A purging displacement pry structure for a hydrogen pipeline

Abstract

A kind of purging replacement pry structure for hydrogen pipeline, including gas storage structure, first stop valve, first pressure reducing valve, first pressure detection device, gas filter, second pressure reducing valve, second pressure detection device, pressure relief valve, second stop valve, purging interface in turn along gas supply pipeline;It further includes control unit;Control unit receives the pressure information of first pressure monitoring device and second pressure monitoring device in real time, and adjusts the opening of first pressure reducing valve and second pressure reducing valve according to pressure information;Control unit inputs the safety threshold of pressure relief valve, closes first stop valve when pressure relief valve opens, and opens first stop valve after gas pressure is normal;Control unit opens and closes second stop valve according to the information fed back by the system to be purged to release purging gas.The utility model solves the problems of insufficient pressure control precision, incomplete impurity filtration, delayed emergency response and poor integration adaptability existing in traditional purging mode.

Description

Technical Field

[0001] The utility model belongs to the field of pipeline skid-mounted systems, and particularly relates to a purging and replacement skid-mounted structure for hydrogen pipelines. Background Art

[0002] The hydrogen manifold pipeline skid is an integrated gas transportation and distribution system based on the skid-mounted design concept, mainly used for the centralized collection, pressure stabilization, transportation and safety control of hydrogen. Its core structure is to pre-integrate and install multiple gas storage units (such as cylinder groups), manifold pipelines, pressure regulating devices, valve assemblies, safety protection components and control modules on a steel skid frame to form a compact and standardized functional module.

[0003] During startup, shutdown, maintenance or emergency conditions of the hydrogen manifold pipeline skid, the purging function must be relied on to ensure system safety. After the system is first put into use or after a long-term shutdown, the pipeline may contain residual air (including oxygen), moisture or other impurities. If hydrogen is directly introduced, when hydrogen and oxygen are mixed to a certain concentration, it is easy to cause deflagration or explosion when encountering a fire source. Therefore, it is necessary to purge and replace impurities such as oxygen in the pipeline with an inert gas until the volume content of oxygen drops to a safe threshold before hydrogen can be introduced. During system operation, if the hydrogen concentration in the pipeline becomes abnormal or oxygen is mixed in due to valve leakage, pressure fluctuation or equipment failure, a dangerous mixture may be formed. At this time, it is necessary to purge in time to dilute and discharge the dangerous gas to avoid the concentration reaching the explosion limit. Before the system is shut down or maintained, it is necessary to purge and replace the residual hydrogen in the pipeline to prevent sparks or static electricity generated by tool collision during maintenance from causing danger, and at the same time avoid the residual gas mixing with air to form a safety hazard.

[0004] At present, the purging modules supporting the hydrogen manifold pipeline skid still have many technical defects and are difficult to meet the industrial requirements of high safety and automation. Most existing modules use a single pressure reduction structure or manual control valves, and cannot achieve precise control of the purging pressure. If the pressure is too high, it may cause pipeline vibration, damage to seals, or even static electricity caused by too fast gas flow rate; if the pressure is too low, it cannot effectively replace impurities or residual gas, and there is a risk of incomplete purging. Most purging modules rely on manual operation to start or stop the purging process, and it is necessary to manually monitor the gas concentration in the pipeline and judge the purging end point. This is not only inefficient but also prone to safety hazards due to human misjudgment. Existing modules are difficult to be linked with the gas detection device and alarm system of the system to be purged in real time. When the hydrogen concentration in the pipeline is insufficient or the oxygen concentration exceeds the standard, the purging program cannot be automatically triggered; when there is an emergency shutdown or a fault alarm, the purging protection cannot be quickly started, and the lag is likely to expand the safety risk. Content of the Utility Model

[0005] The purpose of this utility model is to provide a purging and replacement skid-mounted structure for hydrogen pipelines, so as to solve the technical problems of inaccurate pressure control, low efficiency due to reliance on manual operation, fragmented functions and poor adaptability, and insufficient fault tolerance under abnormal conditions in existing hydrogen pipeline purging modules.

[0006] To achieve the above objectives, the specific technical solution of the purging and replacement skid-mounted structure for hydrogen pipelines according to this utility model is as follows:

[0007] A purging and displacement skid structure for hydrogen pipelines includes the following components arranged sequentially along the gas supply pipeline:

[0008] Gas storage structure, used for storing purge gas;

[0009] The first shut-off valve is used to control the opening and closing of the purging gas into the subsequent gas supply pipeline;

[0010] The first pressure reducing valve reduces the pressure of the purging gas for the first time;

[0011] The first pressure detection device detects the pressure of the purge gas after the first pressure reduction;

[0012] Gas filters remove impurities from the purge gas;

[0013] The second pressure reducing valve reduces the pressure of the purging gas a second time;

[0014] The second pressure detection device detects the pressure of the purge gas after the second pressure reduction.

