Emergency protection device for gas pipeline leakage

Abstract

The invention relates to the technical field of gas pipeline protection, in particular to a gas pipeline leakage emergency protection device which can perform emergency protection and ensure safe operation of a pipeline when the gas pipeline leaks through an active and passive dual protection mechanism, real-time pressure monitoring and automatic control.

Description

Technical Field

[0001] The present invention relates to the technical field of gas pipeline protection, and in particular to a gas pipeline leakage emergency protection device. Background Art

[0002] Gas pipeline leakage emergency protection means that during the gas transmission process, when a gas leak occurs in the pipeline, the preset detection and control means can be used to quickly detect the leak, locate the leak point, and take effective measures to contain the leak and prevent the accident from expanding.

[0003] At present, emergency protection for gas pipeline leakage mainly relies on external environment monitoring and pipeline internal air pressure monitoring. External environment monitoring is to install combustible gas sensors around the gas pipeline to monitor the combustible gas concentration in the environment in real time. When the sensor detects that the gas concentration exceeds the set threshold, it triggers the alarm system to prompt a potential gas leak. This method is suitable for open or semi-open environments and can monitor gas leaks in a large area. However, the method of monitoring combustible gas leaks through the external environment cannot detect the problem at the first time when the gas leaks, which may cause the gas to spread in the environment, increasing the safety risk, and it is difficult to effectively confirm the specific leakage point location, and it is impossible to carry out targeted leakage treatment, which makes it difficult to quickly solve the leakage problem; pipeline internal air pressure monitoring is to install a gas sensor inside the gas pipeline. An air pressure sensor is installed to monitor the air pressure changes in the pipeline in real time. When a pipeline leaks, it will cause abnormal changes in air pressure. The sensor can detect the pressure drop or fluctuation in time, and then cut off the main valve through the control system to prevent further leakage of gas. However, when monitoring the air pressure inside the pipeline, although the air pressure sensor can detect the leak in time through the pressure change, it cannot quickly determine the specific location of the leak, which limits the accuracy of subsequent emergency treatment measures; and the existing technology mainly relies on timely control of cutting off the main valve to prevent gas leakage, but cannot effectively deal with the residual combustible gas in the pipeline. Since the leak point cannot be quickly located, the remaining gas in the pipeline may continue to leak under the action of residual pressure, further increasing the risk of gas accumulation and explosion; therefore, it is necessary to develop a gas pipeline leakage emergency protection device. Summary of the invention

[0004] In view of the above-mentioned defects and problems, the present invention provides a gas pipeline leakage emergency protection device, which can perform emergency protection when a gas pipeline leaks through active and passive dual protection mechanisms, real-time pressure monitoring and automatic control, thereby ensuring the safe operation of the pipeline.

