Method and device for detecting hydrogen leakage of hydrogen refueling station and electronic equipment

Abstract

The embodiment of the invention discloses a hydrogen refueling station hydrogen leakage detection method and device and electronic equipment. The method comprises the steps that in response to the fact that the actual flow difference value between upstream and downstream pipelines in the hydrogen refueling station is larger than a flow difference threshold value, flow data of all the pipelines in the hydrogen refueling station after the pipelines are connected into leakage detection branches are detected; and in response to the fact that the flow data corresponding to the first pipeline meets the hydrogen leakage condition, determining a target area, in which the local amplification image corresponding to the first pipeline changes to a target color within a first preset duration, as a hydrogen leakage position. In addition, the method further comprises the step of determining the minimum pipeline path so as to isolate the pipeline section corresponding to the minimum pipeline path. According to the embodiment of the invention, even if the hydrogen leakage amount is small at the initial stage of hydrogen leakage, and no matter where the leakage position is, the leakage pipeline and the specific leakage position can be determined in time, so that the leakage pipeline can be isolated in time at the initial stage of leakage, and potential safety hazards are reduced.

Description

Technical Field

[0001] The embodiments of this specification belong to the field of hydrogen leakage detection in hydrogen refueling stations, and particularly relate to a hydrogen leakage detection method, device, and electronic device for hydrogen refueling stations. Background Art

[0002] Hydrogen is a colorless, odorless, and highly flammable gas at normal temperature and pressure. Since hydrogen molecules are very small, they are easy to leak through tiny pores. To ensure the safety of hydrogen refueling stations, it is necessary to detect hydrogen leakage in hydrogen refueling stations. Currently, generally, hydrogen concentration sensors are installed at fixed positions to detect the hydrogen concentration in the nearby environment and alarm when the concentration exceeds the standard. However, due to the strong diffusion ability and good escape property of hydrogen, the hydrogen concentration may not be maintained during leakage, and it can only be detected when the concentration reaches a very high level. Coupled with the uncertainty of the leakage location, it leads to untimely detection of small hydrogen leaks or at the initial stage of leakage, posing a safety risk. Summary of the Invention

[0003] The embodiments of the present disclosure provide a hydrogen leakage detection method, device, and electronic device for hydrogen refueling stations, aiming to solve one or more of the above problems and other potential problems.

[0004] According to the first aspect of the present disclosure, a hydrogen leakage detection method for a hydrogen refueling station is provided. The method includes detecting the flow rate data of each pipeline in the hydrogen refueling station after connecting to a leakage detection branch in response to the actual flow rate difference between the upstream and downstream pipelines in the hydrogen refueling station being greater than a flow rate difference threshold. The method further includes, in response to the flow rate data corresponding to a first pipeline among the pipelines connected to the leakage detection branch satisfying the hydrogen leakage condition, after reconnecting the first pipeline to the hydrogen refueling station, determining the target area where the local enlarged image corresponding to the first pipeline changes to a target color within a first preset duration as the hydrogen leakage location. The hydrogen leakage condition at least includes that the flow rate data is continuously greater than a first error value within a second preset duration. In addition, the method further includes determining the minimum pipeline path covering all hydrogen leakage locations to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station.

[0005] According to a second aspect of the present disclosure, a hydrogen leakage detection device for a hydrogen refueling station is provided. The device includes a flow data detection module configured to detect the flow data of each pipeline in the hydrogen refueling station after connecting to a leakage detection branch in response to the actual flow difference between the upstream and downstream pipelines in the hydrogen refueling station being greater than a flow difference threshold. The device further includes a leakage location determination module configured to determine, in response to the flow data corresponding to a first pipeline among the pipelines connected to the leakage detection branch satisfying the hydrogen leakage condition, the target area where the partial enlarged image corresponding to the first pipeline changes to a target color within a first preset duration after the first pipeline is connected back to the hydrogen refueling station as the hydrogen leakage location. The hydrogen leakage condition includes at least that the flow data is continuously greater than a first error value within a second preset duration. In addition, the device further includes a pipeline isolation module configured to determine the minimum pipeline path covering all hydrogen leakage locations to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station.

[0006] According to a third aspect of the present disclosure, an electronic device is provided, including one or more processors and a memory associated with the one or more processors. The memory is used to store program instructions, and when the program instructions are read and executed by the one or more processors, the method provided according to the first solution is executed.

[0007] According to a fourth aspect of the present disclosure, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the method provided according to the first aspect is implemented.

[0008] It should be understood that the content described in the summary of the invention section is not intended to limit the key or important features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In combination with the drawings and with reference to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements, where: Figure 1 A schematic diagram showing an example environment in which multiple embodiments of the present disclosure can be implemented; Figure 2 A flowchart showing the process of a hydrogen leakage detection method for a hydrogen refueling station according to some embodiments of the present disclosure; Figure 3 A flowchart showing the complete process of hydrogen leakage detection for a hydrogen refueling station according to some embodiments of the present disclosure; Figure 4 A flowchart showing the CFD simulation process according to some embodiments of the present disclosure; Figure 5The structural schematic diagram of the hydrogen leakage detection device of the hydrogen refueling station according to some embodiments of the present disclosure is shown; Figure 6 The schematic block diagram of the electronic device according to some embodiments of the present disclosure is shown. Detailed implementation manners

[0010] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present specification will be clearly and completely described below in conjunction with the corresponding drawings of the embodiments of the present specification. Apparently, the described embodiments are only a part rather than all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present application.

