Intra-tunnel hydrogen pipeline accident chain blocking device, pipeline system and method

Abstract

The invention relates to an in-tunnel hydrogen pipeline accident chain blocking device and a hydrogen pipeline system and method.The in-tunnel hydrogen pipeline accident chain blocking device comprises an outer sleeve arranged on the periphery of a hydrogen pipeline, an interlayer space can be formed between the outer sleeve and the hydrogen pipeline, and the outer sleeve is provided with a pressure detection element to detect the pressure in the interlayer space; the pressure detection element is connected with a control system, the outer sleeve is connected with a protective gas inlet pipe and a gas exhaust pipe, the protective gas inlet pipe is connected with a protective gas source and provided with a purging control valve, the gas exhaust pipe is provided with an emptying valve, and the control valve and the emptying valve are connected with the control system. By means of the blocking device, the problems that in the prior art, response lags behind, and single pain points are handled are solved, and the safety of hydrogen energy conveying is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure gas pipeline safety protection, and particularly relates to an accident chain blocking device, a pipeline system and a method for a hydrogen pipeline in a tunnel. Background Art

[0002] The statements herein only provide background art related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous maturity and improvement of the development and utilization technology of hydrogen energy, for large-scale centralized hydrogen production and long-distance hydrogen transportation, pipeline transportation has the characteristics of large transportation volume, long distance, and low energy consumption loss, and is the most economical way.

[0004] Most of the inlets and outlets of the tunnels through which the pipelines pass are provided with portal seals, which belong to enclosed spaces. Compared with the open environment, the hydrogen transmission pipelines in the tunnels are more likely to cause degradation of material properties due to the hydrogen embrittlement effect, accelerating pipeline corrosion. After the pure hydrogen pipeline corrodes and leaks, the leaked hydrogen mixes with air and is flammable and explosive when encountering fire, posing a great fire safety risk. In addition, most of the mountainous areas where the pipelines pass through tunnels belong to remote areas with a regional grade of first-class. After a leakage and explosion accident occurs in the gas transmission pipeline, the response time and arrival time for maintenance and repair are both relatively long, and it is difficult to maintain and repair the pipeline in the tunnel. Currently, the pipeline design in the tunnel is usually mainly single-layer pipelines, and a heat insulation layer and a protective layer are installed outside the pipelines. During long-term operation, the pipeline may leak hydrogen due to material fatigue, external mechanical damage or welding defects, etc. Once the pipeline ruptures, high-pressure hydrogen will quickly spray out from the leakage point and rapidly diffuse in the enclosed space of the tunnel, and then easily accumulate at the top of the tunnel, forming a local high-concentration dangerous area. If the leakage cannot be detected and controlled in time, it is extremely easy to cause fire and explosion accidents. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an accident chain blocking device, a hydrogen pipeline system and a method for a hydrogen pipeline in a tunnel, to construct a three-level prevention and control system of "vacuum monitoring - automatic pressure relief - nitrogen replacement", and to realize the full-process accident chain blocking from the early detection of hydrogen micro-leakage, rapid isolation and pressure relief to complete inerting, so as to improve the safety level of hydrogen transportation.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a device for blocking an accident chain of a hydrogen pipeline in a tunnel, which includes an outer sleeve arranged on the outer periphery of the hydrogen pipeline. A sandwich space can be formed between the outer sleeve and the hydrogen pipeline. A pressure detection element is installed on the outer sleeve to detect the pressure in the sandwich space, and the pressure detection element is connected to a control system. The outer sleeve is connected with a protective gas inlet pipe and a gas discharge pipe. The protective gas inlet pipe is connected to a protective gas source, and a purging control valve is provided on the protective gas inlet pipe. A vent valve is provided on the gas discharge pipe, and the control valve and the vent valve are connected to the control system.

[0008] When the air pressure value transmitted by the pressure detection element to the control system is greater than the set threshold value, the control system controls the purging control valve and the vent valve to open, discharges the gas in the sandwich layer, and purges the sandwich space with the protective gas at the same time.

[0009] Optionally, it further includes a first valve and a second valve. The first valve is used to be installed at the inlet end of the hydrogen pipeline, and the second valve is used to be installed at the outlet end of the hydrogen pipeline.

