Hydrogen transport cylinder explosion-proof pressure relief protection assembly

Abstract

The application relates to the technical field of hydrogen energy cylinder safety protection, and discloses a hydrogen transport cylinder explosion-proof pressure relief protection assembly. In the application, the upper end of a hydrogen transport cylinder is provided with a sealing cover main body, the upper end of the sealing cover main body is provided with an upper sealing cover, one side of the upper sealing cover is provided with a pressure relief pipe, the sealing cover main body and the upper sealing cover form an integral wrapping protection structure, a reset spring continuously pushes an activity plate under normal conditions, a sealing plate at the top of the activity plate is clamped into a movable cavity in the inner wall of the pressure relief pipe, the pressure relief port is completely blocked, and a hydrogen gas leakage channel is blocked, when overpressure occurs in the hydrogen transport cylinder, high-pressure hydrogen gas enters a pressure relief cavity and exerts a lateral thrust on the activity plate, the pre-tightening force of the reset spring is overcome, the activity plate is driven to slide in the pressure relief cavity, the sealing plate is separated from the pressure relief port along with the activity plate, the pressure relief cavity is communicated with an external space, high-pressure hydrogen gas is first subjected to pressure buffering in the pressure relief cavity and then slowly discharged through the pressure relief port, and direct spraying of high-pressure hydrogen gas to form a high-speed jet flow is avoided.

Description

Technical Field

[0001] This application belongs to the field of hydrogen energy cylinder safety protection technology, specifically a hydrogen transport cylinder explosion-proof pressure relief protection component. Background Technology

[0002] Hydrogen energy, as a clean and low-carbon energy source, is being widely applied in road transportation, distributed energy storage, and industrial raw material supply. High-pressure hydrogen storage cylinders are core equipment in long-distance hydrogen logistics systems, relying on vehicle-mounted transport to transfer hydrogen between refueling stations and users. Currently, high-pressure hydrogen storage commonly uses 35MPa and 70MPa composite material cylinders, with integrated safety pressure relief components at the cylinder ends—an essential safety feature for pressure vessels. Hydrogen possesses unique physical and chemical properties, including small molecules, high permeability, and low ignition energy. Therefore, cylinder valve assemblies and pressure relief components have design requirements far exceeding those of conventional industrial cylinders in terms of sealing, vibration resistance, and resistance to hydrogen embrittlement. The industry continues to promote the integrated development of various pressure relief protection structures.

[0003] The existing hydrogen transport cylinder standard system generally requires cylinders to be equipped with over-temperature and over-pressure protection structures. The mainstream protection methods include two types: rupture disc pressure relief structures and fusible plug pressure relief structures. Rupture discs rely on a set pressure to achieve rupture and release, suitable for handling instantaneous pressure overload conditions. Fusible plugs use the high-temperature melting of a fusible alloy to open the passage, and are mostly used in fire and external exposure to high temperatures. Many manufacturers integrate pressure relief components into the cylinder head combination valve, achieving integrated valve assembly and facilitating unified installation and management of the entire vehicle's cylinder modules. The ongoing development of vehicle-mounted storage and transportation scenarios continues to drive the miniaturization and modularization of pressure relief devices to adapt to the compact installation requirements of containerized cylinder bundles and vehicle-mounted hydrogen storage cylinder groups.

[0004] However, the high-pressure hydrogen discharged by the traditional pressure relief structure lacks a buffer and flow guiding structure, which can easily form a high-speed jet. At the same time, the continuous vibration during transportation can cause the assembly position to loosen, posing a risk of minor leakage, making it difficult to meet the high-standard safety requirements of long-distance hydrogen transportation. Summary of the Invention

[0005] The purpose of this application is to provide an explosion-proof pressure relief protection component for hydrogen transport cylinders, in order to solve the problems that the high-pressure hydrogen discharged by the traditional pressure relief structure lacks a buffer and flow guiding structure, easily forms a high-speed jet, and at the same time, the continuous vibration during transportation can easily cause the assembly position to loosen, posing a small leakage hazard, and making it difficult to meet the high standard safety requirements of long-distance hydrogen transportation.