[0005] The solution adopted by the present invention to solve its technical problem is: a gas pipeline leakage emergency protection device, including a gas supply main pipe, the gas supply main pipe includes a main pipe proximal end and a main pipe distal end, and also includes an emergency protection mechanism, the emergency protection device includes a main pipe body and an auxiliary pipe body, and the main pipe proximal end and the main pipe distal end are respectively connected to the air inlet and the air outlet of the main pipe body; an inner pipe body is installed at the inner end of the main pipe body, the inner pipe body includes a moving section and a fixed section, the moving section is slidably sleeved on the fixed section, and a pressure sensor for detecting a critical pressure value is arranged between the fixed section and the moving section, and The outer end surface of the moving section is provided with a conical surface, and ribs are evenly distributed radially on the inner wall of the inner tube body. The main oil cylinder is matched and sleeved in the axial channel surrounded by the ribs. A conical body is fixed on the push rod of the main oil cylinder, and the conical body can cooperate and seal with the conical surface; a male cavity is provided at the rear end of the main tube body, and the male cavity is connected to the negative pressure channel inside the inner tube body, and the male cavity is connected to the negative pressure unit; an auxiliary oil cylinder is provided in the auxiliary tube body, and the electric push rod can drive the composite piston of the auxiliary oil cylinder to move, control the auxiliary oil cylinder to supply oil to the main oil cylinder, so that the main oil cylinder pushes and pulls the push rod and drives the conical body synchronously; The pressure supply main pipe and the negative pressure channel are positive pressure and negative pressure respectively, and the cone is sealed and fitted to the end of the inner tube under the action of positive pressure thrust and negative pressure pulling force; the push rod can apply active thrust when it moves, and when the push rod continues to increase the active thrust until the pressure sensor detects that the pressure between the cone and the inner tube reaches the critical pressure value, the electric push rod controls the push rod to stop moving, and at this time the cone is kept in a balanced state, neither over-pressed nor pushed away; when gas leakage in the gas supply main causes the positive pressure thrust applied to the cone to decrease, the composite piston will release the compressed energy, control the movement of the push rod to make the cone open the negative pressure channel, and at the same time the cone will block the air inlet and connect the air outlet to the negative pressure channel, the gas in the gas supply main is sucked into the negative pressure tank by negative pressure, and at the same time, when the pressure sensor detects that the critical pressure value has changed, it can control the main valve of the gas supply main to close.

[0006] Furthermore, when the air supply main is in normal air supply and the negative pressure port is in negative pressure suction, when the push rod moves, the active thrust of the push rod can overcome the positive pressure thrust of the air supply main and the negative pressure pull of the negative pressure port, and the active thrust is less than the combined force of the positive pressure thrust in the air supply main and the negative pressure pull in the negative pressure port. The difference between the active thrust of the push rod and the combined force is the critical pressure value. When the active thrust increases, the pressure sensor can detect in real time whether the pressure between the cone and the inner tube body reaches the set critical pressure value. When the pressure sensor detects that the pressure between the cone and the inner tube body reaches the critical pressure value, the active thrust is the same as the combined force of the positive pressure thrust and the negative pressure pull; the cone remains in a balanced position, neither over-pressed nor pushed away, and the cone still blocks the inner tube body.

[0007] Furthermore, the ribs are evenly spaced, the ventilation gaps between adjacent ribs form a negative pressure channel, the negative pressure port is connected to the negative pressure channel through the public cavity, and the negative pressure port can perform negative pressure suction through the negative pressure channel.

[0008] Furthermore, the oil chamber of the auxiliary oil cylinder is connected to the rear chamber of the main oil cylinder through an oil pipe, and the electric push rod drives the composite piston of the auxiliary oil cylinder to move, so that the auxiliary oil cylinder can supply oil to the main oil cylinder, so that the main oil cylinder pushes and pulls the push rod to control the movement of the cone.

[0009] Furthermore, a vent pipe is mounted inside the push rod of the electric push rod, and the vent pipe is connected with the air hole of the composite piston, so that the gas inside the composite piston can be discharged through the vent pipe when the composite piston is compressed.

[0010] Furthermore, an auxiliary blocking body is provided at the air outlet of the main body, the end face of the auxiliary blocking body is provided with an auxiliary inclined surface, and a matching inclined surface corresponding to the auxiliary inclined surface is provided on the conical body, and the auxiliary blocking body can cooperate with the conical body to assist in blocking the air outlet.

[0011] Furthermore, the composite piston comprises a left piston and a right piston, and the left piston is connected to the right piston via a spring.