[0015] The pressure relief valve automatically opens to release air pressure when it exceeds a preset safety threshold.

[0016] The second shut-off valve is used to control the on / off state of the purge gas output;

[0017] The purge interface is used to connect to the system to be purged;

[0018] It also includes control units that are respectively connected to the first shut-off valve, the first pressure reducing valve, the first pressure detection device, the second pressure reducing valve, the second pressure detection device, the pressure relief valve, and the second shut-off valve;

[0019] The control unit receives pressure information from the first pressure monitoring device and the second pressure monitoring device in real time, and adjusts the opening degree of the first pressure reducing valve and the second pressure reducing valve according to the pressure information; the control unit inputs the safety threshold of the pressure relief valve, closes the first shut-off valve when the pressure relief valve is open, and opens the first shut-off valve after the gas pressure is normal; the control unit opens and closes the second shut-off valve to release the purging gas according to the information fed back by the system to be purged.

[0020] As a further improvement of this utility model, the system to be purged is a hydrogen supply pipeline. When the hydrogen volume content in the system to be purged is ≤96% or the oxygen volume content is ≥4%, the control unit opens the second shut-off valve and outputs purging gas; when the oxygen volume content is ≤0.5%, the control unit closes the second shut-off valve to complete the purging.

[0021] As a further improvement of this utility model, the purging gas is an inert gas, and the gas storage structure consists of several gas storage cylinders, each connected to the gas supply pipeline by a metal corrugated pipe.

[0022] As a further improvement of this utility model, the gas filter has a filtration accuracy greater than 600 mesh.

[0023] As a further improvement of this utility model, the pressure of the purging gas after passing through the second pressure reducing valve is 0.5 to 0.8 MPa.

[0024] As a further improvement of this utility model, the control unit has an audible and visual alarm function, which issues an alarm signal when overpressure, excessive gas concentration, or valve failure occurs.

[0025] As a further improvement of this utility model, the control unit has a manual / automatic switching function. In automatic mode, it runs according to a preset program, while in manual mode, each valve can be controlled individually through the operation panel.

[0026] As a further improvement of this utility model, the first shut-off valve and the second shut-off valve are electric shut-off valves, and also have a manual emergency operation function.

[0027] As a further improvement of this utility model, the first pressure reducing valve and the second pressure reducing valve are provided with manual adjustment knobs, so that the purging gas pressure can be manually adjusted when the control unit malfunctions.

[0028] Beneficial effects:

[0029] Two-stage pressure reduction is achieved by sequentially installing a first and a second pressure-reducing valve along the gas supply pipeline. Combined with real-time pressure monitoring by the first and second pressure detection devices, the control unit dynamically adjusts the opening of the pressure-reducing valves based on pressure information, stabilizing the purging gas pressure within the target range. This effectively prevents pipeline vibration and seal failure due to excessive pressure, or incomplete purging due to excessively low pressure. Simultaneously, the pressure relief valve automatically opens to release pressure when it exceeds a preset safety threshold. Combined with the control unit's linkage logic of closing the first shut-off valve during pressure relief, this forms multiple layers of pressure safety protection, fundamentally reducing the safety risks caused by overpressure.

[0030] The integrated design of the control unit, the first shut-off valve, the second shut-off valve, and the pressure detection device enables automated start-up and shutdown of the purging process and dynamic pressure adjustment, eliminating the need for continuous manual monitoring and operation. This solves the problems of low efficiency and delayed pressure regulation in traditional manual control modes. The control unit automatically opens and closes the second shut-off valve to release purging gas based on feedback information from the system to be purged, ensuring that the purging timing precisely matches the system requirements, avoiding ineffective or insufficient purging, and significantly improving the reliability of the purging operation.

[0031] The module integrates functions such as gas storage structure, pressure reduction, filtration, pressure detection, and control along the gas supply pipeline, forming a complete purging function chain. It eliminates the need for additional, scattered components, adapting to the compact installation requirements of hydrogen pipeline skid-mounted systems. The gas filter's impurity removal function prevents particulate contaminants from entering the system to be purged, thus avoiding pipeline blockage or equipment damage, improving the cleanliness of the purging gas, and ensuring the stable operation of the system to be purged.

