Hydrogen leakage detection system

Abstract

The utility model discloses a hydrogen leakage detection system. The problem that safe, stable and economical operation of the hydrogen refueling station is affected due to the fact that hydrogen leakage cannot be comprehensively detected in time in an existing hydrogen refueling station is solved. The system comprises diffusion pipelines correspondingly connected between a diffusion tower and hydrogen adding / discharging equipment, hydrogen sensors and one-way valves which are respectively connected in the diffusion pipelines, hydrogen detectors which are respectively used for detecting the hydrogen concentration at the hydrogen adding / discharging equipment, and combustible gas alarm controllers which are correspondingly in communication connection with the hydrogen detectors, the PLC is in corresponding communication connection with the combustible gas alarm controller and the hydrogen sensor, the audible and visual alarm is electrically connected with the PLC, and the emergency cut-off valve is used for controlling on and off of a hydrogen channel of the hydrogen adding / discharging equipment and is electrically connected with the PLC. The system can timely and effectively monitor hydrogen leakage at each device and the diffusion pipeline in the hydrogen refueling station, and is safe and efficient.

Description

Technical Field

[0001] This application relates to the field of new energy technologies, and particularly to a hydrogen leakage detection system. Background Art

[0002] A hydrogen refueling station is an essential infrastructure for providing hydrogen to fuel cell vehicles and is also an important part of the hydrogen energy industry. The process flow of most existing hydrogen refueling stations is to transport 20 MPa low-pressure hydrogen to the hydrogen refueling station by a tube trailer, and then the hydrogen is transferred to a compressor by a hydrogen unloading column. After compression, the 45 MPa or 90 MPa high-pressure hydrogen is stored in corresponding high-pressure cylinder groups. When refueling a vehicle, the hydrogen dispenser takes hydrogen from the corresponding cylinder group as needed and refuels it into the fuel cell vehicle.

[0003] Hydrogen is a highly dangerous gas. On the one hand, due to its low density and high-pressure storage, hydrogen is prone to leakage, and it is colorless and odorless, making it difficult to detect after leakage. On the other hand, hydrogen is flammable and explosive, with an explosion limit of 4.0% - 75.6% (volume fraction), a small ignition energy, and it is flammable and explosive when encountering fire, and is more likely to cause an explosion in a confined space. In addition, when hydrogen enters the metal, it is likely to cause a decrease in the ductility and strength of the metal, leading to hydrogen embrittlement, which in turn affects the safety of hydrogen pipeline equipment. In the processes of hydrogen unloading, pressurization, hydrogen storage, hydrogen refueling, and gas discharge in a hydrogen refueling station, there are characteristics such as diverse equipment, long pipelines, many valves, and many connection parts, which increases the potential safety hazard of hydrogen leakage.

[0004] In the process of implementing the technical solutions in the embodiments of this application, the inventors of this application found that the hydrogen leakage detection devices currently arranged in hydrogen refueling stations are generally set outside the equipment and at a certain distance from the leakage part. When the detector detects hydrogen leakage and triggers an alarm, a certain amount of hydrogen has already leaked, posing a great safety hazard. In addition, when the manual gas discharge valve or safety valve installed on the pipeline fails and has internal leakage, hydrogen will be discharged and lost through the gas discharge pipeline. On the one hand, it causes hydrogen loss, and on the other hand, the system pressure is insufficient due to air leakage, affecting the safe and stable operation of the hydrogen refueling station.

[0005] The information disclosed in this background art section is only used to deepen the understanding of the background art of this disclosure, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] In view of at least one of the above technical problems, the present disclosure provides a hydrogen leakage detection system, aiming to solve the problem that the safe, stable, and economic operation of existing hydrogen refueling stations is affected due to the inability to detect hydrogen leakage in a timely and comprehensive manner.

[0007] According to one aspect of the present disclosure, there is provided a hydrogen leakage detection system, which includes respective vent pipes correspondingly connected between the vent tower and the hydrogen addition / removal equipment, hydrogen sensors and one-way valves respectively installed in each of the vent pipes, respective hydrogen detectors for detecting the hydrogen concentration at the hydrogen addition / removal equipment, a combustible gas alarm controller communicatively connected to each of the hydrogen detectors correspondingly, a PLC controller communicatively connected to the combustible gas alarm controller and the hydrogen sensors correspondingly, an audible and visual alarm electrically connected to the PLC controller, and emergency cut-off valves respectively for controlling the on / off of the hydrogen passage of the hydrogen addition / removal equipment and electrically connected to the PLC controller.