[0010] Optionally, pressure detection elements are provided at both ends of the outer sleeve.

[0011] Optionally, the outer sleeve is connected to the tops of multiple piers, and the piers are used to support the outer sleeve and the hydrogen pipeline.

[0012] Optionally, the outer sleeve is made of seamless steel pipe, and its two ends are used for full penetration welding and fixing with the hydrogen pipeline.

[0013] Optionally, the outer sleeve is further provided with a vacuum interface communicating with the internal space of the sandwich layer, and the vacuum interface is connected to a vacuum pumping system.

[0014] Optionally, the control system is further connected to an alarm system. When the pressure value transmitted by the pressure detection element to the control system is greater than the set threshold value, the control system controls the alarm system to give an alarm.

[0015] In a second aspect, an embodiment of the present invention provides a hydrogen pipeline system in a tunnel, which includes a hydrogen pipeline and the device for blocking an accident chain of a hydrogen pipeline in a tunnel described in the first aspect. A first valve is provided at the inlet end of the hydrogen pipeline, a second valve is provided at the outlet end, and the outer sleeve is sleeved and fixed on the outer periphery of the hydrogen pipeline, and a sandwich space is formed between the outer sleeve and the hydrogen pipeline.

[0016] In a third aspect, an embodiment of the present invention provides a method for blocking an accident chain of a hydrogen pipeline system in a tunnel:

[0017] Assemble the device for blocking an accident chain of a hydrogen pipeline in a tunnel with the hydrogen pipeline;

[0018] After the pressure value detected by the pressure detection element of the outer sleeve pipe is greater than the set threshold value, a signal is sent to the control system. The control system controls the first valve and the second valve to close, and controls the vent valve and the purge control valve to open. While discharging the gas in the interlayer space through the gas discharge pipe, the protective gas inlet pipe is used to introduce the protective gas into the interlayer space. The protective gas is used to purge the clamping space and displace the hydrogen gas, until the concentration of hydrogen gas in the mixed gas is reduced to below the set lower explosion limit value.

[0019] Optionally, after the hydrogen pipeline accident chain blocking device in the tunnel is assembled with the hydrogen pipeline, the interlayer space is evacuated to maintain a negative pressure state with a set vacuum degree in the clamping space.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. For the accident chain blocking device and the hydrogen pipeline system of the present invention, the outer sleeve pipe is sleeved outside the hydrogen pipeline, and the formed interlayer space is connected to the protective gas inlet pipe and the gas discharge pipe. The outer sleeve pipe is provided with a pressure detection element for detecting the gas pressure in the clamping space. When the hydrogen pipeline leaks, the pressure detection element detects an increase in pressure. The control system can immediately open the vent valve on the gas discharge pipe and the purge control valve on the protective gas inlet pipe. While discharging the gas in the interlayer, the protective gas is used to purge the clamping space, so as to displace the leaked hydrogen in the clamping space with the protective gas, ensure that the concentration of hydrogen is reduced below the lower explosion limit, prevent explosion and fire phenomena, completely cover the whole process from leakage detection to emergency disposal, solve the pain points of lagging response and single disposal in the traditional technology, significantly improve the safety of hydrogen energy transportation, and are applicable to high-risk scenarios such as tunnels and hydrogen storage stations. At the same time, the double-layer pipeline is formed through the setting of the outer sleeve pipe. The double-layer pipeline significantly reduces the leakage probability of the internal hydrogen pipeline due to hydrogen embrittlement corrosion and mechanical damage through the cooperative protection mechanism of the inner and outer pipes, and significantly improves the safety and durability of the pipeline under harsh working conditions.

