A sealing structure and sealing method for the mouth of a type IV hydrogen storage bottle

Abstract

The present invention discloses a sealing structure and a sealing method for the mouth of a type IV hydrogen storage gas cylinder, and belongs to the technical field of high-pressure hydrogen storage gas cylinders. The sealing structure of the mouth of a type IV hydrogen storage gas cylinder provided by the present invention comprises an aluminum alloy valve seat, an aluminum alloy locking device and a plastic liner; a limit groove, an overflow sealing groove and a continuous sealing groove are arranged on the vertical section and the horizontal section of the aluminum alloy valve seat, the overflow sealing groove is filled with carbon fiber felt strips, and the overflow sealing groove and the continuous sealing groove are interference filled with high-temperature resistant sealant; the mouth section of the plastic liner is located between the aluminum alloy valve seat and the aluminum alloy locking device; the bottle shoulder and the mouth section of the plastic liner are limitedly matched with the aluminum alloy valve seat through the limit groove, and a high-temperature resistant sealant is arranged on the contact interface between the two. The design of the sealing structure of the present invention can effectively ensure the sealing effect of the high-temperature resistant sealing layer between the plastic liner and the specific position of the aluminum alloy valve seat, and has a longer sealing life.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure hydrogen storage cylinders, and in particular to a sealing structure of a bottle mouth of a type IV hydrogen storage cylinder and a sealing method thereof. Background Art

[0002] The information disclosed in the background of the invention is only intended to enhance the understanding of the overall background of the invention and should not be necessarily regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Hydrogen energy is a new type of clean energy, and the safe storage and transportation of hydrogen energy is a key technology for the development of hydrogen energy. Type IV hydrogen storage cylinders require a hydrogen storage pressure of 70MPa and a hydrogen storage density greater than 5%. To meet this requirement, the liner must be made of plastic, which is relatively light and more suitable for passenger car applications. Currently, Type IV hydrogen storage cylinders have become a research hotspot around the world.

[0004] At present, during the operation of Type IV hydrogen storage cylinders, gas leakage easily occurs at the connection between the plastic liner and the valve seat of the cylinder mouth, which is also the main failure mode of the engineering application of the hydrogen storage cylinder, resulting in reduced safety and reliability of Type IV cylinders. Due to the need for strength and rigidity, the liner of the hydrogen storage cylinder must be designed with metal materials for the mouth. Due to the difference in thermal expansion performance between the metal mouth and the plastic liner, the joint sealing problem is also a key technical issue for the overall reliability of the cylinder.

[0005] The mouth of the current IV-type hydrogen storage bottle mainly adopts the BOSS structure to prevent leakage, and uses seals (such as rubber rings, O-rings, etc.) for sealing. For example, patent CN116293434A (publication date: 2023.06.23) discloses a BOSS structure bottle mouth sealing structure for IV-type hydrogen storage cylinders. The axial inner and outer surfaces of the end cap and the inner and outer surfaces of the BOSS structure are arranged with threaded designs to achieve a fastening connection between the end cap, BOSS structure, bottle mouth valve and external tube sheet and other metal connectors. At the same time, the inner surface of the upper end of the plastic liner is provided with a taper, and the sealing ring in the sealing groove of the lower conical surface of the end cap is interference-fitted to assume the sealing function. However, the processing difficulty of the internal thread design is relatively large, and the sealing ring is prone to aging, has a short service life, and is prone to sealing failure, so the sealing safety and stability are relatively low.

[0006] Therefore, how to provide a connection and combination method between the plastic liner at the mouth of a Type IV hydrogen storage cylinder and the metal material, which has a simple structure, low processing difficulty, higher sealing safety, and longer sealing life, is an urgent problem to be solved. Summary of the invention

[0007] In view of this, the present invention provides a sealing structure for the mouth of a type IV hydrogen storage cylinder and a sealing method thereof, which has good gas sealing performance, long sealing life, can ensure the connection stability between the plastic liner and the metal material, and has low processing difficulty.