[0008] In some embodiments of the present disclosure, the hydrogen leakage detection system further includes a display terminal installed in the control room and communicatively connected to the PLC controller correspondingly.

[0009] In some embodiments of the present disclosure, the hydrogen addition / removal equipment includes a compressor, a hydrogen storage container, a hydrogen filling machine, and a hydrogen unloading column.

[0010] In some embodiments of the present disclosure, the one-way valve is installed at a downstream position of the vent pipe corresponding to the hydrogen sensor.

[0011] In some embodiments of the present disclosure, the hydrogen sensor is a pipeline-type hydrogen sensor with a threaded interface provided at the probe head, and the hydrogen sensor is correspondingly threadedly connected to the vent pipe.

[0012] In some embodiments of the present disclosure, each of the hydrogen detectors is respectively installed in the corresponding space range above the hydrogen addition / removal equipment through a bracket.

[0013] In some embodiments of the present disclosure, the hydrogen detector and the combustible gas alarm controller are correspondingly connected by a multi-line system.

[0014] In some embodiments of the present disclosure, the PLC controller and the combustible gas alarm controller correspondingly obtain the low / high limit alarm signal output by the combustible gas alarm controller through electrical connection and obtain the monitoring data of the hydrogen detector through RS485 communication connection.

[0015] One or more technical solutions provided in the embodiments of the present application have at least any one of the following technical effects or advantages:

[0016] 1. By the hydrogen sensors installed in each vent pipe, the hydrogen concentration in the corresponding vent pipe is monitored in real time. Thus, according to the working state of whether the hydrogen refueling station is discharging hydrogen, it can be determined whether there is a leakage in the corresponding pipeline valve based on the monitoring value of the hydrogen sensor, thereby avoiding economic losses caused by hydrogen leakage and ensuring the normal operation of the equipment in the hydrogen refueling station.

[0017] 2. The one-way valve installed downstream of the hydrogen sensor in the vent pipe can avoid the adverse impact on the measurement accuracy of the hydrogen sensor due to the backflow of vented hydrogen. At the same time, by restricting the gas flow direction in the pipe, it can prevent the backflow gas from polluting the system.

[0018] 3. Each hydrogen detector can monitor the leakage of hydrogen addition / removal equipment in a timely and effective manner and feedback it to the combustible gas alarm controller and the PLC controller in a timely manner to trigger corresponding control actions. In addition, the emergency cut-off valve can respond to cut off the pipeline in a timely manner according to the leakage situation determined by the PLC controller, ensuring the working safety of the hydrogen refueling station. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structural principle of the hydrogen leakage detection system in an embodiment of the present application.

[0020] Figure 2 It is a schematic diagram of part of the working process of the hydrogen leakage detection system in an embodiment of the present application.

[0021] In the above figures, 1 is a vent tower, 2 is a vent pipe, 3 is a hydrogen sensor, 4 is a one-way valve, and 5 is a hydrogen detector. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The programs involved or relied on in the following embodiments are all conventional programs or simple programs in the technical field. Those skilled in the art can make conventional selections or adaptive adjustments according to specific application scenarios. The devices such as sensors involved in the following embodiments are all conventional commercially available products unless otherwise specified.

[0023] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0024] To solve the problem that the overall safe, stable and economic operation of the existing hydrogen refueling station is affected due to the inability to detect hydrogen leakage in a timely and comprehensive manner, this example discloses a hydrogen leakage detection system. Refer to Figure 1 , the hydrogen addition / removal equipment in the station is respectively connected to the vent tower 1 through the vent pipe 2, so that the hydrogen at each equipment can be transported to the vent tower through the vent pipe for effective and safe venting. Among them, in this embodiment, the hydrogen addition / removal equipment includes a compressor, a hydrogen storage container, a hydrogen refueling machine and a hydrogen unloading column.

[0025] Considering that when the manual relief valve or safety valve installed in the hydrogen transmission pipeline fails and internal leakage occurs, the hydrogen in the pipeline will flow through the relief pipeline to the relief tower for relief. On the one hand, this causes a loss of the hydrogen gas source, resulting in a waste of resources and affecting the economic benefits of the hydrogen refueling station. On the other hand, since part of the hydrogen leaks through the relief pipeline, the hydrogenation system will have insufficient pressure due to air leakage, affecting the normal operation of the hydrogenation system. Therefore, in this embodiment, hydrogen sensors 3 are respectively installed in each relief pipeline 2 between the hydrogen addition / removal equipment and the relief tower 1. Among them, in order to facilitate the installation of the hydrogen sensor 3, the hydrogen sensor 3 in this example is a pipeline-type hydrogen sensor with a threaded interface at the sensor probe head, and an opening matching the size of the threaded interface is provided at the relief pipeline 2. Thus, the hydrogen sensor 3 is connected to the relief pipeline 2 by threading to obtain information such as the hydrogen concentration in the relief pipeline 2.

