Tank for pressurized gas
Through a composite structural design, including parallel tubes, end shells, and a filament-wound airtight lining, the problems of lightweighting and airtightness of pressurized gas tanks under high pressure are solved, making them suitable for hydrogen storage on vehicles.
Patent Information
- Application Number
- CN202510848452.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-06-24
- Filing Date
- 2025-06-24
- Publication Date
- 2025-12-26
AI Technical Summary
Existing pressurized gas tanks are difficult to keep lightweight and lack airtightness when subjected to high pressure, especially flat composite material structures that are easily damaged under mechanical stress.
The composite structure design includes parallel tubes and end shells. The tubes are manufactured by extrusion, the end shells are injection molded, the filaments are wound and welded, and the intermediate components are combined to form an airtight lining, ensuring the airtightness and mechanical strength of the structure.
This invention achieves a pressurized gas tank that remains lightweight and airtight under high pressure, making it suitable for use in vehicles, especially hydrogen engines or fuel cell systems.
Smart Images
Figure CN121206362A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The invention relates to a tank for storing pressurized gas. BACKGROUND
[0002] Pressurized gas tanks are commonly used to load a vehicle with gas. The storage pressure of the gas can be high, up to pressures of the order of 1000 bars.
[0003] The gas is for example hydrogen intended to be used to propel the vehicle by direct combustion in a hydrogen engine or by generating electricity in a fuel cell.
[0004] Tanks of this type must be light enough to withstand the pressure involved so as not to reduce the weight budget of the vehicle. It is also known for such tanks to be made of composite material. Known embodiments use a composite structure comprising fibres embedded in a resin matrix. This structure acts as a framework for the tank, guaranteeing its shape and taking up mechanical stresses. However, such a material cannot be gas-tight. The entire inner surface of the structure is therefore lined with a thermoplastic liner to make it gas-tight.
[0005] For the purpose of integrating the tank into the vehicle, it is advantageous for the tank to have a flattened shape. Spherical or cylindrical shapes most likely provide uniform resistance to mechanical stresses caused by the pressure. On the other hand, the more the flattened shape departs from the spherical shape, the greater the mechanical stresses generated.
[0006] Embodiments therefore seek to obtain a flattened tank. SUMMARY
[0007] The invention provides an original solution to this problem using an original embodiment of parallel tubes and structure.
[0008] To this end, the object of the invention is a tank for pressurized gas, in particular pressurized hydrogen, comprising a composite structure and a liner, in which the liner comprises at least two parallel tubes extending substantially in a first direction, and a common end housing sealingly closing all the tubes at each end thereof, and the structure comprises a basic structure surrounding each tube and a general structure surrounding the assembly of tubes and end housing.
[0009] Particular features or embodiments, which can be used individually or in combination, are:
[0010] - the tubes are made by extrusion,
[0011] - the end housing is injection moulded,
[0012] - the end housing is welded to the tube ends,
[0013] - the basic structure is produced by filament winding around the tubes and / or the general structure is produced by filament winding around the assembly of tubes and end housing,
[0014] - the liner also comprises intermediate pieces which take the shape of the cross section of the tube assembly, inserted and welded between the end of the tube and the end shell,
[0015] - one end tube has a partially circular cross section, preferably a substantially D-shaped cross section,
[0016] - the intermediate tubes have an oblong cross section, preferably a rectangular cross section with rounded corners.
[0017] Another object of the application is a method for manufacturing a tank for pressurized gas, in particular pressurized hydrogen, comprising a composite structure and a liner, the method comprising the following steps:
[0018] - manufacturing the tubes by extrusion of two end tubes and at least zero intermediate tubes,
[0019] - creating the elementary structure around each tube by filament winding,
[0020] - assembling the tubes in parallel,
[0021] - welding the end shell to each tube end, preferably by insertion of intermediate pieces,
[0022] - creating the global structure of the assembly around the tubes and the end shell by filament winding. BRIEF DESCRIPTION OF DRAWINGS
[0023] The application will be better understood by reading the following description, given solely by way of example, and in reference to the appended drawings, in which:
[0024] [ Figure 1 ] shows a first end of a tank according to the application in exploded perspective view,
[0025] [ Figure 2 ] shows the other end of the tank of Figure 1 in exploded perspective view,
[0026] [ Figure 3 ] shows the assembled tank shown in Figure 1 in cross section in the plane passing through the X axis of the tubes.
[0027] [ Figure 4 ] shows the complete tank in perspective view.
