Method for manufacturing high pressure composite pressure vessel and related products

Abstract

A method for manufacturing a high pressure composite pressure vessel, wherein the high pressure is 70 bar (1000 PSI or 7 MPa) or more, the method comprising providing an expandable core container, which defines an annular section between end domes. A neatly arranged non-continuous fiber reinforced composite material is wrapped in alignment with multiple load paths present in the expandable core container, and the load paths are located above the annular section and the end domes. The fiber length of the neatly arranged non-continuous fiber composite material in the prepreg tape is at least 5 mm and up to 100 mm. Next, the continuous fiber reinforced composite material is wrapped along the annular section and not along the end domes. The expandable core container can be pressurized and heated to strengthen the composite outer coating. Finally, the container is cooled under pressure to form a high pressure composite pressure vessel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 193,426, filed on May 26, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The invention relates to a pressure vessel, in particular to a high-pressure composite material pressure vessel and a manufacturing method thereof. Background Art

[0004] Hydrogen is a zero-emission fuel and fuel cells using hydrogen can make the most efficient use of the stored energy. The problem is that hydrogen has a very low density and must be compressed at high pressure to store enough energy for many applications. For applications such as ground transportation, e-mobility and especially Urban Air Mobility (UAM), weight reduction must be minimized. Composite wrapped pressure vessels (COPVs) have a high strength-to-weight ratio compared to metal pressure vessels, but existing technologies are not ideal.

[0005] It is well known that composite materials can be used to reduce the weight of pressure vessels since the 1980s. Pressure vessels are classified according to increasing composite content as follows:

[0006] Type I: All metal structure;

[0007] Type II: Metal lining wrapped with composite material only;

[0008] Type III: Metal lining, all-composite outer covering;

[0009] Type IV: All-composite construction with polymer lining; and

[0010] Type V: All-composite structure without lining;

[0011] The most advanced technology for COPV is to use thermosetting composite materials for wire winding. For example, U.S. Patent No. 4,699,288 teaches to use a wire winding layer of thermosetting composite materials and an elastic liner to improve damage resistance. However, the elastic liner increases weight.

[0012] Filament winding is a standard composite manufacturing process that involves the automated winding of continuous fiber composites onto closed cross-section structures such as cylinders. Filament winding involves winding continuous fibers (e.g. carbon fibers) around a polymer liner (in the case of Type IV COPVs) in a thermosetting matrix (e.g. epoxy resin), which is then consolidated at elevated temperatures to cross-link the resin.

[0013] There are several issues with this approach, including: filament winding limits possible fiber paths, resulting in excess fiber at the dome tip (reduced diameter but the same amount of fiber winding); thermoset resin reinforcement causes shrinkage and debonding, causing fiber wrinkling and reducing the ability of the fiber to withstand applied loads; thermoset resins are more brittle than thermoplastic resins, reducing damage resistance.

[0014] The current state of the art attempts to reduce these problems through increasingly sophisticated thermoset composite filament winding strategies. For example, U.S. Patent No. 10,436,388 B2 teaches controlling the wrapping pattern of the filament winding to limit the induced stresses generated during the winding process and the excessive accumulation of end domes. However, the resulting discontinuities can lead to stress concentrations in the structure, thereby reducing structural efficiency and fatigue life. Therefore, the 10,436,388 patent is not suitable for the application of thermoset composite filament winding. Figure 1 and the present patent application Figure 1 A wire-wound COPV is shown, such as the applicant's Figure 2 As shown, the COPV has excessive accumulation at the end domes and interlayer drop, resulting in stress variations.

[0015] There is a need to increase damage tolerance of COPVs to improve safety, increase fatigue life to extend service life, and improve recyclability at the end of service life. Thermoplastic composites can be used to achieve these and other advantages.

[0016] U.S. Patent Nos. 6,716,503B1 and 6,893,604B2 teach a product and method of manufacturing a thermoplastic composite pressure vessel, including cooling and pressurizing the interior while heating the exterior to consolidate a continuous fiber thermoplastic composite. This technology has been shown to achieve fiber translation close to the theoretical value at low pressure (less than 1000PSI, 7Mpa, 70 bar), where fiber translation refers to the value of the theoretical weight of the fiber required to withstand the pressure in the cylinder divided by the actual weight of the fiber. This is because when the fiber is in the molten thermoplastic matrix, the internal pressure forces the fiber to rearrange to distribute the applied load more evenly. It has been proven that this method can reduce weight by 20%, extend fatigue life and improve damage resistance compared to similar thermoset composite pressure vessels. In addition, consistent fiber translation can reduce the variation of burst pressure, thereby reducing the safety factor and further reducing weight. It should be noted that the present invention is not limited to thermoplastic composite COPVs, and is equally beneficial for thermoset and thermoplastic COPVs or their combinations. U.S. Patent No. 6,893,604B2 Figure 2 A method of making a reinforced thermoplastic storage container is shown.