[0032] The control unit closes the first shut-off valve when the pressure relief valve is opened and reopens it after the air pressure returns to normal, forming an automatic protection closed loop when the pressure is abnormal. Combined with the manual / automatic switching and manual emergency operation of valves in the subsequent claims, it ensures that the system can still maintain the basic purging function through manual intervention when the control unit or electrical components fail, adapting to emergency needs under complex working conditions and improving the module's fault tolerance and stability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a purging and replacement skid structure for a hydrogen pipeline according to the present invention;

[0034] The markings in the diagram are as follows: 1. Gas supply pipeline; 2. Gas storage structure; 3. First shut-off valve; 4. First pressure reducing valve; 5. First pressure detection device; 6. Gas filter; 7. Second pressure reducing valve; 8. Second pressure detection device; 9. Pressure relief valve; 10. Second shut-off valve; 11. Purge port. Detailed Implementation

[0035] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0036] Implementation example:

[0037] like Figure 1The diagram illustrates a purging and replacement skid-mounted structure for hydrogen pipelines. Along the gas supply pipeline 1, a gas storage structure 2, a first shut-off valve 3, a first pressure reducing valve 4, a first pressure detection device 5, a gas filter 6, a second pressure reducing valve 7, a second pressure detection device 8, a pressure relief valve 9, a second shut-off valve 10, and a purging interface 11 are sequentially integrated. A control unit enables the coordinated control of all components. This module is mounted on a steel skid frame, forming a compact, integrated structure suitable for safe purging operations of skid-mounted systems for combustible gases such as hydrogen and natural gas.

[0038] The gas storage structure 2 uses four 40L high-pressure gas cylinders, each with a rated working pressure of 15MPa, for storing nitrogen as the purging gas. The gas cylinders are connected to the gas supply pipeline 1 via a flexible stainless steel corrugated pipe. The corrugated pipe has a nominal diameter of DN15, a pressure resistance rating of ≥3.0MPa, and is connected at both ends with angle valves. The high-pressure cylinders can store sufficient nitrogen to meet long-term purging needs; the stainless steel corrugated pipe has good flexibility and shock resistance, absorbing pipeline vibration and installation errors, while also being high-pressure resistant and corrosion-resistant, ensuring a tight connection and preventing nitrogen leakage.

[0039] Both the first shut-off valve 3 and the second shut-off valve 10 are electrically operated shut-off valves. The valve body is made of 304 stainless steel, and the seals are made of high-pressure resistant nitrile rubber. Each electrically operated shut-off valve is equipped with a mechanical manual operating lever on top, allowing manual rotation to open or close the valve in case of power failure or control unit malfunction. The electric shut-off valve has a response time of ≤50ms, enabling rapid execution of the control unit's switching commands and meeting the real-time requirements of automatic purging. The manual operating lever design ensures manual intervention capability in emergency situations, improving system reliability.

[0040] The first pressure reducing valve 4 is a pilot-operated high-pressure pressure reducing valve with an inlet pressure of 1–15 MPa and an outlet pressure adjustment range of 0.5–2 MPa. The second pressure reducing valve 7 is a precision pressure reducing valve with an outlet pressure adjustment range of 0.1–1 MPa. Both are made of brass, and the valve port seals are made of polytetrafluoroethylene (PTFE). A graduated manual adjustment knob is located on the side of each pressure reducing valve, with an adjustment accuracy of ±0.02 MPa. The two-stage pressure reducing valves connected in series form a stepped pressure reduction. The first pressure reducing valve 4 initially reduces the high-pressure nitrogen gas in the cylinder to 1–1.5 MPa, and the second pressure reducing valve 7 further precisely adjusts it to the target purging pressure of 0.5–0.8 MPa. Combined with the dynamic adjustment of the control unit, this ensures pressure stability. The manual adjustment knob allows direct pressure adjustment in case of control unit failure, ensuring basic purging functionality.

[0041] Both the first pressure detection device 5 and the second pressure detection device 8 employ diffused silicon pressure transmitters, with measurement ranges of 0–2.5 MPa (first pressure detection device) and 0–1.6 MPa (second pressure detection device), respectively, outputting a standard current signal to the control unit. The pressure transmitters are threadedly connected to the gas supply pipeline, and the gauges feature digital displays. Real-time monitoring of pressure data after two stages of pressure reduction ensures stable signal transmission. The control unit can dynamically adjust the pressure reducing valve opening based on feedback values, achieving closed-loop pressure control. The digital display allows on-site inspectors to visually monitor the pressure status.

