Pressure Vessels

Abstract

The invention relates to a hybrid pressure vessel having a fiber composite component and a metal component. The invention also relates to a production method for such a hybrid pressure vessel. The hybrid pressure vessel according to the invention has a liner with an inner surface and an outer surface, with an outer diameter DL, and a metal boss with an outer diameter DB, which is suitable for accommodating a valve, the hybrid pressure vessel having a storage volume in the interior, the liner being tubular, and the outer diameter DB of the boss being at least as large as the outer diameter DL of the liner.

Description

Technical Field

[0001] The invention relates to a hybrid pressure vessel having a fiber composite component and a metal component. The invention further relates to a method for producing such a hybrid pressure vessel. Background Art

[0002] The market for pressure vessels, in particular those reinforced with fiber composite materials (abbreviated here and below as "FCM"), continues to grow. The increased production of natural gas and fracked gas makes it necessary to store them in pressure vessels, in particular in countries without a corresponding pipeline network. In addition, the automotive industry, which is heavily involved in the development of fuel cell vehicles, requires that the fuel be stored in pressure vessels in the form of gaseous hydrogen under high pressure. Other types of vehicles using hydrogen can be railway vehicles, aircraft or ships. Even in spacecraft, applications are conceivable. With regard to the transportation of pressure vessels, it is desirable that they should be lightweight pressure vessels, since the transportation of heavy-weight pressure vessels is associated with the consumption of unnecessary large amounts of energy, resulting in excessively high transportation costs.

[0003] The cylindrical fiber-reinforced pressure vessels currently in use have a reinforcement layer consisting of an FCM made of fibers embedded in a matrix material which is wound as an outer layer by a winding method onto an inner container of the pressure vessel, known as a liner, which serves as a winding core. Winding is the preferred process for producing the fiber composite layer, which is efficient in terms of time and cost. While the inner container, for example, ensures the gas-tightness of the pressure vessel, the reinforcement layer made of FCM provides the pressure vessel with the necessary mechanical stability. For type 3 pressure vessels, a metal inner container (metal liner) consisting, for example, of aluminum or steel is used; in the case of type 4 pressure vessels, the non-load-bearing inner container (liner) is made of plastic. Plastic liners are usually produced by blow molding, rotational molding or welding of separate components. Due to the specific manufacturing methods, the most commonly used materials are thermoplastics, such as polyamides, or polyethylene, in particular high-density polyethylene.

[0004] The metal boss is used to connect valves or as the end of a Type 4 container; in this case, it can be embodied as a closed boss. The outer diameter of the boss is much smaller than the outer diameter of the liner.

[0005] Pressure vessels have to withstand very high internal pressures. Currently, for example, hydrogen tanks for cars are filled with a pressure of about 700 bar. In particular, the pressure vessel must not burst even in the event of a collision. Such pressure vessels are therefore designed with a cylindrical center part that is closed on both sides by so-called "pole caps." The FCM is wound as a reinforcement layer onto the cylindrical center part and the pole caps. The reinforcement layer can be produced, for example, with a fiber winding method, in which the winding of the pressure vessel takes place in a separate operation. In other words, the fibers are wound circumferentially or crosswise or in the form of spiral layers onto the plastic lining in one operation.

[0006] The connection between the boss and the pressure vessel is particularly important. The boss must be connected to the pressure vessel in a pressure-resistant manner, since it must withstand high internal pressures; the same applies to its connection to the pressure vessel. The boss must also be tightly connected to the pressure vessel. Hydrogen is a highly explosive gas with very small molecules; therefore, it is particularly important for the transport of hydrogen that the pressure vessel is completely sealed, even for hydrogen at high pressures.

[0007] According to German patent application DE102016221978A1, a hybrid component made of a hollow fiber composite component and at least one metal force transmission component is known, the at least one metal force transmission component being used to transmit force to the fiber composite component via the force transmission component, the fiber composite component comprising a first end and a second end along a provided main axis, wherein at least the first end is an open end. At least one first portion of the open end has an inner surface facing the main axis and an opposite outer surface extending along the main axis, the first portion tapering in the direction of the first end. The force transmission component comprises a correspondingly formed inner core for resting on the inner surface of the first portion and a metal outer rim for at least partially resting on the outer surface of the first portion with an inner force transmission surface adapted to the inner core and the first portion, the inner core and the outer rim being suitably adjusted so that after the outer rim has been placed on the first portion, the inner core can be pulled through the first open end by a traction connection in the direction of the outer rim, so that in this way a suitable press fit of the outer rim can be produced on the FCM of the first portion so that force can be transmitted to the fiber composite component via the force transmission component. However, the mixing assembly is not suitable as a pressure vessel because it does not have a liner and a boss through which the mixing assembly can be filled and evacuated.

[0008] From French patent application FR1554072A a mixing pressure vessel is known having a liner with an inner surface and an outer surface with different outer diameters depending on the translational position, and a metal boss with an outer diameter suitable for housing a valve.