[0017] Data provided by the U.S. Department of Energy on the current status of compressed hydrogen storage technology include the following. Regarding the current state of the art in fiber translational efficiency, Figure 3 . Changes in fiber and manufacturing achieve higher safety factors and weight, providing Figure 4 .

[0018] However, relative to the products and methods of manufacturing the thermoplastic composite pressure vessels described above (see U.S. Patent Nos. 6,716,503B1 and 6,893,604B2), the advantages of this method cannot be realized under high pressure. High pressure here generally refers to pressures above 70 bar (1000PSI or 7Mpa); for example, compressed hydrogen is typically greater than 700 bar and compressed natural gas is typically greater than 200 bar. The reason why it cannot be achieved under high pressure is that high-strength fibers, such as carbon fibers, do not have sufficient elongation to accommodate the expansion of thick-walled laminates due to the volume coefficient during the reinforcement process. When the inner layer expands due to internal pressure, the continuous carbon fibers can only elongate to about 1.5% before breaking, and the breakage may be catastrophic, resulting in rupture. According to the understanding of the art, the volume coefficient refers to the thickness of the unreinforced composite laminate divided by the reinforced thickness.

[0019] In addition, it is well known that continuous fibers can improve strength and modulus compared to non-continuous fibers. For example, the strength and modulus of chopped carbon fibers filled with PEEK polymer are 0.33 and 43GPa respectively, while the strength and modulus of continuous fiber PEEK prepreg are 2.1 and 138GPa respectively (PEEK refers to Polyetheretherkeytone, a high-performance thermoplastic polymer). Prepreg here refers to pre-impregnated composite tape, that is, the fibers are fixed in the polymer matrix in the form of tapes.

[0020] What is needed in the art is a method of making a high pressure composite container for hydrogen storage applications, etc., that is lightweight, damage resistant, low cost, and recyclable, as well as such a high pressure composite container.

[0021] US Patent Nos. 4,699,288; 10,436,388; 6,716,503 Bl; and 6,893,604 are hereby incorporated by reference in their entirety.

[0022] In addition, JP2001074199A discloses a non-continuous fiber reinforced composite internal pressure vessel, which is formed by two injection molded half shells made of non-continuous fiber reinforced composite materials. The two half shells are connected at the edges by welding, and the reinforcement part, such as continuous fiber or strip-shaped unidirectional prepreg, is only wrapped around the welding part.

[0023] US2005 / 0006824A9 discloses a preform and an expandable core consisting of two parts. The expandable core is inserted into one of the preforms and then closed by the other preform. The preform is manufactured by cutting and spreading thermoplastic reinforcing fibers in a mixed form onto a vacuum-supplied screen, and then spraying resin or heating to bond the fibers into the shape of the preform.

[0024] US5822838A discloses a composite outer clad pressure vessel, the inner liner of which is made of a metal with a high elastic modulus and high ductility, a high performance composite outer cladding, and a high performance film adhesive at the outer cladding / liner interface. The metal liner can be made of titanium alloy sheet material, the components are manufactured using a combination of spin forming and machining, and the tank body is assembled using electron beam welding. The composite outer cladding is filamentarily wound around a titanium liner coated with an adhesive, and the outer cladding and adhesive are then co-cured in an oven to form an integrated tank structure. Summary of the invention

[0025] The present invention provides a method for manufacturing a lightweight, damage-resistant, low-cost, recyclable high-pressure composite container for hydrogen storage and other applications, and also provides such a high-pressure composite container. That is, the present invention is applicable to COPVs and other structures that need to contain gas and / or liquid at high pressure while minimizing weight. In improving the state of the art of COPVs and thereby increasing the energy storage capacity of pressure vessels, the present invention employs a novel combination of existing (at least partial) technologies.

[0026] With respect to the five types of pressure vessels described above, the present invention is primarily directed to type IV pressure vessels, which have a higher energy storage efficiency (energy content / pressure vessel weight) and whose liner has reduced permeability. However, type V pressure vessels may also be manufactured according to the present invention, provided that the manufacturing process includes a mandrel that is expandable for providing internal pressure during reinforcement and removed after reinforcement, as described herein. Such mandrels include, but are not limited to, inflatable materials, shape memory materials, and dissolvable materials.