[0026] To avoid the pollution caused by the reverse entry of the relieved hydrogen into the system, and at the same time to improve the measurement accuracy of the hydrogen sensor 3, in this embodiment, refer to Figure 1 , check valves 4 are respectively installed in each relief pipeline 2 corresponding to the hydrogen addition / removal equipment to control the gas flow direction in the corresponding relief pipeline 2. Among them, in this example, the check valve 4 is arranged at the downstream position of the hydrogen sensor 3, so that the relieved gas flowing back into the system pipeline can be intercepted, thereby avoiding the reverse flow of the gas into the system from affecting the measurement accuracy of the hydrogen sensor 3 and ensuring that the measurement data of the hydrogen sensor 3 can accurately reflect the hydrogen parameters in the corresponding relief pipeline.

[0027] In addition, considering that there is also a risk of hydrogen leakage in the hydrogen addition / removal equipment in the hydrogen refueling station, in order to detect its leakage situation in a timely and effective manner, in this embodiment, hydrogen detectors 5 are respectively arranged in the upper space range of the hydrogen addition / removal equipment. In this example, brackets are used to fixedly install the hydrogen detectors 5 in the upper space range corresponding to the hydrogen addition / removal equipment, and the distance between the hydrogen detector 5 and the hydrogen addition / removal equipment is controlled to be less than 2 m. Thus, by using the characteristic that the hydrogen density is less than the air density and will diffuse upward after leakage, leakage diffusion detection is carried out above the hydrogen addition / removal equipment, and at the same time, the distance between the hydrogen detector and the hydrogen addition / removal equipment is controlled to avoid the problem that the concentration of hydrogen decreases after diffusion due to too large a distance between the two, which affects the detection accuracy.

[0028] Refer to Figure 1 , in this embodiment, the hydrogen leakage detection system further includes a combustible gas alarm controller respectively communicatively connected to each hydrogen detector 5. Each hydrogen detector 5 establishes an RS485 communication connection with the combustible gas alarm controller by means of a multi-core cable system, so as to avoid problems such as data delay and ensure that the monitoring data of the hydrogen detector 5 can be transmitted to the combustible gas alarm controller in a timely and effective manner.

[0029] To be able to make corresponding effective response actions in a timely manner according to the system monitoring data, this system is equipped with a PLC controller. In this example, the PLC uses the Siemens S7-1200 series. Taking the PLC controller as the core of the system control, it receives the monitoring data of each sensor and detector, and makes timely response actions according to the preset. Specifically, see Figure 1 On the one hand, the PLC controller establishes an electrical connection with the combustible gas alarm controller, thereby obtaining the low / high limit alarm signals output by the combustible gas alarm controller corresponding to the monitoring data fed back by each hydrogen detector; on the other hand, the PLC controller also establishes an RS485 communication connection with the combustible gas alarm controller to correspondingly obtain the real-time monitoring data of each hydrogen detector. In addition, the PLC controller also establishes an RS485 communication connection with each hydrogen sensor 3 respectively to obtain information such as the hydrogen concentration in the corresponding dispersion pipeline monitored by each hydrogen sensor.

[0030] To facilitate the staff to timely master the real-time monitoring information of each monitoring point, in this example, a display terminal is set in the hydrogen filling station control room. The display terminal and the PLC controller establish a communication connection through Ethernet for data exchange, and display the position layout information, real-time monitoring data, and alarm information of each hydrogen sensor and hydrogen detector through the display terminal.

[0031] In addition, to achieve timely alarm and control after the hydrogen concentration at each monitoring point exceeds the limit, in this embodiment, see Figure 1 The PLC controller is also electrically connected to an audible and visual alarm and an emergency cut-off valve respectively. Each emergency cut-off valve is respectively arranged in the hydrogen pipeline corresponding to each hydrogen addition / removal device to control the on / off of the corresponding pipeline. When the hydrogen concentration exceeds the set low limit, the PLC controller correspondingly outputs a control instruction to control the audible and visual alarm to give an audible and visual alarm; when the hydrogen concentration exceeds the set high limit, the PLC controller drives the corresponding emergency cut-off valve to act while controlling the audible and visual alarm to give an audible and visual alarm, timely closing the hydrogen passage and reducing the safety risk.