[0022] 2. For the accident chain blocking device and the hydrogen pipeline system of the present invention, the outer sleeve pipe is provided with a vacuum interface and is connected to a vacuum pumping system through the vacuum interface. After the accident chain blocking device is installed on the hydrogen pipeline, the vacuum pumping system can be used to evacuate the air, realizing ultra-high sensitivity leakage detection, which is far superior to the traditional atmospheric pressure interlayer monitoring method. The vacuum environment can not only early warn of micro-leakage, but also accurately trigger the exhaust of gas and the purge of protective gas when leakage occurs, forming an active prevention and control closed loop, and improving the safety of hydrogen energy transportation. Description of the Drawings

[0023] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0024] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0025] Figure 2 It is a schematic diagram of the control principle of Embodiment 1 of the present invention;

[0026] Figure 3 It is a schematic diagram of the overall structure of the verification test system of the present invention;

[0027] Wherein, 1. First valve, 2. Second valve, 3. Vent valve, 4. Purge control valve, 5. First pressure sensor, 6. Second pressure sensor, 7. Interlayer space, 8. Hydrogen pipeline, 9. Gas discharge pipe, 10. Protection gas inlet pipe, 11. Leak hole, 12. Pier, 13. Experimental pipeline, 14. Pressure transmitter, 15. PLC controller, 16. Host computer, 17. Hydrogen inlet pipe, 18. Hydrogen cylinder, 19. Hydrogen cylinder control valve, 20. Hydrogen cylinder outlet pressure gauge, 21. Control valve 1, 22. Vacuum pump, 23. Vacuum control valve, 24. Nitrogen inlet pipe, 25. Nitrogen cylinder, 26. Nitrogen cylinder control valve, 27. Nitrogen cylinder pressure gauge, 28. Control valve 3, 29. Exhaust pipeline, 30. Control valve 2. Detailed implementation mode

[0028] Embodiment 1

[0029] This embodiment provides a device for blocking the accident chain of a hydrogen pipeline in a tunnel, as Figure 1 shown, including an outer sleeve, the outer sleeve is used for sleeving and fixing on the outer periphery of the hydrogen pipeline 8, a closed interlayer space 7 is formed between the outer sleeve and the hydrogen pipeline 8, a pressure detection element is provided on the outer sleeve for detecting the gas pressure in the interlayer space, one end of the outer sleeve is connected to the protection gas inlet pipe 10, the outlet end of the protection gas inlet pipe 10 is communicated with the clamping space 7, and the inlet end is connected to the protection gas source. In this embodiment, nitrogen is used as the protection gas, the protection gas source is a nitrogen source, and an existing nitrogen generation device can be used as the nitrogen source, which will not be described in detail here. A purge control valve 4 is provided on the protection gas inlet pipe, and the purge control valve 4 is used to control the on and off of the protection gas inlet pipe 10. The other end of the outer sleeve is provided with a gas discharge pipe 9, the gas discharge pipe 9 is communicated with the interlayer space 7 for discharging the gas in the interlayer space 7, a vent valve 3 is provided on the gas discharge pipe 9, and the vent valve 3 is used to control the on and off of the gas discharge pipe 9. The outer sleeve is also provided with a vacuum interface, the vacuum interface is connected to a vacuum pumping system, and an existing device can be used as the vacuum pumping system, which will not be described in detail here. The vacuum pumping system is used to evacuate the interlayer space so that the clamping space maintains a set negative pressure state.

[0030] The outer sleeve is made of seamless steel pipe. Preferably, the outer sleeve is made of X65 high-strength steel pipe with a yield strength ≥ 450 MPa and a Charpy impact energy ≥ 100 J. It has better impact resistance than the inner X52 hydrogen transmission pipeline. At the same time, its intergranular corrosion rate is controlled below 0.1 mm / year to ensure long-term structural integrity in the hydrogen permeation environment.

[0031] The outer sleeve can effectively resist the impact of falling rocks in the tunnel, construction collisions, and the risk of hydrogen leakage. The outer sleeve and the hydrogen pipeline achieve double guarantees of mechanical protection and corrosion protection through differential material selection.

[0032] Both ends of the outer sleeve and the hydrogen pipeline are fixed by full penetration welding to form a sealed sandwich space.

[0033] The lower part of the outer sleeve is fixed to the top of multiple piers 12, and the bottom ends of the piers 12 are used to be fixed on the foundation, realizing the support for the outer sleeve and the hydrogen pipeline.

[0034] The pressure detection element uses a pressure sensor. In this embodiment, pressure sensors are provided at both ends of the outer sleeve, namely pressure sensor one 5 and pressure sensor two 6, and the pressure sensors at both ends are symmetrically arranged relative to the center of the outer sleeve.

[0035] The pressure sensor is connected to the control system and can transmit the collected gas pressure information of the sandwich space to the control system.