[0009] According to US patent application US5758796A, a pressure vessel is known, which comprises a liner with an end wall arrangement, which is formed by combining two rigid end wall elements at a fixed mutual distance by a connecting element and an elastic circumferential wall plate fixed to the two end wall elements so as to close a space between them. The two end wall elements are formed from an aluminum alloy by an extrusion process. The connecting piece is a tube made of an aluminum alloy, which is manufactured by an extrusion process and has a large number of connecting holes in the tube wall. The circumferential wall plate consists of an aluminum foil and is cylindrical so as to close the space between the two end wall elements. A spiral reinforcement layer and a belt reinforcement layer are provided around the liner, both of which consist of glass fibers.

[0010] According to German patent application DE102011105627A1, a method for assembling a composite pressure vessel is known. The end of a tubular element is assembled into a circular groove formed in an end cap. A sealing device can be located in the circular groove. The end cap includes an annular groove in the outer surface of the end cap body portion. A first material layer is formed on the outer surface of the tubular element. The first material layer includes a first composite material with fibers oriented in a circumferential direction relative to the tubular element. A second material layer is formed on the first material layer, and a portion of the second material layer is arranged in an annular groove, including a second composite material, which includes fibers oriented axially relative to the tubular element. A third material layer is adjacent to the second material layer and is formed in the annular groove, including a third composite material with fibers having an orientation in a circumferential direction relative to the tubular element.

[0011] For reasons of installation geometry, it is desirable to have corresponding pressure vessels with a small outer diameter. In pressure vessels with a small outer diameter, the ratio between the outer diameter of the boss and the outer diameter of the liner is much smaller or almost equal. On the one hand, the valve must be accommodated, requiring a minimum outer diameter of the boss; on the other hand, the production of very long liners is not without disadvantages, especially in mass production methods such as blow molding or rotational molding. Summary of the invention

[0012] The object of the present invention is to provide a hybrid pressure vessel having an outer diameter which is as small as possible and an outer diameter of the liner which is within the range of the outer diameter of the boss, which hybrid pressure vessel meets the same burst safety and leak-tightness requirements as known hybrid pressure vessels having a larger outer diameter. Furthermore, the object of the present invention is to provide a method for the production of such a hybrid pressure vessel.

[0013] The first object is achieved by a hybrid pressure vessel having a liner with an inner surface and an outer surface, an outer diameter DL, and a metal boss with an outer diameter DB, which is suitable for accommodating a valve, the hybrid pressure vessel having a storage volume inside, the liner being tubular, and the outer diameter DB of the boss being at least as large as the outer diameter DL of the liner.

[0014] The term "pressure vessel" includes all types and shapes of pressure vessels, which include an inner container, also referred to as a liner, for example made of a thermoplastic material, which has been mechanically reinforced on the outside by a fiber composite material so that the pressure vessel meets the requirements in terms of pressure resistance. In the present disclosure, a hybrid pressure vessel is understood to be a pressure vessel composed of different materials, in particular a plastic liner and a metal boss. Known pressure vessels are cylindrical and have raised terminals on both sides of a cylindrical center part. These terminals are called pole caps and are used for pressure-tight sealing of the center part. In order to strengthen the pressure vessel, an outer layer made of a fiber composite material is wrapped around the outside of the inner container, possibly forming the outer surface of the pressure vessel at the same time. The inner container can be produced by various techniques, for example by welding, injection molding or blow molding. After production, for example by welding, the pole caps can also be placed on the center part. For example, a separate pole cap can be manufactured by injection molding. On the one hand, pressure vessels with thermoplastic inner containers have a very low weight, which is important, for example, for applications in means of transport, and on the other hand, since suitable thermoplastics have a sufficiently low hydrogen permeability and the outer layer made of fiber composite materials provides the required rigidity, for example hydrogen contents can be stored at high pressure with low losses.

[0015] A hybrid pressure vessel is a pressure vessel composed of several different materials.

[0016] Typically, the fiber composite material FCM used for the fiber composite layer consists of two main components, which are fibers in this article, embedded in a matrix material that creates a strong bond between the fibers. The fiber composite material can be wound by one fiber or by a plurality of fibers, wherein the fibers are wound close to each other and in contact with each other. The wound fibers have been impregnated with a matrix material. This results in a fiber layer on which additional fibers are wound in another fiber layer until the fiber composite material has the desired thickness and forms a corresponding fiber layer with this thickness. The outer layer is wound with several plies made of a fiber composite material, wherein different plies may contain fibers arranged at different fiber angles relative to the cylindrical axis of the pressure vessel. In one embodiment, each fiber layer made of the first and / or additional fibers (e.g., the second fibers) comprises a plurality of fiber plies. Composites give the fiber composite material higher quality properties, such as higher strength, than any of the two individual components involved can provide. When the elastic modulus of fiber in the longitudinal direction exceeds the elastic modulus of matrix material, when the elongation at break of matrix material exceeds the elongation at break of fiber, or when the fracture resistance of fiber exceeds the fracture resistance of matrix material, the reinforcing effect of fiber in the fiber direction is realized. The fiber that can be used is any kind of fiber, such as glass fiber, carbon fiber, ceramic fiber, steel fiber, natural fiber or synthetic fiber. The matrix material for fiber composite layer is usually thermosetting plastic. The material properties of fiber and matrix material are known to those skilled in the art, and as a result, those skilled in the art can select the appropriate combination of fiber and matrix material to produce fiber composite materials for specific applications. In this article, the separate fiber layer in the fiber composite area can include a single fiber or a plurality of identical or different fibers.