[0012] The beneficial effects of the present invention are as follows: the present invention has a unique structure and an ingenious design. When the air supply main pipe is in a normal working state, the cone can be sealed and fitted to the end of the inner tube body under the action of the positive pressure thrust of the pressure supply main pipe and the negative pressure pulling force of the negative pressure channel; when the push rod moves, it can exert an active thrust, drive the cone and overcome the positive pressure thrust and the negative pressure pulling force, and the active thrust is smaller than the combined force of the positive pressure thrust in the air supply main pipe and the negative pressure pulling force in the negative pressure port, and the difference between the active thrust of the push rod and the combined force is a critical pressure value. When the push rod continues to increase the active thrust until the pressure sensor detects that the pressure between the cone and the inner tube body reaches the critical pressure value, the electric push rod controls the push rod to stop moving, so that the cone can be kept in a flat The cone is in a balanced state, neither over-pressed nor pushed away, and the cone can still block the inner tube; when the gas leaks in the pipeline and causes the positive pressure thrust applied to the cone to decrease, the pressure sensor can send a signal to the controller. At the same time, due to the decrease in the positive pressure thrust, the composite piston is triggered to release the compressed energy storage, and the push rod is controlled to move so that the cone opens the negative pressure channel. At the same time, the cone blocks the air inlet and connects the air outlet to the negative pressure channel. The gas in the pipeline is sucked into the negative pressure tank by the negative pressure, thereby realizing passive mechanism protection. At the same time, when the pressure sensor detects that the pressure between the cone and the inner tube exceeds the critical pressure value, it can send a signal to the controller to control the closure of the main valve of the gas supply main, thereby realizing active mechanism protection. The design of the cone, inner tube and pressure sensor can monitor the pressure changes in the gas main in real time. When a leak occurs in the gas main causing the internal pressure to drop, the pressure sensor can detect it immediately and quickly trigger the emergency protection mechanism, which greatly shortens the response time and improves the sensitivity to gas pipeline leaks, ensuring that the leak can be effectively controlled in the early stages to prevent the accident from expanding. No matter where the gas leak occurs in the gas main, the residual pressure and residual combustible gas in the gas main can be quickly cleared by negative pressure suction. It also has a double cut-off mechanism, which can automatically cut off the main valve electrically and mechanically, avoiding the problem of untimely cut-off of the main valve due to power outages or line failures. Appearance; adopting active and passive dual protection mechanisms, it can not only maintain pressure balance under normal gas supply conditions, but also automatically start the passive negative pressure suction function when a leak occurs in the pipeline, and actively control the main valve to close; mechanically cut off the main air inlet while opening the far end of the main pipe and the negative pressure channel, and as the pressure in the far end of the main pipe changes from high to low, the cone continues to move toward the far end, ensuring that the far end of the main pipe eventually changes from high pressure to negative pressure. When the cone moves to the leftmost end, it can cooperate with the auxiliary blocking body to close the far end of the main pipe to avoid introducing a large amount of air into the negative pressure tank, ensuring that the negative pressure tank is always in a negative pressure state, avoiding the negative pressure tank from leaking pressure outward again, and finally harmlessly treating the gas in the negative pressure tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is one of the overall structural schematic diagrams of the present invention.

[0014] Figure 2 It is a side view of the present invention.

[0015] Figure 3 This is one of the internal cross-sectional views of the emergency protection mechanism.

[0016] Figure 4 This is the second internal cross-sectional view of the emergency protection mechanism.

[0017] Figure 5 Schematic diagram of the structure of the composite piston.

[0018] Figure 6 It is the electronic control flow chart of the present invention.

[0019] Figure 7 It is a flow chart of the preliminary operation of the present invention.

[0020] Figure 8 It is a working state flow chart of the present invention.