[0006] The technical solution adopted in this application is as follows: A hydrogen transport gas cylinder explosion-proof pressure relief protection component includes a hydrogen transport gas cylinder, a sealing cover body is provided at the upper end of the hydrogen transport gas cylinder, an upper sealing cover is provided at the upper end of the sealing cover body, a pressure relief pipe is provided on one side of the upper sealing cover, a pressure relief chamber is provided inside the pressure relief pipe, a return spring is provided at one end of the pressure relief chamber, a movable plate is provided at one end of the return spring, the movable plate is slidably connected to the inside of the pressure relief chamber, a pressure relief port is provided at the upper end of the pressure relief pipe, a sealing plate corresponding to the pressure relief port is provided at the upper end of the movable plate, and a movable cavity corresponding to the sealing plate is provided on the inner wall of the pressure relief pipe.

[0007] By adopting the above technical solution, the main body of the sealing cover and the upper sealing cover form an integral protective structure. Under normal conditions, the return spring continuously pushes the movable plate, causing the sealing plate at the top of the movable plate to be inserted into the movable cavity of the pressure relief pipe, completely sealing the pressure relief port and blocking the hydrogen leakage channel. When overpressure occurs inside the hydrogen transport cylinder, high-pressure hydrogen enters the pressure relief cavity and applies a lateral thrust to the movable plate, overcoming the preload of the return spring and causing the movable plate to slide inside the pressure relief cavity. The sealing plate is simultaneously disengaged from the pressure relief port along with the movable plate, and the pressure relief cavity is connected to the external space. The high-pressure hydrogen first completes pressure buffering inside the pressure relief cavity and then slowly discharges through the pressure relief port, avoiding the formation of a high-speed jet by direct injection of high-pressure hydrogen, and reducing the safety hazard of electrostatic ignition of hydrogen from the source.

[0008] In a preferred embodiment, the lower end of the sealing cover body is provided with a sealing elastic soft cover corresponding to the hydrogen transport gas cylinder, and the sealing elastic soft cover is attached to the outer surface of the hydrogen transport gas cylinder.

[0009] By adopting the above technical solution, the sealing elastic soft cover is fitted between the outer wall of the hydrogen transport gas cylinder mouth and the bottom of the sealing cover body, tightly fitting the outer surface of the hydrogen transport gas cylinder to form an annular sealing buffer layer. The bumps and vibrations generated during long-distance vehicle transportation will be elastically absorbed by the sealing elastic soft cover, offsetting the vibration stress at the threaded connection between the sealing cover body and the hydrogen transport gas cylinder mouth. At the same time, the sealing elastic soft cover itself can fill the tiny assembly gaps at the cylinder mouth, reducing the possibility of slight leakage of high-pressure hydrogen from the cylinder mouth joint, and forming a double-layer sealing protection system for the cylinder mouth together with the sealing cover body.

[0010] In a preferred embodiment, a limit slider is provided on the lower inner wall of the pressure relief chamber, and the lower end of the movable plate is slidably connected to the outer surface of the limit slider.

[0011] By adopting the above technical solution, the limiting slider can play a radial limiting and guiding role on the movable plate, constraining the movable plate to slide smoothly and horizontally only along the axial direction of the pressure relief chamber, avoiding the movable plate from being offset vertically or tilted and stuck due to airflow impact during the pressure relief action, ensuring that the movable plate can move smoothly and quickly open the pressure relief passage under overpressure conditions, and ensuring that the pressure relief protection action response is stable and reliable.

[0012] In a preferred embodiment, a first sensing element is provided on one side of the lower end of the movable plate, a second sensing element corresponding to the first sensing element is provided on one side of the inner wall of the pressure relief chamber, and an alarm is provided at the upper end of the pressure relief pipe, the alarm being electrically connected to the second sensing element.

