DE102017206521A1 - pressure vessel - Google Patents

Abstract

The invention relates to a pressure vessel, preferably a vehicle, comprising a liner for storing a fluid, preferably hydrogen, having a cylinder area and two cap areas at the opposite ends of the cylinder area; and a fiber reinforced laminate surrounding the liner, comprising: a first fibrous layer surrounding the cylinder region and wound around a longitudinal axis of the cylindrical region and a second fibrous layer surrounding the cylindrical region and both cap regions and braided at least in the cap region.

Description

The technology disclosed herein relates to a pressure vessel, in particular for use in a vehicle, and to a method of manufacturing the pressure vessel.

Known pressure vessels typically include a liner and a fiber reinforced laminate surrounding the liner. The liner may be made of a metal, a metal alloy or a plastic. For example, a liner made of aluminum or of an aluminum alloy is expedient. The fuel is stored in the liner and the liner is i.d.R. responsible for the tightness of the pressure vessel. For example, if storing hydrogen, the liner is i.d.R. designed to avoid hydrogen permeation. A metallic design can be load-bearing as well as, like a polymer liner, not load-bearing. Usually, the liner thickness is chosen to be as thin as possible because the strength of the fiber reinforced layer is much higher and thus a thinner overall wall thickness can be achieved

The fiber reinforced layer has i.d.R. Cross and peripheral layers on. To compensate for axial stresses, helical layers are wound. In the i.d.R. cylindrical peripheral area are i.d.R. so-called "hoop layers", which provide for a reinforcement in the circumferential direction. The circumferential positions extend in the circumferential direction of the pressure vessel and are oriented at an angle of close to 90 ° to the pressure vessel longitudinal axis.

It is a preferred object of the technology disclosed herein to reduce or eliminate at least one disadvantage of a previously known solution or to suggest an alternative solution. Other preferred objects may result from the beneficial effects of the technology disclosed herein. The object (s) is / are solved by the subject matter of the independent claims. The dependent claims are preferred embodiments.

Thus, the object is achieved by a pressure vessel comprising a liner. The liner is designed to store a fluid, preferably hydrogen. The pressure vessel is used in particular in a vehicle. The liner is substantially cylindrical and thus has a cylinder area. According to the cylinder area, a longitudinal axis is defined. The two ends of the cylinder area are each closed by a cap area. In at least one of the two cap areas, an opening for a connection can be provided. The cap regions and the cylinder region arranged therebetween are in particular advantageously integrally formed.

The liner surrounds a fiber-reinforced laminate. For the fiber-reinforced laminate are preferably fiber-reinforced plastics (also abbreviated FVK or FKV) used, for example. Carbon fiber reinforced plastics (CFRP) and / or glass fiber reinforced plastics (GRP). The fiber reinforced laminate suitably comprises reinforcing fibers embedded in a plastic matrix. In particular, the matrix material and the nature and the proportion of reinforcing fibers can be varied in order to set the desired mechanical and / or chemical properties. Preferably, continuous fibers are used as reinforcing fibers.

Between the liner and the fiber-reinforced laminate, a transport layer (English: breather layer) may be provided. The transport layer may in particular be designed to be permeable to gas in such a way that fuel diffused through the liner can flow into other regions, for example in the direction of the ends of the pressure vessel. For this purpose, the transport layer can form, for example, microchannels or microcolumns. However, such a transport layer does not have to be provided.

The fiber reinforced laminate comprises a first fiber layer. The first fiber layer surrounds the cylinder region and is wound around the longitudinal axis of the cylinder region. In particular, it is provided that the first fiber layer surrounds the complete cylinder area and leaves the two cap areas free, at least for the most part. The first fiber layer is preferably wound perpendicular to the longitudinal axis. However, it is also provided that the first fiber layer is wound at an angle between -15 ° and + 15 ° to the perpendicular to the longitudinal axis, in particular at an angle between -10 ° and + 10 ° to the perpendicular to the longitudinal axis. The "first fiber layer" is not limited to a single layer. Rather, many layers are preferably wound on top of each other.