[0036] Both the purge control valve 4 and the vent valve 3 are electrically controlled valves. The purge control valve 4 and the vent valve 3 are connected to the control system and can receive the instructions of the control system to work.

[0037] The control system is also connected to the alarm system. The control system can control the alarm system to give an alarm. Preferably, the alarm system uses an existing audible and visual alarm system, which will not be described in detail here.

[0038] It also includes a first valve 1 and a second valve 2. The first valve 1 is used to be installed at the inlet end of the hydrogen pipeline, and the second valve is installed at the outlet end of the hydrogen pipeline. Both the first valve 1 and the second valve 2 are electrically controlled valves and are connected to the control system and can receive the instructions of the control system to work.

[0039] The control system uses a PLC controller. The control system is connected to the upper computer and can display the received information on the upper computer. At the same time, the staff can send instructions to the control system through the upper computer.

[0040] As Figure 2As shown in the figure, in this embodiment, on-site devices such as the pressure sensor and each valve serve as the field layer, the control system serves as the logic control layer, and the upper computer and the HMI interface serve as the human-machine dialogue layer.

[0041] The pressure sensor can collect the pressure information of the on-site working conditions and transmit it to the control system, realizing the on-site feedback. The control system processes the feedback pressure information and records and displays it on the upper computer. At the same time, the control system identifies whether a leakage occurs based on the received pressure information. After identifying a leakage, the control system calculates the required amount of protective gas through logical operation processing, and then drives the output to control on-site devices such as the purge control valve, the vent valve, and the protective gas source to work. The staff can also send instructions to the control system through the upper computer to manually control the work of the on-site devices.

[0042] Specifically,

[0043] The human-machine dialogue layer (upper computer and HMI interface) is responsible for issuing instructions and monitoring the status, and real-time displays key parameters such as the pressure curve and the valve status; the logic control layer (PLC core processor) synchronously executes leakage identification, logical judgment, and instruction generation through high-speed operation. When the detected pressure > 10 Pa, it immediately sends a synchronous control instruction to the field layer through the PROFIsafe protocol; after receiving the instruction, the field layer (devices such as valves and sensors) synchronously completes the sound and light alarm of the sound and light alarm system, the shutdown of the first valve and the second valve, and the nitrogen purge action (the purge control valve and the vent valve are opened) within 80 ms, and feeds back the execution status to the control system in real time. A closed loop is formed through the two-way data flow between each layer to ensure that the full-process response time from leakage detection to safe disposal < 100 ms, and all operation data is automatically stored and traceable.

[0044] Embodiment 2

[0045] This embodiment provides a hydrogen pipeline system in a tunnel, including a hydrogen pipeline, and also including the accident chain blocking device for the hydrogen pipeline in the tunnel described in Embodiment 1. The outer sleeve is coaxially sleeved on the outer periphery of the hydrogen pipeline, and both ends of the outer sleeve are fixed to the hydrogen pipeline by full penetration welding. A sealed sandwich space is formed between the outer sleeve and the hydrogen pipeline. The outer sleeve and the hydrogen pipeline are supported by a plurality of piers 12. A first valve 1 is provided at the inlet end of the hydrogen pipeline, and a second valve 2 is provided at the outlet end.

[0046] The remaining structures of the hydrogen pipeline system can adopt the existing technology and will not be described in detail here.

[0047] Embodiment 3

[0048] This embodiment provides an accident chain blocking method for the hydrogen pipeline system in the tunnel described in Embodiment 2, including the following steps:

[0049] First, assemble the accident chain blocking device with the hydrogen pipeline. Put the outer sleeve on the outer periphery of the hydrogen pipeline, and then fix the outer sleeve and the hydrogen pipeline by full penetration welding to form a completely enclosed sandwich space. Connect the protective gas inlet pipe with the protective gas source, connect the vacuum interface to the vacuum pumping system through the vacuum pumping pipeline, and set a valve on the vacuum pumping pipeline to control the on and off of the vacuum pumping pipeline. Connect each valve and pressure sensor to the control system.

[0050] The vacuum pumping system works to maintain a negative pressure state with a set vacuum degree in the sandwich space. In this embodiment, the vacuum degree in the sandwich space is maintained at a negative pressure state of ≤10 Pa. The vacuum environment can improve the detection sensitivity of hydrogen micro-leakage to the 0.1 sccm level to achieve early warning.

