Hydrogen leakage diffusion non-uniform concentration gradient gas cloud minimum ignition energy test and blast-to-pedigree experiment device and experiment method thereof

Abstract

The invention discloses a hydrogen leakage diffusion non-uniform concentration gradient gas cloud minimum ignition energy test and blast-to-pedigree experiment device and an experiment method thereof. Comprising a visual semi-open test chamber, a premixing and flow regulation and control system, a gas temperature regulation and control system, a flow field wind speed regulation and control system, an environment water mist regulation and control system, an adjustable high-pressure ignition system, a non-uniform hydrogen injection system, a data acquisition system, a program control system and a time sequence synchronous controller. According to the hydrogen leakage diffusion non-uniform concentration gradient gas cloud minimum ignition energy test and blast-to-pedigree experiment device, a plurality of gas cloud forms such as local enrichment or concentration gradient advancing along with time can be constructed through cooperation of the position-adjustable non-uniform hydrogen injection system and the premixing and flow regulation and control system, and the injection position and key parameters can be reproduced; and moreover, dynamic monitoring of concentration distribution can be realized through a data acquisition system, and a researcher is helped to establish a corresponding relation of the gas cloud concentration along with time and space changes.

Description

Technical Field

[0001] This invention relates to an experimental apparatus, and more particularly to an experimental apparatus and method for testing the minimum ignition energy of a hydrogen leakage diffusion non-uniform concentration gradient gas cloud and its combustion-detonation transformation. Background Technology

[0002] With the rapid development of hydrogen energy utilization and storage equipment, the fire and explosion risks caused by hydrogen leakage and diffusion have become more prominent. Hydrogen diffuses rapidly, has a low density, requires little energy to ignite, and develops combustion quickly. Once leaked in plant buildings, stations, energy storage compartments, or semi-open interconnected spaces, it often forms a non-uniform gas cloud that varies with time and location. This gas cloud exhibits significant concentration differences at different heights and on different planes and is easily affected by ventilation, temperature, and humidity, leading to unstable ignition sensitivity and combustion development. When the gas cloud encounters an ignition source locally, it may develop from a weak combustion into a deflagration, generating significant pressure rise and propagation risks. Therefore, it is necessary to establish a repeatable gas cloud construction method and achieve dynamic monitoring of concentration distribution and quantitative determination of minimum ignition energy to support safety assessments and protective design.

[0003] Existing research largely focuses on overall parameter measurements under homogeneous gas mixtures or a few fixed operating conditions, making it difficult to reflect the time-varying process of concentration distribution under leakage diffusion conditions. Some devices only support single-point injection or fixed injection positions, with limited injection timing and flow rate adjustment capabilities, resulting in difficulties in stably reproducing gas cloud morphology and gradients. On the other hand, minimum ignition energy testing often suffers from problems such as difficulty in reproducing ignition locations, insufficient energy grading, and reliance on single signals for criteria, making it difficult to establish a stable correspondence between "local concentration—ignition energy—response characteristics." Furthermore, multi-channel measurements lack a unified time reference and coordinate calibration, making it difficult to synchronize pressure, temperature, concentration, and images, thus limiting reliable analysis of gas cloud evolution and combustion-detonation mechanisms. Therefore, an integrated and reproducible experimental platform is still needed for the dynamic characterization of non-uniform gas clouds and the precise determination of minimum ignition energy. Summary of the Invention

[0004] Purpose of the invention: To provide a test apparatus and method for testing the minimum ignition energy of hydrogen leakage diffusion non-uniform concentration gradient gas cloud and the combustion-detonation transition, so as to solve the problems mentioned in the background art.

[0005] Technical solution: The present invention provides a test device for minimum ignition energy of hydrogen leakage diffusion non-uniform concentration gradient gas cloud and combustion-detonation conversion experimental device, including a visual semi-open test chamber, a premixing and flow control system, a gas temperature control system, a flow field wind speed control system, an environmental water mist control system, an adjustable high-pressure ignition system, a non-uniform hydrogen injection system, a data acquisition system, a program control system and a timing synchronization controller.

[0006] A non-uniform hydrogen injection system is installed in an adjustable position within a semi-open, visual test chamber to inject a mixed gas, which forms a gas cloud within the chamber. A premixing and flow control system supplies the mixed gas to the non-uniform hydrogen injection system, with adjustable flow rate and duration. A gas temperature control system regulates the temperature of the mixed gas entering the system. A flow field and wind speed control system delivers airflow to the semi-open test chamber, with adjustable airflow strength and direction. An environmental water mist control system generates water mist within the chamber, with adjustable concentration. The adjustable high-voltage ignition system is installed in the semi-open visual test chamber for ignition, and its output voltage, discharge duration, and repetition frequency are all adjustable. The data acquisition system collects data such as pressure, temperature, images, and hydrogen concentration inside the semi-open visual test chamber and uploads the data to the program control system through a timing synchronization controller. The program control system uses the timing synchronization controller to uniformly control the premixing and flow control system, gas temperature control system, flow field wind speed control system, environmental water mist control system, adjustable high-voltage ignition system, and data acquisition system.