[0021] In the figure: 1-air supply main pipe, 11-main pipe proximal end, 12-main pipe distal end, 13-main valve, 2-emergency protection mechanism, 21-main pipe body, 22-air inlet, 23-air outlet, 24-inner pipe body, 241-moving section, 242-fixed section, 25-rib plate, 26-negative pressure channel, 27-axial channel, 28-main oil cylinder, 29-push rod, 210-conical body, 211-public cavity, 212-negative pressure port, 213-negative pressure unit, 214-auxiliary blocking body, 215-pressure sensor, 3-auxiliary pipe body, 31-auxiliary oil cylinder, 32-oil pipe, 33-electric push rod, 34-compound piston, 341-left piston, 342-right piston, 343-spring, 35-vent pipe, 35-air hole. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Embodiment 1, gas pipeline leakage emergency protection mainly relies on external environment monitoring and pipeline internal air pressure monitoring. The prior art method of monitoring combustible gas leakage through external environment cannot detect leakage problems in the first time, and cannot effectively confirm the leakage point. When internal air pressure monitoring is adopted, the prior art method of installing air pressure sensors in pipelines can detect leakage problems in time through pressure changes, but cannot quickly determine the leakage location. In addition to timely controlling and cutting off the main valve, this method cannot effectively solve the combustible gas in the pipeline in time. Since this method cannot timely determine the leakage location, the remaining combustible gas in the pipeline will continue to leak under the action of residual pressure, increasing the risk factor.

[0024] In response to the above problems, the present embodiment provides a gas pipeline leakage emergency protection device, which aims to quickly clear the residual pressure and residual gas in the pipeline by negative pressure suction when a leak occurs at any position in the pipeline through the set emergency protection mechanism, and has a double cut-off mechanism to avoid the problem of untimely cut-off of the main valve due to factors such as power outages or line failures.

[0025] like Figure 1-3 As shown, the gas supply main pipe 1 includes a main pipe proximal end 11 and a main pipe distal end 12, a main valve 13 is arranged on the main pipe proximal end 11, the emergency protection mechanism 2 is arranged between the main pipe proximal end 11 and the main pipe distal end 12, the emergency protection mechanism 2 is composed of a main pipe body 21 and an auxiliary pipe body 3, an air inlet 22 and an air outlet 23 are respectively opened inside the main pipe body 21, the main pipe proximal end 11 is connected to the air outlet 23 of the main pipe body 21, and the main pipe distal end 12 is connected to the air inlet 22 of the main pipe body 21.

[0026] like Figure 3-4 As shown, an inner tube body 24 is fixedly installed at the inner right end of the main tube body 21, and the inner tube body 24 includes a movable section 241 and a fixed section 242. The movable section 241 can be slidably mounted on the fixed section 242 through a sliding rod, and a pressure sensor 215 for detecting a critical pressure value is arranged between the fixed section 242 and the movable section 241. The pressure sensor 215 can be arranged to be at least three, and the sum of the three pressure sensors 215 reflects the critical pressure value. The pressure sensor 215 can be installed on the end face of the fixed section 242, and a conical surface is opened on the outer end face of the movable section 241, that is, a conical surface is opened on the outer port of the inner tube body 24.

[0027] Ribs 25 are evenly distributed radially on the inner wall of the inner tube body 24. The ribs 25 are evenly distributed and can surround an axial channel 27, and the ventilation gaps between adjacent ribs 25 form a negative pressure channel 26. A master cylinder 28 is matched and mounted in the axial channel 27. The ribs 25 can support the master cylinder 28. A cone 210 is fixed on the push rod 29 of the master cylinder 28. The cone 210 can match the cone surface of the outer port of the inner tube body 24 to form a matching sealing structure.

[0028] An auxiliary blocking body 214 is provided at the air outlet 23 of the main body 21 . The end face of the auxiliary blocking body 214 is provided with an auxiliary inclined surface, and a matching inclined surface corresponding to the auxiliary inclined surface is provided on the cone 210 . The auxiliary blocking body 214 can cooperate with the cone 210 to assist in blocking the air outlet 23 .

[0029] The rear end of the main tube 21 is sealed with a male cavity 211, which is connected to the negative pressure channel 26 inside the inner tube 24, and is connected to the negative pressure unit 213. The negative pressure unit 213 adopts a negative pressure tank, and the negative pressure tank can be preset to a negative pressure state.

