A method, device and electronic equipment for detecting hydrogen leakage in a hydrogen refueling station

Abstract

The embodiments of this specification disclose a method, device and electronic device for detecting hydrogen leaks in a hydrogen refueling station. The method includes, 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, detecting the flow data of each pipeline in the hydrogen refueling station after connecting to the leakage detection branch. The method also includes, in response to the existence of flow data corresponding to the first pipeline meeting the hydrogen leakage condition, determining the target area of ​​the local enlarged image corresponding to the first pipeline, which changes to the target color within a first preset time period, as the hydrogen leakage location. In addition, the method also includes determining the minimum pipeline path to isolate the pipeline section corresponding to the minimum pipeline path. In the embodiments of this specification, even if the hydrogen leakage amount is small in the early stage of hydrogen leakage, and no matter where the leakage occurs, the leaking pipeline and the specific location of the leakage can be determined in time, and the leaking pipeline can be isolated in time at the early stage of leakage to reduce safety hazards.

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 method, device, and electronic equipment for hydrogen leakage detection in hydrogen refueling stations. Background Art

[0002] Hydrogen is a colorless, odorless, and highly flammable gas at room temperature and pressure. Because hydrogen molecules are very small, they can easily leak out through tiny pores. To ensure the safety of hydrogen refueling stations, hydrogen leak detection is required. Currently, this is generally done by installing hydrogen concentration sensors in fixed locations to detect the hydrogen concentration in the surrounding environment and alarm when the concentration exceeds the standard. However, due to the strong diffusion ability and good evasion of hydrogen, the hydrogen concentration may not be maintained during leakage and can only be detected when the concentration reaches a very high level. Coupled with the uncertainty of the leak location, small amounts of hydrogen leaks or early leaks are not detected in a timely manner, posing a safety risk. Summary of the Invention

[0003] Embodiments of the present disclosure provide a method, device, and electronic device for detecting hydrogen leaks in a hydrogen refueling station, aiming to solve one or more of the above-mentioned problems and other potential problems.

[0004] According to the first aspect of the present disclosure, a method for detecting hydrogen leaks in a hydrogen refueling station is provided. The method includes, 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, detecting the flow data of each pipeline in the hydrogen refueling station after it is connected to the leakage detection branch. The method also includes, in response to the flow data corresponding to the first pipeline in each pipeline connected to the leakage detection branch meeting the hydrogen leakage condition, determining the target area of ​​the local enlarged image corresponding to the first pipeline that changes to the target color within a first preset time period as the hydrogen leakage location after the first pipeline is connected back to the hydrogen refueling station, the hydrogen leakage condition at least includes the flow data being continuously greater than a first error value within a second preset time period. In addition, the method also includes determining the minimum pipeline path covering all hydrogen leakage locations to isolate the pipeline section corresponding to the minimum pipeline path within the hydrogen refueling station.

[0005] According to the second aspect of the present disclosure, a hydrogen leak detection device for a hydrogen refueling station is provided. The device includes a flow data detection module, which is configured to detect the flow data of each pipeline in the hydrogen refueling station after it is connected to the leakage detection branch 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, which is configured to detect the flow data of each pipeline in the hydrogen refueling station after it is connected to the leakage detection branch in response to the flow data corresponding to the first pipeline in each pipeline connected to the leakage detection branch meeting the hydrogen leakage condition. After the first pipeline is connected back to the hydrogen refueling station, the target area of ​​the local enlarged image corresponding to the first pipeline that changes to the target color within a first preset time period is determined as the hydrogen leakage location. The hydrogen leakage condition at least includes that the flow data is continuously greater than the first error value within a second preset time period. In addition, the device also includes a pipeline isolation module, 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 within the hydrogen refueling station.

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

[0007] According to a fourth aspect of the present disclosure, a computer program product is provided, comprising a computer program, wherein 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 contents described in the Summary of the Invention section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0010] Figure 1 A schematic diagram illustrating an example environment in which various embodiments of the present disclosure may be implemented;

[0011] Figure 2 A schematic flow chart showing a method for detecting hydrogen leaks in a hydrogen refueling station according to some embodiments of the present disclosure is shown;

[0012] Figure 3 A schematic flow chart showing the complete process of hydrogen leak detection at a hydrogen refueling station according to some embodiments of the present disclosure;

[0013] Figure 4A schematic diagram showing a flow chart of a CFD simulation process according to some embodiments of the present disclosure is shown;

[0014] Figure 5 A schematic structural diagram of a hydrogen leakage detection device for a hydrogen refueling station according to some embodiments of the present disclosure is shown;

[0015] Figure 6 A schematic block diagram of an electronic device according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0016] To make the purpose, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0017] The terms "including" and "having" and any variations thereof in this specification and claims and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or apparatuses. Depending on the context, the word "if" as used herein may be interpreted as "at..." or "when..." or "in response to determining" or "in response to detecting".