[0011] The terms "including" and "having" and any variations thereof in the present specification, the claims and the above drawings are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes unlisted steps or units, or optionally further includes other steps or units inherent to these processes, methods, products or devices. Depending on the context, the word "if" as used herein may be interpreted as "when", "while" or "in response to determining" or "in response to detecting".

[0012] As described above, hydrogen is a colorless, odorless, and highly flammable gas at normal temperature and pressure, and it is easy to leak through tiny pores. The explosion limit of hydrogen is that the volume density reaches 4% - 75%, that is, when the volume concentration of hydrogen in the air is between 4% and 75%, it will explode when encountering a fire source. In the prior art, generally, a hydrogen concentration sensor is installed at a fixed position to monitor the hydrogen concentration in the environment near the equipment. When the detected hydrogen concentration exceeds the set threshold and lasts for a period of time, the hydrogen concentration sensor will issue an alarm. However, due to the strong diffusion ability and good escape property of hydrogen, when hydrogen leaks, especially when the leakage hole area is small or in the initial stage of hydrogen leakage, the diffusion of hydrogen is extremely susceptible to environmental factors, resulting in the inability to maintain or continuously increase the hydrogen concentration. In this way, the hydrogen concentration sensor cannot detect the situation of a small amount of hydrogen leakage in the hydrogen refueling station. Even if it is detected, the hydrogen leakage concentration has already accumulated to a certain extent, and it is impossible to respond to the hydrogen leakage situation in time for safety treatment. Once the best treatment time is missed and the hydrogen concentration exceeds 15%, there is a risk of explosion. In addition, when the hydrogen concentration sensor is arranged at a position on the pipeline of the hydrogen refueling station far from the actual leakage position, the hydrogen leakage position is far from the sensing range of the hydrogen concentration sensor, and the possibility of being detected by the hydrogen concentration sensor is lower. Even if it can be detected, the hydrogen has accumulated from a small leakage amount to a large leakage amount, or has transitioned from the initial stage of hydrogen leakage to the later stage of hydrogen leakage. When the hydrogen concentration accumulates and diffuses to a position where the hydrogen concentration sensor can detect it, the best disposal time has been missed, posing a safety hazard.

[0013] In view of this, the embodiments of the present disclosure propose a hydrogen leakage detection solution for a hydrogen refueling station. In the embodiments of the present disclosure, by monitoring the fluctuation of the flow difference between the upstream and downstream pipelines in the pipeline of the hydrogen refueling station, the possible hydrogen leakage situations during the hydrogen refueling process or during the shutdown of the hydrogen refueling station are identified, and the pipelines that may have leaks are respectively connected to specially set leakage detection branches for preliminary leakage localization to locate the pipeline where the leakage is located. So that after the pipeline is connected back to the hydrogen refueling station, the hydrogen leakage position on the pipeline can be determined by determining the area that changes to the target color in the partial enlarged image of the pipeline, and according to the pipeline section that covers each hydrogen leakage position and has the minimum total path, the pipeline section where the leakage occurs can be isolated in a timely manner.

[0014] Through the above method, the leakage condition of the pipeline in the hydrogen refueling station can be preliminarily judged based on the change of the actual flow difference between the upstream and downstream pipelines. After the preliminary judgment that leakage may occur, the flow fluctuation conditions of each pipeline after connecting to the leakage detection branch can be detected respectively by connecting to the leakage detection branch, and then the specific pipeline where the leakage occurs can be further judged according to the flow fluctuation conditions. For the first pipeline judged to have a leakage, the specific leakage location can be determined by determining the target area that changes to the target color over time in the partial enlarged view of the pipeline. In this way, even in the initial stage of hydrogen leakage when the hydrogen leakage amount is small and regardless of the leakage location, the pipeline where the leakage occurs can be determined in time, and there is no need to wait for the hydrogen-sensitive material at the leakage location to completely change to the target color (that is, there is no need to wait until the hydrogen leakage concentration reaches a certain level so that the hydrogen-sensitive material can completely react and change color). The leakage location of hydrogen can be quickly determined by determining the color change conditions of each area in the partial enlarged image, and then the pipeline with leakage can be isolated in time at the best disposal time when hydrogen just starts to leak, minimizing the safety hazards caused by hydrogen leakage.