Furthermore, the fiber-reinforced laminate comprises a second fiber layer. The second fiber layer is braided at least at the two cap areas. The braiding takes place with at least two fiber strands. The second fiber layer surrounds the two cap areas and possibly the cylinder area.

It is preferably provided that the first fiber layer lies under the second fiber layer. The first fiber layer is applied before the second fiber layer. The second fiber layer preferably rests on the first fiber layer and surrounds the first fiber layer resting on the cylinder region and the two cap regions.

According to an alternative, it is preferably provided that the second fiber layer lies under the first fiber layer. The second fiber layer is applied before the first fiber layer. As a result, the second fiber layer, which is braided at least in the cap regions, lies below the wound first fiber layer. The first fiber layer preferably rests on the second fiber layer and surrounds in the cylinder region the second fiber layer resting on the cylinder region and both cap regions.

For braiding the second fiber layer no finished braided fabrics are laid or wound, but the second fiber layer is directly braided. The "second fiber layer" is not limited to a single layer. Rather, many layers are preferably braided one above the other.

According to a variant, the complete second fiber layer, ie in the cap regions and in the cylinder region, is braided.

In an alternative variant, the second fiber layer is braided in the cap areas and wound in the cylinder area. The braided fiber strands preferably pass directly into the cylinder area and are wound in the cylinder area, so that the same fiber strands are used for the cap areas and the cylinder area.

The arrangement of the first fiber layer, and thus the circumferential layers within or underneath the second fiber layer, as disclosed herein, ensures that the peripheral layers are as close as possible to the liner. As a result, comparatively few circumferential layers have to be used to absorb the internal pressure load, which reduces the total material input for the fiber-reinforced laminate. It is taken into account that the outer layers of the fiber-reinforced laminate are loaded much less. The layers lying further inwards can thus absorb much more tension. The outer braided second fiber layer is at least in the cap areas directly on the liner and thus can ideally absorb the axial load.

When first wound, a "step" builds up in the laminate between the cap and the barrel area. The height of the step corresponds to the thickness of the wound fiber layer. This level can lead to spike and discontinuity. This can be avoided by first applying the braided fiber layer.

It should also be noted that the wound fiber layer is wound in the cylindrical region with a relatively high yarn tension. This can lead to improved compaction of the underlying fibrous layer, which can lead to better mechanical properties, e.g. less pores, high fiber volume content, etc.

Due to the compression of the container wall with increasing internal pressure, the inner layers are stretched more extensively in the circumferential direction than the outer layers. Therefore, in order to achieve more uniform loading of all fiber layers, it is advantageous to position the circumferentially stiffer layers externally, i. So braiding inside, wrapped peripheral layers outside.

On the other hand, there are also advantages in that the wound first fiber layer is arranged inside and the braided second fiber layer outside: The inner peripheral layers are stiffer and stronger and can better support the high stresses (generated from the internal pressure). The braided fibers have an optical advantage because they look better than wound fibers. The overall deformation of the pressure vessel in the circumferential direction may be lower because the rigid layers are inside.

It is also possible to arrange a plurality of first and second fiber layers alternately one above the other. As a result, some of the wound circumferential layers (first fiber layers) are located between braided fiber layers (second fiber layers).

In a preferred embodiment, however, it is provided that all wound circumferential layers are arranged radially within the braided second fiber layer. Respectively. In the alternative embodiment, it is preferably provided that all wound circumferential layers are arranged radially outside the braided second fiber layer. The fiber-reinforced laminate comprises only a first fiber layer and a second fiber layer, so that wound and braided layers are not arranged alternately. This results in a very simple production, since there is no need to change between winding and braiding.

The second fiber layer is braided from at least two fiber strands. The "fiber strand" is a single thread in its simplest form. However, the "fiber strand" can also be a multiplicity of parallel threads or a fabric band. The two fiber strands are alternately superimposed when producing the second fiber layer, so that a braided fiber layer is.