[0018] As previously mentioned, hydrogen is a colorless, odorless, and highly flammable gas at room temperature and pressure, easily leaking through tiny pores. Its explosion limit is a volume density of 4%-75%. This means that when the volume concentration of hydrogen in air is between 4% and 75%, it will explode when exposed to a fire source. In the prior art, hydrogen concentration sensors are typically installed in fixed locations to monitor the hydrogen concentration in the environment near the equipment. When the detected hydrogen concentration exceeds a set threshold and remains constant for a period of time, the sensor issues an alarm. However, due to its strong diffusion capacity and good evasion properties, hydrogen leakage, especially when the leak hole is small or in the early stages of a leak, is highly susceptible to environmental factors, causing the hydrogen concentration to fail to maintain or to continue to rise. Consequently, hydrogen concentration sensors are unable to detect even small hydrogen leaks within hydrogen refueling stations. Even if they do detect a leak, the hydrogen concentration has already accumulated, making it impossible to respond promptly and implement safe treatment. Once the optimal treatment time is missed and the hydrogen concentration exceeds 15%, there is a risk of explosion. In addition, when the position of the hydrogen concentration sensor arranged on the pipeline of the hydrogen refueling station is far away from the actual leakage location, the hydrogen leakage location is far away 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 to a large leakage, or has transitioned from the early stage of hydrogen leakage to the late stage of hydrogen leakage. When the hydrogen concentration accumulates and diffuses to the position where the hydrogen concentration sensor can be detected, the optimal disposal time has been missed, and there is a safety hazard.

[0019] To address this issue, embodiments of the present disclosure propose a hydrogen leak detection solution for hydrogen refueling stations. In these embodiments, by monitoring the fluctuations in the flow rate difference between upstream and downstream pipelines in the hydrogen refueling station pipeline, possible hydrogen leaks at the hydrogen refueling station during the hydrogenation process or during station outages are identified. Pipelines with potential leaks are connected to a specially designed leak detection branch for preliminary leak location. Once the pipeline is connected back to the hydrogen refueling station, the location of the hydrogen leak can be determined by identifying the area in the locally enlarged image of the pipeline that changes color toward the target. Leaking pipeline sections can then be isolated promptly based on the pipeline section that covers each hydrogen leak location and has the smallest total path.

[0020] Through the above method, a preliminary judgment can be made on the leakage of the hydrogen station pipeline by the change in the actual flow difference between the upstream and downstream pipelines. After the preliminary judgment is made that a leak may occur, the flow fluctuation of each pipeline after the connection is detected by connecting to the branch by connecting the leak detection branch. Then, based on the flow fluctuation, the specific pipeline where the leak occurs can be further determined. For the first pipeline determined to have a leak, the specific location of the leak can be determined by identifying the target area that changes to the target color over time in the partial enlarged image of the pipeline. In this way, even in the early stages of a hydrogen leak, when the hydrogen leakage amount is small, and regardless of the location of the leak, the leaking pipeline can be promptly determined. There is no need to wait for the hydrogen-sensitive material at the leak 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 for the hydrogen-sensitive material to fully react and change color). The location of the hydrogen leak can be quickly determined by determining the color change of each area in the partial enlarged image. The leaking pipeline can then be isolated in a timely manner at the optimal time when the hydrogen leak just begins, thereby minimizing the safety hazards caused by the hydrogen leak.

[0021] Figure 1 1 is a schematic diagram of an example environment 100 in which various embodiments of the present disclosure may be implemented. Figure 1As shown, environment 100 may include a terminal 110, a hydrogen cylinder 120, a compressor 150, a hydrogen dispenser 160, and a camera 180. Terminal 110 may be any device with computing or processing capabilities. For example, 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 hydrogen cylinder 120 is transported to hydrogen dispenser 160 through a hydrogen pipeline under the negative pressure generated by compressor 150, allowing hydrogen dispenser 160 to refill the hydrogen. Generally speaking, the hydrogen pipeline between hydrogen cylinder 120 and compressor 150 is referred to as the upstream pipeline, and the pipeline between compressor 150 and hydrogen dispenser 160 is referred to as the downstream pipeline. A first flowmeter 141 can detect the flow rate of the upstream pipeline, and a second flowmeter 142 can detect the flow rate of the downstream pipeline. Depending on the actual configuration of the hydrogen refueling station, the number of upstream and downstream pipelines may be one or more, and the pipelines may be connected in series or in parallel. The terminal can obtain the flow rate collected by the flow meter through a communication connection, calculate the actual flow difference 111 between the upstream and downstream pipelines, and compare it with the flow difference threshold 112. If the actual flow difference 111 is greater than the flow difference threshold 112, a branch connection instruction 113 is generated to control each pipeline to connect to the leak detection branch to detect the flow data of each pipeline after connection 114. The leak detection branch can include a test bottle 170 and a third flow meter 143 for detecting flow data. The test bottle 170 can be a small hydrogen bottle or an empty bottle. The method of connecting the pipeline to the leakage detection branch can be achieved by controlling the opening and closing of the pneumatic valves on the pipeline through 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 leakage detection branch. The first pneumatic valve 131, the second pneumatic valve 132, and the third pneumatic valve 133 can also be closed, and the fourth pneumatic valve 134 can be opened to connect the downstream pipeline to the leakage detection branch. In scenarios 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 terminal 110 finds that the flow data 114 of the first pipeline 116 in each pipeline connected to the leakage detection branch meets the hydrogen leakage condition 115, the terminal 110 collects a local 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 a first preset time period in the local enlarged image 117 to determine the hydrogen leakage location 118, and generates an isolation instruction 119 to control the corresponding pneumatic valve to close, so as to isolate the pipeline section covering each hydrogen leakage location 118 and wait for staff to go and handle it.