[0027] While it is well known that continuous fibers have higher strength and modulus than discontinuous fibers, it is not generally understood by those skilled in the art that there is a critical fiber length beyond which the strength and / or modulus do not increase significantly. This is the point at which the bonding between the fiber and the matrix exceeds the strength of the fiber. Figure 5 The relationship between fiber length and certain properties (modulus, strength and impact) is shown, and it is shown that fibers with a length of 10 to 100 mm can retain most, if not all, of the properties when aligned in the prepreg tape. Thus, the present invention uses an aligned non-continuous fiber composite material, allowing the fibers to move within the composite material before it is fully consolidated.

[0028] Thus, the present invention provides a product and method for manufacturing a high pressure composite pressure vessel for applications such as hydrogen storage that is lightweight, damage resistant, low cost and recyclable. The present invention extends the prior art of thin wall pressure vessels to high pressure applications such as compressed hydrogen storage. More specifically, the present invention advances the art by improving upon the method disclosed in U.S. Patent No. 6,893,604B2 to expand the pressure range and improve the structural efficiency of high pressure COPVs and similar structures. The present invention is particularly useful for deformable storage containers (deformable storage methods are described below).

[0029] In one embodiment, the present invention relates to a method for manufacturing a high-pressure composite pressure vessel, the method comprising the following steps: providing a neatly arranged non-continuous fiber composite; wrapping an expandable core with a non-continuous fiber reinforced composite so that the fibers are roughly aligned with the load path present in the pressurized COPV; pressurizing the expandable core and optionally heating the wrapped COPV to expand the core, thereby applying pressure to the composite outer coating; heating the COPV to reinforce the composite outer coating; providing a method for limiting expansion; and cooling the reinforced COPV under pressure. The composite material can be a thermoplastic composite or a thermosetting composite. The expandable core can be a polymer liner, an airbag and / or a shape memory airbag. The means of limiting expansion can include continuous fiber composite coating, molds and / or high temperature polymer films or any other suitable means.

[0030] In another embodiment, the present invention relates to a high-pressure composite pressure vessel, wherein the method of manufacturing the pressure vessel includes providing a neatly arranged non-continuous fiber composite; wrapping an expandable core with a non-continuous fiber reinforced composite so that the fibers are roughly aligned with the load path present in the pressurized COPV; pressurizing the expandable core and optionally heating the wrapped COPV to expand the core, thereby applying pressure to the composite outer coating; heating the COPV to reinforce the composite outer coating; providing a method for limiting expansion; and cooling the reinforced COPV under pressure, wherein the COPV cooled under pressure is the pressure vessel (product) of the present invention made by these manufacturing steps. The composite material can be a thermoplastic composite material or a thermosetting composite material. The expandable core can be a polymer liner, an airbag and / or a shape memory airbag. The means of limiting expansion can include a continuous fiber composite outer coating, a mold and / or a high temperature polymer film. The high-pressure composite pressure vessel can be conformable. A conformable pressure vessel is a non-cylindrical pressure vessel that is designed to adapt to a given space to maximize the use of the space.

[0031] The present invention, in another embodiment, is directed to a high pressure pressure vessel comprising a body configured to contain a pressurized medium and withstand a pressure of the medium generally greater than 70 bar (1000 PSI or 7 MPa). The pressure vessel may be a COPV, comprising a wall that contains the medium and withstands the high pressure of the medium, wherein the wall is made of a composite material. The wall may be made of a non-continuous fiber reinforced composite material such that the fibers are generally aligned with the load path in the pressurized COPV. The pressure vessel may contain compressed hydrogen generally greater than 700 bar or compressed natural gas generally greater than 200 bar.

[0032] An advantage of the present invention is that it provides an improved method of storing compressed gases and / or liquids at high pressures.

[0033] Another advantage of the present invention is that it provides improved damage tolerance, improved fatigue life, reduced cost, improved fatigue life and recyclability.

[0034] Another advantage of the present invention is that its applications include, but are not limited to, hydrogen, compressed natural gas, and air.

[0035] Another advantage of the present invention is that it can be used in applications where weight must be minimized, such as launch vehicles, air transportation, and ground transportation. Other applications can benefit from reduced cost, damage resistance, improved fatigue life, and recyclability.