[0017] The term "thermoplastic" refers to plastics that can be thermoplastically deformed within a specific temperature range. This process is reversible, i.e., can be repeated an unlimited number of times by cooling and reheating to the molten state, provided that the material does not thermally decompose due to overheating. This distinguishes thermoplastics from thermosets and elastomers. Another unique feature of thermoplastics is that, contrary to, for example, thermosets, they can be welded.

[0018] The term "tubular" refers here to a shape which corresponds at least substantially to a substantially circular tube, in particular a tube having a substantially constant inner and outer diameter, respectively. In particular, an essential feature of a tubular liner is that it can be cut to length from a circular tube within the limits of common manufacturing tolerances, independently of whether the diameter of the tube is partially or completely modified again in a subsequent manufacturing step.

[0019] The liner of the hybrid pressure vessel according to the invention does not have a pole cap known from the prior art. In particular, the outer diameter of the hybrid pressure vessel according to the invention is determined by the boss, which, due to the need to accommodate the valve, must have a certain minimum diameter. In particular, the outer diameter of the liner of the hybrid pressure vessel according to the invention is on the order of magnitude of the outer diameter of the boss. In this way, the hybrid pressure vessel according to the invention can also be installed in small installation spaces, for example in vehicles. Since the shape of the liner is not a true three-dimensional shape, the liner is also very easy to manufacture. The two-dimensional cross-section of the tubular liner is essentially circular, wherein its third dimension can be described by only one parameter, namely its length. Therefore, such a liner does not have to be manufactured by the methods commonly used in the prior art for the manufacture of the liner, such as blow molding, rotational molding or welding of separate components. Instead, simpler production methods such as extrusion, pultrusion or spinning can also be used. By this method, the corresponding semi-finished products can also be manufactured in large lengths very accurately and economically, and tubular linings can also be produced by simply cutting such semi-finished products to a certain length.

[0020] With a large ratio of the outer diameter of the boss relative to the outer diameter of the liner, the reinforcing fibers required for reinforcing the container can be deposited in a well-defined manner in the circumferential direction until the outer diameter of the boss is reached. This is advantageous in terms of loads, since the circumferential plies will be optimally positioned on the inner surface of the laminate. The transition between the outer contours of the liner and the boss can be coordinated and thus correspond to the loads.

[0021] The liner is made of a plastic material that is at least partially plastically deformable under pressure, and the hybrid pressure vessel additionally has at least one outer layer applied to the liner for reinforcing the liner and a boss with an extrusion ring and a mating piece for accommodating a valve and sealing a storage volume relative to the liner, the liner comprising a cylindrical connecting area with an outer surface and an inner surface for connecting the boss; the extrusion ring is positioned on one side of the connecting area of ​​the liner, and the mating piece is positioned on the other side of the connecting area of ​​the liner, for generating a sealing pressure between the extrusion ring, the connecting area of ​​the liner and the mating piece; the mating piece has a suitably formed groove on its side facing the connecting area of ​​the liner, the groove having a first edge facing the storage volume and a second edge in the opposite direction, for accommodating a sealing ring sealed under sealing pressure; the dimensions of the groove and the sealing ring are determined and the lining material is provided to form a first sealing bead and a second sealing bead, which, under the sealing pressure, protrude at least into two gaps between the sealing ring and the first edge and the second edge, respectively, due to the plastic deformation ability of the lining material.

[0022] The inner container consists of a plurality of parts, at least a tubular liner and a boss at the end face of the tubular liner. At least one boss is suitable for accommodating a valve for filling or removing a medium from the mixing pressure container, respectively. The boss on the opposite side can be embodied as a closed boss.

[0023] The plastically deformable inner container material has its own firm and stable characteristics, and at the same time has a certain fluidity, so that it can be plastically deformed under high pressure at least at its surface, and is therefore suitable for the contour of the extruded surface without large deformation. In addition, the inner container has the function of providing an airtight storage volume for storing the filling gas in the pressure vessel, so that the inner container material should be airtight, such as metal or plastic; in the case of plastic, PA or PE is preferably used as a single-layer or multi-layer system. The filling gas can be any gas, such as hydrogen. In particular, because of the simple manufacturing method, materials that are not suitable for methods known in the prior art (such as blow molding, rotational molding or welding) can be selected for semi-finished lining products. Such materials, such as UHMW-PE (ultra-high molecular polyethylene) or PET, for example, can also have better permeability characteristics and / or better temperature performance, in particular better low-temperature performance, and less water absorption than materials commonly used to produce linings. The outer layer provides mechanical stability for the pressure vessel, so that the functions of gas impermeability and pressure resistance are divided between the two components, the inner container and the outer layer. The outer layer may be, for example, a fiber composite layer that is wrapped around the inner container or applied to the inner container by other techniques.

