A sealing device suitable for long-term storage of hydrogen gas cylinders

Abstract

The present invention relates to the field of valves, and particularly to a sealing device suitable for long-term storage of hydrogen gas cylinders, which includes an outer cylinder, a cover plate, an inner cylinder, a bottle mouth valve, a cam, a thimble, a locking nut and a gasket; the lower end of the outer cylinder is threadedly connected to the hydrogen gas cylinder, the cover plate is threadedly connected to the outer cylinder, and the inner cylinder is threadedly connected to the outer cylinder; the bottle mouth valve, the cam, the thimble and the gasket are installed in the inner cylinder and fixed by the locking nut, and the thimble is placed between the bottle mouth valve and the cam; there are multiple sealing rings inside the device to ensure sealing. The sealing device in the present invention is installed outside the bottle mouth of the gas cylinder, used to collect the hydrogen gas escaping from the bottle mouth valve, provides two-stage buffer spaces, and discharges it outward in time before taking out the gas cylinder to ensure the safety of the device.

Description

Technical Field

[0001] The present invention relates to the field of valves, and particularly to a sealing device suitable for long-term storage of hydrogen cylinders. Background Art

[0002] With the expansion of the application field of hydrogen energy, hydrogen storage technology has developed rapidly. High-pressure gaseous hydrogen storage is one of the common hydrogen storage methods at present. The high-pressure gaseous hydrogen storage technology stores hydrogen in cylinders, and the cylinder pressure can reach 70 MPa G. During actual operation, the hydrogen in the cylinder is output after being decompressed. The hydrogen-filled cylinders have a storage requirement. During long-term storage, the following problems exist:

[0003] First: Hydrogen has a small molecular weight and high diffusibility. Coupled with the high storage pressure, it poses a challenge to sealing.

[0004] Second: When high-pressure hydrogen cylinders are stored for a long time, if the diffused hydrogen does not flow smoothly, it will bring potential safety hazards and cause waste of resources. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a sealing device suitable for long-term storage of hydrogen cylinders. It is applied outside the cylinder mouth of the cylinder and is provided with two-stage buffer spaces for collecting the hydrogen diffused from the bottle mouth valve, slowing down the diffusion speed of hydrogen, and ensuring the safety of the cylinder during long-term storage.

[0006] The technical solution adopted by the present invention to solve the problem is: A sealing device suitable for long-term storage of hydrogen cylinders includes a cylinder, an outer cylinder, a cover plate, an inner cylinder, a bottle mouth valve, and a switch assembly; the outer cylinder is a hollow stepped cylindrical structure with both ends open. The lower end of the stepped cylindrical structure is threadedly connected to the hydrogen cylinder mouth, and the cover plate is screwed to the upper end of the stepped cylindrical structure. The lower end of the inner cylinder is provided with a cavity and a hydrogen flow channel communicating with the cavity; the inner cylinder passes through the cover plate, and the lower end surface of the inner cylinder is sealed with the upper end of the hydrogen cylinder mouth, and the cavity forms a first-stage gas chamber; a second-stage gas chamber is formed between the inner cylinder and the outer cylinder; the bottle mouth valve is installed on the hydrogen flow channel, and the opening and closing of the bottle mouth valve are controlled by the switch assembly.

[0007] Preferably, the volume of the first-stage gas chamber is 3% - 5% of the volume of the hydrogen cylinder, and the volume ratio of the second-stage gas chamber to the first-stage gas chamber is between 10 and 20.

[0008] Preferably, sealing rings are provided between the inner cylinder and the cover plate, between the outer cylinder and the cover plate, between the outer cylinder and the cylinder, and between the inner cylinder and the cam switch assembly to seal the hydrogen flow channel.

[0009] Preferably, the switch assembly includes a cam, a gasket, and a locking nut.

[0010] The cam is installed at the side-facing interface of the pressure reducing valve and is sequentially divided into four parts along the axis of the interface. The outermost part is connected to the side-facing interface through a lock nut, and the lock nut presses the gasket and the outermost part; a groove is provided on the second part adjacent to the outermost part, and the opening and closing limit structures of the cam are installed in the groove to prevent the valve from automatically closing; the third part is the convex surface of the cam, and its position corresponds to the switch execution part. The convex surface of the cam changes the opening and closing mode of the bottle mouth valve from linear motion to rotational motion. Sealing rings are provided on the second part and the fourth part, and the double-sealing-ring structure cancels out the axial force received by the cam. A key slot is provided on the end face of the outermost part, and the driving force for the rotation of the cam is provided through the key slot.

[0011] Preferably, the hydrogen flow channel is a vertical flow channel provided inside the inner cylinder, and the ejector pin is placed inside the hydrogen flow channel and is located between the bottle mouth valve and the cam.