[0036] Another advantage of the present invention is that it overcomes the catastrophic failure caused by the breakage of the continuous carbon fibers described above. The present invention achieves this by using an improved method for thick wall COPVs in high pressure applications.

[0037] Another advantage of the present invention is that it provides an embodiment of a manufacturing method in which a thermoplastic high pressure composite overwrapped pressure vessel can be reinforced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] With reference to the following description of the embodiments of the present invention in conjunction with the accompanying drawings, the above and other features and advantages of the present invention, as well as the methods for achieving these features and advantages, will become more clearly understood, and the present invention will also be better understood:

[0039] Figure 1 is a picture of a composite material wrapped pressure vessel according to U.S. Patent No. 10,436,388;

[0040] Figure 2 is a perspective view showing different stress levels of a composite wrapped pressure vessel according to U.S. Patent No. 10,436,388;

[0041] Figure 3 is data from the U.S. Department of Energy on the state of the art regarding fiber translation efficiency;

[0042] Figure 4 It was the U.S. Department of Energy that provided data on fiber and manufacturing changes that resulted in higher safety factors and weights;

[0043] Figure 5 It is a summary graph of fiber length and certain properties (modulus, strength and impact), which shows that fibers with a length of 10 to 100 mm can maintain most, if not all, of the properties when they are aligned in the prepreg tape;

[0044] Figure 6 is a flow chart showing one embodiment of a manufacturing method according to the present invention;

[0045] Figure 7 is a chart showing a comparison of a tailored universal feedstock for molding (TuFF) with other discontinuous fiber reinforced and continuous fiber composites;

[0046] Figure 8 is a graph from Hexcel showing that stretched broken fibers have higher performance than continuous fibers;

[0047] Fig. 9 is a perspective view of a filament winding method that can be used to apply aligned non-continuous fiber reinforcement materials according to the present invention;

[0048] Fig.10 is a perspective view of a fiber placement method that can be used to apply aligned non-continuous fiber reinforcement materials according to the present invention;

[0049] Fig.11 is a perspective view of a fiber patch placement method according to the present invention, which can be used to apply a uniformly arranged non-continuous fiber reinforcement material;

[0050] Fig.12 is a flow chart showing another embodiment of a manufacturing method according to the present invention, and a side view of the method steps;

[0051] Fig.13 is a partial cutaway perspective view of a pressure vessel;

[0052] Fig.14 is a cross-sectional view of one embodiment of a pressure vessel according to the present invention; and

[0053] Fig.15 includes two illustrations, namely two side views of a group of pressure vessels, one of which is a group of three pressure vessels showing non-conforming pressure vessels and the other (just below the group of non-conforming pressure vessels) is a group of three pressure vessels of conforming pressure vessels;

[0054] Fig.16is an example of a pressure vessel that can be manufactured using the method of the present invention;

[0055] Fig.17A is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0056] Fig. 17B is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0057] Fig.18 is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0058] Fig.19 is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0059] Fig. 20 is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0060] Fig.21 is another example of a pressure vessel that can be manufactured using the method of the present invention;

[0061] Fig. 22 is another example of a pressure vessel that can be manufactured using the method of the present invention; and

[0062] Fig.23 is another example of a pressure vessel that can be manufactured using the method of the present invention.

[0063] Corresponding reference characters indicate corresponding parts throughout the several views.The examples set out herein illustrate embodiments of the invention and these examples are not to be construed as limiting the scope of the invention in any way. DETAILED DESCRIPTION

[0064] Referring now to the drawings, and more particularly to Figure 6 , a flow chart of a method for manufacturing a high pressure composite pressure vessel according to the present invention is shown. The method for manufacturing a high pressure composite pressure vessel according to the present invention comprises: providing or otherwise using a non-continuous fiber composite material in an aligned manner so that the fibers can move before reinforcement; wrapping an expandable core with a non-continuous fiber reinforced composite material in an aligned manner so that the fibers are approximately aligned with the load path present in the pressurized COPV; pressurizing the expandable core and optionally heating the wrapped COPV so that the expandable core applies pressure to the composite outer sheath; heating the COPV to reinforce the composite outer sheath; providing a method for limiting expansion; and cooling the reinforced COPV under pressure.

[0065] The present invention uses a composite material reinforced with aligned discontinuous fibers. The material methods used to produce such aligned discontinuous fiber composite materials can be conventional, but those skilled in the art will appreciate that some methods are more advantageous. These methods include: maximum alignment of fibers in a single direction; minimum fiber length exceeding a critical fiber length; random arrangement of fiber breaks within the composite material; fiber breaks occurring at weak points along continuous fibers.