[0024] The sealing ring positioned in the groove does not completely fill the groove in the counterpart, but leaves a gap on both sides of the groove toward the inner surface of the counterpart, and the first gap and the second gap are used to provide redundancy of the sealing effect. The configuration of the assembly of the boss, combined with the appropriate fluidity of the inner container material and the sealing bead formed subsequently, ensures an improved sealing effect while ensuring the reliable positioning of the assembly of the boss in the pressure vessel. In addition, even if the two sealing beads cause pressure changes, the sealing ring is stably maintained in the groove. This sealing concept provides triple redundancy when sealing the storage volume: the series seal (I) is relative to the first sealing bead protruding from the counterpart, (II) is toward the sealing ring via the connection area of ​​the liner, and (III) is relative to the second sealing bead of the liner in the connection area of ​​the boss, which greatly improves the reliability and durability of the seal. By forming the sealing bead due to the sealing pressure applied by the boss, the boss is additionally self-sealing. The sealing concept is independent of the material of the extrusion ring and the material of the boss, however, the same material has at least less fluidity than the inner container material.

[0025] Due to the sealing concept according to the invention, the specific pressure vessel has a very flexible structure, so that customized bosses can be easily adapted by appropriate configuration of the squeeze ring. In addition, the integration of additional sleeves for integrating sensor systems, measuring sensors or other components protruding into the pressure vessel is still possible.

[0026] In a further advantageous embodiment, the compression ring is positioned on the inner surface of the connection region of the liner and the counterpart is positioned on the outer surface of the connection region of the liner to generate a sealing pressure between the compression ring, the connection region of the liner and the counterpart.

[0027] This principle can also be reversed. In an alternative embodiment, the extrusion ring is positioned on the outer surface of the connection area of ​​the liner, and the counterpart is positioned on the inner surface of the connection area of ​​the liner to generate a sealing pressure between the extrusion ring, the connection area of ​​the liner and the counterpart. However, in this embodiment, the sealing concept that provides for the gas inside the pressure vessel to flow around the end face of the liner, thus contributing to the sealing effect, is not applied.

[0028] In one embodiment, the squeeze ring is dimensioned such that the inner container material, due to its plastic deformation capacity, forms a third bead around the squeeze ring on its bottom side pointing toward the storage volume. In this way, a sliding of the squeeze ring toward the storage volume is prevented. In this way, the initially set sealing pressure on the sealing ring is maintained. Moreover, in the event of an impact to the pressure vessel, the squeeze ring can no longer slide or fall into the storage volume.

[0029] In another embodiment, the squeeze ring or counterpart is formed so that there is an open gas connection to the storage volume between the storage volume and the upper end of the connection area of ​​the liner. Thus, the pressure inside the storage volume also exists at the top of the connection area of ​​the liner.

[0030] In a further embodiment, the pressing ring comprises an outer surface facing the connection area of ​​the liner and an opposite inner surface, the area of ​​the outer surface of the pressing ring resting on the connection area of ​​the liner being smaller than the area of ​​its inner surface. Due to the different area ratios between the inner surface and the outer surface, there is a gas connection between the storage volume and the upper end of the connection area of ​​the liner, the sealing pressure is additionally increased by the pressure inside the storage volume of the pressure vessel, and if the pressure in the storage volume increases (for example, if the storage volume is filled with gas, for example, up to 500 bar), the pressing ring is additionally pressed against the counterpart, further increasing the sealing effect and its reliability.

[0031] The groove may comprise a contour adapted to the shape of the sealing ring in a stress-free state. In this way, no undefined cavity is formed behind the sealing ring, further improving the sealing effect of the sealing ring.

[0032] The sealing ring may be an O-ring. On the one hand, the O-ring has reliable sealing properties and on the other hand, a suitable profile inside the groove most easily provides this type of ring. The curvature of the groove is adapted to the curvature of the surface of the O-ring. The sealing ring, i.e. in this case the O-ring, may be made of any material suitable for gas sealing.

[0033] The boss may comprise an additional safety element interconnecting the compression ring and the counterpart. This prevents the compression ring from sliding relative to the counterpart, in particular towards the counterpart.

[0034] The safety element can be supported in the counterpart and at least on its side facing the extrusion ring comprises a thread, which is arranged for engaging the upper end of the extrusion ring. The safety element can be, for example, a banjo bolt or a correspondingly shaped ring with a passage opening for exerting pressure on the upper end of the connection area of ​​the liner.

[0035] The counterpart of the valve connector can include a connection device for accommodating the valve so as to be stable with respect to pressure. For example, the valve can be screwed into the corresponding thread in a pressure-resistant manner as the connection device of the counterpart.

