High pressure composite vessel

Abstract

The present invention relates to a high-pressure composite container having at least a plastic liner, a plastic case, and a metal end portion rubber-coated by the plastic case. In this technical solution, the plastic liner of the sealing structure is composed only of the plastic case and the metal end portion, resulting in a simple sealing structure. The metal end portion and the cylinder opening valve together compress the sealing ring of the cylinder opening valve, thereby creating a stable compression amount on the sealing ring, ultimately resulting in excellent sealing performance for the high-pressure gas cylinder. Furthermore, the metal end portion and the plastic case are well-aligned in both the axial and circumferential directions, so that the relative position between the metal end portion and the plastic case does not change under alternating high and low pressures and temperatures, preventing deformation or misalignment of the sealing surface of the plastic case. Finally, the high-pressure gas cylinder has excellent resistance to alternating high and low pressures and temperatures.

Description

[Technical field]

[0001] The present invention relates to the technical field of high pressure composite containers, and in particular to a polymeric plastic liner high pressure composite container for filling with high pressure gas. [Background technology]

[0002] Many taxis have been retrofitted to use compressed natural gas (CNG) instead of fuel, and the working pressure of a CNG high-pressure gas cylinder is generally 20 MPa. Some automobile manufacturers, such as AUDI and GM, have popularized vehicles that use CNG or a mixture of CNG and fuel oil. And automobiles that use hydrogen medium batteries have also become a hotspot at present, and the working pressure of hydrogen storage high-pressure gas cylinders is generally 35 MPa and 70 MPa, and 70 MPa type IV cylinders (high-pressure plastic liner composite containers) are currently a hotspot of research and development. In addition to automobiles, high-pressure gas cylinders are also fully applied in other fields, for example, some liquefied petroleum gas in Europe adopts plastic liner composite containers (working pressure is 2 MPa). Large quantities of high-pressure containers are widely used in daily life, and traditional pure metal or metal liner composite containers have the problem of being heavy and difficult to transport, and the higher the storage pressure, the more complex the manufacturing process of the metal-plastic liner becomes, which increases the cost and also poses the risk of corrosion by high-pressure gas. In order to meet the demand for weight reduction, high-pressure plastic liner composite containers have been created. Due to the characteristics of plastic, this type of product has excellent performance such as corrosion resistance, fatigue resistance and light weight, and the main manufacturers are Toyota, Hexagon (Norway), Quantum (USA), etc. Compared with pure metal or metal-lined composite containers, it is more difficult to ensure the sealing performance of high-pressure plastic-liner composite containers. The main reason is that the materials of the plastic liner housing and the metal end are different (the plastic liner needs to be sealed with the cylinder opening valve, so the end of the plastic liner needs to be made of metal material), and during repeated use of the gas cylinder, the connection between the plastic liner and the metal end will loosen, resulting in a deterioration of the sealing performance. Therefore, forming the plastic case and the metal end into a good and durable sealing and gas permeation resistance performance is the core technology that plastic-liner high-pressure composite containers are trying to break through.

[0003] In view of the current situation, the connection between the metal end and the plastic liner has become a research hotspot and difficulty. Figure 1 shows a high-pressure plastic liner composite container formed by attaching a metal end 01 to a plastic liner 02 and then wrapping it with a fiber composite layer 03. Figure 2 is a diagram illustrating the sealing structure of the end face. It is impossible for the metal end 01 to contact the plastic liner over a large surface area in the process, that is, even if it is feasible, it is costly. This structure does not consider the positional restrictions along the axis of the metal end 01 and the plastic liner 02. This structure does not consider the filling pressure, which is the constant change in the internal pressure of the plastic liner when winding, so that a gap may occur at the connection between the metal end 01 and the plastic liner, which may cause leakage. This structure does not consider the positional restrictions when the gas cylinder opening is subjected to the installation torque, and the bonding strength between the metal end 01 and the fiber composite layer 03 is reduced after installation. And in this structure, the escape path P of the compressed gas is short, which increases the risk of compressed gas escaping, especially small molecule gas CNG, hydrogen gas, helium gas, etc. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a high-pressure composite container that solves the problem of the deterioration of sealing performance, high and low pressure resistance, and temperature alternating performance during repeated use of a conventional high-pressure composite container with a plastic case and metal end. [Means for solving the problem]

[0005] The present invention is realized by the following technical solutions. The high pressure composite vessel comprises a plastic case and a plastic liner having metal ends rubber-coated by the plastic case.