[0008] In a first aspect, the present invention provides a sealing structure for a bottle mouth of a type IV hydrogen storage gas cylinder, comprising an aluminum alloy valve seat, an aluminum alloy locking device and a plastic liner; the aluminum alloy valve seat is located at the innermost side of the bottle mouth; the plastic liner comprises, from bottom to top, a bottle body vertical section, a bottle body shoulder and a bottle mouth section; the bottle mouth section of the plastic liner is located between the aluminum alloy valve seat and the aluminum alloy locking device; the bottle body shoulder and the bottle mouth section of the plastic liner are limitedly matched with the aluminum alloy valve seat through a limiting groove;

[0009] The aluminum alloy valve seat comprises a vertical section and a horizontal section, and a continuous sealing groove, an overflow sealing groove and a limit groove are arranged on the vertical section and the horizontal section of the aluminum alloy valve seat; the overflow sealing groove is tightly filled with carbon fiber felt strips;

[0010] The aluminum alloy locking device is located outside the vertical section of the aluminum alloy valve seat, and the upper part of the aluminum alloy locking device is fastened with the upper part of the vertical section of the aluminum alloy valve seat by using threads;

[0011] A high temperature resistant sealant is arranged on the contact interface between the plastic liner and the aluminum alloy valve seat, and the overflow sealing groove and the continuous sealing groove are interference filled with the high temperature resistant sealant.

[0012] Preferably, the bulk density of the carbon fiber felt strip is 0.05-0.2 g / cm 3 .

[0013] Preferably, the cross-sectional shape of the limiting groove is rectangular, so as to prevent relative movement between the plastic liner and the aluminum alloy valve seat.

[0014] Furthermore, the depth of the limiting groove is 2-5 cm, and the width of the groove is 1-5 cm; the inner surface of the limiting groove is provided with rough micropores with a diameter of 2-5 μm to increase the surface bonding firmness and friction between the plastic liner and the aluminum alloy valve seat.

[0015] Preferably, the outer side of the vertical section of the aluminum alloy valve seat is provided with a first continuous sealing groove, a first overflow sealing groove and a first limit groove in sequence from top to bottom; the upper part of the horizontal section of the aluminum alloy valve seat is provided with a second limit groove, a second overflow sealing groove, a second continuous sealing groove, a third overflow sealing groove and a third limit groove in sequence along the direction from the outer side of the gas cylinder to the center axis of the gas cylinder.

[0016] Preferably, the cross section of the overflow sealing groove is an arc with a central angle of 220-320° and a radius of 0.5-2 cm.

[0017] Preferably, the continuous sealing groove is a plurality of arc grooves connected in parallel, the number of the arc grooves is 2-5, and the cross-section of the arc groove is an arc with a central angle of 60-180° and a radius of 0.5-2 cm.

[0018] Preferably, a carbon fiber composite material protective layer and a mixed fiber protective layer are sequentially provided on the outer surfaces of the vertical section of the bottle body and the shoulder of the bottle body of the plastic liner from the inside to the outside; the carbon fiber composite material protective layer comprises carbon fiber and resin, the carbon fiber is selected from any one of T300, T700, T800 and T1000, and the resin is selected from epoxy resin or phenolic resin; the mixed fiber of the mixed fiber protective layer is mixed with high modulus carbon fiber and high tenacity fiber; the high modulus carbon fiber is selected from any one of M40, M55, M60, M40J, M55J or M60J, and the high tenacity fiber is selected from any one of aramid fiber or UHMWPE fiber.

[0019] Preferably, the bottle mouth section of the plastic liner is connected to the aluminum alloy locking device in a gradient manner; and the inner lower portion of the aluminum alloy locking device is arranged as a rounded transition structure.

[0020] In a second aspect, the present invention provides a sealing method based on the sealing structure of the bottle mouth of the above-mentioned IV type hydrogen storage cylinder, comprising the following steps:

[0021] A high temperature resistant sealant is applied at the contact position between the outer surface of the aluminum alloy valve seat and the plastic liner, the overflow sealing groove and the continuous sealing groove are interference filled with the high temperature resistant sealant, and then the plastic liner is prepared by injection molding, and the plastic liner and the aluminum alloy valve seat are limitedly matched through the limit groove;

[0022] Under the tightening action of the thread of the aluminum alloy locking device, the sealant in the continuous sealing groove overflows and is stored in the carbon fiber felt strip in the overflow sealing groove, and is heated and cured to achieve interface sealing.