[0066] Manufacturers of aligned discontinuous fiber materials / reinforcement materials include, but are not limited to, the University of Delaware, Montana State University, Hexcel Corporation (Dublin, California), Pepin Assoc. (Greenville, Maine), Pharr Yarns (McAdenville, North Carolina), Schappe Techniques (Chanoz, France), and Advanced Composites Group Ltd. (ACG, Sinor, Derbyshire, UK). The products of these manufacturers vary to some extent, and those skilled in the art can select the most suitable product according to the specific application.

[0067] Continuing along this line of thought, Figure 7 The following data from shows that aligned discontinuous fiber reinforcements can be as strong or stronger than continuous fiber reinforcements in composite structures. The University of Delaware has developed Tailored Universal Forming Feedstock (TuFF). Figure 7 The chart shows a comparison of TuFF with other discontinuous fiber reinforcements and continuous fiber composites.

[0068] the following Figure 8 Data from Hexcel Corporation shows that stretched-broken fibers have higher performance than continuous fibers (stretch-broken fibers refer to continuous fiber prepregs where the continuous fiber prepreg has been stretched so that some of the individual fibers break, forming neatly aligned non-continuous fiber tapes). (For more information, see the following website link:

[0069] https: / / www.researchgate.net / publication / 268049934_CHARACTERIZATI ON_ OF_STRETCH_BROKEN_CARBON_FIBER_COMPOSITES_-

[0070] _IM7_FIBER_IN_8552_RESIN_-

[0071] _STRETCHED_AT_PREPREG_LEVEL / figures? lo=1 )

[0072] Regarding the fiber application process, those skilled in the art can select from various existing (at least partial) methods according to the specific application, by which the aligned non-continuous fiber reinforcement materials are applied to form a composite material structure. Now, three such methods that can be used in the present invention are summarized.

[0073] The first method to apply aligned non-continuous fiber reinforcements was filament winding. U.S. Patent No. 6,893,604 B2 (Manufacture of Reinforced Thermoplastic Storage Containers) teaches a filament winding method for continuous fiber reinforcements. Filament winding is a simple method for wrapping enclosed structures, such as pressure vessels. However, this method requires winding a continuous strip in a manner that approximates a geodesic path, which may not be consistent with the direction of applied loads to the structure, including the COPV. Filament winding can also cause end domes of the COPV to accumulate, adding weight and thus reducing the efficiency of the structure. In theory, a cylindrical pressure vessel would require twice as much reinforcement in the circumferential direction as in the axial direction. However, filament winding does not allow for the placement of fibers in a purely circumferential or axial direction. Fig. 9 One embodiment of a wire winding method that can be used according to the present invention is shown.

[0074] The second method for applying aligned, non-continuous fiber reinforcements is fiber placement. Fiber placement lays composite fibers in any orientation and can automatically start and cut composite tapes. However, this method is not as fast as filament winding due to the need to track the surface with compaction rollers and cut and restart the prepreg. Automated fiber placement (AFP), a standard composite manufacturing process that involves automatically placing continuous fiber composites onto a structure, including cutting and starting strips to optimize the structure, can be adapted and adopted. Fig.10 One embodiment of a fiber placement method that can be used in accordance with the present invention is shown.

[0075] A third method for applying aligned discontinuous fiber reinforcement is fiber patch preforming. Fiber patch preforming is an automated process for placing small patches of composite materials onto a structure. For example, fiber patch preforming automates the placement of fiber reinforced composite patches onto a mold. Fiber patch preforming enables aligned discontinuous fiber reinforcements on structures such as COPVs by making the patches longer than the minimum fiber length, compensating for cutouts, and placing the fibers in the load path. Fig.11 One embodiment of a fiber patch placement method that may be used in accordance with the present invention is shown.

[0076] With respect to the reinforcement process, the present invention provides a development of an existing process. U.S. Patent No. 6,893,604 B2 (Reinforced Thermoplastic Storage Container Manufacturing) teaches pressurizing the interior of a pressure vessel, heating it from the outside, and then cooling the interior. This approach can also be used in the present invention, with the key differences being the use of a neatly aligned non-continuous fiber composite material, and a method of allowing the fiber reinforcement material to expand in order to compensate for the volume factor of the COPV during the reinforcement process, and a method of limiting the expansion.

