A confined space hydrogen safety active and passive integrated protection method and system

Abstract

The present invention relates to a method and system for the integrated active and passive protection of hydrogen safety in confined spaces. The specific protection method is as follows: establishing a proportional test model and a simulation model of a confined space hydrogen utilization system, and conducting numerical simulation analysis; carrying out identification of hazardous sources in confined spaces, determining the installation positions of confined space hydrogen leakage collection devices and hydrogen concentration sensors, and formulating hydrogen micro-leakage criteria based on the hydrogen concentration change rate, hydrogen concentration mutation amount, and hydrogen concentration threshold; determining the layout of the confined space exhaust system and explosion pressure relief system. The protection system includes active protection devices and passive protection devices. Compared with the prior art, the present invention verifies the accuracy of the simulation model, continuously optimizes and adjusts the simulation model until the accuracy meets the requirements, and the results obtained are more reliable and more consistent with the actual situation. The integrated active and passive protection device for hydrogen safety proposed by the present invention has both early warning and protection functions, and comprehensively and efficiently realizes the prevention and control of system hydrogen safety.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen refueling station safety, and in particular to a confined space hydrogen safety integrated active and passive protection method and system. Background Art

[0002] Building a new power system based on photovoltaic power generation and wind power generation has become a research hotspot. Among them, the hydrogen-electricity coupling system with hydrogen energy as the core is an important trend in the future.

[0003] However, compared to conventional energy sources like methane and natural gas, hydrogen has lower ignition energy, a greater diffusion coefficient, and a wider flammability range, posing significant safety risks in production applications. Furthermore, most distributed integrated energy application systems utilize compact, enclosed container structures. If hydrogen leaks from hydrogen-related equipment within the container, the hydrogen is more likely to accumulate and form a flammable cloud, increasing the risk of explosions and explosions, compared to conventional hydrogen utilization systems such as hydrogen refueling stations and hydrogen production plants. In practical applications, hydrogen concentration sensors are often deployed to detect and locate hydrogen leaks, but these sensors have slow response times and inaccurate positioning, resulting in delayed warnings. Regarding hydrogen safety protection devices, isolation is generally employed, but container structures are inherently complex and compact. Installing internal isolation walls would reduce space utilization and potentially exacerbate the consequences of an accident. Ventilation systems can also be used to reduce hydrogen concentration, but determining the optimal layout of the exhaust system to rapidly reduce ambient hydrogen concentration remains a challenge.

[0004] Therefore, developing a security protection method and device for active and passive integrated protection of hydrogen safety in confined spaces is of great significance for accident prevention and resolution. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art by providing an integrated active and passive hydrogen safety protection method and system for confined spaces. The accuracy of the computational fluid dynamics simulation model is verified through a confined space microleakage test. The model is continuously optimized and adjusted until the accuracy meets the required level. Simulation analysis is based on the optimized and revised model, resulting in more reliable results that better align with actual conditions.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a confined space hydrogen safety active and passive integrated protection method, comprising the following steps:

[0008] S1: Establish a scale test model of the confined space hydrogen utilization system, conduct hydrogen leakage tests, and clarify the leakage characteristics and diffusion laws of hydrogen leakage in confined spaces in actual applications;

[0009] S2: Establish a simulation model of the confined space hydrogen utilization system, conduct numerical simulation analysis on the temporal and spatial evolution of hydrogen leakage and diffusion in the confined space, and use the geometric experimental model in S1 to measure the accuracy of the simulation model;

[0010] S3: Conduct confined space hazard source identification. Based on the numerical simulation analysis results in S2, determine the installation locations of the confined space hydrogen leakage collection device and hydrogen concentration sensor. Develop a hydrogen micro-leakage criterion based on the hydrogen concentration change rate, hydrogen concentration mutation amount, and hydrogen concentration threshold to determine and quickly locate hydrogen leakage in confined spaces.