[0023] Preferably, the coating thickness of the high temperature resistant sealant coated on the contact interface between the aluminum alloy valve seat and the plastic liner is 0.5-2mm; the high temperature resistant sealant is selected from heat-resistant modified vinyl silicone rubber or low benzene silicone rubber; the heat resistant temperature of the high temperature resistant sealant is 150-350°C, the tensile strength is 5-9.5MPa, the elongation at break is 500-1000%, and the tear strength is 25-50kN / m; the temperature of the heating and curing molding is 100-200°C.

[0024] Preferably, after the step of limiting the plastic liner and the aluminum alloy valve seat through the limiting groove, it also includes winding carbon fiber composite materials and mixed fibers in sequence from the inside to the outside on the outer surface of the vertical section of the bottle body and the shoulder of the bottle body of the plastic liner to form a carbon fiber composite material protective layer and a mixed fiber protective layer.

[0025] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0026] (1) The present invention ensures the matching connection between the plastic liner and the aluminum alloy valve seat by opening multiple groups of limit grooves in the vertical section and the horizontal section of the aluminum alloy valve seat; and fills the overflow sealing groove with carbon fiber felt strips. Through the pre-tightening overflow effect of the high-temperature resistant sealing colloid in the continuous sealing groove, the felt strips in the overflow sealing groove are effectively filled. The combination of the carbon fiber felt strips and the sealant improves the connection strength of the interface and ensures the sealing effect of the interface.

[0027] (2) The present invention utilizes the internal and external assembly clamping force of the aluminum alloy locking device and the aluminum alloy valve seat, and through the combined sealing structure design of continuous sealing grooves, overflow sealing grooves and multiple groups of limit grooves, effectively ensures the sealing effect of the high-temperature resistant sealing layer between the plastic liner and the specific position of the aluminum alloy valve seat, and gives full play to the comprehensive mechanical properties of the sealant such as tear resistance, friction resistance, and tensile and compressive resistance. When the gas cylinder head is subjected to complex stress, the force coordination of the multi-material components is ensured. Compared with existing sealing rubber rings, O-rings and other seals, it has a longer sealing life and achieves a stable sealing effect.

[0028] (3) The thread design of the present invention is only located between the aluminum alloy locking device and the aluminum alloy valve seat, and the thread connection range is small, which mainly plays a tightening role. At the same time, there is no need to place a sealing ring in the thread groove. Therefore, the process operation is simple and the processing difficulty is low.

[0029] (4) The present invention opens multiple groups of continuous sealing grooves on the surface of the aluminum alloy valve seat, coats a high-temperature resistant sealing layer colloid during the assembly process of the hydrogen storage cylinder, and simultaneously completes the curing and sealing of the high-temperature sealing colloid during the assembly and curing process of the cylinder, thereby effectively ensuring the sealing effect of the hydrogen storage cylinder mouth.

[0030] (5) The present invention increases the surface bonding firmness and friction between the plastic liner and the aluminum alloy valve seat by roughening the inner surface of the limit groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute an improper limitation of the present invention. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0032] In order to show the positions of various parts, the distances or sizes between them are exaggerated in the figure, and the schematic diagram is for illustration only.

[0033] Figure 1 This is a schematic cross-sectional view of the overall structure of the sealing structure of the mouth of a Type IV hydrogen storage gas bottle according to Example 1 of the present invention;

[0034] In the figure, 1. aluminum alloy valve seat; 2. aluminum alloy locking device; 3. plastic liner; 4. first continuous sealing groove; 5. first overflow sealing groove; 6. first limiting groove; 7. second limiting groove; 8. second overflow sealing groove; 9. second continuous sealing groove; 10. third overflow sealing groove; 11. third limiting groove; 12. carbon fiber felt strip; 13. thread; 14. mixed fiber protective layer; 15. carbon fiber composite material protective layer. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0037] Example 1

[0038] This embodiment provides a sealing structure for the mouth of a type IV hydrogen storage cylinder, such as Figure 1 As shown, it includes an aluminum alloy valve seat 1, an aluminum alloy locking device 2 and a plastic liner 3; the aluminum alloy valve seat 1 is located at the innermost side of the bottle mouth; the plastic liner 3 includes a bottle body vertical section, a bottle body shoulder and a bottle mouth section from bottom to top.