[0006] The metal end includes two rubber covering parts, a first rubber covering part and a second rubber covering part, the first rubber covering part is installed on the outer edge part of the metal end, the second rubber covering part is installed on the lower part of the cylinder opening valve mounting hole of the metal end, and the second rubber covering part is a plurality of parallel concave grooves installed along the cylinder opening valve mounting hole of the metal end.

[0007] The plastic case has a first rubber coating layer formed on both the upper and lower surfaces of the first rubber coating portion, and a second rubber coating layer formed on the inside of the second rubber coating portion, and the first rubber coating layer and the second rubber coating layer are connected by a transition layer.

[0008] The first rubber cover layer, the second rubber cover layer and the transition layer form an end of the plastic case and are integrally connected to the body of the plastic case to form the plastic case.

[0009] Preferably, the first rubber-coated portion has a first rubber-coated hole penetrating from top to bottom, and during the rubber-coating process, the material of the plastic case extends into the first rubber-coated hole to form a connection portion connecting the upper and lower surfaces of the first rubber-coated layer.

[0010] Preferably, a second rubber-covered hole is provided on the lower end surface of the metal end around the cylinder opening valve mounting hole, and the second rubber-covered hole communicates with the groove.

[0011] Preferably, the minimum diameter of the second rubber-covered portion is greater than the diameter of a cylinder opening valve mounting hole in the metal end.

[0012] Preferably, the outer surface of said second rubber covering layer is provided with two or more sealing surfaces, the two or more sealing surfaces being non-coplanar.

[0013] Preferably, the plastic case selectively adopts thermoplastics currently used in the industry, including but not limited to one or more combinations of PA, PE, PPA, PPS, polyester, PP, POM or EVOH, based on the permeation characteristics of the molecular weights of different carrier high pressure gases.

[0014] Preferably, the plastic case is manufactured from two or more thermoplastic layers, and a gas barrier layer is provided between two adjacent thermoplastic layers.

[0015] Preferably, the plastic liner has a fiber reinforced layer disposed on its outer surface.

[0016] Preferably, a cylinder opening valve is installed in the cylinder opening valve mounting hole of the metal end, and a seal ring is installed between an outer surface of the cylinder opening valve and the second rubber coating layer. Effect of the Invention

[0017] The plastic liner of the sealing structure in this technical solution is only composed of a plastic case and a metal end, and the sealing structure is simple. The metal end and the cylinder opening valve both compress the sealing ring of the cylinder opening valve, so that the sealing ring forms a stable compression amount, and finally the high pressure gas cylinder has good sealing performance. In addition, the metal end and the plastic case are well positioned in both the axial and circumferential directions, and when high and low pressure and temperature alternate, the relative position between the metal end and the plastic case does not change, and the sealing surface of the plastic case does not deform or shift, and finally the high pressure gas cylinder has good resistance to high and low pressure and temperature alternation. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing a prior art high pressure plastic liner composite container. [Diagram 2]2 is an enlarged schematic diagram showing a sealing structure at a portion A in FIG. 1. [Diagram 3] FIG. 1 is a schematic diagram showing a high-pressure composite container of the present invention. [Figure 4] FIG. 2 is a schematic diagram showing the structure of a metal end portion of the present invention. [Diagram 5] 10 is a schematic diagram showing the structure of the metal end portion of the present invention in another direction. FIG. [Figure 6] FIG. 2 is an axial cross-sectional view of a metal end of the present invention. [Figure 7] FIG. 7 is an enlarged schematic diagram showing a portion B in FIG. 6. [Figure 8] FIG. 2 is a schematic diagram showing a rubber covering structure of a metal end region. [Figure 9] FIG. 9 is an enlarged schematic diagram showing a portion C in FIG. 8. [Figure 10] FIG. 2 is a schematic diagram showing a structure in which a fiber-reinforced layer is wrapped around the outside of a plastic liner. [Figure 11] FIG. 1 is a schematic diagram showing a structure in which a cylinder opening valve with a seal ring is installed. [Figure 12] FIG. 4 is a schematic diagram showing another rubber coating structure of a metal end portion of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The technical solution of the present invention will be described in detail below with reference to examples. However, the following examples are illustrative and can only be used to interpret and explain the technical solution of the present invention, and cannot be construed as a limitation on the technical solution of the present invention.