[0015] Figure 1 FIG. shows a schematic diagram of an exemplary environment 100 in which multiple embodiments of the present disclosure can be implemented. As Figure 1As shown, the environment 100 may include a terminal 110, a hydrogen cylinder 120, a compressor 150, a hydrogen dispenser 160, and a camera 180. The terminal 110 may be any device with computing or processing capabilities. For example, the terminal 110 may include, but is not limited to, a mobile phone, a tablet computer, a desktop computer, a server, etc. Under normal circumstances, the hydrogen in the hydrogen cylinder 120 will be transported to the hydrogen dispenser 160 through a hydrogen pipeline under the negative pressure generated by the compressor 150, enabling the hydrogen dispenser 160 to perform hydrogen refueling. Generally speaking, the hydrogen pipeline between the hydrogen cylinder 120 and the compressor 150 is called the upstream pipeline, and the pipeline between the compressor 150 and the hydrogen dispenser 160 is called the downstream pipeline. The first flowmeter 141 can detect the flow rate of the upstream pipeline, and the second flowmeter 142 can detect the flow rate of the downstream pipeline. Depending on the actual settings of the hydrogen refueling station, the number of upstream and downstream pipelines can be one or more, and the pipelines can be connected in series or in parallel. The terminal can obtain the flow rate collected by the flowmeter through communication connection, calculate the actual flow rate difference 111 between the upstream and downstream pipelines, and compare it with the flow rate difference threshold 112. If the actual flow rate difference 111 is greater than the flow rate difference threshold 112, a branch access instruction 113 is generated to control each pipeline to be connected to the leak detection branch respectively to detect the flow rate data 114 after each pipeline is connected. The leak detection branch may include a test bottle 170 and a third flowmeter 143 for detecting flow rate data. The test bottle 170 can be a small hydrogen cylinder or an empty bottle. The method of connecting the pipeline to the leak detection branch can be achieved by controlling the opening and closing of the pneumatic valves on the pipeline by the terminal 110. For example, the first pneumatic valve 131, the second pneumatic valve 132, and the fourth pneumatic valve 134 can be closed, and the third pneumatic valve 133 can be opened to connect the upstream pipeline to the leak detection branch. Additionally, the first pneumatic valve 131, the second pneumatic valve 132, and the third pneumatic valve 133 can be closed, and the fourth pneumatic valve 134 can be opened to connect the downstream pipeline to the leak detection branch. In a scenario where the overall pipeline structure is more complex, in order to be able to independently distinguish each pipeline for separate detection, pneumatic valves can be added between different pipelines accordingly. After the flow rate data 114 of the first pipeline 116 in each pipeline connected to the leak detection branch by the terminal 110 meets the hydrogen leakage condition 115, the terminal 110 captures a partially enlarged image 117 of the first pipeline 116 through the camera 180, and then determines the target area that changes to the target color within the first preset duration in the partially enlarged image 117 to determine the hydrogen leakage location 118, and generates an isolation instruction 119 to control the corresponding pneumatic valve to close to isolate the pipeline sections covering each hydrogen leakage location 118 and wait for the staff to go for processing.

[0016] Figure 2The flowchart shows the hydrogen leakage detection method 200 of some embodiments of the present disclosure. The method 200 can be executed by the terminal 110, for example. As Figure 2 shown, at block 202, the method 200 can detect the flow rate data of each pipeline in the hydrogen refueling station after connecting to the leakage detection branch in response to the actual flow rate difference between the upstream and downstream pipelines in the hydrogen refueling station being greater than the flow rate difference threshold. In this embodiment, by using the flow meters installed at each pipeline of the hydrogen refueling station, the flow rates of each upstream pipeline and downstream pipeline can be collected respectively, and the actual flow rate difference between the upstream and downstream pipelines can be calculated therefrom. When the hydrogen flow rate in the pipeline does not change significantly and the model and structure of the pipeline do not change, although the flow rate difference between the upstream and downstream pipelines will show certain fluctuations, under normal circumstances, this flow rate difference should not change significantly either and is near a specific value. If the pipeline leaks, some hydrogen will flow out of the pipeline from the leakage point, causing the detectable flow rate in the pipeline to decrease, and thus the actual flow rate difference to increase. Therefore, the flow rate difference threshold can be determined in advance. The flow rate difference threshold can be regarded as the maximum flow rate difference between the upstream and downstream pipelines determined after considering the normal flow rate fluctuation error. Among them, the flow rate difference threshold can be set according to manual experience for different hydrogen flow rates, pipeline models, and pipeline structures. It can also be pre-tested in a test environment for the flow rate difference of the pipeline under different hydrogen flow rates, and the average value of the test data can be used as the flow rate threshold under this condition, etc.

[0017] If the actual flow rate difference is greater than the flow rate difference threshold, it is considered that the pipeline may have leaked. To further determine whether the pipeline has actually leaked and determine the specific location of the leak, each pipeline of the hydrogen refueling station can be connected to the leakage detection branch in sequence to detect the flow rate data of each pipeline after connecting to the leakage detection branch. The process of connecting the pipeline to the leakage detection branch can be regarded as a process of temporarily separating a certain pipeline from the overall pipeline structure and connecting it separately to the leakage detection branch. This process can be specifically realized by controlling the opening and closing of the pneumatic valves installed on each pipeline. There is also a flow meter installed on the leakage detection branch, which is used to detect the flow rate data of the pipeline through the flow meter on the leakage detection branch after a certain pipeline is connected to the leakage detection branch. Among them, the flow rate data can include continuously collected flow rate values, flow rate directions, flow rate curves changing with time, etc.