[0036] In another advantageous embodiment, the counterpart has at least one additional appropriately shaped groove for absorbing axial forces on its side facing the connection area of ​​the liner. In this way, axial forces can be absorbed very easily because it is easy to form a counterpart with an additional groove.

[0037] The liner can be made of a thermoplastic material. This is the obvious choice, as thermoplastics can be easily and cheaply processed to form a semi-finished pipe. The liner can consist of, for example, HDPE, PA, UHMW-PE or PET.

[0038] Alternatively, the thermoplastic lining material may also be a fiber-reinforced thermoplastic. In one embodiment, the reinforcing fibers may be carbon fibers.

[0039] Alternatively, the liner can be made of a thermosetting material, in particular a fiber-reinforced thermosetting material. The hybrid pressure vessel according to the invention has a tubular liner. Tubular liners or semi-finished liners consisting of thermosetting plastics are relatively easy to manufacture, for example using a pultrusion process. In this way, thermosetting liners can be produced inexpensively. They can also offer advantages in terms of stability and permeability.

[0040] The present invention further relates to a method for manufacturing a hybrid pressure vessel according to the present invention, the method comprising the following steps:

[0041] 1) Provide prefabricated tubular lining,

[0042] 2) placing the extrusion ring into or onto the connection area of ​​the liner,

[0043] 3) forming at least a first sealing bead and a second sealing bead which, in the case of a groove and a sealing ring of corresponding dimensions, under the sealing pressure, due to the plastic deformation capacity of the lining material, protrude into the two gaps between the sealing ring and the first edge or the second edge, respectively, in order to seal the storage volume to be produced,

[0044] 4) manufacturing an outer layer on the lining, and

[0045] 5) Position the valve (5) into the boss (4).

[0046] With the manufacturing method according to the invention, a hybrid pressure vessel can be efficiently manufactured, the outer diameter of which is determined by the boss. In particular, for the hybrid pressure vessel according to the invention, the outer diameter of the liner can be on the order of magnitude of the outer diameter of the boss; in this way, it can also be installed in a small installation space, for example in a vehicle. The shape of the liner is not a true three-dimensional shape. The tubular liner has a substantially circular cross-section as a two-dimensional shape; its third dimension can be described by only one parameter, namely the length. Therefore, such a liner does not have to be produced by the methods commonly used in the prior art for the manufacture of the liner, such as blow molding, rotational molding or welding of separate components. On the contrary, there are also simpler manufacturing methods, such as extrusion, pultrusion or spinning. With this method, the corresponding semi-finished product can be manufactured very accurately and economically, and also in large lengths, the tubular liner being produced by simply cutting such a semi-finished product to a certain length.

[0047] In a further advantageous embodiment, the method further comprises the step of forming a third bead around the extrusion ring on the bottom side of the extrusion ring facing the storage volume due to the plastic deformability of the lining material.

[0048] In another advantageous embodiment, the outer layer has an inner ply and an outer ply, the outer ply being wound around the inner ply and the boss. By separating into different plies, each ply can be made of a different material. The outer ply is a fiber composite layer.

[0049] In another advantageous embodiment, the prefabricated semi-finished tube of the inner ply is a fiber composite tube covered with a circumferential ply having an angle increasing from the inside to the outside relative to the longitudinal axis of the fiber composite tube. The winding angle can be increased, for example, from 80° to 84° and then to 88°. In this way, the load on the circumferential packing is made more uniform. This can be achieved, for example, by changing the roving number.

[0050] The inner ply can also be manufactured separately, for example prefabricated as a tube, which offers advantages in terms of straightness and roundness, especially if the inner ply is also wound as a fiber composite ply, since it can be manufactured precisely on a metal winding mandrel.

[0051] The cylindrical semi-finished tube can be extruded.

[0052] Cylindrical semi-finished tubes can also be produced by pultrusion or by spinning.

[0053] All of these methods have been proven to be effective, depending on the material to be treated. A person skilled in the art knows these methods and can select a method suitable for the material to be treated.

[0054] In another advantageous embodiment, the tubular liner is cut to length from a cylindrical semi-finished tube. In other words, the semi-finished product is not a tubular liner, but a tubular liner cut to length from a longer tube. The manufacture of a longer semi-finished product has advantages in terms of efficiency over the individual forming of the tubular liner.

[0055] In a further advantageous embodiment, the outer plies are wound from FCM at a winding angle of between 30° and 90°, preferably between 35° and 90°, particularly preferably between 40° and 90°, relative to the longitudinal axis of the liner. The ratio between the outer diameter of the liner or container, respectively, and the neck of the boss results in a winding angle in the second laminated package to be wound, which does not require consolidation by additional circumferential plies. Since in this embodiment the boss completely absorbs the internal pressure, the fibers of the second laminated package only need to absorb the axial forces of the boss generated by the internal pressure, and not the radial forces generated in type 4 containers according to the prior art.