[0012] Preferably, the position of the opening and closing limit structures ensures that when the cam is rotated in one direction, the convex surface of the cam presses down the ejector pin and the bottle mouth valve opens; when rotated in the other direction, the convex surface of the cam disengages from the ejector pin and the bottle mouth valve closes. The above two-way rotation limit is achieved by the contact of the opening and closing limit structures with the two end faces of the groove.

[0013] Preferably, during the opening process of the bottle mouth valve, after the tip of the convex surface of the cam rotates to the lowest point, it continues to move until the tip of the convex surface of the cam forms a small angle β with the vertical direction and reaches the open position limit; the range of β is 3° to 18°.

[0014] Preferably, the range of β is 5° to 10°.

[0015] Preferably, the cover plate is a cylindrical barrel-shaped structure with a central threaded hole at the bottom, and the inner wall surface of the barrel-shaped structure is screwed and sealed with the outer surface of the outer cylinder.

[0016] A method for using the sealing device includes:

[0017] Install the sealing device on the hydrogen gas cylinder mouth;

[0018] The hydrogen gas escaping from the gas cylinder first enters the first-stage gas chamber. After a certain pressure is established in the first-stage gas chamber, it enters the second-stage gas chamber through dispersion;

[0019] When it is necessary to remove the hydrogen gas cylinder stored for a long time, the bottle mouth valve is opened through the switch assembly, the hydrogen gas in the first-stage gas chamber is discharged outward, the bottle mouth valve is closed, and then the inner cylinder is rotated upward through the thread to make the first-stage gas chamber communicate with the second-stage gas chamber. The hydrogen gas in the second-stage gas chamber flows into the first-stage gas chamber. The bottle mouth valve is opened again through the switch assembly to discharge the hydrogen gas in the device outward;

[0020] After discharging the hydrogen gas in the first-stage gas chamber, unscrew the outer cylinder from the hydrogen gas cylinder and safely remove the hydrogen gas cylinder.

[0021] The beneficial effects of the present invention compared with the prior art are as follows:

[0022] 1. The sealing device in the present invention is installed outside the gas cylinder opening, and two-stage decompression and buffering spaces are designed, so that the pressure difference between the hydrogen pressure and the external pressure is small, and the escape of hydrogen can be slowed down within a certain period of time.

[0023] 2. Two-stage gas chambers are designed in the sealing device of the present invention. Through the reasonable design of the two-stage gas chambers, the escaped hydrogen is stored step by step in the two-stage gas chambers, which can slow down the escape speed of hydrogen. Before the hydrogen gas cylinder is put into use, the bottle mouth valve is opened to release the escaped gas, and the hydrogen gas cylinder can be safely taken out.

[0024] 3. Existing patents on the sealing of hydrogen gas cylinders all complete the sealing through valves or valve combinations. The method of increasing the buffering space is not involved in the above technology. Increasing the buffering space will improve the safety of the seal, but at the same time, it will cause the volume of the sealing components to be relatively large. The present invention is applicable to the long-term storage of hydrogen gas cylinders and needs to ensure its safety. Therefore, a scheme combining the bottle mouth valve and increasing the buffering space is adopted to further improve the sealing performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the sealing device of the present invention;

[0026] In the figure: 1 is the gas cylinder, 2 is the outer cylinder, 3 is the cover plate, 4 is the inner cylinder, 5 is the bottle mouth valve, 6 is the cam, 7 is the ejector pin, 8 is the lock nut, and 9 is the gasket;

[0027] Figure 2 It is a schematic diagram of the switch assembly. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be further described below in conjunction with the embodiments.

[0029] As Figure 1 shown, the sealing device of the present invention includes: a gas cylinder 1, an outer cylinder 2, a cover plate 3, an inner cylinder 4, a bottle mouth valve 5, a cam 6, an ejector pin 7, a lock nut 8 and a gasket 9; the lower end of the outer cylinder 2 is threadedly connected to the hydrogen gas cylinder 1, the cover plate 3 is threadedly connected to the outer cylinder 2, and the inner cylinder 4 is threadedly connected to the cover plate 3; the bottle mouth valve 5, the cam 6, the ejector pin 7 and the gasket 9 are installed in the inner cylinder 4 and fixed by the lock nut 8, and the ejector pin 7 is placed between the bottle mouth valve 5 and the cam 6; a plurality of sealing rings are provided inside the device to ensure sealing.

[0030] Both sides of the cover plate 3 are threadedly connected to the outer cylinder 2, and a threaded round hole is provided at the center of the cover plate 3 for the installation of the inner cylinder 4.