[0013] By adopting the above technical solution, under normal sealing conditions, the reset spring presses the movable plate tightly, and the first and second sensing plates separate from each other, the alarm circuit is in the open state, and the alarm does not activate. When the hydrogen transport cylinder is overpressurized and pushes the movable plate to slide and release pressure, the first sensing plate moves synchronously with the movable plate and fits tightly with the second sensing plate. The conductive circuit is instantly connected, and the alarm immediately emits an audible and visual alarm signal. On-site maintenance personnel can identify the cylinder overpressure abnormality at the first time, and promptly carry out ventilation, isolation, and pressure relief to avoid the risk of continuous hydrogen leakage and accumulation leading to an explosion, thereby improving safety.

[0014] In a preferred embodiment, a sealing slot is provided on one side of the inner wall of the pressure relief port, and one end of the sealing plate is inserted into the interior of the sealing slot.

[0015] By adopting the above technical solution, under normal conditions, the sealing plate at the top of the movable plate is fully inserted into the sealing slot. The sealing slot and the sealing plate are interlocked to form a bent sealing contact surface, which effectively increases the sealing contact area and improves the structure's ability to block high-pressure hydrogen. Even if the pressure relief pipe experiences slight vibration and displacement during transportation, the sealing plate can still be stably locked in the sealing slot, making it less prone to gap leakage.

[0016] In a preferred embodiment, sealing gaskets are adhered to the inner walls on both sides of the sealing slot.

[0017] By adopting the above technical solution, the sealing gasket relies on its own elasticity to fill the micron-level gap between the sealing plate and the inner wall of the sealing slot, which can adapt to the slight displacement of the components caused by vehicle transportation vibration, dynamically compensate for the sealing gap, and completely eliminate the problem of slight leakage of hydrogen from the pressure relief port under both static and dynamic bumpy conditions.

[0018] In a preferred embodiment, the main body of the sealing cover is made of explosion-proof material.

[0019] By adopting the above technical solution, the main body of the sealing cover is made of high-strength flame-retardant and explosion-proof alloy material and is wrapped around the outside of the hydrogen transport gas cylinder mouth. It can resist the mechanical impact caused by stone impact and box collision during transportation, protect the internal cylinder valve and other precision components, and can isolate the hydrogen transport gas cylinder body from direct contact with external open flames and high-temperature heat sources. Even if hydrogen is discharged from the pressure relief port for a short time, it can prevent external fire sources from igniting the leaked hydrogen, which greatly improves the explosion-proof safety performance of the entire set of components.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of this application are: In this application, the main body of the sealing cover and the upper sealing cover form an integral protective structure. Under normal conditions, the return spring continuously pushes the movable plate, causing the sealing plate at the top of the movable plate to be inserted into the movable cavity of the pressure relief pipe, completely sealing the pressure relief port and blocking the hydrogen leakage channel. When overpressure occurs inside the hydrogen transport cylinder, high-pressure hydrogen enters the pressure relief cavity and applies a lateral thrust to the movable plate, overcoming the preload of the return spring and causing the movable plate to slide inside the pressure relief cavity. The sealing plate is simultaneously disengaged from the pressure relief port along with the movable plate, and the pressure relief cavity is connected to the external space. The high-pressure hydrogen first completes pressure buffering inside the pressure relief cavity and then slowly discharges through the pressure relief port, avoiding the formation of a high-speed jet by direct injection of high-pressure hydrogen, and reducing the safety hazard of electrostatic ignition of hydrogen from the source. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the front structure of the hydrogen transport cylinder in this application; Figure 2 This is a schematic diagram of the internal structure of the pressure relief pipe in this application; Figure 3 This is a schematic diagram of the internal structure of the sensing component in this application; Figure 4 This is a schematic diagram of the internal structure of the sealing slot in this application.