[0022] Figure 21 shows a flow chart of a hydrogen refueling station hydrogen leak detection method 200 according to some embodiments of the present disclosure. The method 200 may be executed by the terminal 110, for example. Figure 2 As shown, at block 202, method 200 may detect flow data for each pipeline within the hydrogen refueling station after it is connected to the leak detection branch in response to the actual flow difference between the upstream and downstream pipelines within the hydrogen refueling station being greater than a flow difference threshold. In this embodiment, flow meters installed at each pipeline in the hydrogen refueling station can collect the flow rates of each upstream and downstream pipeline, and use this to calculate the actual flow difference between the upstream and downstream pipelines. If the hydrogen flow rate within the pipeline does not change significantly, and the pipeline model and structure do not change, the flow difference between the upstream and downstream pipelines will fluctuate to some extent. However, under normal circumstances, this flow difference should not change significantly and remain around a specific value. If a pipeline leaks, some hydrogen will flow out of the pipeline from the leak, reducing the detectable flow rate in the pipeline and increasing the actual flow difference. Therefore, a flow difference threshold can be predetermined. The flow difference threshold can be considered as the maximum flow difference between the upstream and downstream pipelines after accounting for normal flow fluctuation errors. Among them, the flow difference threshold can be set according to manual experience for different hydrogen flow rates, pipeline models and pipeline structures. The flow difference of the pipeline at different hydrogen flow rates can also be tested in advance in a test environment, and the average value of the test data can be used as the flow threshold under this condition.

[0023] If the actual flow difference is greater than the flow difference threshold, it is considered that the pipeline may have leaked. In order to further determine whether the pipeline has actually leaked and to determine the specific location of the leak, each pipeline of the hydrogen station can be connected to the leak detection branch in turn to detect the flow data of each pipeline after it is connected to the leak detection branch. The process of connecting a pipeline to the leak detection branch can be regarded as a process of temporarily separating a pipeline from the overall pipeline structure and connecting it to the leak detection branch alone. This process can be achieved by controlling the opening and closing of the pneumatic valves provided on each pipeline. A flow meter is also provided on the leak detection branch, which is used to detect the flow data of a pipeline through the flow meter of the leak detection branch after a pipeline is connected to the leak detection branch. Among them, the flow data may include the continuously collected flow value, the direction of the flow, the flow curve that changes with time, etc.

[0024] At block 204, method 200 may, in response to flow data corresponding to a first pipeline among the pipelines connected to the leak detection branch meeting a hydrogen leak condition, determine, after the first pipeline is connected back to the hydrogen refueling station, a target area of ​​the partially enlarged image corresponding to the first pipeline that changes to a target color within a first preset time period as a hydrogen leak location. The hydrogen leak condition includes at least flow data continuously exceeding a first error value for a second preset time period. In this embodiment, the leak 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 within the leak detection branch, the pipeline and branch should form a relatively sealed structure. This ensures that gas flow only briefly occurs in the connected pipeline when it is first connected to the leak detection branch due to the pressure difference between the pipeline and the branch. After the pressures on both sides reach equilibrium, the flow data collected by the flow meter should indicate that the flow rate approaches zero. Taking into account the existence of errors, a first error value can be set. If, among the pipelines connected to the leak detection branch, the flow data corresponding to the first pipeline meets the hydrogen leakage condition, that is, the flow data represents that after the branch is connected, the flow meter can still continue to collect a flow greater than the first error value after the pressures of both sides are consistent, then it means that there is a leak in the first pipeline, causing the gas in the test gas cylinder to continue to flow toward the leak hole under the action of the negative pressure generated by the leak hole, thereby allowing the flow meter to continue to collect a non-zero flow.