[0011] S4: Based on the operating process of the confined space hydrogen utilization system and the data from the hydrogen concentration sensor in S3, formulate hydrogen leakage safety protection measures and execution logic, and determine the layout plan of the confined space exhaust system;

[0012] According to the simulation analysis results of hydrogen explosion simulated by the simulation model in S2, the layout plan of the confined space explosion pressure relief system is determined, thereby realizing the active and passive integrated protection of hydrogen safety in confined spaces.

[0013] Furthermore, in S1, a 1:1 scale test model was constructed and manufactured using UG (Unigraphics NX) modeling software based on the actual distributed hydrogen energy storage system structure. The scale test model is a test representative replica of the actual distributed hydrogen energy storage system structure, with all or part of the characteristics of the actual structure. Model experiments were conducted in conjunction with actual operating conditions.

[0014] Furthermore, in S2, the accuracy rate is the accuracy of the simulation model in simulating the spatiotemporal evolution of hydrogen in a confined space, and the accuracy includes the accuracy of simulating the spatial distribution of hydrogen in the confined space and the accuracy of simulating the concentration evolution of hydrogen at the same position.

[0015] Furthermore, in S2, FLACS fluid dynamics simulation software was used to analyze the spatiotemporal evolution of hydrogen leakage and diffusion in confined spaces, and the simulation analysis results were compared with the model test results in S1, that is, the hydrogen concentration measured by the hydrogen concentration sensor in the model test was compared with the hydrogen concentration simulation results of the monitoring point at the same position in the simulation analysis to verify the accuracy of the simulation model.

[0016] Furthermore, the parameters of the simulation model are set according to actual working conditions, and the accuracy judgment standard of the simulation model is: if the accuracy of the hydrogen concentration at the simulation detection point is greater than or equal to 80%, then the simulation model can simulate the leakage and diffusion behavior of hydrogen in a confined space.

[0017] Furthermore, in S3, the hydrogen leakage collection device includes a hydrogen leakage collection device and a hydrogen concentration sensor, wherein the hydrogen leakage collection device is used to form a confined space to facilitate the accumulation of hydrogen; and the hydrogen concentration sensor is used to detect the hydrogen concentration in the collection device;

[0018] The installation position of the hydrogen leakage collection device is based on the simulation analysis results and is installed at a point where hydrogen is likely to accumulate;

[0019] The arrangement principle of the hydrogen concentration sensor is as follows: based on the results of fluid dynamics simulation, a fast-response hydrogen concentration sensor is arranged at a location where hydrogen is likely to accumulate;

[0020] Based on the results of hazard source identification, high-precision hydrogen concentration sensors are arranged near points where hydrogen leakage is likely to occur.

[0021] Furthermore, in S3, the hydrogen micro-leakage criterion based on the hydrogen concentration change rate, hydrogen concentration mutation amount and hydrogen concentration threshold is specifically to combine the judgment of the hydrogen concentration sensor with the graded warning, the perceived hydrogen concentration and the alarm time, and determine the leakage location according to the position of the sensor that generates the warning signal.

[0022] Furthermore, in S4, the protective measures include using sound and light alarms, system shutdown, opening and closing valves, and starting an exhaust system;

[0023] The execution logic is to formulate the security logic when hydrogen leakage occurs in different working conditions and different equipment according to the warning level of the hydrogen concentration sensor and the hydrogen leakage location;

[0024] Furthermore, in S4, the layout principle of the exhaust system is as follows: based on the simulation analysis results in S2, ventilation grids and forced exhaust devices are set at locations in the confined space where hydrogen is likely to accumulate, and through influencing factor analysis, the influence of different exhaust locations on the accumulation of combustible clouds after hydrogen leakage is analyzed to obtain an exhaust system layout plan that is less likely to cause combustible cloud accumulation;

[0025] The layout principle of the explosion relief system is: according to the simulation analysis results of hydrogen explosion in confined space, pressure relief panels are set at locations with higher explosion pressure.