[0030] like Figure 3-4 As shown, an auxiliary oil cylinder 31 is arranged in the auxiliary pipe body 3, and the oil chamber of the auxiliary oil cylinder 31 is connected to the rear chamber of the main oil cylinder 28 through an oil pipe 32, and an electric push rod 33 is installed on the auxiliary pipe body 3, which can drive the composite piston 34 of the auxiliary oil cylinder 31 to move, so that the auxiliary oil cylinder 31 can supply oil to the main oil cylinder 28, so that the main oil cylinder 28 can push and pull the push rod 29 and synchronously drive the cone 210, as shown in FIG. Figure 5 As shown, the composite piston 34 is a composite structure, including a left piston 341 and a right piston 342. The left piston 341 and the right piston 342 are connected by a spring 343. The composite piston 34 has a certain matching pressure, and a vent pipe 35 can be installed in the push rod 29 of the electric push rod 33. The vent pipe 35 is connected to the air hole 35 of the right piston 342 in the composite piston 34, so that when the composite piston 34 is compressed, the gas inside it can be discharged through the vent pipe 35, and the gas discharged from the vent pipe 35 can be discharged from the auxiliary pipe body 3.

[0031] The pressure change detection in the gas supply main pipe 1 can be achieved by installing an auxiliary pressure sensor in the gas supply pipeline. At the same time, the pressure change in the gas supply main pipe 1 can also be detected by the pressure sensor 215 arranged at the end of the inner tube body 24.

[0032] The pressure supply main pipe and the negative pressure channel 26 are respectively positive and negative pressures. The positive pressure thrust between the air inlet 22 and the air outlet 23 will press the left end surface of the cone 210, while the negative pressure pulling force of the negative pressure port 212 will adsorb the right end surface of the cone 210. The cone 210 will be subjected to the positive pressure thrust and the negative pressure pulling force at the same time, so that it is tightly attached to the cone surface of the end of the inner tube 24. When the push rod 29 moves, it can exert active thrust, and can push the cone 210, so that the pressure between the cone 210 and the inner tube 24 approaches the critical pressure value. When the push rod 29 continues to increase the active thrust until the pressure sensor 215 detects that the pressure between the cone 210 and the inner tube 24 reaches the critical pressure value, the electric push rod 33 controls the push rod 29 to stop moving, and at this time the cone 210 is kept in a balanced state, neither being over-pressed nor pushed away; at this time, the cone 210 forms a pressure of the critical pressure value on the conical surface of the inner tube 24, That is to say, under normal air supply state and negative pressure suction state, when the push rod 29 moves, the active thrust of the push rod 29 can overcome the positive pressure thrust and negative pressure pull existing at this time, and the active thrust is less than the combined force of the positive pressure thrust in the air supply main pipe 1 and the negative pressure pull in the negative pressure port 212. The difference between the active thrust of the push rod 29 and its combined force is the critical pressure value. When the active thrust increases, the pressure sensor 215 can detect in real time whether the pressure between the cone 210 and the inner tube 24 reaches the set critical pressure. Force value, when the pressure sensor 215 detects that the pressure between the cone 210 and the inner tube 24 reaches the critical pressure value, the active thrust is equal to the combined force of the positive thrust and the negative pressure pull; the cone 210 remains in a balanced position, neither over-pressed nor pushed away, and the cone 210 still blocks the inner tube 24; at this time, the cone 210 maintains the working maintenance pressure; when the active thrust reaches the critical value, the original active thrust plus the critical pressure value is equal to the positive thrust plus the negative pressure pull.