[0056] In another advantageous embodiment, the connection area of ​​the tubular liner is constricted. The constriction can be performed, for example, by temperature effects and can be cylindrical or conical. The constriction can result in slightly more wall thickness in the outer area of ​​the boss for accommodating the liner.

[0057] In another advantageous embodiment, the extrusion ring is brought into position by means of a mounting device. In the case of an internal extrusion ring, the ring can be positioned by means of a mounting device, for example by means of bosses, to facilitate mounting.

[0058] In a further advantageous embodiment, the extrusion ring is subjected to a temperature treatment before installation, so that at installation there is a large temperature difference between the ring and the liner, due to which the extrusion ring is placed on the liner or inserted into the liner with clearance until its desired position, in which the extrusion ring presses the liner by balancing its temperature with the temperature of the liner. The ring can be placed in its final position, for example, by vertically positioning the mixing pressure vessel and lowering the extrusion ring into its final position by gravity. If a magnetic material is used for the extrusion ring, it can be brought into its final position by using magnets on the outside, even if the extrusion ring is located on the inside. This also helps to facilitate installation.

[0059] The embodiments listed above can be used alone or in any combination to implement the device according to the invention, even deviating from the mutual references in the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] These and other aspects of the present invention are illustrated in detail in the accompanying drawings as follows:

[0061] Figure 1 shows in cross section a portion of a mixing pressure vessel according to the invention;

[0062] Figure 2 It is a schematic representation of the sealing concept;

[0063] Figure 3 shows in cross section a portion of another embodiment of a mixing pressure vessel according to the invention;

[0064] Figure 4 A portion of a further embodiment of a mixing pressure vessel according to the invention is shown in cross section. DETAILED DESCRIPTION

[0065] Figure 1 A portion of a hybrid pressure vessel 1 according to the invention is shown in cross section. The pressure vessel has a tubular liner 2 covered by an inner sheet layer 31 and an outer sheet layer 32 of an outer layer 3. The inner sheet layer 31 of the outer layer is also tubular. The end face of the inner sheet layer 31 abuts against a counterpart 42 of a boss 4 forming a terminal of the hybrid pressure vessel 1. The boss 4 is formed of a metallic material. The outer sheet layer 32 is wound around the inner sheet layer 31 of the outer layer, which also partially covers the boss 4, so that the boss 4 is integrally connected to the tubular liner 2 and the inner sheet layer 31 of the outer layer 3. The outer diameter of the hybrid pressure vessel 1 is determined by the outer diameter of the boss 4, which must have a certain minimum diameter due to the need to accommodate a valve 5 (not shown in the figure). In particular, the outer diameter of the liner 2 is of the order of magnitude of the outer diameter of the boss 4. Due to the diameter ratio of the outer diameter of the boss 4 being greater than the outer diameter of the liner 2, in the case of a fiber composite tube, the reinforcing fibers of the inner ply 31 of the outer layer 3 required for reinforcing the container can be deposited in a clearly defined manner until the outer diameter of the boss 4 is reached. This is advantageous in terms of load stresses, because optimally, the circumferential plies will be positioned on the inner surface of the laminate. The transition between the outer contours of the liner 2 and the boss 4 can be coordinated and therefore consistent with the load. Internally, in the connection area 23 of the liner 2, there is an extrusion ring 41, which squeezes the liner 2 onto the counterpart 42 of the boss 4 in the connection area 23 of the liner 2. There are at least two grooves 421 in the counterpart 42. One of these grooves 421 contains a sealing ring 6 in the form of an O-ring.

[0066] Figure 2 Schematic representation of a sealing concept with a counterpiece 42, the connection region 23 of the boss 2, the squeeze ring 41 and the formed sealing beads 24a, 24b, 24c. Figure 2In a, the inner surface 42i of the counterpart 42 slides on the outer surface 23a of the connection area 23. The sealing ring 6, embodied here as an O-ring, is positioned in the groove 421, wherein gaps L1 and L2 exist relative to the edges 421a and 421b, wherein no material of the O-ring 6 is present in the gaps. In addition, the groove 421 has a contour adapted to the shape of the O-ring 6 in an unloaded state, so that the ring does not twist when the counterpart 42 slides. After the counterpart 42 has slid on the connection area 23, the O-ring 6 is compressed, so that the gaps L1 and L2 are reduced, but still exist due to the size of the groove 421 and the O-ring 6. At this time, a sealing bead has not yet been formed, since the sealing pressure AD required for this purpose is only generated after the extrusion ring 41 has been positioned on the connection area 23 from the inside. As Figure 2 As shown in FIG. 2 , the outer surface 41a of the extrusion ring 41 now slides from the inside onto the inner surface 23i of the connection area 23. These two steps (sliding on the counterpart 42 and sliding in the extrusion ring 41) can also be performed in the reverse order. Figure 2 The result shown in Fig. c is the same. When the pressing ring 41 has been placed in the appropriate position on the inner surface 23i of the connecting area 23, the sealing pressure AD acts between the pressing ring 14, the connecting area 23 and the counterpart 42. Due to the sealing pressure AD, in the case of a correspondingly sized groove 241 and an O-ring 6, due to the plastic deformation capacity of the lining material, a first sealing bead 24a and a second sealing bead 24b are formed, which protrude into the two gaps L1, L2 between the O-ring 6 and the first edge 421a and the second edge 421b, respectively, and which together with the conventional seal (O-ring to the connecting area) form a seal of the storage volume SV with triple redundancy relative to the outer surface of the pressure vessel 1. In addition, the pressing ring 41 is dimensioned here so that the lining material, due to its plastic deformation capacity, additionally forms a third bead 24c around the pressing ring 41 on the bottom surface 41u of the pressing ring 41 pointing to the storage volume SV. This third bead 24c supports a seal with triple redundancy as long as the third bead 24c holds the extrusion ring in place and prevents it from sliding or falling into the liner. Figure 2 In Figure c, an embodiment is indicated (shown in dotted lines) in which boss 4 comprises an additional safety element 43 interconnecting extrusion ring 41 and counterpart 42. This safety element 43 is a screw held in counterpart 42, the thread of which establishes a secure connection with a corresponding hole in the upper surface 41o of extrusion ring 41.