[0077] Any suitable means may be used to heat, pressurize, and restrict expansion. Heating methods include, but are not limited to, the following: internal heated liquid; internal heated gas; external heated gas; internal infrared heating; external infrared heating; external flame heating. Pressurization methods include, but are not limited to, the following: internal pressurized gas; internal pressurized liquid; external vacuum; internal pressurization and external vacuum.

[0078] View Now Fig.12 , another embodiment of the method for manufacturing a pressure vessel of the present invention is shown in the figure (arrows pointing downward from the text block indicate the progress of the method, and arrows pointing to the left of the text block indicate the description of a specific step). This embodiment of the method of the present invention can be used together with Figure 6 The embodiments of the method of the present invention shown are used in combination, but Fig.12 The embodiments shown focus primarily on illustrating the types of fibers used in some stages of the process. Fig.12 In a first step, a polymer liner is provided. Next, the polymer liner is wrapped with neatly arranged non-continuous fibers. Next, the polymer liner is wrapped with continuous fibers, and the wrapping of the continuous fibers can be used in two steps, in two different directions or in a single step. The outer coating of the continuous fibers will limit the expansion under the action of heat and internal pressure during the consolidation process. Consolidation then occurs. The consolidation step optionally includes a coolant 54; on the other hand, the coolant 54 is optionally not used in the manufacturing method. Finally, the COPV of the present invention is obtained.

[0079] Reference now Fig.13 and Fig.14 , a composite material wrapped pressure vessel 100 is shown. The pressure vessel includes a high-density polymer liner 102 wrapped with a carbon fiber composite material 104. This is an embodiment of the general design of the present invention, and it can be seen that Fig.13 The carbon fiber composite material in the embodiment does not explicitly show the discontinuous fiber layer of the present invention. The boss 106 includes a valve 108 and a heat activated pressure release device 110, which is activated by a temperature sensor 112 located inside the container 100. In addition, a dome protective layer 114 can be added to provide additional protection from accidental damage.

[0080] Fig.14 is a simplified cross-sectional view through a pressure vessel of the present invention. Fig.14 The discontinuous fiber layer 116 of the COPV of the present invention is now explicitly shown. More specifically, Fig.14 The high voltage COPV 100 is shown as having a cylindrical shape. It can be understood that although Fig.14 A cylindrical COPV is shown, but the COPV may be formed into other shapes, such as a sphere, or a shape that conforms to the space occupied by the COPV, which may be asymmetric. Fig.14 One end of the COPV has an opening 107 in the boss for receiving hydrogen, etc. The COPV also includes an inner layer 118, for example formed as a polymer liner. The middle layer may include neatly arranged non-continuous fibers 116, i.e., the neatly arranged non-continuous fiber reinforced composite material described above. The outer layer 120 may include a continuous fiber layer, i.e., a continuous fiber reinforced composite material. Fig.14 As shown, the composite material does not build up on the end domes like conventional filament-wound COPVs.

[0081] Now please refer to Fig.15 , a group of three pressure vessels 100a are shown at the top of the figure within a rectangular restraint or bracket 130. As non-deformable pressure vessels, they maintain a circular cross-section within the bracket (e.g., a cylindrical pressure vessel). Each pressure vessel has an outer composite layer. As shown, there is a large amount of wasted space 132a between the bracket and the outer surface of each pressure vessel. The wasted space can be calculated as, where "r" is the radius of the circle. Therefore, the area of ​​the circle is πr 2 , the area of ​​the square is (2r) 2 Therefore, we can use πr 2 / (2r) 2 To express the ratio of the area of ​​the circle to the area of ​​the square, this equals π / 4, which itself equals 79%. This means that the area of ​​wasted space is about 21%, which is equivalent to the amount of space wasted in a non-conforming pressure vessel drawing in a rectangular bracket.

[0082] On the other hand, a conformable pressure vessel at least partially conforms to the shape of its support, e.g. Fig.15 100b (below a group of three non-conformal pressure vessels). The conformal pressure vessels are not circular in cross-section, but rather square, like their rectangular supports or housings 130, which may be composite materials as shown. The arrows indicate where the conformal pressure vessels are expanded to maximize their area / volume. One skilled in the art will appreciate that the wasted space 132b is much smaller than the wasted space 132a.