Preferably, the two fiber strands are in the cylinder area, if in the cylinder area is braided, each with an angle α between 20 ° and 70 ° to the longitudinal axis. In each case the smaller or acute angle is measured. Particularly preferably, the angle α is between 30 ° and 60 °.

Furthermore, it is preferably provided that the second fiber layer is braided from three fiber strands. The third fiber strand, which is used in addition to the two fiber strands described above, lies at an angle β between -15 ° and 15 ° to the longitudinal axis. In turn, the smaller or acute angle is measured.

The technology disclosed herein further includes a method of manufacturing a pressure vessel. These are in particular the pressure vessel described above. In the method, the first step is to provide a liner which is designed to store a fluid. The liner has a barrel portion and two cap portions at opposite ends of the barrel portion.

A fiber-reinforced laminate surrounding the liner is produced. For this purpose, a first fiber layer is wound around the cylinder region, wherein the first fiber layer is wound around a longitudinal axis of the cylinder region. The first fiber layer is preferably wound perpendicular to the longitudinal axis. However, it is also provided that the first fiber layer is wound with +/- 15 °, in particular +/- 10 °, deviation from the vertical.

Furthermore, a second fiber layer is applied, which is braided at least at the two cap areas. As already described, the second fiber layer in the cylinder region can also be braided or wound

The winding of the first fiber layer preferably takes place before the application of the second fiber layer. Alternatively, preferably, the second fiber layer is applied first, and then the first fiber layer is wound so that the first fiber layer lies under the second fiber layer.

In a preferred embodiment, it is provided that all wound circumferential layers are arranged radially within the braided second fiber layer. In the alternative embodiment, it is provided that all wound circumferential layers are arranged radially outside the braided second fiber layer. The fiber-reinforced laminate comprises only a first fiber layer and a second fiber layer, so that wound and braided layers are not arranged alternately.

The second fiber layer is braided from at least two fiber strands. The "fiber strand" is a single thread in its simplest form. However, the "fiber strand" can also be a multiplicity of parallel threads or a fabric band. The two fiber strands are alternately superimposed when producing the second fiber layer, so that a braided fiber layer is.

Preferably, the two fiber strands in the cylinder region are each at an angle α between 1 ° and 70 °, preferably between 10 ° and 60 °, to the longitudinal axis.

Furthermore, it is preferably provided that the second fiber layer is braided from three fiber strands. The third fiber strand, which is used in addition to the two fiber strands described above, lies at an angle β between -15 ° and 15 ° to the longitudinal axis.

Preferably, in the method, a tear-off fabric is wound on the first-produced fiber layer. This is followed by a curing of this fiber layer and then a tearing of the tear-off fabric. This results in a rough surface on the fiber layer, which has a positive effect on the adhesion of the further fiber layer.

1. (i) Vorzugsweise wird die erste Faserschicht mit trockenen, nicht-imprägnierten Fasern gewickelt. Vor dem Aufflechten mit trockenen Fasern der zweiten Faserschicht wird die erste Faserschicht mit Harz infiltriert und ausgehärtet. Nach dem Aufflechten mit trockenen Fasern wird die zweite Faserschicht mit Harz infiltriert und ausgehärtet.
2. (ii) Vorzugsweise wird die erste Faserschicht mit pre-imprägnierten (Towpreg) oder nass-imprägnierten (Nasswickeln) Fasern gewickelt. Vor dem Aufflechten der zweiten Faserschicht wird die erste Faserschicht ausgehärtet. Nach dem Aufflechten mit trockenen Fasern wird die zweite Faserschicht mit Harz infiltriert und ausgehärtet.
3. (iii) Vorzugsweise wird die erste Faserschicht mit trockenen, nicht-imprägnierten Fasern gewickelt. Nach dem Aufflechten mit trockenen Fasern der zweiten Faserschicht werden beide Faserschichten mit Harz infiltriert und ausgehärtet.
4. (iv) Vorzugsweise wird die erste Faserschicht mit, pre-imprägnierten Fasern (Towpreg) gewickelt. Nach dem Aufflechten mit pre-imprägnierten Fasern (Towpreg) der zweiten Faserschicht werden beide Faserschichten ausgehärtet.
5. (v) Vorzugsweise wird die erste Faserschicht mit nassen, imprägnierten Fasern gewickelt. Vor dem Aufflechten der zweiten Faserschicht wird die erste Faserschicht ausgehärtet.