[0018] At block 204, in response to the flow data corresponding to the first pipeline in each pipeline of the access leakage detection branch satisfying the hydrogen leakage condition, after reconnecting the first pipeline to the hydrogen refueling station, the method 200 may determine the target area where the partial enlarged image corresponding to the first pipeline changes to the target color within the first preset duration as the hydrogen leakage location. The hydrogen leakage condition includes at least that the flow data is continuously greater than the first error value within the second preset duration. In this embodiment, the leakage detection branch may include a test gas cylinder for testing. When the connected pipeline is isolated from other pipelines and there is no negative pressure generated by a compressor in the leakage detection branch, the pipeline and the branch should form a relatively airtight structure, so that when the pipeline is first connected to the leakage detection branch, due to the air pressure difference between the pipeline and the branch, gas will flow briefly. After the pressures on both sides are balanced, the flow data collected by the flowmeter should indicate that the flow tends to zero. Considering the existence of errors, a first error value may be set. If, among the pipelines connected to the leakage detection branch, the flow data corresponding to the first pipeline satisfies the hydrogen leakage condition, that is, the flow data indicates that after connecting to the branch, the flowmeter can still continuously collect a flow greater than the first error value after the pressures on both sides are the same, it means that there is a leakage in the first pipeline, causing the gas in the test gas cylinder to continuously flow to the leakage hole under the negative pressure generated by the leakage hole, and thus the flowmeter keeps collecting a non-zero flow.

[0019] At this time, since the hydrogen leakage is in the initial stage, the amount of hydrogen leakage may be small. Even if the surface of the pipeline is pre-coated with a hydrogen-sensitive material that will change color to the target color after contacting hydrogen, the hydrogen-sensitive material may not change color completely to the target color because the amount of hydrogen in contact reaction is too small. That is, the discolored area generated by the hydrogen-sensitive material contacting hydrogen is not obvious, and the color cannot change to the target color temporarily. In addition, the reaction discoloration of the hydrogen-sensitive material takes time and there is a certain lag. Moreover, the camera used for monitoring normally captures a large-range image covering all pipelines, resulting in a poor detection effect of the traditional detection method that directly determines whether there is leakage and the leakage location based on whether there is an area of the target color in the image, and it is difficult to identify a small and inconspicuous discoloration on a specific area of a specific pipeline. Therefore, in this embodiment, after determining the first pipeline with leakage through the leakage detection branch, the first pipeline will be connected back to the hydrogen refueling station first, and then the camera will be controlled to continuously capture local magnified images of the position where the first pipeline is located, and compare the local magnified images before and after the first preset duration (for example, 20 seconds) to determine the target area where the pixel value in the image changes and the color changes towards the target color (for example, the pixel value changes to the pixel value corresponding to the target color), and determine this target area as the hydrogen leakage location. In this way, even in the initial stage of hydrogen leakage when the hydrogen-sensitive material cannot react and change color completely to the target color over a large area, the hydrogen leakage location can be quickly determined to achieve a rapid response to hydrogen leakage. After determining the hydrogen leakage location, the corresponding staff can be directly sent the hydrogen leakage location and an alarm message can be generated to remind the staff to go to deal with it in time.

[0020] Among them, the reason for determining the hydrogen leakage location after connecting the first pipeline back to the hydrogen refueling station is that the process of judging the hydrogen leakage location needs to wait at least for the first preset duration, and in order to ensure the detection accuracy, the leakage detection branch can only detect one pipeline at a time. If the hydrogen leakage location is directly determined in the leakage detection branch, the leakage detection efficiency of the overall pipeline will be significantly affected. In other embodiments, if the number of pipelines in the hydrogen refueling station is small, it is also possible to directly determine the hydrogen leakage location in the state of connecting the leakage detection branch.

[0021] At block 206, method 200 may determine a minimum pipeline path that covers all hydrogen leakage locations to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station. In this embodiment, since there may be multiple hydrogen leakage locations, the minimum path among the pipeline paths that connect and cover all hydrogen leakage locations will be determined to overall isolate the pipeline section composed of each pipeline corresponding to the minimum pipeline path. The reason for overall isolating the pipeline section instead of separately isolating each pipeline with hydrogen leakage is that the hydrogen used in the hydrogen refueling station is generally high-pressure hydrogen, and pipeline structure damage may occur when the pipeline leaks. Compared with isolating a shorter local section, isolating a longer overall section is more likely to cause a significant pressure fluctuation, resulting in a chain reaction of successive ruptures at other weak points. Therefore, the method of isolating the entire section is used to improve the safety of isolation. The isolation process can be achieved by closing the pneumatic valves corresponding to the pipeline section.

[0022] In this way, through the flow rates of each pipeline that are originally collected during the normal hydrogen transportation process, the upstream and downstream flow rate differences can be calculated to preliminarily judge the hydrogen leakage situation. When it is judged that there may be a leakage, each pipeline will be actively connected to the leakage detection branch for investigation in a timely manner to determine the pipeline with leakage and the hydrogen leakage location on the pipeline, and isolate the corresponding pipeline section in the hydrogen refueling station, so that the hydrogen leakage problem may be discovered and solved in the initial stage, avoiding the need for a relatively high hydrogen leakage concentration to detect the leakage problem, and reducing potential safety hazards. This improves the automatic safety prevention and control capabilities of the hydrogen refueling station during the hydrogen refueling process and during the shutdown of the hydrogen refueling station. Moreover, after some pipelines are isolated, the hydrogen refueling station may still be able to carry out hydrogen refueling normally (even if refueling cannot be carried out after isolation, the leakage can be repaired as soon as possible with the intervention of maintenance personnel to ensure that the hydrogen refueling station resumes normal operation as soon as possible). This not only reduces the operation and maintenance costs and safety risks, but also improves the utilization rate of the hydrogen refueling station.