[0020] As shown in Fig. 3, the object of the present application is to provide a high pressure composite vessel 1 for storing a high pressure gaseous medium with a plastic liner. The high pressure composite vessel has a plastic liner, which is made of a rubber-coated structure of a plastic case 3 and a metal end 2. Then, a fiber reinforced layer 4 is wound on the outside of the plastic liner, and a cylinder opening valve 5 with a sealing ring 6 having a certain system function is installed in a cylinder opening valve mounting hole 23 of the metal end.

[0021] The type of gas to be stored is not limited in this application. All gases that need to be stored at high pressure can be applied to the high pressure composite container of this application, such as hydrogen gas, CNG, helium gas, nitrogen gas, etc., with a pressure of more than 1 MPa, for example, 10 MPa, 20 MPa, 30 MPa, 50 MPa, 70 MPa, 80 MPa or higher, on the premise that the material of the plastic case and the metal end portion can withstand the corresponding pressure.

[0022] In the high pressure composite container 1 of the technical solution of the present application, winding a fiber reinforced layer on the outside of the plastic liner is a common technique in conventional high pressure composite containers. Here, it is only mentioned that the high pressure composite container also includes a fiber-reinforced layer and needs to be wound on the outside of the plastic liner. Specifically, what kind of fiber is used in the fiber reinforced layer, and whether the resin to be mixed with the fiber is a thermoplastic resin or a thermosetting resin can be selected according to the production needs of the enterprise, and does not affect the realization of the technical solution of the present application. Similarly, the winding method or winding method of the fiber reinforced layer is not described in this application.

[0023] The high pressure composite vessel 1 is equipped with a cylinder opening valve 5, the structure or function of the cylinder opening valve varies with the application location of the high pressure composite vessel, and the corresponding functional system contained therein is not included in the scope of protection of this application. The important point in the technical solution of this application is the sealing structure technology of the plastic liner, and there are certain improvements to the cylinder opening valve and its sealing ring to be combined with the plastic liner, and the specific improvements will be described later.

[0024] The focus of this technical solution is the sealing structure of the plastic liner. Those skilled in the art will understand that the high pressure gas stored in the container will not only leak through the valve, but also leak through the container wall and the connection point between the two parts of the container under high pressure, which will have an adverse effect. The technical solution of this application is just an improvement on the sealing of the plastic liner.

[0025] As shown in Figures 4 to 7, the plastic liner of the present application uses a specific metal end 2. The metal end 2 of the present application includes a metal end body 21, a through cylinder opening valve mounting hole 23 is installed along the axial direction of the metal end body, and a looped link-shaped extension 22 extends along the radial direction in the center of the outer surface of the metal end body 21, and the thickness of the extension gradually decreases from the thickness when it extends outward from the metal end body.

[0026] A first rubber-covered portion 24 having a substantially annular shape and shorter than the circumference of the extension portion is provided on the upper surface of the outer edge of the extension portion 22. The first rubber-covered portion is provided with 4 to 10 first rubber-covered holes 25 that penetrate from top to bottom, and the hole diameter of the first rubber-covered holes is 5 to 10 mm.

[0027] The cylinder opening valve mounting hole 23 includes at least a first mounting hole 231, a second mounting hole 232 and a third mounting hole from top to bottom, not counting the top guide corner. Here, the hole diameter of the second mounting hole is the smallest, and the hole diameter of the third mounting hole is the largest. The third mounting hole, i.e., the second rubber covering part of the present application, is provided with a plurality of parallel grooves 271 in the third mounting hole, and three grooves are provided in this embodiment.

[0028] Four to ten second rubber-covered holes 26 are provided in the axial direction around the cylinder opening valve mounting hole, and each of the second rubber-covered holes 26 is connected to a recessed groove 271 .