[0039] The aluminum alloy valve seat 1 includes a vertical section and a horizontal section. The outer side of the vertical section is provided with a first continuous sealing groove 4, a first overflow sealing groove 5 and a first limiting groove 6 in sequence from top to bottom; the upper part of the horizontal section is provided with a second limiting groove 7, a second overflow sealing groove 8, a second continuous sealing groove 9, a third overflow sealing groove 10 and a third limiting groove 11 in sequence along the outer side of the gas cylinder toward the center axis of the gas cylinder; the first overflow sealing groove 5, the second overflow sealing groove 8 and the third overflow sealing groove 10 are tightly filled with carbon fiber felt strips 12.

[0040] A hollow sleeve is assembled between the aluminum alloy valve seat 1 and the aluminum alloy locking device 2. The aluminum alloy locking device 2 is located outside the vertical section of the aluminum alloy valve seat 1. The upper part of the aluminum alloy locking device 2 is fastened to the upper part of the vertical section of the aluminum alloy valve seat 1 by using threads 13.

[0041] The mouth section of the plastic liner 3 is located between the aluminum alloy valve seat 1 and the aluminum alloy locking device 2, and the bottle shoulder and mouth section of the plastic liner 3 are filled and combined with the aluminum alloy valve seat 1 through the first limiting groove 6, the second limiting groove 7 and the third limiting groove 11.

[0042] The cross-sectional shapes of the first limiting groove 6, the second limiting groove 7 and the third limiting groove 11 are rectangular, which are used to prevent relative movement between the plastic liner 3 and the aluminum alloy valve seat 1. The first continuous sealing groove 4 and the second continuous sealing groove 9 are three arc grooves connected in parallel. The outer surface of the vertical section of the bottle body and the shoulder of the bottle body of the plastic liner 3 is sequentially provided with a carbon fiber composite material protective layer 15 and a mixed fiber protective layer 14 from the inside to the outside.

[0043] The bottle mouth section of the plastic liner 3 is connected to the aluminum alloy locking device 2 in a gradient manner, so that the two can be better matched. The inner lower part of the aluminum alloy locking device 2 is set as a rounded transition structure.

[0044] Example 2

[0045] This embodiment provides a sealing method for the sealing structure of the mouth of a type IV hydrogen storage gas bottle based on embodiment 1. The specific parameters of the sealing structure are:

[0046] The cross-sectional rectangular depth of the first limiting groove 6, the second limiting groove 7 and the third limiting groove 11 is 2 cm, the groove width is 1 cm, and the inner surface is roughened to arrange rough micropores with a diameter of 2 microns. The arc groove cross-section of the first continuous sealing groove 4 and the second continuous sealing groove 9 is an arc with a central angle of 150° and a radius of 0.5 cm (the groove width is 0.97 cm). The cross-section of the first overflow sealing groove 5, the second overflow sealing groove 8 and the third overflow sealing groove 10 is an arc with a central angle of 270° and a radius of 0.5 cm (the groove width is 0.71 cm), and the bulk density of the carbon fiber felt strip 12 is 0.05 g / cm 3 .

[0047] The sealing method is as follows:

[0048] Fill the first overflow seal groove 5, the second overflow seal groove 8 and the third overflow seal groove 10 of the aluminum alloy valve seat 1 with carbon fiber felt strips 12, and apply 1mm high temperature resistant modified vinyl silicone rubber at the contact position between the outer surface of the aluminum alloy valve seat 1 and the plastic liner 3, and apply high temperature resistant sealant in the first overflow seal groove 5, the second overflow seal groove 8, the third overflow seal groove 10, the first continuous seal groove 4 and the second continuous seal groove 9 of the aluminum alloy valve seat 1. The coating adopts a preheating process of brushing in batches, first brushing a layer of colloid, then preheating it at 100℃ to change it from a flowing colloid to a semi-gel state with relatively low fluidity, and then brushing it again, and repeating this 3 times. The heat-resistant temperature of the modified vinyl silicone rubber is in the range of 150-350℃, its tensile strength is in the range of 5-9.5MPa, its elongation at break is in the range of 500-1000%, and its tear strength is in the range of 25-50kN / m.

[0049] The plastic liner 3 is prepared by injection molding, and a carbon fiber composite material protective layer 15 and a mixed fiber protective layer 14 are sequentially wound on the outer surface of the shoulder of the bottle body and the vertical section of the bottle body of the plastic liner 3. The carbon fiber composite material protective layer 15 adopts T800 high-strength carbon fiber, and the resin is epoxy resin; the mixed fiber protective layer 14 adopts M55 high modulus carbon fiber and high-tenacity aramid fiber mixed in a ratio of 2:1.