[0022] The markings in the diagram are: 1. Hydrogen transport cylinder; 2. Sealing elastic soft cover; 3. Sealing cover body; 4. Upper sealing cover; 5. Pressure relief pipe; 6. Sealing slot; 7. Sealing plate; 8. Pressure relief port; 9. Movable chamber; 10. Alarm; 11. Return spring; 12. Limit slider; 13. Movable plate; 14. Pressure relief chamber; 15. Sensor 1; 16. Sensor 2; 17. Sealing gasket. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Reference Figure 1-4 An explosion-proof pressure relief protection component for a hydrogen transport gas cylinder includes a hydrogen transport gas cylinder 1. A sealing cover body 3 is located at the upper end of the hydrogen transport gas cylinder 1. An upper sealing cover 4 is located at the upper end of the sealing cover body 3. A pressure relief pipe 5 is located on one side of the upper sealing cover 4. A pressure relief chamber 14 is formed inside the pressure relief pipe 5. A return spring 11 is located at one end of the pressure relief chamber 14. A movable plate 13 is located at one end of the return spring 11 and is slidably connected inside the pressure relief chamber 14. A pressure relief port 8 is located at the upper end of the pressure relief pipe 5. A sealing plate 7 corresponding to the pressure relief port 8 is located at the upper end of the movable plate 13. A movable cavity 9 corresponding to the sealing plate 7 is formed on the inner wall of the pressure relief pipe 5. The sealing cover body 3 and the upper sealing cover 4 form an integral enclosure. The protective structure, under normal conditions, has a return spring 11 continuously pushing the movable plate 13, causing the sealing plate 7 at the top of the movable plate 13 to engage with the movable cavity 9 inside the pressure relief pipe 5, completely sealing the pressure relief port 8 and blocking the hydrogen leakage channel. When overpressure occurs inside the hydrogen transport cylinder 1, high-pressure hydrogen enters the pressure relief chamber 14 and applies a lateral thrust to the movable plate 13, overcoming the preload of the return spring 11 and causing the movable plate 13 to slide inside the pressure relief chamber 14. The sealing plate 7 disengages from the pressure relief port 8 simultaneously with the movable plate 13, and the pressure relief chamber 14 is connected to the external space. The high-pressure hydrogen first undergoes pressure buffering inside the pressure relief chamber 14 before being slowly discharged through the pressure relief port 8, avoiding the formation of a high-speed jet by direct injection of high-pressure hydrogen and reducing the safety hazard of electrostatic ignition of hydrogen from the source.

[0025] Reference Figure 1 The lower end of the sealing cover body 3 is provided with a sealing elastic soft cover 2 corresponding to the hydrogen transport cylinder 1. The sealing elastic soft cover 2 is attached to the outer surface of the hydrogen transport cylinder 1. The sealing elastic soft cover 2 is sleeved between the outer wall of the bottle mouth of the hydrogen transport cylinder 1 and the bottom of the sealing cover body 3, forming an annular sealing buffer layer by tightly fitting the outer surface of the hydrogen transport cylinder 1. The bumps and vibrations generated during long-distance transportation will be elastically absorbed by the sealing elastic soft cover 2, which will offset the vibration stress at the threaded connection between the sealing cover body 3 and the bottle mouth of the hydrogen transport cylinder 1. At the same time, the sealing elastic soft cover 2 itself can fill the small assembly gaps at the bottle mouth, reducing the possibility of slight leakage of high-pressure hydrogen from the bottle mouth joint. Together with the sealing cover body 3, it forms a double-layer sealing protection system for the bottle mouth.

[0026] Reference Figure 2 The lower inner wall of the pressure relief chamber 14 is provided with a limiting slider 12. The lower end of the movable plate 13 is slidably connected to the outer surface of the limiting slider 12. The limiting slider 12 can play a radial limiting and guiding role for the movable plate 13, constraining the movable plate 13 to slide smoothly and horizontally only along the axial direction of the pressure relief chamber 14. This prevents the movable plate 13 from being offset vertically or tilted and stuck due to airflow impact during the pressure relief action, ensuring that the movable plate 13 can move smoothly and quickly open the pressure relief passage under overpressure conditions, and ensuring that the pressure relief protection action response is stable and reliable.