[0029] The metal end is preferably made of metal according to the corrosion resistance and high pressure resistance of different carrier gas media, for example, aluminum alloy, stainless steel, and other metal materials are used to meet hydrogen gas corrosion resistance.

[0030] As shown in Figures 8 and 9, the plastic case 3 and the metal end 2 are bonded together by rubber coating to form a plastic liner. Specifically, the metal end is used as an insert member, and the rubber-molded plastic case is injected during the injection molding process, so that the first rubber coating portion 24 and the second rubber coating portion 27 of the metal end are fully enveloped by the plastic material.

[0031] In this application, thermoplastics currently used in the industry are selectively adopted according to the permeation characteristics of different molecular weights of carrier gases, such as PA, PE, PPA, PPS, polyester, PP, POM, EVOH, etc. At the same time, the plastic case can also adopt multiple thermoplastic layers of the above-mentioned materials, and a gas barrier layer is installed between two adjacent thermoplastic layers to prevent small molecules of carrier gas such as hydrogen molecules from permeating through the material.

[0032] The plastic case 2 has a first rubber coating layer 32 formed on both the upper and lower surfaces of the first rubber coating portion 24, and a second rubber coating layer 33 formed on the inside of the second rubber coating portion 27, with the first rubber coating layer 32 and the second rubber coating layer 33 being connected by a transition layer 34.

[0033] The first rubber coating layer 32, the second rubber coating layer 33 and the transition layer 34 form the ends of the plastic case and are integrally connected to the body of the plastic case to form the plastic case.

[0034] During the rubber coating process, the plastic case material extends into the first rubber-coated hole to form a connection part 31 connecting the upper and lower surfaces of the first rubber-coated layer. The plastic case material extends into the second rubber-coated hole and is simultaneously rubber-coated into the groove of the second rubber-coated part, and is integrally connected with the plastic case material in the second rubber-coated hole, forming a locking structure with the metal end, so as to avoid the loss of sealing at the sealing part caused by rotation or axial displacement between the metal end and the plastic case.

[0035] In another embodiment of the present application, the metal end 200 includes a first rubber covering part 201 and a second rubber covering part 202, the first rubber covering part does not have a first rubber covering hole, the second rubber covering part does not have a second rubber covering hole, and the plastic case 300 directly rubber covers the metal end. The final rubber covering structure is shown in Figure 12.

[0036] In the plastic housing material of the present application, three sealing surfaces are formed on the outer surface of the second rubber covering part from top to bottom, namely, a first sealing surface 331, a second sealing surface 332 and a third sealing surface 333, and the three sealing surfaces are not located on the same plane. In other embodiments of the present application, the specific number of sealing surfaces is determined according to the specific manufacturing process and the actual sealing part demand of the product.

[0037] As shown in FIG. 10, a fiber reinforced layer 4 is wrapped around the outer surface of the plastic liner to strengthen the high pressure composite vessel and resist the pressure of the internal high pressure gas.

[0038] As shown in FIG. 11, in order to install the cylinder opening valve 5 with the sealing ring 6, in this technical solution, the cylinder opening valve and the plastic case are directly sealed by the sealing ring, and a certain compression action is generated on the sealing ring, which avoids the two-time sealing that is first sealed by the metal end and the plastic case and then sealed by the cylinder opening valve and the metal end in the conventional plastic liner structure, and thereby avoids the problem of relatively poor sealing performance.

[0039] The materials of the seal ring are preferentially selected and used, such as FKM, EPDM, FVMQ, PTFE, silicone resin, etc., and are preferentially selected for hydrogen corrosion resistance and low temperature resistance properties, such as FKM, EPDM, PTFE, etc.

[0040] The plastic case 3 forms three sealing surfaces on the second rubber coating layer, which can meet the sealing needs of two seal rings at different positions from the axial direction of the cylinder opening valve, and further improve the sealing performance. In addition, by providing sealing requirements such as sealing plugs during the process sealing inspection of the high pressure composite vessel, it is possible to avoid the problem of the sealing performance of the final product being attenuated due to the sealing of the cylinder opening valve after the sealing surface is damaged at the sealing position during the process inspection.