[0025] At this time, since the hydrogen leakage is in the early stages, the amount of hydrogen leakage may be small. Even if the surface of the pipeline is pre-coated with a hydrogen-sensitive material that changes color to the target color after contact with hydrogen, the hydrogen-sensitive material cannot completely change color to the target color because the amount of hydrogen reacted is too small. That is, the color change area produced by the hydrogen-sensitive material contacting hydrogen is not obvious, and the color cannot temporarily change to the target color. In addition, the reaction and color change of the hydrogen-sensitive material takes time and there is a certain lag. The camera used for monitoring normally collects a large range of images covering all pipelines. As a result, the traditional method of directly judging whether there is a leak and the leakage location based on whether there is an area of ​​the target color in the image has poor detection effect, and it is difficult to identify a small area of ​​subtle color change on a specific pipeline. Therefore, after the present embodiment determines that the first pipeline with a leak is leaking through the leak detection branch, it will first connect the first pipeline back to the hydrogen filling station, and then control the camera to continuously collect local magnified images of the location of the first pipeline, and compare the local magnified images before and after the first preset time length (for example, 20 seconds) to determine the target area where the pixel value in the image changes and the color changes toward the target color (for example, the pixel value changes to the pixel value corresponding to the target color), and determine the target area as the hydrogen leakage location. In this way, even in the early stage of hydrogen leakage when the hydrogen-sensitive material cannot fully react and change color to the target color over a large area, the location of the hydrogen leak can be quickly determined to achieve a rapid response to the hydrogen leak. After determining the hydrogen leak location, the hydrogen leak location can be directly sent to the corresponding staff, and an alarm message can be generated to remind the staff to go and deal with it in time.

[0026] The reason for determining the hydrogen leak location after connecting the first pipeline back to the hydrogen refueling station is that the process of determining the hydrogen leak location requires waiting for at least a first preset time period. To ensure detection accuracy, the leak detection branch can only detect one pipeline at a time. If the hydrogen leak location is determined directly in the leak detection branch, the overall pipeline leak detection efficiency will be significantly affected. In other embodiments, if the number of pipelines in the hydrogen refueling station is small, the hydrogen leak location can also be determined directly while the leak detection branch is connected.

[0027] At block 206, method 200 may determine a minimum pipeline path that covers all hydrogen leak locations, thereby isolating the pipeline section corresponding to the minimum pipeline path within the hydrogen refueling station. In this embodiment, since there may be multiple hydrogen leak locations, a minimum path among the pipeline paths that connect and cover all hydrogen leak locations is determined to isolate the entire pipeline section consisting of the pipelines corresponding to the minimum pipeline path. The reason for isolating the entire pipeline section, rather than isolating each pipeline with a hydrogen leak separately, is that the hydrogen used in hydrogen refueling stations is generally high-pressure hydrogen, which may cause pipeline structural damage when leaking. Compared to isolating a longer entire section, isolating a shorter local section is more likely to cause significant pressure fluctuations, leading to a chain reaction of ruptures at other weak points. Therefore, isolating the entire section improves isolation safety. The isolation process can be achieved by closing the pneumatic valve corresponding to the pipeline section.

[0028] In this way, the flow rate of each pipeline, which would have been collected during the normal process of hydrogen transportation, can be used to calculate the difference between the upstream and downstream flow rates to make a preliminary judgment on the hydrogen leakage situation. When it is determined that there may be a leak, each pipeline can be actively connected to the leak detection branch for investigation, so as to promptly determine the leaking pipeline and the location of the hydrogen leak on the pipeline, and isolate the corresponding pipeline sections in the hydrogen filling station, so that the hydrogen leakage problem can be discovered and solved in the early stage, avoiding the need for a high hydrogen leakage concentration to detect the leak problem, and reducing safety hazards. This improves the automated safety control capabilities of the hydrogen filling station during the hydrogen filling process and during the shutdown of the hydrogen filling station, and the hydrogen filling station can still carry out hydrogen filling normally after some pipelines are isolated (even if filling cannot be carried out after isolation, the leak can be repaired as soon as possible with the intervention of operation and maintenance personnel to ensure that the hydrogen filling station resumes normal operation as soon as possible). This not only reduces operation and maintenance costs and safety risks, but also improves the utilization rate of the hydrogen filling station.

[0029] Figure 3 A flow chart illustrating a complete process 300 for hydrogen leak detection at a hydrogen refueling station according to some embodiments of the present disclosure is provided. In process 300, a standard flow difference 312 between upstream and downstream pipelines is retrieved from a pre-configured database corresponding to the pipelines using the hydrogen flow rate 311 in combination with the pipeline model and structure. Considering that changes in pipeline pressure 313 and hydrogen temperature 314 in actual situations can have a certain impact on the flow difference, the standard flow difference 312 is first corrected based on the pipeline pressure 313 and hydrogen temperature 314. This corrected difference is then used as a flow difference threshold 315, which is then used to compare and determine the actual flow difference.

