Since the 1990's heavy vehicles have been taking advantage of compressed natural gas (CNG) engines. However, light vehicles, such as passenger cars, still have yet to achieve widespread adoption. Both private and public players began to identify technological hurdles to CNG passenger vehicle growth. Industry realized that if certain storage issues could be solved natural gas offered incredible untapped opportunity. However, current CNG storage solutions, both for integrated vehicles and converted vehicles, are still bulky and expensive cylinder based systems. For the integrated systems, various sized cylindrical tanks are integrated into the vehicle chassis design. For the converted vehicles, a big tank is placed in the trunk, eliminating storage or spare tires.
In view of the foregoing, a need exists for an improved fluid storage system and method in an effort to overcome the aforementioned obstacles and deficiencies of conventional fluid storage systems such as CNG storage systems, and the like.
It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.
Since currently-available fluid storage systems are deficient, a conformable pressure vessel that has high strength and durability with relatively low weight can prove desirable and provide a basis for a wide range of application, such as storing fluids such as CNG in cavities of various sizes, including in vehicles. This result can be achieved, according to various example embodiments disclosed herein, by the systems and methods for a conformable pressure vessel as illustrated in the figures and described herein.
Turning to
In various embodiments, the body 105 can define a plurality of coupling holes 120 that extend between the cavity 110 and an external surface of the end cap 100. In some embodiments, pairs of coupling holes 120 can be aligned along a common axis (e.g., axis H1 or H2) and a portion of the coupling holes can be aligned along parallel axes (e.g., axis H1 and H2 are shown being parallel). However, in further embodiments, configurations of coupling holes can be in any suitable regular or irregular configuration. Additionally, in further embodiments, coupling holes 120 can be any suitable size and shape and may not extend completely through the body 105.
Turning to
As illustrated in
As shown in
In further embodiments, the end caps 100 and flexible body 205 can be coupled in one or more suitable ways, including a mechanical coupling (e.g., threads, slot-and-pin), an adhesive, a weld (e.g., a laser weld), a wrapping, co-molding, or the like. In embodiments where a laser weld is used it may be desirable to select materials where a first material is transparent to the laser and a second material absorbs laser light. Accordingly, in some embodiments, end caps 100 can comprise a material or have an opacity that absorbs laser light and the flexible body 205 can comprise a material or have an opacity that is transparent to laser light.
The flexible connector 200 can be made in various suitable ways. For example, in some embodiments, portions of the flexible connector 200 can be made with injection molding, blow molding, compression molding, three-dimensional printing, milling, or the like.
In block 420, the first and second end caps 100 are positioned with the narrow ends 106 facing each other and aligned on a common axis X (e.g., as shown in
The end caps 100 and flexible body 205 can be made of any suitable materials. In some embodiments, the end caps 100 are rigid and the flexible body 205 is substantially more flexible than the end caps 100. In various embodiments, the materials for the end caps 100 and flexible body 205 can be selected based on their flexibility, rigidity, ability to couple or bond with each other, ability to couple or bond with other materials, fluid permeability, and the like. For example, in some embodiments, the end caps 100 can comprise Nylon, High Density Polyethylene (HDPE), ethylene-vinyl acetate, linear low-density polyethylene (LLDPE), ethylene vinyl alcohol (EVOH), polyurethane, or the like. The flexible body 205 can be made of various suitable materials including flexible plastics, ethylene-vinyl acetate, thermoplastic urethane, butyl rubber, and the like.
Turning to
In some embodiments, tubing 500 can comprise Nylon, High Density Polyethylene (HDPE), ethylene-vinyl acetate, linear low-density polyethylene (LLDPE), ethylene vinyl alcohol (EVOH), polyurethane, or the like. In one preferred embodiment, the end caps 100 can comprise Nylon 6 (PA6). In various embodiments, the end caps 100 and tubing 500 can comprise the same material or the material of end caps 100 and tubing 500 can be chosen based on compatibility for bonding, welding, coupling, and the like.
In various embodiments, the end cap 100 and tubing 500 can be shaped to improve coupling. In some embodiments, a chamfer at the end of the end cap 100 and tubing 500 can substantially improve the coupling generated by a laser weld, or the like. One example embodiment is shown in
As illustrated in
Although a liner 550 can comprise flexible connectors 200 and tubing 500 as illustrated in
In various embodiments, the connector portion 610 can have a diameter that is smaller than the tubing portions 630, with the taper portion 625 providing a transition between the diameter of the connector portion 610 and the tubing portion 630. However, further embodiments can comprise a liner 550 with portions having one or more suitable diameter and in further embodiments, a liner 550 can have portions that are non-cylindrical, which can include various suitable shapes.