[0027] Reference Figure 3 A sensor 15 is installed on one side of the lower end of the movable plate 13, and a sensor 16 corresponding to the sensor 15 is installed on one inner wall of the pressure relief chamber 14. An alarm 10 is installed at the upper end of the pressure relief pipe 5. The alarm 10 is electrically connected to the sensor 16. Under normal sealing conditions, the reset spring 11 presses the movable plate 13 tightly, and the sensor 15 and the sensor 16 are separated from each other. The alarm circuit is in the open state, and the alarm 10 does not start. When the hydrogen transport cylinder 1 is over-pressurized and pushes the movable plate 13 to slide and depressurize, the sensor 15 moves synchronously with the movable plate 13 and fits tightly with the sensor 16. The conductive circuit is instantly connected, and the alarm 10 immediately emits an audible and visual alarm signal. On-site maintenance personnel can identify the cylinder over-pressure abnormality at the first time and carry out ventilation, isolation, and depressurization in a timely manner to avoid the risk of explosion caused by continuous leakage and accumulation of hydrogen, thereby improving safety.

[0028] Reference Figure 4 A sealing slot 6 is provided on one side of the inner wall of the pressure relief port 8. One end of the sealing plate 7 is inserted into the inside of the sealing slot 6. Under normal conditions, the sealing plate 7 at the top of the movable plate 13 is fully inserted into the inside of the sealing slot 6. The sealing slot 6 and the sealing plate 7 form a bent sealing contact surface by interlocking, which effectively increases the sealing contact area and improves the structure's ability to block high-pressure hydrogen. Even if the pressure relief pipe 5 experiences slight vibration and displacement during transportation, the sealing plate 7 can still be stably locked in the sealing slot 6, and it is not easy for gaps to leak.

[0029] Reference Figure 4 Sealing gaskets 17 are bonded to the inner walls of both sides of the sealing slot 6. The sealing gaskets 17 fill the micron-level gap between the sealing plate 7 and the inner wall of the sealing slot 6 by their own elasticity. They can adapt to the small displacement of the components caused by vehicle transportation vibration, dynamically compensate for the sealing gap, and completely eliminate the problem of slight leakage of hydrogen from the pressure relief port 8 under both static and dynamic bumpy conditions.

[0030] Reference Figure 1 The main body 3 of the sealing cover is made of explosion-proof material. The entire main body 3 of the sealing cover is made of high-strength flame-retardant and explosion-proof alloy material and is wrapped around the outside of the mouth of the hydrogen transport gas cylinder 1. It can resist the mechanical impact caused by stone impact and box collision during transportation, protect the internal cylinder valve and other precision components, and can isolate the hydrogen transport gas cylinder 1 from direct contact with external open flames and high-temperature heat sources. Even if hydrogen is discharged from the pressure relief port 8 for a short time, it can prevent external fire sources from igniting the leaked hydrogen, which greatly improves the explosion-proof safety performance of the entire set of components.

[0031] The implementation principle of an embodiment of a hydrogen transport cylinder explosion-proof pressure relief protection component of this application is as follows: Under normal pressure and ambient temperature transport conditions, the return spring 11 continuously pushes the movable plate 13 to the left, causing the sealing plate 7 at the top of the movable plate 13 to be fully inserted into the sealing slot 6. The sealing plate 7 compresses the sealing gaskets 17 on both sides, and the sealing gaskets 17 fill the tiny gap between the sealing plate 7 and the sealing slot 6, completely sealing the pressure relief port 8 and blocking the channel for hydrogen gas to leak out of the hydrogen transport cylinder 1. At this time, the sensing plate 15 on the lower side wall of the movable plate 13 and the sensing plate 16 on the inner side wall of the pressure relief chamber 14 are separated from each other. The conductive circuit of the alarm 10 at the top of the pressure relief pipe 5 is in an open state, and the alarm 10 does not activate the audible and visual alarm. The entire assembly remains in a sealed and protected state.