[0031] The lower end of the outer cylinder 2 is threadedly connected to the hydrogen gas cylinder 1, and the upper end is connected to the cover plate 3. The outer cylinder 2 provides a storage space for the escaped gas. A sealing ring is provided at the connection position between the outer cylinder 2 and the inner cylinder 4 to separate the primary gas chamber and the secondary gas chamber.

[0032] The inner cylinder 4 is threadedly connected to the cover plate 3. A vertical hydrogen gas flow channel is provided inside the inner cylinder 4 for the release of the escaped hydrogen. The lower end face of the inner cylinder 4 is connected to the upper end face of the outer cylinder 2. Inside the inner cylinder 4, a bottle valve 5, a cam 6, a thimble 7, a lock nut 8, and a gasket 9 are installed.

[0033] The bottle valve 5 described above can adopt the one-way bottle valve for a hydrogen energy handheld torch proposed in Patent CN114321711A, or other products. It is installed in the inner cylinder 4 and is used to discharge the escaped hydrogen outward.

[0034] The switch assembly, as Figure 2 shown, includes a cam 6, a gasket 9, a lock nut 8, and a screw. The lock nut 8 is threadedly connected to the side interface of the inner cylinder 4 to press the gasket and the cam. The cam is installed at the side interface of the inner cylinder 4 and is sequentially divided into four parts along the interface axis. The outermost part is connected to the side interface through the lock nut 8, and the lock nut 8 presses the gasket 9 and the outermost part. A groove 5-13 is provided on the second part adjacent to the outermost part, and the screw is installed in the groove to form an opening and closing limit structure for the cam to prevent the valve from automatically closing. The third part is the cam convex surface 5-11, and its position corresponds to the switch execution part. The cam convex surface changes the opening and closing mode of the bottle valve from direct movement to rotation. Sealing rings 5-14 are provided on the second part and the fourth part. The double-sealing-ring structure cancels out the axial force received by the cam. A key slot 5-12 is provided on the end face of the outermost part to provide the driving force for the rotation of the cam. Rotating the cam counterclockwise, the cam convex surface 5-11 presses down the thimble, and the bottle valve opens. Rotating the cam 6 clockwise, the cam convex surface 5-11 disengages from the thimble, and the bottle valve closes. The screw is in close contact with one end of the cam groove 5-13, and this is the closed position limit. Rotating the cam counterclockwise, the bottle valve opens. After the tip of the cam convex surface 5-11 rotates to the lowest point and continues to move until the tip of the convex surface forms a small angle β with the vertical direction, the range of β is 3° to 18°, preferably 5° to 10°. The screw is in close contact with the other end of the cam groove 5-13, and the cam cannot continue to rotate counterclockwise. This is the open position limit.

[0035] In hydrogen energy products other than the hydrogen energy handheld torch of the present invention, it is installed in the inner cylinder 4, and rotating the cam 6 drives the thimble 7 to move up and down, which is used to seal or discharge the escaped hydrogen outward.

[0036] In the sealing device described above, sealing rings are provided between the inner cylinder 4 and the cover plate 3, between the inner cylinder 4 and the cam 6, between the outer cylinder 2 and the cover plate 3, and between the outer cylinder 2 and the gas cylinder 1 to seal the hydrogen gas flow channel.

[0037] In the described sealing device, a two-stage gas chamber structure is designed so that the dissipated hydrogen is stored step by step in the two-stage gas chambers, which can slow down the dissipation rate of hydrogen. Before the hydrogen cylinder is put into use, the bottle mouth valve is opened to release the dissipated gas, and the hydrogen cylinder can be safely taken out. The volume of the first-stage gas chamber is 3% - 5% of the volume of the cylinder, and the volume ratio of the two-stage gas chambers to the first-stage gas chamber is between 10 and 20.

[0038] The working principle of the present invention is as follows:

[0039] The inner cylinder 4, the outer cylinder 2 and the cover plate 3 divide the storage space of the dissipated gas into two parts: the first-stage gas chamber and the second-stage gas chamber, and the volume of the first-stage gas chamber is smaller than that of the second-stage gas chamber. The hydrogen dissipated from the cylinder first enters the first-stage gas chamber. After a certain pressure is established in the first-stage gas chamber, it overflows into the second-stage gas chamber. When it is necessary to remove the cylinder 1 stored for a long time, the cam 6 is rotated to drive the thimble 7 to move downward, so that the bottle mouth valve 5 is opened, and the hydrogen in the first-stage gas chamber is discharged outward. The bottle mouth valve 5 is closed, and then the inner cylinder 4 is rotated upward through the thread to make the first-stage gas chamber communicate with the second-stage gas chamber, and the hydrogen in the second-stage gas chamber flows into the first-stage gas chamber. The bottle mouth valve 5 is opened again to discharge the hydrogen in the device outward.