[0042] Gas filter 6 is a cartridge-type precision filter with a 304 stainless steel woven mesh filter element. It has a filtration accuracy of 600 mesh (approximately 23μm), and the inlet and outlet are connected by flanges. A quick-release end cap is located on the top. The 600-mesh filter element effectively intercepts particulate impurities such as rust and dust in nitrogen, preventing impurities from entering downstream pipelines, clogging valves, or contaminating the system to be purged. The quick-release end cap facilitates filter element replacement, and the differential pressure gauge visually reflects the filter element's clogging status, reminding users when maintenance is needed.

[0043] The pressure relief valve 9 is a spring-loaded safety valve, set to open at 1.2 times the target pressure of the second pressure reducing valve 7 (i.e., 0.96 MPa). The valve body is made of cast steel, and the sealing surface is made of copper alloy. The pressure relief port is connected to a safe outdoor high-altitude area via a pipeline. When the pipeline pressure unexpectedly exceeds the safety threshold, the pressure relief valve 9 can automatically open within 0.5 seconds to release the overpressure gas and prevent the pipeline from bursting. The spring-loaded structure has an automatic reset function, automatically closing after the pressure returns to normal, without manual intervention.

[0044] The purge interface 11 uses a snap-fit ​​quick connector with a built-in one-way check valve in the female connector. The connector is made of 304 stainless steel and sealed with an O-ring. The quick connector allows for rapid plug-and-play connection to the system to be purged, resulting in high installation efficiency. The check valve effectively prevents hydrogen or impurities in the system to be purged from flowing back into the purge module, avoiding cross-contamination.

[0045] The control unit, centered around a PLC controller, is equipped with a 7-inch touchscreen. It incorporates a pressure regulation algorithm and purging logic program, supporting manual / automatic mode switching. In automatic mode, it automatically adjusts the pressure reducing valve and opens / closes other valves based on pressure signals and gas concentration information from the system being purged, enabling unattended purging. The touchscreen clearly displays system status, settings, and alarm information. In manual mode, individual components can be controlled independently via panel buttons for convenient operation. Furthermore, the control unit is interlocked with the leak detection system, alarm system, and hydrogen and oxygen content monitoring system of the system being purged.

[0046] In this embodiment, the system to be purged is a hydrogen manifold skid system. The control unit defaults to automatic mode. Nitrogen gas from the storage cylinder enters the gas supply pipeline 1 through a metal bellows. The first shut-off valve 3 is opened, and the nitrogen gas passes through the first pressure reducing valve 4 for initial pressure reduction, the first pressure detection device 5 for monitoring, and then enters the gas filter 6 to remove impurities. The filtered nitrogen gas is precisely adjusted to 0.8 MPa by the second pressure reducing valve 7, and the second pressure detection device 8 monitors the pressure in real time and feeds it back to the control unit. When the system to be purged reports that the hydrogen volume content is ≤96% or the oxygen volume content is ≥4%, the control unit opens the second shut-off valve 7, and the nitrogen gas enters the hydrogen manifold skid system through the purging interface for purging. If the pressure exceeds 0.96 MPa during the purging process, the pressure relief valve 9 automatically opens, and the control unit simultaneously closes the first shut-off valve 3. The valve reopens after the pressure recovers. When the oxygen volume content of the system to be purged is ≤0.5%, the control unit closes the second shut-off valve 10, completing the purging process.