[0051] When a rupture occurs in the hydrogen pipeline to form a leakage hole 11, and the vacuum degree in the sandwich space 7 deteriorates due to the leakage of hydrogen inside the hydrogen pipeline, when the pressure sensor detects that the gas pressure in the sandwich space is greater than the set threshold value, in this embodiment, the set threshold value is 10 Pa, the pressure sensor immediately sends a signal to the control system, and the control system controls the sound and light alarm system to give a sound and light alarm. At the same time, start the emergency procedure: close the first valve 1 and the second valve 2 at both ends of the hydrogen pipeline, open the purge control valve 4 and the vent valve 3, discharge the gas in the sandwich space 7, and inject high-purity nitrogen for purging and replacement to ensure that the hydrogen concentration in the mixed gas drops below the set lower explosion limit in a short time.

[0052] In this embodiment, to optimize the nitrogen usage efficiency and shorten the replacement time while ensuring the hydrogen replacement effect, the nitrogen requirement and replacement speed are calculated.

[0053] Currently, there are usually two methods for calculating the nitrogen requirement:

[0054] (1) For the full-line replacement of the pipeline with nitrogen, the minimum theoretical nitrogen requirement can be calculated according to the following formula:

[0055] V = 7.85×10 -4 D 2 L

[0056] In the formula: V is the minimum theoretical nitrogen requirement for replacement, m 3 ; D is the equivalent diameter of the annular sandwich, which can be obtained by using the existing method, m; L is the length of the sandwich space, m.

[0057] In the actual engineering replacement process, the actual nitrogen requirement is 1.5 - 2.0 times the minimum theoretical requirement.

[0058] (2) The calculation of the nitrogen requirement can be carried out by using the pressurization coefficient method, that is

[0059]

[0060] Where: M is the required amount of nitrogen for replacement production, kg; K is the pressurization coefficient, which is generally taken as 1.2 in actual engineering; V is the volume of the interlayer space, m 3 ; μ is the specific volume of nitrogen.

[0061] During the hydrogen replacement process, it is stipulated that the hydrogen concentration in the interlayer space after replacement < 1%, and the replacement gas flow rate ≥ 1.5 m / s to ensure a turbulent state and avoid gas stratification caused by laminar flow. The dilution replacement model is used for calculation, and the key formulas are as follows:

[0062]

[0063] Where: v is the nitrogen gas flow rate, m / s; is the nitrogen gas volume flow rate, m 3 / h; A is the cross-sectional area of the interlayer space, m 2 ; t is the replacement time, s; V is the volume of the interlayer space, m 3 ; C0 is the initial hydrogen concentration, %; C t is the target concentration, %.

[0064] In this embodiment, the upper computer receives operation instructions through the HMI interface and displays the real-time status, communicates with the PLC using the Modbus TCP protocol, and the sampling period is 100 ms; the alarm event record uses the SQL Server database, and the stored fields include timestamp (accuracy 1 ms), pressure value (0.1 Pa resolution), and the action status of each valve;

[0065] In this embodiment, a synchronous interlock control strategy is adopted. When the pressure sensor detects that the pressure in the interlayer space > 10 Pa, the PLC controls it to immediately trigger a three-level response synchronously: drive the audible and visual alarm system to give an alarm through the DO1 interface output, and at the same time, close the first valve and the second valve at both ends of the hydrogen pipeline through the DO2 interface output. Synchronously open the vent valve and the purge control valve through the DO3 interface and the DO4 interface output, forming a synchronous emergency disposal process of "alarm - block - inerting". All actions are completed within 80 ms after the pressure exceeds the limit. Since the CPU module inside the PLC can only process digital signals, an analog input (AI) module needs to be used to complete the acquisition and conversion of analog signals. The AI module can use existing technologies, which can collect analog signals such as voltage and current in real time and convert them into digital signals that can be processed by the CPU through integrated circuits and analog-to-digital conversion technologies. This system continuously monitors the nitrogen flow feedback signal of the flowmeter at the outlet pipeline of the nitrogen generation equipment through the AI module, and combines the fast computing ability of the CPU to dynamically adjust the control parameters to ensure that the hydrogen concentration drops to a safe value (< 1%) within 18 seconds. A dual-pressure sensor calibration and valve status read-back mechanism is adopted to meet the SIL2 safety level requirements while achieving fast response.