[0030] As an example, the process of correcting the standard flow difference 312 may be:

[0031] Calculation of gas density based on the gas state equation The formula is:

[0032]

[0033] in, For pressure, is the temperature, is the molar mass of the gas, is the gas constant, is the compression factor.

[0034] The gas flow rate is inversely proportional to the density, and the change in the compressibility factor can be ignored, so the corrected standard flow difference (also known as the flow difference threshold) ) can be calculated as:

[0035]

[0036] in, is the standard flow difference, is the standard pressure corresponding to the standard flow difference, is the standard temperature corresponding to the standard flow difference, is the actual pressure, is the actual temperature, is the standard compression factor, is the actual compression factor.

[0037] In block 320, a determination is made as to whether the actual flow rate difference exceeds a flow rate difference threshold. If so, a risk of pipeline leakage is considered, requiring further investigation. In block 331, second pipelines in the hydrogen refueling station that have not been leak-tested during the current detection cycle are identified and connected to the leak detection branch. The actual flow rate difference may also exceed the flow rate difference threshold due to transient fluctuations in the flowmeter data, potentially leading to misjudgments. To avoid frequent pipeline adjustments that affect normal hydrogen delivery, a detection cycle can be pre-set. Pipelines that have already been tested within a detection cycle are considered to be safe in the short term and will not be tested again during the current detection cycle. The length of the detection cycle can be set based on actual needs. For example, if you want to detect anomalies as early as possible, you can set a shorter detection cycle, while if you want to minimize the impact on the normal operation of the pipeline, you can set a longer detection cycle. For any second pipeline, after it is connected to the leak detection branch, the terminal will control the pneumatic valve on the leak detection branch to open, connecting the second pipeline to the leak 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 the gas flow at this time being misjudged as gas flow caused by leakage, we will first wait for the pressure difference between the leakage detection branch and the second pipeline to be less than the error value, that is, the pressure difference between the two approaches zero, and then detect the flow data 332 of the second pipeline.

[0038] In block 340, a determination is made as to whether a first pipeline exists among all pipelines connected to the leak detection branch (or, if only the second pipeline is connected, among all second pipelines) from the hydrogen refueling station. This is defined as a pipeline whose flow data 332 satisfies the hydrogen leak condition. If a pipeline leaks, the flow data will consistently show non-zero flow values ​​(or values ​​above the first error value). Since gas flows toward the leak hole, the flow direction will be from the leak detection branch to the first pipeline. A pipeline that meets these conditions is identified as the first pipeline. In other embodiments, branch leakage conditions may also be set. These conditions may include consistent flow and a flow direction from the pipeline to the leak detection branch. Meeting these conditions indicates that the branch being tested for leaks has leaked, requiring appropriate action. After the first pipeline is identified, a camera-captured image containing the first pipeline is determined. Within this captured image, the first pipeline is zoomed in to produce a partially enlarged image 350 that completely encompasses the circumscribed rectangle of the first pipeline. As an example, the camera's regular shooting angle remains unchanged, and the structure and position of the pipeline generally remain unchanged. Therefore, different pipelines can be distinguished by pre-marking them in the image. The first pipeline can then be quickly identified from the captured image based on the markings, thereby quickly determining the location of the partially enlarged image 350. Because the partially enlarged image 350 is partially enlarged for a specific area, it is easier to identify areas of the target color that are not visible in the captured image.

[0039] In the early stages of a hydrogen leak, due to the low concentration of hydrogen leakage, the actual discoloration area on the pipeline surface is small, or the discoloration is light and inconspicuous, making it difficult to directly identify the target color area. In this case, a comparison can be performed between the partially enlarged images 350 before and after a first preset time period to identify target areas where pixel values ​​have significantly changed over time (i.e., the pixel change value is greater than the preset change value) and the pixel values ​​are approaching the target color. This target area is then identified as the hydrogen leak location, allowing the leak location to be quickly determined before the pipeline surface completely changes to the target color. Furthermore, multiple target areas may be mistakenly identified as hydrogen leak locations. In this case, the average leakage flow rate 361 over the preset time period can be calculated using the flow data 332. The leak hole area of ​​the first pipeline can be calculated based on the average leakage flow rate 361, the pressure 362 upstream of the leak point (i.e., the pressure at the test cylinder location in the leak detection branch), and the hydrogen adiabatic index 363.

[0040] As an example, the process of hydrogen leaking from a pipeline to the atmosphere can be basically regarded as critical flow, and the formula for the leakage process is as follows:

[0041]

[0042] in, is the average leakage flow rate, is the discharge coefficient (depending on the shape of the leak hole), is the leakage hole area, is the pressure upstream of the leak hole, is the hydrogen gas constant, is the hydrogen temperature.