[0023] Figure 3 The flowchart shows the complete process 300 of hydrogen leakage detection in a hydrogen refueling station according to some embodiments of the present disclosure. In process 300, by combining the hydrogen flow rate 311 with the model and structure of the pipeline, the standard flow rate difference 312 between the upstream and downstream pipelines can be queried in the pre-set database corresponding to the pipeline. Considering that in actual situations, changes in pipeline pressure 313 and hydrogen temperature 314 will both have a certain impact on the flow rate difference, the standard flow rate difference 312 will first be corrected according to the pipeline pressure 313 and hydrogen temperature 314, and then the corrected difference will be used as the flow rate difference threshold 315 to compare and judge the actual flow rate difference according to the flow rate difference threshold 315.

[0024] As an example, the process of correcting the standard flow rate difference 312 may be: Calculating Gas Density Based on the Equation of State of Gases The formula is as follows: Wherein, is the pressure, is the temperature, is the molar mass of the gas, is the gas constant, is the compressibility factor.

[0025] The flow rate of the gas is inversely proportional to the density, and the change in the compressibility factor can be ignored. Therefore, the calculation equation for the corrected standard flow rate difference (i.e., the flow rate difference threshold ) can be: Wherein, is the standard flow rate difference, is the standard pressure corresponding to the standard flow rate difference, is the standard temperature corresponding to the standard flow rate difference, is the actual pressure, is the actual temperature, is the standard compressibility factor, is the actual compressibility factor.

[0026] In block 320, it will be determined whether the actual flow rate difference is greater than the flow rate difference threshold. If it is greater, it is considered that there is a risk of pipeline leakage and further verification is required. In block 331, among all the pipelines in the hydrogen refueling station, the second pipelines that have not been subjected to leakage detection during the current detection period will be determined and connected to the leakage detection branch respectively. Among them, the actual flow rate difference may also exceed the flow rate difference threshold due to the instantaneous fluctuation of the data collected by the flow meter, that is, misjudgment may occur. In order to avoid frequent adjustment of the pipeline affecting the normal hydrogen transportation, the detection period can be set in advance. For the pipelines that have been detected during the detection period, it is considered that no abnormality will occur in the short term and the pipeline will not be detected again during the current detection period. The length of the detection period can be set according to actual needs. For example, if it is desired to detect abnormalities as early as possible, the detection period can be set shorter, while if it is desired not to have too much impact on the normal operation of the pipeline, the detection period can be set longer. For any second pipeline, after it is connected to the leakage detection branch, the terminal will control the pneumatic valve on the leakage detection branch to open, so that the second pipeline is connected to the leakage detection branch. At this time, due to the pressure difference between the second pipeline and the leakage detection branch, the gas will flow briefly. In order to avoid misjudging the gas flow at this time as the gas flow caused by leakage, it will first wait until the pressure difference between the leakage detection branch and the second pipeline is less than the error value, that is, the pressure difference between the two approaches zero, and then detect the flow rate data 332 of the second pipeline.

[0027] In box 340, in each pipeline that accesses the leakage detection branch from the hydrogen refueling station (if only the second pipeline is accessed, from each second pipeline), it is determined whether there is a first pipeline, that is, a pipeline where the flow data 332 satisfies the hydrogen leakage condition. If the pipeline leaks, a non-zero (or higher than the first error value) flow value will be continuously detected in the flow data, and since the gas will flow towards the leakage hole, the direction of the flow will be from the leakage detection branch to the first pipeline. The pipeline that meets the above conditions will be determined as the first pipeline. In other embodiments, a branch leakage condition can also be set. The branch leakage condition can include the continuous presence of flow and the flow direction being from the pipeline to the leakage detection branch. Meeting this condition indicates that the leakage detection branch itself has leaked and corresponding processing is also required. After determining the first pipeline, the acquisition image collected by the camera and containing the first pipeline will be determined, and then the first pipeline in the acquisition image will be magnified to obtain a partial magnified image 350 whose picture exactly completely covers the circumscribed rectangle of the first pipeline. As an example, the conventional shooting angle of the camera does not change, and the structure and position of the pipeline generally do not change either. Therefore, different pipelines can be distinguished by pre-labeling different pipelines in the image in advance, and then the required first pipeline can be quickly determined from the acquisition image according to the label to quickly determine the position of the partial magnified image 350. Since the partial magnified image 350 is locally magnified for a specific area, it is easier to identify the area with the target color that cannot be recognized in the acquisition image.