[0028] List of reference signs
[0029] 1 : tank, 2 : structure, 2e : elementary structure, 2g : global structure, 3 : liner, 4 : tubes, 4th : end tube, 4i : intermediate tube, 5, 6 : end shell, 7, 8 : intermediate piece. DETAILED DESCRIPTION
[0030] Reference is made to Figures 1 to 3 The present invention relates to a tank 1 for pressurized gas, in particular pressurized hydrogen.
[0031] In order to withstand the high pressure exerted by the gas, the tank 1 comprises a structure 2. In order to limit the weight and make it easier to install on a vehicle, this structure 2 is preferably made of composite material. In order to ensure a gas-tight seal that the structure 2 cannot provide, in particular with hydrogen gas having very small molecules, the tank 1 also comprises a liner 3.
[0032] In one inventive feature, the liner 3 comprises at least two parallel tubes 4 extending essentially along a first direction X. The liner 3 also comprises two end shells 5, 6. At each end of the tubes 4, the end shells 5, 6 common to all the tubes 4 seal all the tubes 4. According to this same feature, the structure 2 comprises a basic structure 2e surrounding each tube 4 and a global structure 2g surrounding the assembly of tubes 4 and end shells 5, 6.
[0033] According to another feature, the tubes 4 are produced by extrusion. This feature is particularly advantageous because extrusion makes it easy to produce parts in meters, in industry, of any cross-section and of any length. As will be seen later, the basic structure 2e surrounding the tubes 4 can also be made to any desired length, as needed. This means that the tubes 4, and therefore the tank 1, of any length can be simply and industrially produced by extrusion.
[0034] Another feature consists in the end shells 5, 6 being injection molded.
[0035] In order to ensure the desired gas-tightness, the liner 3, and therefore all the parts 4, 5, 6, 7, 8 of the liner, are advantageously made of a thermoplastic material, such as PA6 or any other plastic material of this type.
[0036] Another feature consists in the end shells 5, 6 being welded to the ends of the tubes 4.
[0037] The reference 2 generally designates the structure and all the parts 2e and 2g of the structure.
[0038] Another feature consists in the structure 2 being produced in two successive layers. In one aspect, the basic structure 2e is produced by winding filaments around each individual tube 4. The basic structure 2e is produced by winding the tubes 4 around the X axis by tilting the spool + / - a° with respect to the X axis, a being between 45° and 90°, preferably between 80° and 90°, so as to cross the filaments. The spool is uniformly offset with respect to the X axis along the length of the tubes 4, so that the spool covers the tube 4 almost over its entire length.
[0039] Filament winding is a well-known composite manufacturing technique. It consists in winding filaments, such as threads, strips, etc., made of fibers, usually glass or carbon, around a shaped piece, a mold or a tube 4, coated with a thermosetting or thermoplastic resin in uncured form during winding, then cured.
[0040] Once each tube 4 has been fitted with its elementary structure 2e by filament winding, all the tubes 4 are joined together. They are closed by end shells 5, 6. The assembly comprising the tubes 4 and the end shells 5, 6 receives the overall structure 2g resulting from the filament winding around the assembly of tubes 4 and end shells 5, 6.
[0041] The overall structure 2g results from the winding around the assembly comprising the tubes 4 and the shells 5, 6 welded to the tubes 4. The winding is then carried out in both directions of the plane of the tank 1, i.e. the X axis and the Y axis. The overall structure 2g covers the entire tank 1, in particular the shells 5, 6 not covered by the elementary structure 2e. At the elementary structure 2e, the overall structure 2g forms a second composite layer.
[0042] The shells 5, 6 are preferably assembled to the ends of the tubes 4 by welding. This welding can be carried out using any welding technique, preferably autogenous welding.
[0043] Direct welding can be tricky due to the constraints inherent in the injection molding of the shells 5 and 6. Furthermore, according to another feature, the liner 3 also comprises intermediate pieces 7, 8. This intermediate piece 7 is essentially flat and essentially occupies the cross-sectional shape of the assembly of tubes 4. It is inserted and welded between the first end of the tubes 4 and the first end shell 5. The other intermediate piece 8 is inserted and welded between the other end of the tubes 4 and the second end shell 6.
[0044] The profile of the intermediate pieces 7, 8 (in Figure 3 More particularly visible in the figure, the profile of the intermediate pieces 7, 8 is designed to join the walls of two adjacent tubes 4 on the tube side 4 and to seal them, and to connect to the edges of the end shells 5, 6 on the end shell side. One objective is to give the liner 3 a continuous closed thickness.
[0045] The tubes, generally denoted 4, are divided into end tubes 4e arranged on either side of the stack of tubes 4 along the Y axis and n intermediate tubes 4i arranged between the end tubes 4e. n is a positive integer or zero. The choice of n allows the width of the tank 1 to be determined at will.