[0067] exist Figure 3 In, from Figure 1 The situation is shown in the reverse arrangement; that is, the squeeze ring 41 is now positioned on the outside of the connection area 23 of the lining 2, while the counterpart 42 of the boss protrudes into the connection area 23 of the lining 2 on the inside. Therefore, it must be read in reverse Figure 1 Description.

[0068] exist Figure 4 In, from Figure 1 The situation is basically shown again, in which the lining 2 shrinks in its connection area 23. For example, the shrinkage can occur due to temperature effects, and the shrinkage here is cylindrical. The shrinkage can lead to a slightly greater wall thickness in the outer area of ​​the boss for accommodating the lining. Figure 1 The rest of the description also applies to Figure 4 .

[0069] Reference numerals list

[0070] 1 Mixing pressure vessel

[0071] 2 Lining

[0072] 2i Inner surface of lining

[0073] 2a Outer surface of lining

[0074] 2s End face of lining

[0075] 23 Connection area of ​​lining

[0076] 23i Inner surface of the lining in the connection area

[0077] 23a External surface of the connection area of ​​the lining

[0078] 23o Upper end of the connection area of ​​the lining

[0079] 24a First sealing bead

[0080] 24b Second sealing bead

[0081] 24c Third Bead

[0082] 3 Outer layer

[0083] 31 Inner layer of outer layer

[0084] 32 Outer layer of outer plate

[0085] 4 Boss

[0086] 41 Extrusion Ring

[0087] 41a First side of the extrusion ring

[0088] 41i Second side of the extrusion ring

[0089] 41o Upper end of extrusion ring

[0090] 41u Lower end of the extrusion ring

[0091] 42 matching pieces

[0092] 42i Inner surface of the mating part

[0093] 421 Groove

[0094] 421a First Edge

[0095] 421b Second Edge

[0096] 43 Security Element

[0097] 5. Valve

[0098] 6 Sealing ring

[0099] AD sealing pressure

[0100] GV Gas Connection

[0101] The gap between the first edge or the second edge of L1 and L2 groove and the extrusion ring

[0102] SV storage capacity

Claims

1. A mixing pressure vessel (1) comprising a liner (2) with an inner surface (2i) and an outer surface (2a) having an outer diameter (DL), and a metal boss (4) with an outer diameter (DB), the metal boss (4) being suitable for accommodating a valve (5), the mixing pressure vessel (1) having a storage volume (SV) inside, The liner (2) is tubular, the outer diameter (DB) of the boss (4) is at least as large as the outer diameter (DL) of the liner (2), It is characterized in that The liner (2) is made of a material that is at least partially plastically deformable under pressure, and the hybrid pressure vessel further has at least one outer layer (3) applied to the liner (2) to reinforce the liner (2) and a boss (4) with an extrusion ring (41) and a counterpart (42) for accommodating the valve (5) and for sealing the storage volume relative to the liner (2); the liner (2) includes a cylindrical connecting area (23) with an outer surface (23a) and an inner surface (23i) for connecting the boss (4); the extrusion ring (41) is positioned on one surface (23i, 23a) of the connecting area (23) of the liner (2), and the counterpart (42) is positioned on different surfaces (23a, 23i) of the connecting area (23) of the liner (2) for sealing the storage volume between the extrusion ring (41), the connecting area (23) of the liner (2) and the counterpart (42). (42); the mating piece (42) has a suitably formed groove (421) on its surface (42i) of the connection area (23) facing the liner (2), the groove (421) having a first edge (421a) facing the storage volume (SV) and a second edge (421b) in the opposite direction, for accommodating a sealing ring (6) sealed under the sealing pressure (AD); the dimensions of the groove (421) and the sealing ring (6) are determined and lining material is provided to form a first sealing bead (24a) and a second sealing bead (24b), the first sealing bead (24a) and the second sealing bead (24b) protruding at least in two gaps (L1, L2) between the sealing ring (6) and the first edge (421a) and the second edge (421b) under the sealing pressure (AD) due to the plastic deformation ability of the lining material.