[0083] According to the present invention, both non-conformal and conformal pressure vessels can be manufactured. For example, for non-conformal COPVs, a non-continuous fiber composite material can be used that is aligned and moves during the reinforcement process under the action of internal pressure to more efficiently fill available space, such as in a support or housing. Similarly, the present invention is also applicable to Fig.15The pressure vessel shown below is known as a "conformal reservoir". The present invention can also be used in conformal pressure vessels, so that a non-continuous fiber composite material in an aligned manner can be used, which is moved during the consolidation process under the action of internal pressure so as to more effectively fill the available space of the outer mold. Therefore, the present invention can be used to produce conformal pressure vessels of various shapes. In all cases, the outer cover must be restrained during the consolidation process. Therefore, such conformal pressure vessels with atypical shapes can be adjusted in wall thickness and geometry to provide a container that can save space, have strength and volume comparable to a cylinder, although its shape is not cylindrical, but can be installed and configured.

[0084] Now please refer to Figure 16-23 , various conventional conformable storage containers with various configurations are shown in the figure. That is, the high-pressure COPV of the present invention can be manufactured to have Figure 16-23 Any of the configurations shown in Figure 16-23 Use in any way shown in Figure 16-23 This is provided only as an example and not as a limitation. Figure 16-23 or any other configuration, but the high voltage COPV of the present invention may provide improved performance for any such configuration.

[0085] Fig.16 A cross-sectional view of a conformable storage container in a wing-like structure, such as an aircraft wing, is shown.

[0086] Fig.17A Perspective views of a number of pressure vessels are shown, including multi-cylinder and multi-ball vessels. Fig. 17B A perspective cross-sectional view of a plurality of pressure vessels is shown which are concentric with each other and have an annular configuration.

[0087] Fig.18 A perspective, partially cut-away view of a plurality of pressure vessels is shown that are at least partially concentric with one another and at least partially have an annular configuration, while also having four intersecting membranes.

[0088] Fig.19 A perspective cross-sectional view of a plurality of pressure vessels is shown, one of which is configured as a ring and another of which is configured as a cylinder with rounded ends and no intersection.

[0089] Fig. 20 Perspective views of a plurality of pressure vessels (tanks) are shown at a, b, c and d, respectively, and these pressure vessels (tanks) are generally spherical except for locations where they contact each other.

[0090] Fig.21Three groups, A, B, and C, of ​​multiple pressure vessels, generally referred to as intestines to indicate their interconnected tubular nature, are shown, with each group demarcated by two dividing lines. Group A shows four views of the multiple pressure vessels: a perspective view (bottom); an end view (middle left); a side view (top); and a cross-sectional view taken near the circle in the end view (middle right). The vessels in Group A are generally tubular structures. Group B shows three views of the multiple pressure vessels: a perspective view (bottom view), a top view (upper left view), and a cross-sectional view taken along a vertical line through the middle of the top view (upper right view). The pressure vessels in Group B are disc-shaped with a hole in the center area. Group C shows two views: a perspective view of multiple pressure vessels (top), similar to the perspective view of Group A; and a perspective view of a single pressure vessel within a rectangular box (bottom). Group C shows a comparison of the two configurations in Group C, with the single pressure vessel (bottom) occupying a smaller area of ​​the rectangular box than the multiple pressure vessels (top).

[0091] Fig. 22 shows a perspective view of a vehicle with a plurality of pressure vessels, Fig. 22 Multiple pressure vessels configured in a tank occupy a given space, thereby reducing wasted space.

[0092] Fig.23 A perspective view of a pressure vessel manufactured by Noble Gas Systems is shown, the pressure vessel comprising: a liner, which may be a thermoplastic elastomer, which is flexible and provides a barrier to penetration; and a reinforcing layer, which is made of woven synthetic fibers, for bearing pressure. The pressure vessel is generally linear in shape, and the woven layer allows it to be adaptable without collapsing. The pressure vessel comprises a plurality of generally cylindrical bodies and a plurality of tubular bodies having a diameter smaller than the cylindrical bodies. The cylindrical bodies are connected in series through the tubular bodies, each of which is connected to both ends of the cylindrical body and is connected at Fig.23 folded in the center so that the cylindrical bodies are stacked on top of each other, thus occupying a space of an asymmetrical shape, such as Fig.23 As shown, the pressure vessel is exploded from its container defining an asymmetrically shaped space for easier viewing.

[0093] Although the present invention has been described with respect to at least one embodiment, the present invention may be further modified within the spirit and scope of the present disclosure. Therefore, this application is intended to cover any variation, use or modification of the present invention using its general principles. In addition, this application is intended to cover deviations from the present disclosure in known or customary practices in the art related to the present invention.