[0028] In the initial stage of hydrogen leakage, due to the low hydrogen leakage concentration, the actually discolored area on the pipeline surface is small, or the discolored color is light and the discoloration is not obvious, making it difficult to directly identify the area with the target color. At this time, the partial magnified images 350 before and after the first preset time period can be compared to determine the target area in the image where the pixel value has changed significantly (that is, the pixel change value is greater than the preset change value) over time and the pixel value is approaching the pixel value corresponding to the target color. The target area is used as the hydrogen leakage position to quickly determine the leakage position before the pipeline surface is completely discolored to the target color. In addition, it is possible that multiple target areas are misidentified as the hydrogen leakage position. At this time, the average leakage flow 361 within the preset time period can be calculated through the flow data 332, and the leakage hole area of the first pipeline can be calculated based on the average leakage flow 361, the pressure upstream of the leakage point 362 (that is, the pressure at the position of the test gas cylinder of the leakage detection branch), and the hydrogen adiabatic index 363.

[0029] As an example, the process of hydrogen leaking from the pipeline to the atmosphere can be basically regarded as critical flow, and the formula for the leakage process is as follows: Wherein, is the average leakage flow rate, is the discharge coefficient (depending on the orifice shape of the leakage hole), is the area of the leakage hole, is the pressure upstream of the leakage hole, is the hydrogen gas constant, is the hydrogen temperature.

[0030] After determining the area of the leakage hole, the deviation value between the area of the region and the area of the leakage hole is minimized, that is, the region that best matches the area of the leakage hole is used as the finally determined hydrogen leakage position 360. In block 370, the pipeline section will be isolated according to the hydrogen leakage position 360.

[0031] In addition, in block 380, to prevent a large - area burst of the pipeline directly resulting in a rapid and large - scale leakage of hydrogen in special cases, hydrogen concentration sensors can still be set to detect the hydrogen leakage concentration outside the pipeline. Under normal circumstances, the leaking pipeline will be isolated in time, making it impossible for the hydrogen concentration sensor to detect a sufficient concentration. In specific cases, due to the rapid and large - scale leakage of hydrogen, the hydrogen concentration sensor can still detect that the hydrogen leakage concentration is greater than the preset safety concentration. At this time, it is considered that there is a greater safety risk in the pipeline. To ensure the safety of the maintenance personnel going to the repair site and to avoid an explosion before the arrival of the maintenance personnel, the pipeline section can be simulated by means of CFD gas cloud simulation 381 to obtain the simulation results. The simulation results can be a constructed three - dimensional model. In the model, in addition to the pipeline section, there are particles distributed around the pipeline section to represent hydrogen. According to the range of particle distribution, the range of hydrogen leakage can be determined, and then a series of control instructions are generated and sent to the nitrogen explosion suppression system of the hydrogen refueling station to perform linkage control on the nitrogen explosion suppression system. Specifically, the control instructions can include a nitrogen injection instruction 382 to control the corresponding nitrogen nozzles that can cover the hydrogen leakage range, so that the nitrogen nozzles inject nitrogen into the determined leakage range to reduce the concentration of hydrogen in the air and reduce the risk of explosion.

[0032] Figure 4A flowchart of the CFD simulation process 400 of some embodiments of the present disclosure is shown. In process 400, according to the determined hydrogen leakage location 410, combined with the pipeline design parameters (such as diameter, length, orientation, etc.) that can be queried, a pipeline geometric model 421 of the leaking pipeline is first constructed in the CFD gas cloud simulation model 420, and the shape (default to circular if the shape cannot be confirmed) and area of the leakage hole are defined. Next, the pipeline geometric model 421 can be meshed 422. The meshing 422 can include using denser meshes near the leakage hole and in key areas (such as the pipeline wall, around obstacles) to improve the resolution, and setting boundary layer meshes near the pipeline wall to capture the viscous effect of the gas on the wall. At the same time, a physical model 423 is also constructed in the CFD gas cloud simulation model 420. The physical model 423 can include a turbulence model (such as the Large Eddy Simulation (LES) model) for simulating hydrogen diffusion accompanied by turbulence, and a multi-component transport model (such as the Fluent model) for defining the mixing process of hydrogen and air, and boundary conditions 424 are set for the physical model 423. The boundary conditions 424 can include pressure and flow velocity boundary conditions set according to the actual working conditions, setting the leakage hole as a velocity inlet, setting environmental boundaries, etc. In block 425, the leakage source parameters can be set, and the parameters mainly include the leakage hole area and the leakage mass flow rate, and all these data can be obtained in the foregoing process. Finally, the CFD gas cloud simulation model 420 can set pressure-velocity coupling through a solver to select the SIMPLE or PISO algorithm for solution, and finally output the simulation result 430. The above process can be directly implemented using CFD simulation software such as ANSYS Fluent, COMSOL Multiphysics, OpenFOAM, etc.

[0033] Figure 5 A schematic structural diagram of a hydrogen leakage detection device 500 for a hydrogen refueling station according to some embodiments of the present disclosure is shown. Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the method embodiment. As Figure 5As shown, the device 500 includes a flow data detection module 501, which is configured to detect the flow data of each pipeline in the hydrogen refueling station after connecting to the leakage detection branch respectively in response to the actual flow difference between the upstream and downstream pipelines in the hydrogen refueling station being greater than the flow difference threshold. The device also includes a leakage location determination module 502, which is configured to determine, in response to the flow data corresponding to the first pipeline among the pipelines connected to the leakage detection branch satisfying the hydrogen leakage condition, after reconnecting the first pipeline to the hydrogen refueling station, the target area where the partial enlarged image corresponding to the first pipeline changes to the target color within the first preset duration as the hydrogen leakage location. The hydrogen leakage condition includes at least that the flow data is continuously greater than the first error value within the second preset duration. In addition, the device further includes a pipeline isolation module 503, which is configured to determine the minimum pipeline path covering all hydrogen leakage locations, so as to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station.