[0032] See Figure 2 After this system starts to work, each hydrogen detector respectively monitors the hydrogen concentration information at its layout position in real time. In this example, the set low limit alarm value is 10%LEL, and the set high limit alarm value is 40%LEL.

[0033] When there is no hydrogen leakage in each device in the system, that is, when the combustible gas alarm controller monitors that the hydrogen concentration value at each point is below 10%LEL of the set lower explosion limit through each hydrogen detector, the combustible gas alarm controller does not send an alarm signal to the PLC controller. At this time, each emergency cut-off valve is normally open, and there is no output from the audible and visual alarm.

[0034] When the hydrogen detector detects that the hydrogen concentration at the corresponding hydrogen adding / unloading equipment exceeds the set lower explosion limit of 10%LEL, the combustible gas alarm controller outputs a low limit alarm signal to the PLC controller, and then the PLC controller controls the sound and light alarm to send out a sound and light alarm signal to remind the staff to inspect the equipment.

[0035] When the hydrogen detector detects that the hydrogen concentration at the corresponding hydrogen filling / unloading equipment exceeds the set lower explosion limit of 40%LEL, the combustible gas alarm controller outputs a high-limit alarm signal to the PLC controller, and the PLC controller then controls the sound and light alarm to send out sound and light alarm signals to remind the staff to check the equipment; at the same time, the interlock control emergency shut-off valve closes the corresponding hydrogen pipeline to ensure the safety of the hydrogen filling station.

[0036] In addition, after the system is started, each hydrogen sensor at the vent pipe simultaneously monitors the hydrogen concentration in the vent pipe in real time. When there is no venting demand at the hydrogen refueling station, there should be no hydrogen in the vent pipe. The PLC controller determines whether the hydrogen concentration value monitored by the hydrogen sensor is zero when there is no venting demand based on the working status of the hydrogen refueling station. Otherwise, when the value of a hydrogen sensor rises abnormally, it is determined that there is a leakage problem in the pipeline valve corresponding to the hydrogen sensor.

[0037] Although some preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0038] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the inventive concept. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A hydrogen leakage detection system, characterized in that, It includes each vent pipe correspondingly connected between the vent tower and the hydrogen addition / removal equipment, a hydrogen sensor and a check valve respectively arranged in each of the vent pipes, each hydrogen detector respectively used to detect the hydrogen concentration at the hydrogen addition / removal equipment, a combustible gas alarm controller correspondingly communicatively connected to each of the hydrogen detectors, a PLC controller communicatively connected correspondingly to the combustible gas alarm controller and the hydrogen sensor, an audible and visual alarm electrically connected to the PLC controller, and an emergency cut-off valve respectively used to control the on / off of the hydrogen passage of the hydrogen addition / removal equipment and electrically connected to the PLC controller.

2. The hydrogen leakage detection system according to claim 1, characterized in that It further includes a display terminal arranged in the control room and communicatively connected correspondingly to the PLC controller.

3. The hydrogen leakage detection system according to claim 1, wherein The hydrogen addition / removal equipment includes a compressor, a hydrogen storage container, a hydrogen filling machine, and a hydrogen removal column.

4. The hydrogen leakage detection system according to claim 1, wherein The check valve is arranged at the downstream position of the vent pipe corresponding to the hydrogen sensor.

5. The hydrogen leakage detection system according to claim 1, wherein The hydrogen sensor is a pipeline-type hydrogen sensor with a threaded interface at the probe head, and the hydrogen sensor is correspondingly threadedly connected to the vent pipe.

6. The hydrogen leakage detection system according to claim 1, characterized in that, Each of the hydrogen detectors is respectively arranged in the corresponding space range above the hydrogen addition / removal equipment through a bracket.

7. The hydrogen leakage detection system according to claim 1, characterized in that, The hydrogen detector and the combustible gas alarm controller are correspondingly connected by a multi-line system.

8. The hydrogen leakage detection system according to claim 1, wherein The PLC controller and the combustible gas alarm controller correspondingly obtain the low / high limit alarm signal output by the combustible gas alarm controller through electrical connection and obtain the monitoring data of the hydrogen detector through RS485 communication connection.

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