat-conducting connection with the cooling layer (7) at least over a length of 0.2 m, 0.5 m or 0.8 m and has a cross-sectional area which corresponds at most to half of the cross-sectional area of the removal line (10), wherein the boil-off line (18) preferably has a diameter of a maximum of 10 mm, a maximum of 6 mm or a maximum of 4 mm.
  8. A device (1) according to any one of claims 1 to 7, wherein the cryogenic container (2) has a longitudinal axis (L) which preferably forms an axis of rotation of the cryogenic container (2), with the removal line (10) passing through an end cap arranged essentially normal to the longitudinal axis (L) or through a jacket of the cryogenic container (2) that is located between end caps.
  9. A vehicle comprising an engine and a device (1) according to any one of claims 1 to 8, wherein the removal line (10) is connected to the engine for supplying cryogenic fluid as a fuel for the engine.
  10. A computer program product for a device (1) according to any one of claims 1 to 9 in connection with claim 3, comprising commands which, when the program is executed by a computer, prompt the latter to perform the following steps: - opening the thermal bridge switch (11) when no cryogenic fluid flows through the removal line (10); - closing the thermal bridge switch (11) when cryogenic fluid flows through the removal line (10), at least when cryogenic fluid is actively removed through the removal line (10) and preferably also when cryogenic fluid is discharged from the cryogenic container (2) through the removal line (10) after a predetermined maximum pressure has been reached in the cryogenic container (2) via the removal line (10).

Description

The invention relates to a device comprising a cryogenic container, in particular a hydrogen container, with an inner container and an outer container enclosing the inner container, wherein a cooling layer is arranged between the inner container and the outer container, at least partially enclosing the inner container and being insulated from both the inner container and the outer container, wherein a withdrawal line is led through and passes through both the inner container and the cooling layer and the outer container. According to the state of the art, liquefied gases can be stored in containers ("cryogenic containers") for use as fuel, for example, in an engine. Liquefied gases are gases that exist in the liquid state at their boiling point, the boiling point of 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. In the field of automotive engineering, cryogenic fluid can serve as fuel for a vehicle, for which purpose the cryogenic container is carried on the vehicle. Cryogenic containers are typically mounted on the side of the vehicle frame and must have sufficient insulation to ensure the cryogenic fluid remains at a low temperature for as long as possible, since these containers are not actively cooled, at least when the vehicle is stationary. For example, hydrogen at a temperature of up to -253 °C is introduced into the cryogenic chamber. The cryofluid inside the chamber is continuously heated by the constant heat input, which also increases the pressure within the chamber. Once the pressure exceeds a certain threshold, gaseous cryofluid is released to reduce the pressure. It is evident that there is an effort to improve the insulation of the cryogenic chamber to reduce the heat input and thus increase the time between releases of cryofluid. It is therefore known from the prior art to create the cryogenic container with an inner container and an outer container that is vacuum-insulated from the inner container. Further developments, such as those in the... AT 504 888 B1 revealed provide for Insulating shells, usually made of metal, are provided between the inner and outer containers. These serve two purposes: firstly, as radiation shields, and secondly, to provide thermal mass. This additional thermal mass can be maintained at the temperature of the cryofluid during vehicle operation and absorbs the initial heat input after the vehicle is switched off, thus keeping the cryofluid cold for a longer period. A cryogenic container with a thermally conductive shield between the inner and outer containers is used in the US 3 705 498 A shown, where a thermal bridge exists between the shield and a extraction line. Also the DE 10 2005 035647 shows a cryogenic container in which a pipe system is attached to a cooling shield. The purpose of the invention is now to further develop and optimize such cryogenic containers with cooling layers between the inner and outer containers. This problem is solved in a first aspect of the invention by a device comprising a cryogenic container, in particular a hydrogen container, with an inner container and an outer container enclosing the inner container, wherein a cooling layer is arranged between the inner container and the outer container, at least partially enclosing the inner container and being insulated from both the inner container and the outer container, wherein a withdrawal line is led through and passes through both the inner container and the cooling layer and the outer container, wherein the device comprises a thermal bridge switch configured to establish contact between the cooling layer and the withdrawal line in a closed position to form a thermal bridge and to disconnect the cooling layer from the withdrawal line in an open position to eliminate the thermal bridge. The thermal bridge switch enables, for the first time, the selective creation and separation of heat transfer between the cooling layer and the dispensing line. This can be used, in particular, to cool the cooling layer as quickly as possible when cryogenic fluid is dispensed from the cryogenic container, or to prevent heat input into the cooling layer as soon as no more cryogenic fluid is being dispensed from the cryogenic container, thus keeping the cooling layer cold for as long as possible. This is because, regardless of the temperature of the dispensing line, no heat can flow from the dispensing line to the cooling layer or vice versa, depending on which component has the higher temperature at any given time. This makes it possible to choose an installation location independent of the temperature profile of the extraction line and improves the overall packaging of the system. Without a thermal bridge switch, the connection would have to be made at the point on the extraction line where it has the same temperature as t