In some embodiments, a corrugated liner 550B can be made by forming various pieces of the liner 550B and then coupling the pieces together. For example, connector portion 610 can be manufactured separately from the taper portion 625 and/or the tubing portion 630. Such separate portions can be subsequently coupled together to form the liner 550B.
However, in one embodiment, the liner 550B can be generated via extrusion molding systems 700 shown in
In various embodiments, a vacuum can pull the material of the extruded tube 720 to conform to negative contours defined by the mated dies 710. In various embodiments, such a manufacturing process can be beneficial because liners 550B can be made seamlessly, with no welds, and using a single material.
In some embodiments, liners 550 having varying lengths of the connector portion 610, taper portion 625 and/or the tubing portion 630, can be made by selectively choosing the order of dies 710 such that desired portions are made longer or shorter. For example,
As illustrated in
After making contact for a required period of time, die halves 710 separate and rotate back through the track 705. Some embodiments can be loaded with a fixed number and order of dies 710 as illustrated in
However, in some embodiments, it can be desirable to form a liner 550 that has varying lengths of the tubing portion 630 and/or connector portion 610. For example, in some embodiments, a liner 550 can be produced that fits into an irregular or non-rectangular cavity, which can require a liner 550 to have tubing portions 630 of variable lengths.
Accordingly, as illustrated in
Further embodiments can comprise a shuttle corrugation machine (not shown) for generating a liner 550. In such embodiments, corresponding mold halves are aligned for a period of time to form tubing geometry. However instead of each mold half being coupled to the adjacent mold path, and being continuously rotated to return mold halves, a shuttle corrugation machine can use a linear rail return system. In this system, individual molds can be decoupled once molds have reached the ends of the track, and the molds can be separated and returned to the beginning of the corrugation line by way of linear rail. In such embodiments, various suitable mechanisms for interchanging dies on a shuttle corrugator can be used, including mechanisms similar to those discussed above.
In further embodiments, liners 550 can be made in any suitable way. For example, in one embodiment, portions of a liner 550 can be formed via blow-molding, rotational molding, injection-overmolding, or the like. In such embodiments, formed portions of the liner 550 can be assembled via any suitable method, including welding, an adhesive, or the like. One embodiment can comprise injection-overmolding of rotationally molded chambers, which can be desirable because some implementations of such a method can eliminate the need for a welded joint. Another embodiment can comprise hourglass connectors, with overmolded metal smaller diameter tubing. A further embodiment can comprise smaller diameter metal tubing rotationally overmolded with individual chambers (i.e., large diameter and taper). One embodiment can comprise swaging straight plastic or metallic extrusions to generate a taper and a small diameter. Another embodiment can comprise necked down straight plastic tubing to form variable diameter plastic tubing.
A still further embodiment can comprise a continuous liner made by hydroforming an elastomer. Such an embodiment can be generated in a heated closed mold process, at room temperature without a mold, or the like. Yet another embodiment can comprise continuous variable diameter extrusion, heat forming, or the like. In such an embodiment, after extrusion of tank geometry the liner 550 can be bent into final configuration via a method comprising heat forming bends.
In some embodiments, it can be desirable to generate a liner 550 in a vertical configuration. In other words, a manufacturing method can including forming the liner 550 with the main axis of the liner 550 being parallel to gravity during such forming. In some embodiments, such a manufacturing configuration can be desirable for reducing gravity induced sagging of the liner 550 that can be generated in non-vertical manufacturing. For example, in some non-vertical manufacturing, the liner 550 can be thicker on a lower half due to gravity pulling non-solid material downward.
Additionally, although example configurations of a liner 550 are shown and described herein, these examples should not be construed to be limiting on the wide variety of liners 550 that are within the scope and spirit of the present disclosure. For example, some embodiments can comprise asymmetric corrugations and/or asymmetric tapers. In further embodiments the geometry of a liner 550 can be configured for desirable flow of a fluid through the liner 550, and such a configuration can be determined based on computational fluid dynamics calculations, analytical flow calculations, experimental tests, or the like.
In various embodiments, it can be desirable for portions of the liner 550 to not buckle when bent. For example, in some embodiments, corrugations can be included in a liner 550 as illustrated in
In some embodiments, it can be desirable to design the liner 550 so that it will deform in a predictable manner under internal pressure and/or an external constraint (e.g., a braid, filament winding, or the like, as discussed in more detail herein). In further embodiments, the liner 550 can be configured to operate at, and maintain integrity at, a wide range of temperatures, including −80° C. to +40° C.; −100° C. to +80° C.; and the like. In still further embodiments, the liner 550 can be designed to provide desirable thermal conductivity and/or to not be substantially susceptible to failure by electrostatic discharge after many cycles of filling and emptying with a fluid.