Different fibers can be used in the process. This is described here by way of example with reference to the variant in which first the first fiber layer is wound. The reverse order arises when the second fibrous layer is first braided:

1. (i) Preferably, the first fibrous layer is wound with dry, non-impregnated fibers. Before braiding with dry fibers of the second fibrous layer, the first fibrous layer is infiltrated with resin and cured. After being braided with dry fibers, the second fibrous layer is infiltrated with resin and cured.
2. (ii) Preferably, the first fibrous layer is wound with pre-impregnated (towpreg) or wet-impregnated (wet-winding) fibers. Before the braiding of the second fiber layer, the first fiber layer is cured. After being braided with dry fibers, the second fibrous layer is infiltrated with resin and cured.
3. (iii) Preferably, the first fibrous layer is wound with dry, non-impregnated fibers. After braiding with dry fibers of the second fiber layer, both fiber layers are infiltrated with resin and cured.
4. (iv) Preferably, the first fibrous layer is wound with preimpregnated fibers (towpreg). After braiding with preimpregnated fibers (towpreg) of the second fiber layer, both fiber layers are cured.
5. (v) Preferably, the first fibrous layer is wrapped with wet, impregnated fibers. Before the braiding of the second fiber layer, the first fiber layer is cured.

• 1 einen Liner eines hier offenbarten Druckbehälters,
• 2 ein Detail des Druckbehälters mit Liner und faserverstärktem Laminat,
• 3 den Druckbehälter beim Wickeln einer ersten Faserschicht, und
• 4 den Druckbehälter beim Flechten einer zweiten Faserschicht.

The technology disclosed herein will now be explained with reference to the figures. Show it:

• 1 a liner of a pressure vessel disclosed herein,
• 2 a detail of the pressure vessel with liner and fiber reinforced laminate,
• 3 the pressure vessel when winding a first fiber layer, and
• 4 the pressure vessel when braiding a second fiber layer.

The 1 to 4 show a pressure vessel 1 according to the technology presented here and a method for its production.

1 shows a liner 2 of the pressure vessel 1 with a cylinder area 3 and two cap areas 4 at the ends of the cylinder area 3 , The cylinder area 3 is rotationally symmetric to a longitudinal axis 7 , The one cap area 4 has a connection 5 for filling and removing a fluid. In the other cap area 4 there is a lock 6 (Blind Boss).

2 shows in detail a fiber reinforced laminate 8th on the liner 2 , The fiber reinforced laminate 8th comprises a first fiber layer 9 and a second fiber layer 11 , The first fiber layer 9 is located radially inside the second fiber layer 11 , The first fiber layer 9 surrounds the cylinder area 3 , The first fiber layer 9 is at both ends to the cap areas 4 with a rejuvenation 15 educated. The outer edge of the first fiber layer 9 thus approaches tangentially to the cap areas 4 at. The second fiber layer 11 surrounds both the first fiber layer 9 as well as the two cap areas 4 ,

3 shows the production of the first fiber layer 9 , This is a circumferential fiber strand 10 perpendicular to the longitudinal axis 7 around the cylinder area 3 wound. To the cap areas 4 less layers are wound so that the rejuvenation 15 arises.

4 shows the production of the second fiber layer 11 , In the example shown, all peripheral layers and thus the complete first fiber layer 9 radially within the complete second fiber layer 11 arranged. Thus, first of all, the winding of the complete first fiber layer takes place 9 , As already described, but can also first the second fiber layer 11 be braided. In 4 is the first fiber layer for clarity 9 not shown.