[0040] The above shows and describes the basic principle, main features and advantages of the present invention. The present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A sealing device suitable for long-term storage of hydrogen gas cylinders, characterized in that: It includes a gas cylinder, an outer cylinder, a cover plate, an inner cylinder, a bottle mouth valve, and a switch assembly; the outer cylinder is a hollow stepped cylindrical structure with openings at both ends. The lower end of the stepped cylindrical structure is threadedly connected to the hydrogen gas cylinder mouth, and the cover plate is screwed to the upper end of the stepped cylindrical structure. A cavity is provided inwardly at the lower end of the inner cylinder, and a hydrogen gas flow channel is communicated with the cavity. The hydrogen gas flow channel is a vertical flow channel provided inside the inner cylinder; the inner cylinder passes through the cover plate, and the lower end surface of the inner cylinder is sealed with the upper end of the hydrogen gas cylinder mouth, and the cavity forms a primary gas chamber; a secondary gas chamber is formed between the inner cylinder and the outer cylinder; the bottle mouth valve is installed on the hydrogen gas flow channel, and the opening and closing of the bottle mouth valve are controlled by the switch assembly. The cover plate is a cylindrical barrel-shaped structure with a central threaded hole at the bottom.

2. The sealing device according to claim 1, characterized in that: The volume of the primary gas chamber is 3% - 5% of the volume of the hydrogen gas cylinder, and the volume ratio of the secondary gas chamber to the primary gas chamber is between 10 and 20.

3. The sealing device according to claim 1, characterized in that: Sealing rings are provided between the inner cylinder and the cover plate, between the outer cylinder and the cover plate, between the outer cylinder and the gas cylinder, and between the inner cylinder and the cam switch assembly to seal the hydrogen gas flow channel.

4. The sealing device according to claim 1, characterized in that: The switch assembly includes a cam, a gasket, and a locking nut; The cam is installed at the side docking interface of the inner cylinder and is sequentially divided into four parts along the interface axis. The outermost part is connected to the side docking interface through a locking nut, and the gasket and the outermost part are pressed by the locking nut; a groove is provided on the second part adjacent to the outermost part, and the opening and closing limit structures of the cam are installed in the groove to prevent the valve from automatically closing; the third part is the convex surface of the cam, and its position corresponds to the switch execution part. The convex surface of the cam changes the opening and closing mode of the bottle mouth valve from linear motion to rotary motion. Sealing rings are provided on the second part and the fourth part. The double-sealing-ring structure cancels out the axial force received by the cam. A key slot is provided on the end surface of the outermost part to provide the driving force for the rotation of the cam through the key slot.

5. The sealing device according to claim 4, characterized in that: The ejector pin is placed inside the hydrogen gas flow channel and is located between the bottle mouth valve and the cam.

6. The sealing device according to claim 5, characterized in that: The position of the opening and closing limit structures ensures that when the cam rotates in one direction, the convex surface of the cam presses down the ejector pin and the bottle mouth valve opens; when rotating in the other direction, the convex surface of the cam disengages from the ejector pin and the bottle mouth valve closes. The limit of rotation in one direction and the other direction is achieved by the contact of the opening and closing limit structures with the two end surfaces of the groove.

7. The sealing device according to claim 6, characterized in that: During the opening process of the bottle mouth valve, after the tip of the convex surface of the cam rotates to the lowest point, it continues to move until the tip of the convex surface of the cam forms a small angle β with the vertical direction and reaches the open position limit; the range of β is 3° - 18°.

8. The sealing device according to claim 7, characterized in that: The range of β is 5° - 10°.

9. The sealing device according to claim 1, characterized in that: The inner wall surface of the cylindrical barrel-shaped structure is screwed and sealed with the outer wall surface of the outer cylinder.

10. A method for using the sealing device according to any one of claims 1 - 9, characterized in that: Install the sealing device on the hydrogen gas cylinder mouth; The hydrogen gas escaping from the gas cylinder first enters the primary gas chamber. After a certain pressure is established in the primary gas chamber, it enters the secondary gas chamber through dispersion; When it is necessary to remove the hydrogen gas cylinder stored for a long time, the bottle neck valve is opened through the switch assembly, and the hydrogen in the first-stage gas chamber is discharged outward. Then the bottle neck valve is closed, and then the inner cylinder is rotated upward through the thread to make the first-stage gas chamber communicate with the second-stage gas chamber, and the hydrogen in the second-stage gas chamber flows into the first-stage gas chamber. Then the bottle neck valve is opened again through the switch assembly to discharge the hydrogen in the device outward; After discharging the hydrogen in the first-stage gas chamber, unscrew the outer cylinder and the hydrogen gas cylinder, and safely remove the hydrogen gas cylinder.

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