[0050] During the process of tightening the aluminum alloy locking device 2 and the aluminum alloy valve seat 1 through the thread 13, the gel-modified vinyl silicone rubber in the first continuous sealing groove 4 and the second continuous sealing groove 9 overflows and is stored in the carbon fiber felt strips 12 in the first overflow sealing groove 5, the second overflow sealing groove 8 and the third overflow sealing groove 10 under the preload force of the entire system, and the sealing is achieved through the tightening action of the metal thread 13 between the aluminum alloy locking device 2 and the aluminum alloy valve seat 1, the bonding action of the sealant and the sealing action of the carbon fiber felt strips 12. Finally, the simultaneous heating and curing molding of multiple components is completed by heating, and the pre-coated high-temperature sealing layer colloid is simultaneously cured and the interface is synchronously sealed during the molding process.

[0051] Example 3

[0052] The difference from Example 2 is that the cross-sectional rectangular depth of the first limiting groove 6, the second limiting groove 7 and the third limiting groove 11 is 4 cm, and the slot width is 1 cm. The arc groove cross-section of the first continuous sealing groove 4 and the second continuous sealing groove 9 is an arc with a central angle of 120° and a radius of 1 cm (the slot width is 1.73 cm). The cross-section of the first overflow sealing groove 5, the second overflow sealing groove 8 and the third overflow sealing groove 10 is an arc with a central angle of 240° and a radius of 1 cm (the slot width is 1.73 cm). The carbon fiber composite material protective layer 15 adopts T1000 high-strength carbon fiber, and the mixed fiber protective layer 14 adopts M60J high modulus carbon fiber and high-toughness aramid fiber mixed in a ratio of 3:1. 0.8 mm high-temperature resistant modified vinyl silicone rubber is coated on the contact position between the outer surface of the aluminum alloy valve seat 1 and the plastic liner 3.

[0053] The rest is the same as Example 2.

[0054] Example 4

[0055] The difference from Example 2 is that the carbon fiber composite material protective layer 15 uses T1000 high-strength carbon fiber, and the mixed fiber protective layer 14 uses M60J high modulus carbon fiber and high-tenacity UHMWPE fiber (ultra-high molecular weight polyethylene fiber) mixed at a ratio of 5:1. 0.5 mm high-temperature resistant modified vinyl silicone rubber is coated on the contact position between the outer surface of the aluminum alloy valve seat 1 and the plastic liner 3.

[0056] The rest is the same as Example 2.

[0057] Example 5

[0058] The difference from Example 2 is that the bulk density of the carbon fiber felt strip 12 is 0.2 g / cm 3 The carbon fiber composite material protective layer 15 uses T300 high-strength carbon fiber, and the mixed fiber protective layer 14 uses M40J high modulus carbon fiber and high-toughness aramid fiber mixed at a ratio of 8:1. 0.5 mm high-temperature resistant modified vinyl silicone rubber is coated on the contact position between the outer surface of the aluminum alloy valve seat 1 and the plastic liner 3.

[0059] The rest is the same as Example 2.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sealing structure for the mouth of a type IV hydrogen storage bottle, characterized in that: It comprises an aluminum alloy valve seat, an aluminum alloy locking device and a plastic liner; the aluminum alloy valve seat is located at the innermost side of the bottle mouth; the plastic liner comprises a bottle body vertical section, a bottle body shoulder and a bottle mouth section from bottom to top; the bottle mouth section of the plastic liner is located between the aluminum alloy valve seat and the aluminum alloy locking device; the bottle body shoulder and the bottle mouth section of the plastic liner are limitedly matched with the aluminum alloy valve seat through a limiting groove; The aluminum alloy valve seat comprises a vertical section and a horizontal section, and a continuous sealing groove, an overflow sealing groove and a limit groove are arranged on the vertical section and the horizontal section of the aluminum alloy valve seat; the overflow sealing groove is tightly filled with carbon fiber felt strips; The aluminum alloy locking device is located outside the vertical section of the aluminum alloy valve seat, and the upper part of the aluminum alloy locking device is fastened with the upper part of the vertical section of the aluminum alloy valve seat by using threads; A high temperature resistant sealant is provided on the contact interface between the plastic liner and the aluminum alloy valve seat, and the overflow sealing groove and the continuous sealing groove are interference filled with the high temperature resistant sealant; The outer side of the vertical section of the aluminum alloy valve seat is provided with a first continuous sealing groove, a first overflow sealing groove and a first limiting groove in sequence from top to bottom; the upper part of the horizontal section of the aluminum alloy valve seat is provided with a second limiting groove, a second overflow sealing groove, a second continuous sealing groove, a third overflow sealing groove and a third limiting groove in sequence along the outer side of the gas cylinder toward the central axis of the gas cylinder; Through the pre-tightening overflow effect of the high temperature resistant sealing colloid in the continuous sealing groove, the felt strip in the overflow sealing groove is effectively filled.