[0032] When the internal pressure of hydrogen transport cylinder 1 exceeds the standard due to factors such as overfilling, exposure to sunlight and heating, or fire, the high-pressure hydrogen gas inside the cylinder is conducted upward to the sealed cavity formed by the main body of the sealing cover 3 and the upper sealing cover 4. The high-pressure airflow continuously acts on the right end face of the movable plate 13. The airflow thrust overcomes the pre-tightening force of the return spring 11 and pushes the movable plate 13 to slide to the right along the limit slider 12. During the sliding process, the sealing plate 7 moves to the right synchronously with the movable plate 13 and gradually disengages from the sealing slot 6. The pressure relief port 8 and the pressure relief chamber 14 are interconnected. The high-pressure hydrogen gas will not be directly ejected out at high speed, but will first enter the larger pressure relief chamber 14 to complete the expansion buffer and pressure attenuation, and then be discharged at low speed through the pressure relief port 8, eliminating the risk of static sparks generated by the friction between the high-speed hydrogen jet and the air.

[0033] Simultaneously, after the movable plate 13 moves to the right, the lower sensing plate 15 moves synchronously and fits tightly with the sensing plate 16. The two conduct the alarm circuit, and the alarm 10 immediately triggers a high-decibel buzzer and a strong flashing light alarm. On-site escort and maintenance personnel can quickly identify the gas cylinder overpressure fault and promptly ventilate, isolate, and transfer the gas cylinder group to prevent the continuous accumulation of leaked hydrogen gas into an explosive mixture and avoid major safety accidents in advance.

[0034] As the pressure relief chamber 14 continues to release hydrogen, the internal pressure of the hydrogen transport cylinder 1 gradually decreases to the safety standard threshold. The lateral thrust of the hydrogen on the movable plate 13 is less than the elastic pushing force of the return spring 11. The return spring 11 pushes the movable plate 13 to the left to reset, the sealing plate 7 is reinserted into the sealing slot 6, the sealing gasket 17 clamps the sealing plate 7 again, and the pressure relief port 8 is resealed. The pressure relief process stops automatically. The first sensor 15 and the second sensor 16 separate again as the movable plate 13 moves to the left, the alarm circuit is disconnected, the alarm 10 automatically stops the audible and visual prompts, and the components return to a completely sealed normal storage and transportation state. No manual disassembly and reset are required, and it can be reused multiple times.

[0035] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A hydrogen transport gas cylinder explosion-proof pressure relief protection component, comprising a hydrogen transport gas cylinder (1), characterized in that: The upper end of the hydrogen transport cylinder (1) is provided with a sealing cover body (3), the upper end of the sealing cover body (3) is provided with an upper sealing cover (4), a pressure relief pipe (5) is provided on one side of the upper sealing cover (4), a pressure relief chamber (14) is provided inside the pressure relief pipe (5), a return spring (11) is provided at one end of the pressure relief chamber (14), a movable plate (13) is provided at one end of the return spring (11), the movable plate (13) is slidably connected to the inside of the pressure relief chamber (14), a pressure relief port (8) is provided at the upper end of the pressure relief pipe (5), a sealing plate (7) corresponding to the pressure relief port (8) is provided at the upper end of the movable plate (13), and a movable cavity (9) corresponding to the sealing plate (7) is provided on the inner wall of the pressure relief pipe (5).

2. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: The lower end of the sealing cover body (3) is provided with a sealing elastic soft cover (2) corresponding to the hydrogen transport gas cylinder (1), and the sealing elastic soft cover (2) is attached to the outer surface of the hydrogen transport gas cylinder (1).

3. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: The lower inner wall of the pressure relief chamber (14) is provided with a limiting slider (12), and the lower end of the movable plate (13) is slidably connected to the outer surface of the limiting slider (12).

4. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: A sensor plate (15) is provided on one side of the lower end of the movable plate (13), and a sensor plate (16) corresponding to the sensor plate (15) is provided on one side of the inner wall of the pressure relief chamber (14). An alarm (10) is provided at the upper end of the pressure relief pipe (5), and the alarm (10) is electrically connected to the sensor plate (16).

5. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: The sealing slot (6) is provided on one side of the inner wall of the pressure relief port (8), and one end of the sealing plate (7) is inserted into the inside of the sealing slot (6).

6. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: The inner walls on both sides of the sealing slot (6) are bonded with sealing gaskets (17).

7. The explosion-proof pressure relief protection component for hydrogen transport cylinders according to claim 1, characterized in that: The main body of the sealing cover (3) is made of explosion-proof material.

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