[0043] After the leakage hole area is determined, the area with the smallest deviation from the leakage hole area, that is, the area that best matches the leakage hole area, is used as the final hydrogen leakage location 360. In block 370, the pipeline section is isolated based on the hydrogen leakage location 360.

[0044] Furthermore, in block 380, to prevent a large-scale burst in the pipeline under special circumstances, resulting in a rapid and massive hydrogen leak, a hydrogen concentration sensor can still be installed to detect the hydrogen leakage concentration outside the pipeline. Under normal circumstances, the leaking pipeline will be promptly isolated, preventing the hydrogen concentration sensor from detecting a sufficient concentration. However, in certain circumstances, due to the rapid and massive leakage of hydrogen, the hydrogen concentration sensor may still detect a hydrogen leakage concentration greater than the preset safety concentration. In this case, it is considered that the pipeline presents a significant safety risk. To ensure the safety of maintenance personnel heading for repairs and to avoid explosions before the maintenance personnel arrive, the pipeline section can be simulated using CFD gas cloud simulation 381 to obtain simulation results. The simulation result can be a constructed three-dimensional model. In addition to the pipeline section, the model also includes particles distributed around the pipeline section to represent hydrogen. Based on the distribution range of the particles, the scope of the hydrogen leak can be determined, and a series of control instructions can be generated and sent to the nitrogen explosion suppression system of the hydrogen filling station for coordinated control of the nitrogen explosion suppression system. Specifically, the control instructions may include a nitrogen injection instruction 382 to control the corresponding nitrogen nozzle that can cover the hydrogen leakage range, so that the nitrogen nozzle sprays nitrogen into the determined leakage range, reduces the concentration of hydrogen in the air, and reduces the risk of explosion.

[0045] Figure 4A flow chart illustrating a CFD simulation process 400 for some embodiments of the present disclosure is provided. In process 400, based on the determined hydrogen leak location 410 and in combination with queryable pipeline design parameters (e.g., diameter, length, and direction), a pipeline geometry model 421 of the leaking pipeline is first constructed within a CFD gas cloud simulation model 420. The shape (circular if the shape cannot be determined) and area of ​​the leak hole are defined. Next, the pipeline geometry model 421 is meshed 422. Meshing 422 may include using a denser mesh near the leak hole and in critical areas (e.g., pipeline walls and around obstacles) to improve resolution, as well as setting a boundary layer mesh near the pipeline wall to capture viscous interactions between the gas and the wall. Simultaneously, a physical model 423 is constructed within the CFD gas cloud simulation model 420. This model can include a turbulence model (e.g., Large Eddy Simulation (LES)) for simulating hydrogen diffusion accompanied by turbulence, as well as a multi-component transport model (e.g., Fluent) for defining the mixing process of hydrogen and air. Boundary conditions 424 are then set for the physical model 423. Boundary conditions 424 can include pressure and velocity boundary conditions based on actual operating conditions, setting leak holes as velocity inlets, and setting environmental boundaries. In block 425, leak source parameters can be set, primarily including leak hole area and leak mass flow rate, both of which can be obtained through the aforementioned process. Finally, the CFD gas cloud simulation model 420 can be solved using a pressure-velocity coupling solver, selecting either the SIMPLE or PISO algorithm, and outputting simulation results 430. The above process can be directly implemented using CFD simulation software such as ANSYS Fluent, COMSOL Multiphysics, and OpenFOAM.

[0046] Figure 5 The following is a schematic diagram showing the structure of a hydrogen leakage detection device 500 for a hydrogen filling station according to some embodiments of the present disclosure. The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred 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 the relevant parts can be referred to the partial description of the method embodiment. 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 it is connected to the leak 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 also includes a leak location determination module 502, which is configured to determine, in response to the flow data corresponding to the first pipeline in each pipeline connected to the leak detection branch meeting the hydrogen leakage condition, a target area of ​​the locally enlarged image corresponding to the first pipeline that changes to a target color within a first preset time period as the hydrogen leak location after the first pipeline is connected back to the hydrogen refueling station. The hydrogen leakage condition at least includes the flow data being continuously greater than a first error value for a second preset time period. In addition, the device also includes a pipeline isolation module 503, which is configured to determine the minimum pipeline path covering all hydrogen leak locations, so as to isolate the pipeline section corresponding to the minimum pipeline path within the hydrogen refueling station.

[0047] The apparatus 500 further includes a first determination module configured to determine a standard flow difference between upstream and downstream pipelines within the hydrogen refueling station based on the hydrogen flow rate. Furthermore, the apparatus 500 further includes a flow difference correction module configured to correct the standard flow difference based on the current pipeline pressure and ambient temperature to obtain a flow difference threshold.