[0066] The device status is fed back through the PROFI safe protocol, including valve opening, nitrogen flow, interlayer vacuum degree, etc.; the safety loop design should meet the IEC 61511 SIL2 requirements, and a one-out-of-two voting logic is adopted for key signals, that is, when the difference between the two pressure sensors ≤ 5%, the average value is used as the control basis; when the difference > 5%, a system fault alarm is triggered and all valves are closed.

[0067] In a test verification system of this embodiment, as Figure 3 shown, it includes an experimental pipeline 13 for simulating the interlayer space. Pressure transmitters 14 are provided at both ends of the experimental pipeline 13 to detect the pressure in the test pipeline. The pressure transmitters 14 are connected to the PLC controller 15, and the PLC controller 15 is connected to the upper computer 16. The middle of the experimental pipeline 13 is connected to a hydrogen cylinder 18 through a hydrogen inlet pipe 17. A hydrogen cylinder control valve 19 and a hydrogen cylinder outlet pressure gauge 20 are provided at the inlet end of the hydrogen inlet pipe 17. A control valve one 21 is also provided at the outlet end of the hydrogen inlet pipeline. The experimental pipeline 13 is also connected to a vacuum pump 22 through a vacuum pipeline, and a vacuum control valve 23 is provided on the vacuum pipeline. The test pipeline 13 is connected to a nitrogen cylinder 25 through a nitrogen inlet pipe 24. Along the nitrogen flow direction, a nitrogen cylinder control valve 26, a nitrogen cylinder pressure gauge 27, and a control valve three 28 are successively provided on the nitrogen inlet pipe 24. The test pipeline 13 is also connected to an exhaust pipeline 29, and a control valve two 30 is provided on the exhaust pipeline 29.

[0068] Preferably, the first control valve 21, the second control valve 30, and the third control valve 28 are all needle valves capable of precise adjustment.

[0069] For the test verification system of this embodiment, first start the vacuum pump and the vacuum control valve to evacuate the experimental pipeline to establish an initial monitoring environment of ≤ 10 Pa.

[0070] When the system starts, the PLC controller 15 and the upper computer 16 enter the standby state and monitor the system parameters in real time. During the experiment, simulate the hydrogen leakage condition by opening the first control valve 21 and the hydrogen cylinder control valve 19.

[0071] The pressure transmitters 14 installed at both ends of the experimental pipeline 13 collect pressure data in real time and transmit the signals to the PLC controller 15. When the detected pressure exceeds the 10 Pa threshold, the PLC controller 15 immediately starts the interlock control program: first trigger the audible and visual alarm, then close the first control valve 21, and at the same time open the second control valve 30, the third control valve 28, and the nitrogen cylinder control valve 26 to form a complete emergency response chain of "monitoring - blocking - inerting". The upper computer 16 synchronously displays the real-time status of each valve and the pressure change curve.

[0072] To comprehensively verify the system performance, the variable control method is adopted in the experiment: after completing the basic test, simulate different leakage rate conditions by adjusting the aperture of the first control valve 21 and repeat the above test process. This method can quantitatively evaluate the sensitivity, response speed, and inerting efficiency of the system and provide reliable data support for engineering applications. All experimental data are automatically stored in the database to support later retrospective analysis and ensure accurate early warning and rapid disposal in the actual tunnel environment.

[0073] The above test verification system adopts a dual-gas source design of high-purity hydrogen + nitrogen, combines precision needle valves to simulate different leakage conditions, and comprehensively verifies the response effectiveness of the accident chain blocking system.