[0046] The tubes 4, 4e, 4i can have any cross-section. This cross-section is essentially constant along the X axis of the tubes 4. The circular cross-section is the most pressure-resistant. The rectangular cross-section optimizes the volume of useful gas. However, excessively protruding edges can create destructive fractures and are therefore avoided.
[0047] Thus, to optimize the filling volume, according to another feature, the intermediate tubes 4i have an oblong cross section, preferably a rectangular cross section with rounded corners. The pressure resistance of the intermediate tubes 4i is also ensured by the two adjacent tubes 4.
[0048] Conversely, to optimize the pressure resistance, according to another feature, the end tubes 4e have a partially circular cross section on the side of the tube 4e that does not have an adjacent tube, and are substantially straight on the side that is adjacent to an adjacent tube 4. The end tubes 4e thus preferably have a generally "D" shaped cross section. Again, here, to avoid cracking, the two edges that appear at the two corners of the "D" are also advantageously rounded.
[0049] The application also relates to a method of manufacturing a tank 1 for pressurized gas, in particular pressurized hydrogen, comprising a composite structure 2 and a liner 3.
[0050] Such a method comprises the following steps. In a first step, the tubes 4 are manufactured, preferably by extrusion. Two dies are used here: a die with a generally rectangular cross section for any intermediate tube 4i, and a die with a "D" shaped cross section for the two end tubes 4e. The tank 1 requires two end tubes 4e and n intermediate tubes 4i, where n is a positive integer and can be zero. In a second step, each tube 4, 4e, 4i is surrounded by a filament-wound elementary structure 2e that reproduces its cross section shape. In a third step, the tubes 4, 4i, 4e, fitted with their elementary structures 2e, are assembled in the final configuration of the tank 1, in a manner with their X axes parallel. In a fourth step, end shells 5, 6 are welded to each end of the tubes 4 to seal the volume of the tank 1. This assembly is preferably carried out by inserting intermediate pieces 7, 8 between the tubes 4 and the shells 5, 6. Once the tubes 4 and the end shells 5, 6 have been assembled, a fifth step produces the overall structure 2g by filament winding.
[0051] The application has been described and illustrated in detail in the attached drawings and in the foregoing description. This must be considered as illustrative and given by way of example, without limiting the application to this description alone. Many alternative embodiments can be adopted.
Claims
1. A tank (1) for pressurized gas, in particular pressurized hydrogen, comprising a composite structure (2) and a liner (3), characterized in that, The liner (3) comprises at least two parallel tubes (4) extending essentially in a first direction (X) and a common end housing (5, 6) sealingly closing all the tubes (4) at each end thereof, and characterized in that the structure (2) comprises a basic structure (2e) surrounding each tube (4) and an overall structure (2g) surrounding the assembly of tubes (4) and end housings (5, 6).
2. The tank (1) according to claim 1, wherein the tubes (4) are produced by extrusion.
3. The tank (1) according to any one of claims 1 or 2, wherein the end housings (5, 6) are injection molded.
4. The tank (1) according to any one of claims 1 to 3, wherein the end housings (5, 6) are assembled to the ends of the tubes (4) by welding.
5. The tank (1) according to any one of claims 1 to 4, wherein the basic structure (2e) is produced by filament winding around the tubes (4) and / or the overall structure (2g) is produced by filament winding around the assembly of tubes (4) and end housings (5, 6).
6. The tank (1) according to any one of claims 1 to 5, wherein the liner (3) further comprises intermediate pieces (7, 8) in the shape of a cross section of the assembly of tubes (4), inserted and welded between the ends of the tubes (4) and the end housings (5, 6).
7. The tank (1) according to any one of claims 1 to 6, wherein the end tubes (4e) have a partially circular, preferably substantially "D" shaped cross section.
8. The tank (1) according to any one of claims 1 to 7, wherein the intermediate tubes (4i) have an oblong, preferably rectangular cross section with rounded corners.
9. A method for manufacturing a tank (1) for pressurized gas, in particular pressurized hydrogen, comprising a composite structure (2) and a liner (3), characterized in that, The method comprises the following steps: - manufacturing tubes (4) by extrusion of two end tubes (4e) and at least zero intermediate tubes (4i), - producing a basic structure (2e) surrounding each tube (4) by filament winding, - assembling the tubes (4) in parallel, - welding end housings (5, 6) to each tube end (4), preferably by inserting intermediate pieces (7, 8), - producing an overall structure (2g) surrounding the assembly of tubes (4) and end housings (5, 6) by filament winding.