The second fiber layer 11 becomes of three fiber strands 12 . 13 . 14 braided. As a basis, two fiber strands are provided. Optional is a braiding with an additional third fiber strand. The first fiber strand 12 and the second fiber strand 13 lie at an angle α of about 45 ° to the longitudinal axis 7 and are intertwined. The third fiber strand 14 lies at an angle β of 0 ° parallel to the longitudinal axis 7 , The third fiber strand 14 is with the other two fiber strands 12 . 13 intertwined and thus lies alternately above and below one of the two fiber strands 12 . 13 , For the sake of clarity, the third fiber strand 14 only schematically drawn. In the cylinder area 3 may be the second fiber layer 11 either braided or wrapped.

The foregoing description of the present invention is for illustrative purposes only, and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.

LIST OF REFERENCE NUMBERS

1

pressure vessel

2

liner

3

cylinder area

4

cap areas

5

connection

6

shutter

7

longitudinal axis

8th

fiber reinforced laminate

9

first fiber layer

10

Circumferential fiber strand

11

second fiber layer

12

first fiber strand

13

second fiber strand

14

third fiber strand

15

rejuvenation

Claims (10)

Pressure vessel (1), preferably a vehicle, comprising • a liner (2) for storing a fluid, preferably hydrogen, with a cylinder area (3) and two cap portions (4) at the opposite ends of the cylinder portion (3); and a fiber reinforced laminate (8) surrounding the liner (2) comprising: a first fibrous layer (9) surrounding the cylinder region (3) wound around a longitudinal axis (7) of the cylinder region (3); second fiber layer (11) which surrounds the cylinder region (3) and both cap regions (4) and which is braided at least in the cap region (4). Pressure vessel after Claim 1 , wherein the second fiber layer (11) in the cylinder region (3) and in the cap region (4) is braided. Pressure vessel according to one of the preceding claims, wherein the second fiber layer (11) of at least two fiber strands (12, 13) is braided, and wherein the two fiber strands (12, 13) at least in the cylinder region (3) with an angle α between 1 ° and 70 °, preferably between 10 ° and 60 °, to the longitudinal axis (7) lie. Pressure vessel after Claim 3 , wherein the second fiber layer (11) is braided from three fiber strands (12, 13, 14), wherein the third fiber strand (14) with an angle β between -15 ° and 15 ° to the longitudinal axis (7). Pressure vessel according to one of the preceding claims, wherein the first fiber layer (9) is wound perpendicular to the longitudinal axis (7). Pressure vessel according to one of the preceding claims, wherein a plurality of the first and second fiber layers (9, 11) are arranged alternately one above the other. Pressure vessel according to one of Claims 1 to 5 wherein the fiber-reinforced laminate (8) comprises only a first and a second fiber layer (9, 11), and wound and braided layers are not arranged alternately. Method for producing a pressure vessel (1) comprising the following steps: Providing a liner (2) adapted to store a fluid, having a barrel portion (3) and two cap portions (4) at opposite ends of the barrel portion (3); and Producing a fiber-reinforced laminate (8) surrounding the liner (2) with: • winding a first fiber layer (9) around the cylinder region (3), wherein the first fiber layer (9) is wound around a longitudinal axis (7) of the cylinder region (3), and Braiding a second fiber layer (11) at least on the two cap areas (4). Method according to Claim 8 in which a tear-off fabric is wound on the first-produced fiber layer (9) and the tear-off fabric is removed to form a rough surface before the further fiber layer (11) is braided. Method according to one of Claims 8 or 9 in which: the first fiber layer (9) produced is applied with dry, non-impregnated fibers and is infiltrated and cured with resin before application of the further fibrous layer (11) of dry fibers, or • the first fiber layer (9) produced pre-impregnated or wet-impregnated fibers is applied and is cured before the application of the further fiber layer (11), or • the first fiber layer (9) is applied with dry, non-impregnated fibers and after the application of the further fiber layer (11 ) from dry fibers, both fiber layers (9, 11) are infiltrated and cured with resin, or • the first produced fiber layer (9) is applied with preimpregnated fibers and after application of the further fiber layer (11) of preimpregnated fiber both Fiber layers (9, 11) are cured, or • the first fiber layer (9) produced is applied with wet, impregnated fibers and is cured before applying the further fiber layer (11).

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