[0074] By adopting the barrier device, hydrogen pipeline system and accident chain barrier method of this embodiment, through the collaborative work of the pressure sensor and the PLC controller, the pressure fluctuation is captured in real time, ensuring the reliability of the threshold alarm. The vacuum environment can not only provide early warning of micro-leakage, but also accurately trigger a three-level emergency response when a leakage occurs, namely leakage alarm, valve interlock pressure relief, and nitrogen replacement, forming an active prevention and control closed-loop that completely covers the entire process from leakage detection to emergency disposal, solving the pain points of lagging response and single disposal in traditional technologies, significantly improving the safety of hydrogen energy transportation, and being applicable to high-risk scenarios such as tunnels and hydrogen storage stations. At the same time, the double-layer pipeline is formed through the setting of the outer sleeve pipe. The double-layer pipeline realizes double guarantees of mechanical protection and corrosion protection through the collaborative protection mechanism of the inner and outer pipes and differential material selection. The high strength of the outer sleeve pipe can effectively resist external impacts such as falling rocks and construction collisions in the tunnel, and the low intergranular corrosion rate ensures the structural integrity under the long-term hydrogen permeation environment. This design method significantly reduces the leakage probability of the internal hydrogen pipeline caused by hydrogen embrittlement corrosion and mechanical damage, and significantly improves the safety and durability of the pipeline under harsh working conditions.

[0075] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydrogen pipeline accident chain blocking device in a tunnel, characterized in that It includes a jacket pipe arranged around the hydrogen pipeline. A sandwich space can be formed between the jacket pipe and the hydrogen pipeline. A pressure detection element is installed on the jacket pipe to detect the pressure in the sandwich space. The pressure detection element is connected to a control system. The jacket pipe is connected with a protective gas inlet pipe and a gas discharge pipe. The protective gas inlet pipe is connected with a protective gas source. A purge control valve is provided on the protective gas inlet pipe. A vent valve is provided on the gas discharge pipe. The control valve and the vent valve are connected to the control system; When the air pressure value transmitted by the pressure detection element to the control system is greater than the set threshold value, the control system controls the purge control valve and the vent valve to open, discharges the gas in the sandwich layer and purges the sandwich space with the protective gas at the same time.

2. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, wherein, It further includes a first valve and a second valve. The first valve is used to be installed at the inlet end of the hydrogen pipeline. The second valve is used to be installed at the outlet end of the hydrogen pipeline.

3. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, characterized in that Pressure detection elements are provided at both ends of the jacket pipe.

4. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, characterized in that, The jacket pipe is connected to the tops of multiple piers, and the piers are used to support the jacket pipe and the hydrogen pipeline.

5. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, characterized in that, The jacket pipe is made of seamless steel pipe, and its two ends are fixedly welded to the hydrogen pipeline with full penetration welding.

6. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, characterized in that The jacket pipe is also provided with a vacuum interface communicating with the internal space of the sandwich layer, and the vacuum interface is connected to a vacuum pumping system.

7. The hydrogen pipeline accident chain blocking device in a tunnel according to claim 1, wherein The control system is also connected to an alarm system. When the pressure value transmitted by the pressure detection element to the control system is greater than the set threshold value, the control system controls the alarm system to give an alarm.

8. A hydrogen pipeline system in a tunnel, characterized in that, It includes a hydrogen pipeline and the accident chain blocking device for the hydrogen pipeline in the tunnel according to any one of claims 1-7. A first valve is provided at the inlet end of the hydrogen pipeline, and a second valve is provided at the outlet end. The jacket pipe is sleeved and fixed around the hydrogen pipeline, and a sandwich space is formed between the jacket pipe and the hydrogen pipeline.

9. An accident chain blocking method for the hydrogen pipeline system in the tunnel according to claim 8, characterized in that: Assemble the accident chain blocking device for the hydrogen pipeline in the tunnel with the hydrogen pipeline; After the pressure value detected by the pressure detection element of the jacket pipe is greater than the set threshold value, a signal is sent to the control system. The control system controls the first valve and the second valve to close, and controls the vent valve and the purge control valve to open. While discharging the gas in the sandwich space through the gas discharge pipe, the protective gas is introduced into the sandwich space through the protective gas inlet pipe. The sandwich space is purged with the protective gas and the hydrogen is replaced with the protective gas until the hydrogen concentration in the mixed gas drops below the set lower explosion limit value.

10. The accident chain blocking method for the hydrogen pipeline system in the tunnel according to claim 9, characterized in that, After the accident chain blocking device for the hydrogen pipeline in the tunnel is assembled with the hydrogen pipeline, evacuate the sandwich space to maintain a negative pressure state with a set vacuum degree in the sandwich space.

Images