[0048] The flow data detection module 501 includes a pipeline selection unit, which is configured to select a second pipeline that has not been leak-tested within the current detection cycle and connect the second pipeline to the leak detection branch. The leak detection branch can only be connected to one second pipeline at a time. The flow data detection module 501 also includes a flow data detection unit, which is configured to detect flow data in the second pipeline after the second pipeline is connected to the leak detection branch and the pressure difference between the leak detection branch and the second pipeline is less than the error value.

[0049] In the device 500 , the hydrogen leakage condition includes that the flow data is continuously greater than the first error value within a second preset time period, and the flow direction is from the leakage detection branch to the pipeline.

[0050] The leakage location determination module 502 includes an image determination unit configured to determine, based on a captured image including the first pipeline, a partially enlarged image corresponding to the first pipeline, wherein the size of the partially enlarged image matches the circumscribed rectangle of the first pipeline. The leakage location determination module 502 also includes a first determination unit configured to compare the partially enlarged images before and after a first preset time period, and to determine as a hydrogen leak location a target area in the partially enlarged image where a pixel change value exceeds a preset change value and the changed pixel value is closer to a pixel value of a target color.

[0051] The apparatus 500 also includes a calculation module configured to calculate the average leakage flow rate over a preset time period based on the flow rate data. The apparatus 500 also 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. Furthermore, the leakage location determination module 502 also includes a second determination unit configured to determine a target area in the partially enlarged image where the pixel change value is greater than a preset change value and the changed pixel value 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 between the area and the leakage hole area is determined as the hydrogen leakage location.

[0052] Apparatus 500 further includes a simulation module configured to perform a CFD gas cloud simulation on the first pipeline based on the hydrogen leak location in response to a hydrogen leak concentration exceeding a preset safety concentration. Apparatus 500 further includes a nitrogen injection module configured to generate a nitrogen injection instruction based on the simulation results to control the nitrogen nozzle to inject nitrogen toward the hydrogen leak location.

[0053] In the above embodiments, all or part of the embodiments can be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented 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, all or part of the processes or functions described in the embodiments of this specification are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted via 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 via wired (e.g., coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state drive (SSD)).

[0054] Figure 6 1 shows a block diagram of an electronic device 600 that can implement various embodiments of the present disclosure. 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 processor 610, the disk drive 620, the input / output interface 630, the network interface 640, and the memory 650 can be communicatively connected via a communication bus 660.

[0055] The processor 610 may be implemented as a general-purpose CPU, a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and may be used to execute relevant programs to implement the technical solutions provided in this application.

[0056] The memory 650 can be implemented in the form of ROM (Read Only Memory), RAM (Read Access Memory), static memory, dynamic storage devices, etc. The memory 650 can store an operating system 651 for controlling the operation of the electronic device 600 and a basic input and 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 the technical solutions provided in this application are implemented through software or firmware, the relevant program code is stored in the memory 650 and is called and executed by the processor 610.

[0057] The input / output interface 630 is used to connect to an input / output module to enable information input and output. The input / output module can be configured as a component within the device (not shown) or can be externally connected to the device to provide corresponding functions. Input devices may include a keyboard, mouse, touch screen, microphone, various sensors, etc. Output devices may include a display, speaker, vibrator, indicator light, etc.

[0058] The network interface 640 is used to connect to a communication module (not shown) to enable communication between the device and other devices. The communication module can communicate via a wired method (such as USB, network cable, etc.) or a wireless method (such as mobile network, WiFi, Bluetooth, etc.).

[0059] The bus 660 comprises a pathway for transmitting information between the various components of the device (eg, the processor 610 , disk drive 620 , input / output interface 630 , network interface 640 , and memory 650 ).

[0060] It should be noted that although the above device only shows the processor 610, disk drive 620, input / output interface 630, network interface 640, memory 650, bus 660, etc., in a specific implementation, the device may also include other components necessary for normal operation. In addition, those skilled in the art will 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.

[0061] 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 a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0062] In the context of this disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. Furthermore, although operations are depicted in a particular order, this should be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed to achieve the desired result. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of separate embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable subcombination.

[0063] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are merely example forms of implementing the claims.