[0034] The device 500 further includes a first determination module, which is configured to determine the standard flow difference between the upstream and downstream pipelines in the hydrogen refueling station based on the hydrogen flow rate. In addition, the device 500 further includes a flow difference correction module, which is configured to correct the standard flow difference based on the pipeline pressure and ambient temperature at the current moment to obtain the flow difference threshold.

[0035] The flow data detection module 501 includes a pipeline selection unit, which is configured to respectively select a second pipeline that has not been subjected to leakage detection during the current detection period among the pipelines in the hydrogen refueling station, and connect the second pipeline to the leakage detection branch. The leakage detection branch can connect at most one second pipeline at the same time. The flow data detection module 501 further includes a flow data detection unit, which is configured to detect the flow data of the second pipeline after the second pipeline is connected to the leakage detection branch and the pressure difference between the leakage detection branch and the second pipeline is less than the error value.

[0036] In the device 500, the hydrogen leakage condition includes that the flow data is continuously greater than the first error value within the second preset duration, and the flow direction is from the leakage detection branch to the pipeline.

[0037] The leakage location determination module 502 includes an image determination unit, which is configured to determine the partial enlarged image corresponding to the first pipeline based on the acquired image including the first pipeline. The size of the partial enlarged image matches the circumscribed rectangle of the first pipeline. The leakage location determination module 502 further includes a first determination unit, which is configured to compare the partial enlarged images before and after the first preset duration, and determine the target area where the pixel change value in the partial enlarged image is greater than the preset change value and the changed pixel value is closer to the pixel value of the target color as the hydrogen leakage location.

[0038] The device 500 further includes a calculation module configured to calculate the average leakage flow rate within a preset duration based on the flow rate data. The device 500 further includes a second calculation module configured to calculate the leakage hole area of the first pipeline based on the average leakage flow rate, the pressure upstream of the leakage point, and the hydrogen adiabatic index. In addition, the leakage position determination module 502 further includes a second determination unit configured to determine a target area in the partial enlarged image where the pixel change value is greater than a preset change value and the pixel value after the change is closer to the pixel value of the target color. In response to the existence of multiple target areas, the target area with the smallest deviation value between the area of the region and the leakage hole area is determined as the hydrogen leakage position.

[0039] The device 500 further includes a simulation module configured to perform a CFD gas cloud simulation on the first pipeline based on the hydrogen leakage position in response to the hydrogen leakage concentration being greater than a preset safety concentration. The device 500 further includes a nitrogen injection module configured to generate a nitrogen injection instruction based on the simulation result to control the nitrogen nozzle to inject nitrogen towards the hydrogen leakage position.

[0040] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this specification are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a Digital Versatile Disc (DVD)), or a semiconductor medium (such as a Solid State Disk (SSD)), etc.

[0041] Figure 6 The block diagram of an electronic device 600 that can implement multiple embodiments of the present disclosure is shown. As Figure 6As shown, the electronic device 600 includes a processor 610, a disk drive 620, an input / output interface 630, a network interface 640, and a memory 650. The above-mentioned processor 610, disk drive 620, input / output interface 630, network interface 640, and the memory 650 can be communicatively connected via a communication bus 660.

[0042] Among them, the processor 610 can be implemented in the form of a general-purpose CPU, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided in this application.

[0043] The memory 650 can be implemented in the form of a ROM (Read Only Memory), a RAM (Read Access Memory), a static memory, a dynamic storage device, etc. The memory 650 can store an operating system 651 for controlling the operation of the electronic device 600, and a basic input / output system (BIOS) 652 for controlling the low-level operations of the electronic device 600. In addition, a web browser 653, a data storage management system 654, etc. can also be stored. In short, when implementing the technical solutions provided in this application through software or firmware, the relevant program codes are stored in the memory 650 and are called and executed by the processor 610.

[0044] The input / output interface 630 is used to connect to an input / output module to achieve information input and output. The input / output module can be configured as a component in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Among them, the input devices can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output devices can include a display, a speaker, a vibrator, a warning light, etc.

[0045] The network interface 640 is used to connect to a communication module (not shown in the figure) to achieve communication interaction between the device and other devices. Among them, the communication module can achieve communication through a wired method (such as USB, network cable, etc.) or through a wireless method (such as a mobile network, WIFI, Bluetooth, etc.).

[0046] The bus 660 includes a path for transmitting information between various components of the device (such as the processor 610, disk drive 620, input / output interface 630, network interface 640, and the memory 650).

[0047] It should be noted that although the above device only shows the processor 610, disk drive 620, input / input interface 630, network interface 640, and memory 650, bus 660, etc., in the specific implementation process, the device may also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device may only include the components necessary to implement the method of the present application, and does not necessarily include all the components shown in the figure.