2. The sealing structure of the mouth of a type IV hydrogen storage bottle as claimed in claim 1, characterized in that: The bulk density of the carbon fiber felt strip is 0.05-0.2 g / cm 3 ; The cross-sectional shape of the limiting groove is a rectangle.

3. The sealing structure of the mouth of a type IV hydrogen storage bottle as claimed in claim 2, characterized in that: The depth of the limiting groove is 2-5 cm, and the width of the groove is 1-5 cm; the inner surface of the limiting groove is provided with rough micropores with a diameter of 2-5 μm.

4. The sealing structure of the mouth of a type IV hydrogen storage bottle as claimed in claim 1, characterized in that: The cross section of the overflow sealing groove is an arc with a central angle of 220-320° and a radius of 0.5-2 cm; the continuous sealing groove is a plurality of arc grooves connected in parallel, the number of the arc grooves is 2-5, and the cross section of the arc groove is an arc with a central angle of 60-180° and a radius of 0.5-2 cm.

5. The sealing structure of the mouth of a type IV hydrogen storage bottle as claimed in claim 1, characterized in that: A carbon fiber composite material protective layer and a mixed fiber protective layer are sequentially arranged on the outer surfaces of the vertical section of the bottle body and the shoulder of the bottle body of the plastic liner from the inside to the outside; the carbon fiber composite material protective layer comprises carbon fiber and resin, the carbon fiber is selected from any one of T300, T700, T800 and T1000, and the resin is selected from epoxy resin or phenolic resin; the mixed fiber of the mixed fiber protective layer is mixed with high modulus carbon fiber and high tenacity fiber; the high modulus carbon fiber is selected from any one of M40, M55, M60, M40J, M55J or M60J, and the high tenacity fiber is selected from any one of aramid fiber or UHMWPE fiber.

6. The sealing structure of the mouth of a type IV hydrogen storage bottle as claimed in claim 1, characterized in that: The bottle mouth section of the plastic liner is connected to the aluminum alloy locking device in a gradient manner; the inner lower part of the aluminum alloy locking device is arranged as a rounded transition structure.

7. A sealing method based on the sealing structure of the mouth of a type IV hydrogen storage gas bottle according to any one of claims 1 to 6, characterized in that: The steps include: A high temperature resistant sealant is applied at the contact position between the outer surface of the aluminum alloy valve seat and the plastic liner, the overflow sealing groove and the continuous sealing groove are interference filled with the high temperature resistant sealant, and then the plastic liner is prepared by injection molding, and the plastic liner and the aluminum alloy valve seat are limitedly matched through the limit groove; Under the tightening action of the thread of the aluminum alloy locking device, the sealant in the continuous sealing groove overflows and is stored in the carbon fiber felt strip in the overflow sealing groove, and is heated and cured to achieve interface sealing.

8. The sealing method according to claim 7, characterized in that: The coating thickness of the high-temperature resistant sealant coated on the contact interface between the aluminum alloy valve seat and the plastic liner is 0.5-2mm; the high-temperature resistant sealant is selected from heat-resistant modified vinyl silicone rubber or low-benzene silicone rubber; the heat-resistant temperature of the high-temperature resistant sealant is 150-350°C, the tensile strength is 5-9.5MPa, the elongation at break is 500-1000%, and the tear strength is 25-50kN / m; the temperature of the heating and curing molding is 100-200°C.

9. The sealing method according to claim 7, characterized in that: After the plastic liner and the aluminum alloy valve seat are limitedly matched through the limiting groove, the process also includes winding carbon fiber composite materials and mixed fibers in sequence from inside to outside on the vertical section of the bottle body and the outer surface of the shoulder of the bottle body of the plastic liner to form a carbon fiber composite material protective layer and a mixed fiber protective layer.

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