[0026] The present invention also provides a confined space hydrogen safety active and passive integrated protection system, comprising an active protection device and a passive protection device, wherein the active protection device comprises an audible and visual alarm, a forced exhaust component and an emergency stop component;

[0027] The passive protection device is a ventilation grid;

[0028] The ventilation grid and forced exhaust assembly are used to discharge hydrogen out of the system to reduce the hydrogen concentration in the system;

[0029] The sound and light alarm is used for hydrogen micro-leakage alarm;

[0030] The emergency stop assembly is used to send out a protection interlock signal when an emergency occurs, quickly stopping the production process, thereby preventing the accident from expanding and worsening.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] 1. The confined space micro-leakage test adopted in the present invention verifies the accuracy of the computational fluid dynamics simulation model, and continuously optimizes and adjusts the simulation model until the accuracy meets the requirements. The simulation analysis performed is based on the optimized and corrected simulation model, and the results obtained are more reliable and more consistent with the actual situation.

[0033] 2. The sensor layout scheme proposed in the present invention is to arrange fast-response hydrogen concentration sensors at locations where hydrogen is likely to accumulate to detect large leaks, and to arrange high-precision hydrogen concentration sensors near key risk points to monitor micro leaks. This not only achieves rapid early warning of hydrogen leaks, but also can more accurately determine the leakage points, greatly improving the safety of system operation.

[0034] 3. The hydrogen safety active and passive integrated protection system proposed in the present invention has both early warning and protection functions, and can comprehensively and efficiently realize the prevention and control of system hydrogen safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a flow chart of an integrated active and passive protection method for hydrogen safety in confined spaces;

[0036] Figure 2 Schematic diagram of the modeling structure of the hydrogen leakage test in Example 1;

[0037] Figure 3 Schematic diagram of the simulation model of the confined space in Example 1;

[0038] Figure 4 This is a schematic structural diagram of the confined space hydrogen leakage collection device in Example 1;

[0039] Figure 5 is a curve diagram of the combined criterion for hydrogen micro-leakage in Example 1;

[0040] Figure 6 Schematic diagram of hydrogen leakage safety protection and execution logic of the electrolysis hydrogen production system in the charging condition in Example 1;

[0041] Figure 7 Schematic diagram of the layout model of the exhaust device in Example 1;

[0042] Figure 8 Schematic diagram of the hydrogen safety active and passive integrated protection system in Example 1.

[0043] Figure 4 Description of the markup in:

[0044] 1-Sealing cover, 2-Hydrogen concentration sensor. DETAILED DESCRIPTION

[0045] The specific implementation methods of the present invention are described in detail below through examples. These examples are implemented under the premise of the scheme described in the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the following examples.

[0046] The present invention is further described below with reference to the accompanying drawings and specific embodiments. Any features, such as component models, material names, connection structures, preparation methods, materials, structures, or composition ratios, that are not explicitly described in this technical solution are considered to be common technical features disclosed in the prior art.

[0047] Example 1

[0048] This embodiment provides a confined space hydrogen safety active and passive integrated protection method, such as Figure 1 As shown, the following steps are included:

[0049] S1: Establish a scaled test model of the confined space hydrogen utilization system and conduct hydrogen leakage tests to clarify the leakage characteristics and diffusion patterns of hydrogen leaks in confined spaces in actual applications. Based on the actual distributed hydrogen energy storage system structure, a 1:1 scaled test model will be constructed and manufactured using UG (Unigraphics NX) modeling software. The scaled test model is a test representative replica of the actual distributed hydrogen energy storage system structure, incorporating all or part of the actual structure's characteristics. Conduct model experiments based on actual operating conditions.

[0050] S2: Based on the actual engineering model, the CFD-FLACS hydrogen safety simulation software is used to establish a three-dimensional fluid dynamics model of hydrogen leakage and diffusion in confined space, such as Figure 3 As shown in the figure, the simulation parameters are set according to the actual working conditions, and the temporal and spatial evolution of hydrogen leakage and diffusion in the confined space is numerically simulated and analyzed.