Claims

1. A method for manufacturing a high-pressure composite pressure vessel (100), wherein the high-pressure composite pressure vessel is configured to contain gas and / or liquid, the method comprising the following steps: Providing an expandable core container (102; 118) configured to expand under pressure; A neatly arranged non-continuous fiber reinforced composite material (104; 116) is provided, wherein the neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers having a length between 5 mm and 100 mm, wherein the fibers are neatly arranged in a prepreg tape; Wrapping the expandable core container (102; 118) with the neatly arranged non-continuous fiber reinforced composite material (104; 116); Wrapping the expandable core container (102; 118) with a continuous fiber reinforced composite material (120); Expanding the expandable core container (102; 118) by pressurizing the expandable core container (102; 118), and applying pressure to the aligned non-continuous fiber reinforced composite material (104; 116) and the continuous fiber reinforced composite material (120) by expanding the expandable core container (102; 118); heating the expandable core container (102; 118) under pressure and thereby consolidating the composite outer sheath; and The expandable core vessel (102; 118) is cooled under pressure to ultimately form the high pressure composite pressure vessel (100).

2. The method according to claim 1, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 10 mm and 100 mm.

3. The method according to claim 1, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 25 mm and 100 mm.

4. The method according to claim 1, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 50 mm and 100 mm.

5. The method according to claim 1, wherein: The expandable core container (102; 118) defines an annular section between the end domes; The aligned non-continuous fiber reinforced composite material (104; 116) is wrapped in alignment with a plurality of load paths present in the expandable core container (102; 118), the load paths being located above the annular segments and end domes; and The continuous fiber reinforced composite material (120) is wrapped on the neatly arranged non-continuous fiber reinforced composite material (104; 116), and the non-continuous fiber reinforced composite material (104; 116) is wrapped along the annular section but not along the end dome.

6. The method according to claim 5, wherein: The method includes a step of limiting the expansion of the expandable core container (102; 118) after the step of heating the expandable core container (102; 118) and strengthening the composite outer cover and before the step of cooling the expandable core container (102; 118) under pressure to form a high pressure composite pressure vessel.

7. The method according to claim 6, wherein: The step of confining includes using at least one of a continuous fiber composite overwrap, a mold, and a high temperature polymer film.

8. The method according to claim 5, wherein: The composite material (104; 116) of the discontinuous fiber reinforced composite material comprises a thermoplastic composite material or a thermosetting composite material.

9. The method according to claim 5, wherein: The expandable core container (102; 118) includes a polymer liner, bladder, or shape memory bladder.

10. The method according to claim 5, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 10 mm and 100 mm.

11. The method according to claim 5, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 25 mm and 100 mm.

12. The method according to claim 5, wherein: The neatly arranged non-continuous fiber reinforced composite material (104; 116) comprises fibers with a length between 50 mm and 100 mm.

13. The method according to claim 5, wherein: The step of wrapping the expandable core container with the neatly arranged non-continuous fiber reinforced composite material (104; 116) adopts a wire winding process.

14. The method according to claim 5, wherein: The step of wrapping the expandable core container (102; 118) with the aligned non-continuous fiber reinforced composite material (104; 116) adopts a fiber placement process.

15. The method according to claim 5, wherein: The step of wrapping the expandable core container (102; 118) with the aligned non-continuous fiber reinforced composite material (104; 116) uses a fiber patch preforming process, wherein each patch is longer than the minimum fiber length and the patches are laid in a manner to compensate for the cuts.

16. A high-pressure composite pressure vessel (100) configured to contain gas and / or liquid, the high-pressure composite pressure vessel (100) comprising: An expandable core container (102; 118), which delimits an annular section between the end domes; a neatly arranged non-continuous fiber reinforced composite material (104; 116) wrapped on the expandable core container (102; 118), the neatly arranged non-continuous fiber reinforced composite material (104; 116) comprising fibers having a length between 5 mm and 100 mm, wherein the fibers are neatly arranged in the prepreg tape, and the neatly arranged non-continuous fiber reinforced composite material (104; 116) is wrapped in alignment with multiple load paths existing in the expandable core container (102; 118), the load paths being located above the annular segment and the end dome; and A continuous fiber reinforced composite material (120) is wrapped around the neatly arranged non-continuous fiber reinforced composite material (104; 116), wherein the continuous fiber reinforced composite material (120) is wrapped along the annular section but not along the end dome.

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