[0007] Furthermore, the visualization semi-open test chamber includes a semi-open chamber body and an adjustable louvered grille; the semi-open chamber body is a cubic container, and the front side wall is set as a transparent observation window; a top opening is provided at the top of the semi-open chamber body; the adjustable louvered grille is embedded in the middle of the left side wall of the semi-open chamber body; and scales are installed on the lower edge and right edge of the front side of the semi-open chamber body.

[0008] Furthermore, the non-uniform hydrogen injection system includes three gas nozzles; three transverse jet guides are installed on the inner bottom surface of the visualized semi-open test chamber; the three gas nozzles are laterally adjustable and mounted on the three transverse jet guides via bottom guide slider seats; and gas is delivered to the three gas nozzles by a premixing and flow control system.

[0009] Furthermore, the premixing and flow control system includes three gas cylinders and three premixing tanks; the three gas cylinders are used to supply gas to the three premixing tanks; the three premixing tanks are connected to three gas nozzles through gas pipelines; a high-precision mass flow controller and a gas solenoid valve are connected in series on each gas pipeline; each high-precision mass flow controller and each gas solenoid valve are electrically connected to the program control system through a timing synchronization controller.

[0010] Furthermore, the gas temperature control system includes a multi-channel intelligent temperature controller, three sheathed electric heaters, and three branch thermocouples; the three sheathed electric heaters are connected in series on three gas pipelines; the three branch thermocouples are installed on the three gas pipelines and located on the outlet side of the corresponding sheathed electric heaters; each sheathed electric heater and each branch thermocouple is electrically connected to the multi-channel intelligent temperature controller; the multi-channel intelligent temperature controller is electrically connected to the program control system through a timing synchronization controller.

[0011] Furthermore, the flow field wind speed control system includes three explosion-proof fans and three anemometers; a multi-layer mounting rack is installed on the left side of the semi-open chamber; the three explosion-proof fans are mounted on the multi-layer mounting rack, and their air outlets all face the adjustable louver grille; the three anemometers are all installed inside the semi-open chamber and are used to detect the flow velocity of the airflow delivered into the semi-open chamber by the three explosion-proof fans; each explosion-proof fan and each anemometer is electrically connected to the program control system through a timing synchronization controller.

[0012] Furthermore, the environmental water mist control system includes a liquid supply tank, an atomizing liquid supply pump, a liquid flow meter, a liquid solenoid valve, an ultrasonic atomizing device, a pipeline centrifugal pump, and a top-mounted grid-type aerosol distributor. The liquid supply tank is used to store the atomizing liquid. The atomizing liquid supply pump is used to deliver the atomizing liquid from the liquid supply tank to the ultrasonic atomizing device. The liquid flow meter and the liquid solenoid valve are connected in series at the outlet of the atomizing liquid supply pump. The top-mounted grid-type aerosol distributor is horizontally installed at the top opening of the semi-open chamber. The ultrasonic atomizing device is used to atomize the atomizing liquid and is connected to the grid-type paint mist distributor via the pipeline centrifugal pump. The atomizing liquid supply pump, liquid flow meter, liquid solenoid valve, ultrasonic atomizing device, and pipeline centrifugal pump are all electrically connected to the program control system via a timing synchronization controller.

[0013] Furthermore, the adjustable high-voltage ignition system includes an adjustable high-voltage ignition device, a three-dimensional adjustable ignition electrode assembly, and a telescopic bracket; the telescopic bracket is horizontally mounted in an adjustable position within the semi-open compartment; the three-dimensional adjustable ignition electrode assembly is mounted on the end of the telescopic bracket and is electrically connected to the adjustable high-voltage ignition device; the adjustable high-voltage ignition device is electrically connected to the program control system via a timing synchronization controller.

[0014] Furthermore, the data acquisition system includes a hydrogen concentration detection mechanism, an optical infrared acquisition mechanism, a high-frequency pressure acquisition mechanism, and a high-frequency temperature acquisition mechanism. The hydrogen concentration detection mechanism is used to acquire the hydrogen concentration at different points inside the semi-open chamber. The optical infrared acquisition mechanism is used to record dynamic images inside the semi-open chamber and acquire temperature field distribution images. The high-frequency pressure acquisition mechanism and the high-frequency temperature acquisition mechanism are used to acquire the pressure and temperature at different points inside the semi-open chamber, respectively. The hydrogen concentration detection mechanism, the optical infrared acquisition mechanism, the high-frequency pressure acquisition mechanism, and the high-frequency temperature acquisition mechanism are all electrically connected to the program control system through a timing synchronization controller.