[0033] When gas leakage occurs in the gas supply main pipe 1 and the pressure inside the gas supply main pipe 1 decreases, the positive pressure thrust applied to the cone 210 will decrease. Figure 6 As shown, the pressure sensor 215 sends a signal to the controller at the same time, and the composite piston 34 in the energy storage state will release the compressed energy, and the control push rod 29 will move to make the cone 210 open the negative pressure channel 26. At the same time, the cone 210 will block the air inlet 22, and connect the air outlet 23 and the negative pressure channel 26, so that the gas at the air outlet 23 is drawn away through the negative pressure port 212, and the gas in the gas supply main pipe 1 is sucked into the negative pressure tank by negative pressure, realizing a mechanical passive cut-off mechanism. When the pressure sensor 215 detects that the pressure between the cone 210 and the inner tube body 24 exceeds the critical pressure value, and the pressure sensor 215 detects that the critical pressure value changes, it can control the closing of the main valve 13 of the gas supply main pipe 1, realizing an electrically controlled active cut-off mechanism.

[0034] Even if the electric push rod 33 is not working, once the positive pressure thrust decreases, the compound piston 34 will be triggered and release the compressed stored energy, pushing the left piston 341 in the compound piston 34 to move. The spring 343 itself has a certain compression stroke and will continue to push the left piston 341 to move, thereby continuously pushing the push rod 29, enabling the cone 210 to continue to move to the left.

[0035] When the main air inlet 22 is mechanically cut off, the distal end 12 of the main pipe and the negative pressure channel 26 are opened, and as the pressure in the distal end 12 of the main pipe decreases from high to low, the cone 210 will continue to move toward the distal end, ensuring that the distal end 12 of the main pipe eventually changes from high pressure to negative pressure. When the cone 210 moves to the leftmost end, it can cooperate with the auxiliary blocking body 214 to close the distal end 12 of the main pipe to avoid introducing a large amount of air into the negative pressure tank, ensuring that the negative pressure tank is always in a negative pressure state, avoiding the negative pressure tank from releasing pressure to the outside again, and finally rendering the gas in the negative pressure tank harmless.

[0036] like Figure 7 As shown, in the case of someone on duty at the early stage of gas supply, the gas supply main pipe 1 is tested, and after the test is completed, Figure 8 As shown in the flowchart, by starting the electric push rod 33 to control the push rod 29 to move, the cone 210 is kept in a balanced position, thereby realizing real-time detection of the gas supply main in an unattended state during the gas supply period.

[0037] Through the design of the cone 210, the inner tube body 24 and the pressure sensor 215, the pressure changes in the gas supply main pipe 1 can be monitored in real time. When a leak occurs in the gas supply main pipe 1 and causes its internal pressure to drop, the pressure sensor 215 can detect it immediately and quickly trigger the emergency protection mechanism; no matter where the leak occurs in the gas supply main pipe 1, the residual pressure and residual combustible gas in the gas supply main pipe 1 can be quickly cleared by negative pressure suction; and the main valve 13 can be automatically cut off by electric control and mechanically, so as to avoid the problem of untimely cutting off of the main valve 13 due to power outages or line failures; the active and passive dual protection mechanisms are adopted, which can not only maintain pressure balance under normal gas supply conditions, but also automatically start the passive negative pressure suction function when a leak occurs in the pipeline, and actively control the main valve 13 to close.

[0038] Embodiment 2, a gas pipeline leakage emergency protection device in this embodiment is described centering on the differences from Embodiment 1.