Although some preferred embodiments can be configured for storages of a fluid comprising CNG, further embodiments can be configured to store any suitable gas and/or liquid fluid, which may or may not be stored under pressure. For example, fluids such as natural gas, hydrogen, helium, dimethyl ether, liquefied petroleum gas, xenon, and the like can be stored. Additionally, such fluids can be stored at various suitable temperatures including room temperature, cryogenic temperatures, high temperatures, or the like.
In various embodiments, it can be desirable to cover a liner 550 with a braid and/or filament winding. For example, covering a liner 550 with a braid and/or filament winding can be desirable because the braid and/or filament winding can substantially increase the strength of the liner 550 without substantially increasing the weight and size of the liner 550. Braiding and/or a filament can be applied wet or dry in some embodiments.
For example,
In some embodiments, it can be desirable to apply a dry braid 940 to the liner 550, and apply resin to the braid 940 thereafter. For example,
In some embodiments, a braid 940 can be applied to the liner 550 alternatively and/or in addition to a filament covering 940. In such an embodiment, a braiding machine 905 can replace the filament winding machine 800 and/or be included in addition to a filament winding machine 800, or vice versa. Additionally, although
Before the resin cures or hardens, the liner 550 can be folded into a housing 560 (see
Various suitable materials can be used to generate a braid and/or filament winding, including one or more of carbon fibers, aramid fibers (e.g., Kevlar, Technora, Twaron, and the like), Spectra fiber, Certran fiber, polyester fiber, nylon fiber, a metal, and the like. In one preferred embodiment, a thermoplastic fiber (e.g., Nylon) can be commingled with a carbon fiber.
Another embodiment can comprise a multilayer polymer and/or metal. For example, such a liner can be generated via vapor deposition, multilayer extrusion or molding, or the like.
In various embodiments a liner 550 can comprise or consist of any suitable number of layers including one, two, three, four, five, six, seven, eight, nine, ten, or the like. Some layers can comprise the same material in some embodiments, whereas in some embodiments, each of the layers can comprise different materials. In some embodiments (e.g., 17b and 17c), the liner 550 can comprise a symmetrical material layer portion, whereas in other embodiments, the liner 550 can be without a symmetrical layer portion.
In
Additionally, further embodiments of a liner 550 can comprise further layers and/or materials than shown in
Although
The internal shaft 1613 and head 1611 can define a port 1614 that communicates with the cavity 1645. According, the end-coupling 1610 can provide for fluid entering and/or leaving the cavity 1645 defined by the liner 550. In some embodiments, the end-coupling 1610 can comprise a crimp fitting wherein the external shaft 1612, or an associated structure, are crimped to be coupled with the liner 550 and/or braid 1640.
Such crimp fittings can also include the use of glues, adhesives, or the like. For example, in embodiments where external and/or internal shaft 1612, 1613 extend over and surround a portion of the liner 550 comprising corrugations 610, it can be desirable to have a glue, adhesive or other filler material to fill gaps or spaces within corrugations 610, which can improve coupling between the fitting and the liner 550.
The described embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the described embodiments are not to be limited to the particular forms or methods disclosed, but to the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives.
This application is a non-provisional of and claims priority to U.S. Provisional Patent Application No. 62/175,914 entitled SYSTEM AND METHOD FOR A CONFORMABLE PRESSURE VESSEL, filed Jun. 15, 2015, which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. Non-Provisional patent application Ser. No. 14/624,370 entitled COILED NATURAL GAS STORAGE SYSTEM AND METHOD, filed Feb. 17, 2015, which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. Non-Provisional patent application Ser. No. 14/172,831 entitled NATURAL GAS INTESTINE PACKED STORAGE TANK, filed Feb. 4, 2014, which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. Non-Provisional patent application Ser. No. 13/887,201 entitled CONFORMABLE NATURAL GAS STORAGE, filed May 3, 2013, which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. Provisional Patent Application No. 61/642,388 entitled CONFORMING ENERGY STORAGE, filed May 3, 2012, which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. Provisional Patent Application No. 61/766,394 entitled NATURAL GAS INTESTINE PACKED STORAGE TANK, filed Feb. 19, 2013 which is incorporated herein by reference in its entirety and for all purposes.
This invention was made with Government support under DE-AR0000255 awarded by the US DOE. The Government has certain rights in this invention.
Number | Date | Country | |
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62175914 | Jun 2015 | US |