Claims

1. A method for detecting hydrogen leaks in a hydrogen refueling station, characterized in that: The method comprises: In response to a difference in actual flow between upstream and downstream pipelines in the hydrogen refueling station being greater than a flow difference threshold, respectively detecting flow data of each pipeline in the hydrogen refueling station after being connected to a leak detection branch; respectively detecting flow data of each pipeline in the hydrogen refueling station after being connected to the leak detection branch, including: selecting a second pipeline in the hydrogen refueling station that has not been leak-tested in a current detection cycle, and connecting the second pipeline to the leak detection branch, wherein the leak detection branch is connected to at most one second pipeline at a time; and detecting flow data of the second pipeline after the second pipeline is connected to the leak detection branch and the pressure difference between the leak detection branch and the second pipeline is less than a second error value; In response to the flow data corresponding to the first pipeline in each of the pipelines connected to the leak detection branch meeting the hydrogen leakage condition, after the first pipeline is connected back to the hydrogen refueling station, a target area of ​​the local enlarged image corresponding to the first pipeline that changes toward a target color within a first preset time period is determined as a hydrogen leakage location, wherein the hydrogen leakage condition includes that the flow data is continuously greater than a first error value within a second preset time period, and the flow direction is from the leak detection branch to the pipeline; determining the target area of ​​the local enlarged image corresponding to the first pipeline that changes toward a target color within the first preset time period as the hydrogen leakage location, comprising: determining the local enlarged image corresponding to the first pipeline based on a captured image including the first pipeline, wherein the size of the local enlarged image matches the circumscribed rectangle of the first pipeline; and comparing the local enlarged images before and after the first preset time period, and determining the target area in the local enlarged image where a pixel change value is greater than a preset change value and the changed pixel value is closer to the pixel value of the target color as the hydrogen leakage location; and A minimum pipeline path covering all the hydrogen leakage locations is determined, so as to isolate a pipeline section corresponding to the minimum pipeline path within the hydrogen refueling station.

2. The method according to claim 1, characterized in that The method further comprises: Determine the standard flow difference between upstream and downstream pipelines in the hydrogen refueling station based on the hydrogen flow rate; and Based on the pipeline pressure and hydrogen temperature at the current moment, the standard flow difference is corrected and used as the flow difference threshold.

3. The method according to claim 1, characterized in that The method further comprises: Based on the flow data, calculate the average leakage flow within the preset time period; Calculating 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; The step of determining a target area in the partially enlarged image, where the pixel change value is greater than a preset change value and the changed pixel value is closer to the pixel value of the target color, as a hydrogen leakage location includes: Determining a target area in the partially enlarged image where a pixel change value is greater than a preset change value and the changed pixel value is closer to a pixel value of a target color; and In response to the presence of a plurality of target regions, the target region having the smallest deviation between its area and the area of ​​the leakage hole is determined as the hydrogen leakage location.

4. The method according to claim 1, wherein The method further comprises: In response to a hydrogen leakage concentration being greater than a preset safety concentration, performing CFD gas cloud simulation on the pipeline section based on the hydrogen leakage location; and Based on the simulation results, a nitrogen injection instruction is generated to control the nitrogen nozzle to inject nitrogen toward the hydrogen leakage location.

5. A hydrogen leak detection device for a hydrogen refueling station, characterized in that: The device comprises: A flow data detection module is configured to detect the flow data of each pipeline in the hydrogen refueling station after it is connected to the leakage detection branch 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 flow data detection module includes: The pipeline selection unit is configured in each pipeline in the hydrogen refueling station, selects the second pipeline that has not been leak tested in the current detection cycle, and connects the second pipeline to the leakage detection branch. The leakage detection branch can be connected to at most one second pipeline at a time; a flow data detection unit, configured to detect flow data of the second pipeline when 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; A leakage location determination module is configured to, in response to the presence of flow data corresponding to a first pipeline in each pipeline connected to the leakage detection branch meeting a hydrogen leakage condition, determine, after the first pipeline is connected back to the hydrogen refueling station, a target area of ​​a locally enlarged image corresponding to the first pipeline that changes to a target color within a first preset time period as a hydrogen leakage location, wherein the hydrogen leakage condition includes that the flow data is continuously greater than a first error value within a second preset time period and the flow direction is from the leakage detection branch to the pipeline; the leakage location determination module includes: an image determining unit configured to determine, based on the acquired image including the first pipeline, a partially enlarged image corresponding to the first pipeline, wherein a size of the partially enlarged image matches a circumscribed rectangle of the first pipeline; a first determining unit configured to compare the locally enlarged images before and after a first preset time period, and determine a target area in the locally enlarged image where a pixel change value is greater than a preset change value and the changed pixel value is closer to a pixel value of a target color as a hydrogen leakage location; and The pipeline isolation module is configured to determine a minimum pipeline path covering all the hydrogen leakage locations, so as to isolate the pipeline section corresponding to the minimum pipeline path in the hydrogen refueling station.

6. An electronic device comprising: one or more processors, and A memory associated with the one or more processors, the memory being used to store program instructions, wherein when the program instructions are read and executed by the one or more processors, the steps of the method according to any one of claims 1 to 4 are executed.

7. Computer program product comprising a computer program, which, when executed by a processor, implements the method according to any one of claims 1 to 4.

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