[0039] In this embodiment, the piston rod of the auxiliary oil cylinder 31 can be connected to the output end of the electric push rod 33, and a ventilation cavity is installed inside the piston rod, and the ventilation cavity is connected to the air hole 35 of the composite piston 34 and the ventilation pipe 35 respectively.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas pipeline leakage emergency protection device, comprising a gas supply main, the gas supply main comprising a main proximal end and a main distal end, characterized in that: It also includes an emergency protection mechanism, which includes a main pipe body and an auxiliary pipe body, and the proximal end and the distal end of the main pipe are respectively connected to the air inlet and the air outlet of the main pipe body; an inner pipe body is installed at the inner end of the main pipe body, and the inner pipe body includes a moving section and a fixed section. The moving section is slidably sleeved on the fixed section, and a pressure sensor for detecting a critical pressure value is arranged between the fixed section and the moving section, and the outer end face of the moving section is provided with a conical surface, and ribs are radially evenly distributed on the inner side wall of the inner pipe body. The main oil cylinder is matched and sleeved in the axial channel surrounded by the ribs, and a conical body is fixed on the push rod of the main oil cylinder, and the conical body can cooperate and seal with the conical surface; a cavity is arranged at the rear end of the main pipe body, and the cavity is connected to the negative pressure channel inside the inner pipe body, and the cavity is connected to the negative pressure unit; an auxiliary oil cylinder is arranged in the auxiliary pipe body, and the arranged electric push rod can drive the composite piston of the auxiliary oil cylinder to move, control the auxiliary oil cylinder to supply oil to the main oil cylinder, so that the main oil cylinder pushes and pulls the push rod and drives the conical body synchronously; The pressure supply main pipe and the negative pressure channel are positive pressure and negative pressure respectively, and the cone is sealed and fitted to the end of the inner tube under the action of positive pressure thrust and negative pressure pulling force; the push rod can apply active thrust when it moves, and when the push rod continues to increase the active thrust until the pressure sensor detects that the pressure between the cone and the inner tube reaches the critical pressure value, the electric push rod controls the push rod to stop moving, and at this time the cone is kept in a balanced state, neither over-pressed nor pushed away; when gas leakage in the gas supply main causes the positive pressure thrust applied to the cone to decrease, the composite piston will release the compressed energy, control the movement of the push rod to make the cone open the negative pressure channel, and at the same time the cone will block the air inlet and connect the air outlet to the negative pressure channel, the gas in the gas supply main is sucked into the negative pressure tank by negative pressure, and at the same time, when the pressure sensor detects that the critical pressure value has changed, it can control the main valve of the gas supply main to close.

2. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: When the air supply main is in normal air supply and the negative pressure port is in negative pressure suction, when the push rod moves, the active thrust of the push rod can overcome the positive pressure thrust of the air supply main and the negative pressure pull of the negative pressure port, and the active thrust is less than the combined force of the positive pressure thrust in the air supply main and the negative pressure pull in the negative pressure port. The difference between the active thrust of the push rod and the combined force is the critical pressure value. When the active thrust increases, the pressure sensor can detect in real time whether the pressure between the cone and the inner tube body reaches the set critical pressure value. When the pressure sensor detects that the pressure between the cone and the inner tube body reaches the critical pressure value, the active thrust is the same as the combined force of the positive pressure thrust and the negative pressure pull; the cone is maintained in a balanced position, neither over-pressed nor pushed away, and the cone still blocks the inner tube body.

3. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: The ribs are evenly spaced, the ventilation gaps between adjacent ribs form a negative pressure channel, the negative pressure port is connected to the negative pressure channel through the cavity, and the negative pressure port can perform negative pressure suction through the negative pressure channel.

4. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: The oil chamber of the auxiliary oil cylinder is connected to the rear chamber of the main oil cylinder through an oil pipe. The electric push rod drives the composite piston of the auxiliary oil cylinder to move, so that the auxiliary oil cylinder can supply oil to the main oil cylinder, so that the main oil cylinder pushes and pulls the push rod to control the movement of the cone.

5. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: A vent pipe is sleeved inside the push rod of the electric push rod, and the vent pipe is communicated with the air hole of the composite piston, so that the gas inside the composite piston can be discharged through the vent pipe when the composite piston is compressed.

6. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: An auxiliary blocking body is arranged at the air outlet of the main body, an auxiliary inclined surface is provided on the end face of the auxiliary blocking body, and a matching inclined surface corresponding to the auxiliary inclined surface is provided on the cone body. The auxiliary blocking body can match the cone body to assist in blocking the air outlet.

7. A gas pipeline leakage emergency protection device according to claim 1, characterized in that: The composite piston comprises a left piston and a right piston, and the left piston is connected with the right piston via a spring.

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