[0051] In order to ensure that the simulation results can guide practical applications, it is necessary to measure the accuracy of the simulation model. The accuracy refers to the simulation model's simulation accuracy of the spatiotemporal evolution of hydrogen in a confined space. The specific process is: the simulation model is subjected to a model test with the proportional test model in S1, and the obtained results are compared to verify the accuracy of the simulation model. The accuracy includes the accuracy of simulating the spatial distribution of hydrogen in the confined space and the accuracy of simulating the concentration evolution of hydrogen at the same location. The accuracy judgment standard of the simulation model is: if the accuracy of the hydrogen concentration at the simulation detection point is greater than or equal to 80%, then the simulation model can simulate the leakage and diffusion behavior of hydrogen in the confined space.

[0052] S3: If Figure 4 As shown in Figure 2, confined space hazard source identification is carried out. Based on the spatiotemporal evolution of hydrogen leakage and diffusion in confined spaces obtained in S2, the installation locations of the hydrogen leakage collection device and hydrogen concentration sensor are determined. The installation location of the hydrogen leakage collection device should be a point where hydrogen accumulation is likely to occur according to the simulation analysis results. The installation angle of the hydrogen leakage collection device should be determined in combination with the spatiotemporal evolution of hydrogen leakage and diffusion, and should be located in a position that is conducive to the detection of leaked hydrogen.

[0053] The layout principles for hydrogen concentration sensors are as follows: Based on the results of fluid dynamics simulation in S2, fast-response hydrogen concentration sensors are placed at locations where hydrogen is likely to accumulate, enabling global detection of large leaks. Based on the results of hazard source identification, high-precision hydrogen concentration sensors are placed near points prone to hydrogen leaks, enabling near-field detection of micro leaks. The key risk points identified through hazard source identification are shown in Table 1.

[0054] Table 1 Hazard source identification results

[0055]

[0056]

[0057] At the same time, a combined hydrogen micro-leakage criterion of hydrogen concentration change rate, hydrogen concentration mutation amount and hydrogen concentration threshold is formulated, such as Figure 5 As shown in the figure, if the rate of change of hydrogen leakage concentration at a certain moment suddenly increases, or the hydrogen concentration monitoring value suddenly increases, or the hydrogen leakage volume exceeds a certain range, it indicates a hydrogen leak or fault, requiring an alarm and troubleshooting. Therefore, hydrogen concentration sensors placed near hydrogen leakage risk points can detect and issue graded warnings for small hydrogen leaks, preventing large leaks. At the same time, based on the hydrogen concentration sensed by the hydrogen concentration sensor and the hydrogen concentration alarm time, hydrogen leak location can be initially achieved.

[0058] S4: Based on the operating process of the confined space hydrogen utilization system and the data from the hydrogen concentration sensor in S3, hydrogen leakage safety protection measures and execution logic are proposed to determine the layout plan of the confined space exhaust system.

[0059] The security measures include a combination of audible and visual alarms, system emergency shutdowns, valve openings, and ventilation system activation. The execution logic specifically defines a security logic for hydrogen leaks in different operating conditions and for different equipment, based on the different hydrogen concentration warning levels and hydrogen leak locations in S3, to achieve rapid protection against hydrogen leaks. This security logic includes a tiered warning and security measure activation plan, with different security measures implemented for different warning levels. For example, a small leak will be a low-level alarm, shutting down only a specific piece of equipment without impacting the operation of other equipment and systems. A large leak will receive a higher alarm level, resulting in interlocking control measures between the corresponding equipment, and, if necessary, measures such as forced ventilation and system shutdown.