[0047] Hydrogen, as a highly diffusive and flammable gas with a high risk of explosion, requires extremely high purging precision in its pipeline system. The purging module uses a two-stage pressure reduction system to stably control the nitrogen pressure at 0.5–0.8 MPa, preventing vibrations in the hydrogen pipeline or static electricity caused by excessive flow velocity during high-pressure purging. Simultaneously, the control unit is linked to the hydrogen concentration monitoring system, automatically initiating purging when the hydrogen volume content is ≤96% or the oxygen volume content is ≥4%, and stopping only when the oxygen volume content is ≤0.5%. This precisely avoids the explosion risk of hydrogen mixed with oxygen, ensuring the safety of hydrogen pipeline start-up, shutdown, and operation from the source. Hydrogen pipelines are highly sensitive to impurities; even small particles can cause valve jamming or contamination of terminal equipment such as fuel cells. The module's 600-mesh filter deeply removes impurities such as rust and dust from the nitrogen, and combined with stainless steel supply pipes and valves, effectively prevents impurities from entering the hydrogen pipeline system, ensuring the purity of hydrogen delivery and the lifespan of equipment. Addressing the characteristics of hydrogen's susceptibility to leakage and rapid risk diffusion, the modular electric shut-off valve, in conjunction with the PLC controller's rapid logic judgment, can instantly initiate purging in case of abnormal hydrogen concentration or emergency shutdown. The pressure relief valve automatically releases pressure within 0.5 seconds of overpressure, simultaneously cutting off the gas supply and quickly curbing the escalation of risk. Simultaneously, the dual emergency design of the electric shut-off valve's manual operating lever and the pressure reducing valve's manual knob ensures that purging protection of the hydrogen pipeline is maintained even under extreme operating conditions. The module adopts a steel skid-mounted integrated design, highly compatible with the factory prefabrication concept of hydrogen pipeline skid-mounted systems, allowing for on-site connection via quick couplings, significantly shortening the installation cycle. The control unit supports communication and linkage with the main hydrogen skid-mounted system, enabling integration into overall intelligent management and achieving safe and coordinated control throughout the entire process of hydrogen production, storage, and transportation.

[0048] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A purging and displacement skid-mounted structure for hydrogen pipelines, characterized in that, Including those installed sequentially along the gas supply pipeline: Gas storage structure, used for storing purge gas; The first shut-off valve is used to control the opening and closing of the purging gas into the subsequent gas supply pipeline; The first pressure reducing valve reduces the pressure of the purging gas for the first time; The first pressure detection device detects the pressure of the purge gas after the first pressure reduction; Gas filters remove impurities from the purge gas; The second pressure reducing valve reduces the pressure of the purging gas a second time; The second pressure detection device detects the pressure of the purge gas after the second pressure reduction. The pressure relief valve automatically opens to release air pressure when it exceeds a preset safety threshold. The second shut-off valve is used to control the on / off state of the purge gas output; The purge interface is used to connect to the system to be purged; It also includes control units that are respectively connected to the first shut-off valve, the first pressure reducing valve, the first pressure detection device, the second pressure reducing valve, the second pressure detection device, the pressure relief valve, and the second shut-off valve; The control unit receives pressure information from the first pressure detection device and the second pressure detection device in real time, and adjusts the opening of the first pressure reducing valve and the second pressure reducing valve according to the pressure information. The control unit inputs the safety threshold of the pressure relief valve, closes the first shut-off valve when the pressure relief valve is open, and opens the first shut-off valve after the air pressure is normal. The control unit opens and closes the second shut-off valve to release purging gas based on the information fed back from the system to be purged.

2. The purging and replacement skid-mounted structure for hydrogen pipelines according to claim 1, characterized in that, The system to be purged is a hydrogen supply pipeline. When the hydrogen volume content in the system to be purged is ≤96% or the oxygen volume content is ≥4%, the control unit opens the second shut-off valve and outputs purging gas; when the oxygen volume content is ≤0.5%, the control unit closes the second shut-off valve to complete the purging.

3. The purging and replacement skid-mounted structure for hydrogen pipelines according to claim 1, characterized in that, The purging gas is an inert gas, and the gas storage structure consists of several gas cylinders, each connected to the gas supply pipeline by a metal corrugated pipe.

4. The purging and replacement skid-mounted structure for hydrogen pipelines according to claim 1, characterized in that, The gas filter has a filtration accuracy greater than 600 mesh.

5. The purging and replacement skid-mounted structure for hydrogen pipelines according to claim 1, characterized in that, The pressure of the purging gas after passing through the second pressure reducing valve is 0.5 to 0.8 MPa.

6. The purging and replacement skid-mounted structure for hydrogen pipelines according to claim 1, characterized in that, The control unit has an audible and visual alarm function, which issues an alarm signal when overpressure, excessive gas concentration, or valve failure occurs.

7. The purging and replacement skid structure for hydrogen pipelines according to claim 1, characterized in that, The control unit has a manual / automatic switching function. In automatic mode, it runs according to a preset program, while in manual mode, each valve can be controlled individually through the operation panel.

8. The purging and replacement skid structure for hydrogen pipelines according to claim 7, characterized in that, The first and second shut-off valves are electrically operated shut-off valves, and also have a manual emergency operation function.

9. The purging and replacement skid structure for hydrogen pipelines according to claim 7, characterized in that, The first and second pressure reducing valves are equipped with manual adjustment knobs, which allow manual adjustment of the purge gas pressure when the control unit malfunctions.

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