[0041] The plastic liner of this sealing structure is composed of only a plastic case and a metal end, and the sealing structure is simple. The metal end and the cylinder opening valve together compress the seal ring of the cylinder opening valve, so that the seal ring forms a stable compression amount, and finally the high pressure gas cylinder has good sealing performance. In addition, the metal end and the plastic case are well positioned in both the axial and circumferential directions, and when high and low pressure and temperature alternate, the relative position between the metal end and the plastic case does not change, and the sealing surface of the plastic case does not deform or shift, and finally the high pressure gas cylinder has good resistance to high and low pressure and temperature alternation.

[0042] Finally, during the use of the high pressure composite container, the leakage of the carried high pressure gas medium can be prevented, the safety of the use of the high pressure container can be ensured, energy can be saved, the environment can be protected, and the service life of the high pressure composite container can be increased due to its excellent durability.

[0043] The above are only specific embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Any changes or replacements conceivable without creative labor should be included in the protection scope of the present invention, and the protection scope of the present invention should be based on the protection scope limited by the claims. [Explanation of symbols]

[0044] 01 Metal end 02 Plastic Liner 03 Fiber composite layer 1. High pressure composite vessel 2 Metal end 21 Metal end body 22 Stretching section 23 Cylinder opening valve mounting hole 231 First mounting hole 232 Second mounting hole 24 First rubber covering part 25 First rubber covered hole 26 Second rubber covered hole 27 Second rubber covering 271 Groove 3 Plastic case 31 Connection 32 First rubber coating layer 33 Second rubber coating layer 331 First sealing surface 332 Second sealing surface 333 Third sealing surface 34 Transition Layer 4 Fiber Reinforced Layer 5 Cylinder opening valve 6 Seal ring 200 metal end 201 First rubber covering part 202 Second rubber covering part 300 Plastic Case

Claims

1. A high-pressure composite vessel, a plastic liner having a plastic case and a metal end rubber-coated by the plastic case; The metal end includes two rubber covering parts, a first rubber covering part and a second rubber covering part, the first rubber covering part is installed on the outer edge part of the metal end, the second rubber covering part is installed at the bottom of the cylinder opening valve mounting hole of the metal end, and the second rubber covering part is a plurality of parallel concave grooves installed along the cylinder opening valve mounting hole of the metal end; The plastic case has a first rubber covering layer formed on both the upper and lower surfaces of the first rubber covering portion, a second rubber covering layer formed on the inside of the second rubber covering portion, and the first rubber covering layer and the second rubber covering layer are connected by a transition layer, the first rubber covering layer, the second rubber covering layer and the transition layer form an end portion of the plastic case and are integrally connected to a body of the plastic case to form the plastic case; A second rubber-coated hole is provided on the lower end surface of the metal end around the cylinder opening valve mounting hole, and the second rubber-coated hole communicates with the groove. A high-pressure composite vessel characterized by:

2. 2. The high-pressure composite container according to claim 1, characterized in that the first rubber-coated portion has a first rubber-coated hole penetrating from top to bottom, and during the rubber-coating process, the plastic case material extends into the first rubber-coated hole to form a connection portion connecting the upper and lower surfaces of the first rubber-coated layer.

3. 2. The high pressure composite container according to claim 1, wherein the minimum diameter of the second rubber covering portion is larger than the diameter of a cylinder opening valve mounting hole of the metal end portion.

4. 2. The high pressure composite container according to claim 1, wherein the outer surface of the second rubber covering layer is provided with two or more sealing surfaces, the two or more sealing surfaces not being located in the same plane.

5. The high pressure composite container according to claim 1, characterized in that the plastic case selectively adopts a thermoplastic plastic including one or more combinations of PA, PE, PPA, PPS, polyester, PP, POM or EVOH based on the permeation characteristics of the molecular weights of different carrier high pressure gases.

6. 6. The high-pressure composite container according to claim 5, characterized in that the plastic case is manufactured from two or more thermoplastic layers, and a gas barrier layer is provided between two adjacent thermoplastic layers.

7. 2. The high pressure composite container according to claim 1, wherein a fiber reinforced layer is provided on the outer surface of the plastic liner.

8. 2. The high-pressure composite container according to claim 1, characterized in that a cylinder opening valve is installed in a cylinder opening valve mounting hole of the metal end, and a seal ring is installed between an outer surface of the cylinder opening valve and the second rubber coating layer.

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