[0060] Figure 6 What is demonstrated is the hydrogen leakage safety protection and execution logic of the electrolytic hydrogen production system during charging conditions. Specifically, when the hydrogen concentration sensor detects hydrogen leakage in the hydrogen production system, the information obtained by the hydrogen concentration sensor is transmitted to the station control system, and a first-level sound and light warning is issued to remind staff to take necessary measures; if the leakage continues, the warning level is upgraded based on the leakage criteria, and the emergency shutdown system takes interlocking measures to forcibly shut down the equipment involved, and sends a fault signal to the station control system, and takes shutdown measures for the downstream hydrogen storage facilities. The staff then conducts inspection and maintenance until the fault is resolved.

[0061] The layout principle of the exhaust system is as follows: according to the simulation analysis results in S2, ventilation grids and forced exhaust devices are set at the locations where hydrogen is likely to accumulate in the confined space. Since different exhaust layout schemes have different effects on hydrogen leakage and diffusion, the influence of different exhaust positions on the accumulation of combustible clouds after hydrogen leakage is analyzed through different exhaust layout schemes, and the exhaust system layout scheme that is less likely to cause combustible clouds to accumulate is obtained. The exhaust system layout of the confined space hydrogen utilization system is as follows: Figure 7 shown.

[0062] Based on the results of hydrogen explosion simulation analysis, a layout plan for the explosion relief system was determined to mitigate the consequences of explosion accidents, thereby achieving integrated active and passive protection for hydrogen safety in confined spaces. The layout principle of the explosion relief system is to install pressure relief panels at locations with higher explosion pressure based on the results of hydrogen explosion simulation analysis in confined spaces.

[0063] Example 2

[0064] This embodiment provides a hydrogen safety active and passive integrated protection system, such as Figure 8As shown, the system includes passive and active protection devices arranged according to the protection method in Example 1. The passive protection device is a ventilation grille, and the active protection device includes an audible and visual alarm, a forced exhaust assembly, and an emergency stop assembly. The ventilation grille and forced exhaust assembly are used to exhaust hydrogen from the system, reducing the system's hydrogen concentration; the audible and visual alarm is used to warn of minor hydrogen leaks; and the emergency stop assembly is used to issue a protective interlock signal in the event of an emergency, rapidly stopping the production process and preventing the accident from escalating or worsening.

[0065] This integrated protection system can effectively provide rapid early warning and protection against hydrogen accidents in hydrogen-related systems, such as distributed hydrogen energy storage power stations. Furthermore, the warning logic and protection scheme proposed in this invention are also applicable to open spaces such as hydrogen refueling stations, as well as other areas for leak warning of flammable and toxic gases, thus having a wide range of applications.

[0066] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A confined space hydrogen safety active and passive integrated protection method, characterized in that: The following steps are involved: S1: Establish a scale test model of the confined space hydrogen utilization system, conduct hydrogen leakage tests, and clarify the leakage characteristics and diffusion laws of hydrogen leakage in confined spaces in actual applications; S2: Establish a simulation model of the confined space hydrogen utilization system, conduct numerical simulation analysis on the temporal and spatial evolution of hydrogen leakage and diffusion in the confined space, and use the geometric experimental model in S1 to measure the accuracy of the simulation model; S3: Conduct confined space hazard source identification. Based on the numerical simulation analysis results in S2, determine the installation locations of the confined space hydrogen leakage collection device and hydrogen concentration sensor. Develop a hydrogen micro-leakage criterion based on the hydrogen concentration change rate, hydrogen concentration mutation amount, and hydrogen concentration threshold to determine and quickly locate hydrogen leakage in confined spaces. S4: Based on the operating process of the confined space hydrogen utilization system and the data obtained by the hydrogen concentration sensor in S3, develop hydrogen leakage safety protection measures and execution logic, and determine the layout of the confined space exhaust system. The protection measures include using audible and visual alarms, system shutdown, valve opening and closing, and starting the exhaust system. The execution logic is to develop safety protection logic for hydrogen leakage in different working conditions and different equipment according to the warning level of the hydrogen concentration sensor and the location of the hydrogen leakage; According to the simulation analysis results of hydrogen combustion and explosion simulated by the simulation model in S2, the layout plan of the confined space explosion pressure relief system is determined, thereby realizing the active and passive integrated protection of hydrogen safety in the confined space; the layout principle of the exhaust system is: according to the simulation analysis results in S2, ventilation grids and forced exhaust devices are set at the locations where hydrogen is easy to accumulate in the confined space, and through influencing factor analysis, the influence of different exhaust positions on the accumulation of combustible clouds after hydrogen leakage is analyzed, and the exhaust system layout plan in which combustible clouds are not prone to accumulation is obtained; the layout principle of the explosion pressure relief system is: according to the simulation analysis results of hydrogen combustion and explosion in the confined space, pressure relief plates are set at locations with higher explosion pressure.

2. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 1, characterized in that: In S1, the specific process of establishing a scale test model is as follows: based on the actual distributed hydrogen energy storage system structure, a 1:1 scale test model is constructed using UG modeling software and produced and processed. The scale test model is a test representative object that is replicated based on the actual distributed hydrogen energy storage system structure and has all or part of the characteristics of the actual structure.

3. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 1, characterized in that: In S2, the accuracy rate refers to the accuracy of the simulation model in simulating the spatiotemporal evolution of hydrogen in a confined space, and the accuracy includes the accuracy of simulating the spatial distribution of hydrogen in the confined space and the accuracy of simulating the concentration evolution of hydrogen at the same position.

4. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 1, characterized in that: In S2, FLACS fluid dynamics simulation software was used to analyze the spatiotemporal evolution of hydrogen leakage and diffusion in confined spaces, and the simulation analysis results were compared with the model test results in S1. That is, the hydrogen concentration measured by the hydrogen concentration sensor in the model test was compared with the simulation results of the hydrogen concentration at the monitoring point at the same position in the simulation analysis to verify the accuracy of the simulation model.

5. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 3 is characterized in that: The parameters of the simulation model are set according to actual working conditions. The accuracy judgment standard of the simulation model is: if the accuracy of the hydrogen concentration at the simulation detection point is greater than or equal to 80%, then the simulation model can simulate the leakage and diffusion behavior of hydrogen in a confined space.

6. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 1, characterized in that: In S3, the hydrogen leakage collection device includes a sealing cover and a hydrogen concentration sensor, the hydrogen concentration sensor is placed inside the sealing cover, and an opening is provided at the bottom of the sealing cover to form a confined space for collecting the escaped hydrogen; The hydrogen concentration sensor is used to detect the hydrogen concentration in the sealing cover; The installation position of the hydrogen leakage collection device is based on the simulation analysis results and is installed at a point where hydrogen is likely to accumulate; The arrangement principle of the hydrogen concentration sensor is as follows: based on the results of fluid dynamics simulation, a fast-response hydrogen concentration sensor is arranged at a location where hydrogen is likely to accumulate; Based on the results of hazard source identification, high-precision hydrogen concentration sensors are arranged near points where hydrogen leakage is likely to occur.

7. The method for integrated active and passive protection of hydrogen safety in confined spaces according to claim 1, characterized in that: In S3, the hydrogen micro-leakage judgment criterion based on the hydrogen concentration change rate, hydrogen concentration mutation amount and hydrogen concentration threshold is specifically to combine the judgment of the hydrogen concentration sensor with the graded warning, the perceived hydrogen concentration and the alarm time, and determine the leakage location according to the position of the sensor that generates the warning signal.

8. A confined space hydrogen safety active and passive integrated protection system, characterized by: The active protection device and the passive protection device arranged in any one of the protection methods of claims 1 to 7, wherein the active protection device includes an audible and visual alarm, a forced exhaust component and an emergency stop component; The passive protection device is a ventilation grid; The ventilation grid and forced exhaust assembly are used to discharge hydrogen out of the system to reduce the hydrogen concentration in the system; The sound and light alarm is used for hydrogen micro-leakage alarm; The emergency stop assembly is used to send out a protection interlock signal when an emergency occurs, quickly stopping the production process, thereby preventing the accident from expanding and worsening.

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