[0048] The program code for implementing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to the processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the machine, partially on the machine, as an independent software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0049] In the context of the present disclosure, a machine-readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In addition, although the operations are depicted in a particular order, this should be understood to require that the operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present disclosure. Certain features described in the context of separate embodiments can also be implemented combinatorially in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations.

[0050] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. On the contrary, the specific features and acts described above are merely example forms of implementing the claims.

Claims

1. A method for detecting hydrogen leakage in a hydrogen refueling station, characterized in that, The method includes: In response to the actual flow rate difference between the upstream and downstream pipelines in the hydrogen refueling station being greater than the flow rate difference threshold, respectively detecting the flow rate data of each pipeline in the hydrogen refueling station after connecting to the leakage detection branch; In response to the flow rate data corresponding to the first pipeline among the pipelines connected to the leakage detection branch satisfying the hydrogen leakage condition, after reconnecting the first pipeline to the hydrogen refueling station, determining the target area where the partial enlarged image corresponding to the first pipeline changes to the target color within the first preset duration as the hydrogen leakage position, where the hydrogen leakage condition at least includes that the flow rate data is continuously greater than the first error value within the second preset duration; and Determining the minimum pipeline path covering all the hydrogen leakage positions to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station.

2. The method according to claim 1, wherein The method further includes: Based on the hydrogen flow rate, determining the standard flow rate difference between the upstream and downstream pipelines in the hydrogen refueling station; and Based on the pipeline pressure and hydrogen temperature at the current moment, correcting the standard flow rate difference and using it as the flow rate difference threshold.

3. The method according to claim 1 or 2, characterized in that, The step of respectively detecting the flow rate data of each pipeline in the hydrogen refueling station after connecting to the leakage detection branch includes: Among the pipelines in the hydrogen refueling station, respectively selecting a second pipeline that has not undergone leakage detection in the current detection period, and connecting the second pipeline to the leakage detection branch, where the leakage detection branch can connect at most one second pipeline at the same time; and After the second pipeline is connected to the leakage detection branch and the pressure difference between the leakage detection branch and the second pipeline is less than the second error value, detecting the flow rate data of the second pipeline.

4. The method according to claim 1, characterized in that, The hydrogen leakage condition includes that the flow rate data is continuously greater than the first error value within the second preset duration and the flow direction is from the leakage detection branch to the pipeline.

5. The method according to claim 1 or 4, characterized in that The step of determining the target area where the partial enlarged image corresponding to the first pipeline changes to the target color within the first preset duration as the hydrogen leakage position includes: Based on the acquired image including the first pipeline, determining the partial enlarged image corresponding to the first pipeline, where the size of the partial enlarged image matches the circumscribed rectangle of the first pipeline; and Comparing the partial enlarged images before and after the first preset duration, and determining the target area where the pixel change value in the partial enlarged image is greater than the preset change value and the changed pixel value is closer to the pixel value of the target color as the hydrogen leakage position.

6. The method according to claim 5, wherein The method further includes: Based on the flow rate data, calculating the average leakage flow rate within the preset duration; Based on the average leakage flow rate, the upstream pressure at the leakage point, and the hydrogen adiabatic index, calculating the leakage hole area of the first pipeline; The step of determining the target area where the pixel change value in the partial enlarged image is greater than the preset change value and the changed pixel value is closer to the pixel value of the target color as the hydrogen leakage position includes: Determining the target area where the pixel change value in the partial enlarged image is greater than the preset change value and the changed pixel value is closer to the pixel value of the target color; and In response to the existence of multiple target regions, the target region with the smallest deviation value between the region area and the leakage hole area is determined as the hydrogen leakage position.

7. The method according to claim 1, characterized in that, The method further includes: In response to the hydrogen leakage concentration being greater than a preset safety concentration, performing CFD gas cloud simulation on the pipeline section based on the hydrogen leakage position; and Based on the simulation results, generating a nitrogen injection instruction to control the nitrogen nozzle to inject nitrogen towards the hydrogen leakage position.

8. A hydrogen leakage detection device for a hydrogen refueling station, characterized in that, The device includes: A flow data detection module configured to, in response to the actual flow difference between the upstream and downstream pipelines in a hydrogen refueling station being greater than a flow difference threshold, detect the flow data of each pipeline in the hydrogen refueling station after connecting to a leakage detection branch respectively; A leakage position determination module configured to, in response to the flow data corresponding to a first pipeline among the pipelines connected to the leakage detection branch satisfying the hydrogen leakage condition, after the first pipeline is connected back to the hydrogen refueling station, determine the target region where the locally enlarged image corresponding to the first pipeline changes to a target color within a first preset duration as the hydrogen leakage position, where the hydrogen leakage condition at least includes that the flow data is continuously greater than a first error value within a second preset duration; and A pipeline isolation module configured to determine the smallest pipeline path covering all the hydrogen leakage positions to isolate the pipeline section corresponding to the smallest pipeline path in the hydrogen refueling station.

9. An electronic device, including: One or more processors, and A memory associated with the one or more processors, where the memory is used to store program instructions, and the program instructions, when read and executed by the one or more processors, execute the steps of the method according to any one of claims 1 - 7.

10. A computer program product, including a computer program, where the computer program, when executed by a processor, implements the method according to any one of claims 1 - 7.

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