2. The mixing pressure container (1) according to claim 1, It is characterized in that The extrusion ring (41) is positioned on the inner surface (23i) of the connection area (23) of the liner (2), and the counterpart (42) is positioned on the outer surface (23a) of the connection area (23) of the liner (2), for generating a sealing pressure (AD) between the extrusion ring (41), the connection area (23) of the liner (2) and the counterpart (42).

3. The mixing pressure container (1) according to claim 1, It is characterized in that The extrusion ring (41) is positioned on the outer surface (23a) of the connection area (23) of the liner (2), and the counterpart (42) is positioned on the inner surface (23i) of the connection area (23) of the liner (2), for generating a sealing pressure (AD) between the extrusion ring (41), the connection area (23) of the liner (2) and the counterpart (42).

4. The mixing pressure container (1) according to any one of claims 1 to 3, It is characterized in that The extrusion ring (41) is dimensioned so that the lining material, due to its plastic deformability, forms a third bead (24c) around the extrusion ring (41) on its lower surface (41u) pointing towards the storage volume (SV).

5. The mixing pressure container (1) according to claim 1, It is characterized in that The squeeze ring or the counterpart (42) is formed in such a way that an open gas connection (GV) to the storage volume (SV) exists between the upper end (23o) of the connection region (23) of the storage volume (SV) and the liner (2).

6. The mixing pressure container (1) according to claim 5, It is characterized in that The extrusion ring (41) includes a first surface (41a) facing the connection area (23) of the liner (2) and an opposite second surface (41i), and the area of ​​the surface (41a, 41i) of the extrusion ring (42) resting on the connection area (23) of the liner (2) is smaller than the area of ​​the other opposite surface (41i, 41a).

7. The mixing pressure container (1) according to claim 1, It is characterized in that The counterpart (42) has, on its surface (42i) facing the connection region (23) of the lining (2), at least one additional appropriately formed recess for absorbing axial forces.

8. A method for manufacturing a mixing pressure vessel (1) according to any one of claims 1 to 7, It is characterized in that The following steps are involved: 1) providing a prefabricated tubular liner (2), 2) placing an extrusion ring (41) in or on the connection region (23) of the lining (2), 3) forming at least a first sealing bead (24a) and a second sealing bead (24b) which, in the case of a groove (421) and a sealing ring (6) of corresponding dimensions, protrude under a sealing pressure (AD) due to the plastic deformation capacity of the lining material into two gaps (L1, L2) between the sealing ring (6) and the first edge (421a) or the second edge (421b), respectively, in order to seal the storage volume (SV) to be produced, 4) manufacturing an outer layer (3) on the lining (2), and 5) Position the valve (5) into the boss (4).

9. The method according to claim 8, It is characterized in that The method further comprises the step of forming a third bead (24c) (180) around the extrusion ring (41) on its lower surface (41u) facing the storage volume (SV) due to the plastic deformation capability of the lining material.

10. The method according to claim 8 or 9, It is characterized in that The outer layer (3) comprises an inner plate layer (31) and an outer plate layer (32), wherein the outer plate layer (32) is wound around the inner plate layer (31) and the boss (4).

11. The method according to claim 10, It is characterized in that The prefabricated semi-finished tube of the inner plate layer (31) is a fiber composite tube, around which a circumferential plate layer is wound, and the circumferential plate layer has an angle increasing from the inside to the outside relative to the longitudinal axis of the fiber composite tube.

12. The method according to claim 10, It is characterized in that The tubular liner (2) is cut into a certain length from a cylindrical semi-finished tube.

13. The method according to claim 10, It is characterized in that The outer ply (32) is wound by FCM, the outer ply (32) being wound at a winding angle between 30° and 90° relative to the longitudinal axis of the liner (2).

14. The method according to claim 13, It is characterized in that The outer ply (32) is wound at a winding angle between 35° and 90° relative to the longitudinal axis of the liner (2).

15. The method according to claim 14, It is characterized in that The outer ply (32) is wound at a winding angle between 40° and 90° relative to the longitudinal axis of the liner (2).

16. The method according to claim 10, It is characterized in that The tubular lining (2) is constricted in its connection region (23).

17. The method according to claim 10, It is characterized in that The extrusion ring (41) is brought into position by means of a mounting device.

18. The method according to claim 10, It is characterized in that The extrusion ring (41) is subjected to temperature treatment before installation, so that there is a large temperature difference between the extrusion ring (41) and the liner during installation. Due to this temperature difference, the extrusion ring is placed on the liner (2) or inserted into the liner (2) with a gap, and the extrusion ring (41) is brought to its desired position, in which position the extrusion ring (41) compresses the liner (2) by balancing its temperature with the temperature of the liner (2).

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