[0015] Furthermore, the present invention also provides an experimental method for testing the minimum ignition energy of a hydrogen leakage diffusion non-uniform concentration gradient gas cloud and for experimental apparatus for combustion-detonation conversion, comprising the following steps:

[0016] Step 1: Instrument Inspection: Check and confirm that the connections of each system are intact; check and confirm that the components in each system are working properly; check and ensure that the timing synchronization controller and program control system can effectively and accurately control the program and acquire data.

[0017] Step 2: Adjust the monitoring location and data acquisition frequency of the data acquisition system;

[0018] Step 3: Gas configuration and temperature condition setting: According to the test requirements, the mixed gas is configured through the premixing and flow control system, and the gas supply flow rate and duration of the premixing and flow control system to the non-uniform hydrogen injection system are adjusted through the program control system and the timing synchronization controller. The gas temperature control system is used to regulate the temperature of the mixed gas entering the non-uniform hydrogen injection system.

[0019] Step 4: Flow field and environmental water mist conditions: According to the test requirements, adjust the airflow intensity of the flow field wind speed control system to deliver airflow to the visual semi-open test chamber and the water mist concentration generated by the environmental water mist control system through the program control system and the timing synchronization controller.

[0020] Step 5: Construction of a non-uniform hydrogen cloud: Adjust the position of the non-uniform hydrogen injection system according to experimental requirements;

[0021] Step Six: Ignition Condition Setting and Minimum Ignition Energy Test: Adjust the position of the adjustable high-voltage ignition system according to the test requirements, and adjust the discharge parameters of the adjustable high-voltage ignition system through the program control system and the timing synchronization controller.

[0022] The adjustable high-voltage ignition system is controlled by a program control system and a timing synchronization controller for ignition.

[0023] During steps three through six, the program control system and the timing synchronization controller continuously control the data acquisition system to collect and detect data such as pressure, temperature, image, and hydrogen concentration, and the data is recorded by the program control system.

[0024] Step 7: Adjust one of the following parameters: the ignition position of the adjustable high-pressure ignition system, the injection position of the non-uniform hydrogen injection system, the strength of the airflow generated by the flow field wind speed control system, and the concentration of the water mist generated by the environmental water mist control system. Repeat steps 3 to 6 until all experiments are completed.

[0025] Step 8: Clean and shut down the device: After the experiment is completed, the program control system and the timing synchronization controller first shut down the adjustable high-pressure ignition system, then control the flow field wind speed regulation system to continuously generate airflow so that the hydrogen concentration in the visualized semi-open test chamber is lower than the preset safety threshold; clean and drain the environmental water mist regulation system; and finally shut down all system components.

[0026] Step Nine: Check and maintain equipment: Check the components of each system for damage and perform maintenance accordingly;

[0027] Step 10: Summarize and organize the various data collected by the program control system.

[0028] Compared with the prior art, the beneficial effects of this invention are:

[0029] I. This device can repeatedly construct hydrogen gas clouds with non-uniform concentration distribution in a semi-open space. Through multi-gas nozzle injection, adjustable nozzle position, and controlled injection flow rate, various gas cloud morphologies can be formed, such as local enrichment or concentration gradients that progress over time. The injection position and key parameters can be reproduced, facilitating comparative experiments. Simultaneously, the device can achieve dynamic monitoring of concentration distribution through a data acquisition system. Multi-point hydrogen concentration data, along with data on wind speed, temperature, pressure, and visible light and infrared images, are collected synchronously and aligned under a unified time reference and coordinate calibration, thereby helping researchers establish the correspondence between gas cloud concentration and changes in time and space.

[0030] Second, the ignition position of this device supports three-dimensional adjustment and is easy to repeat, enabling zoned and layered ignition tests. The adjustable installation of the three-dimensional adjustable ignition electrode assembly allows for continuous adjustment in the horizontal, vertical, and insertion depth directions, and can be locked in a designated position, ensuring accurate setting and stable reproduction of the ignition point. Simultaneously, the ignition energy can be continuously adjusted or adjusted in stages, and under the condition of simultaneously acquiring response data such as pressure, temperature, concentration, and images, it can be gradually searched and finely determined, thereby improving the resolution and reliability of minimum ignition energy determination.

[0031] Third, this device supports the combined setting of multiple parameters, which helps researchers analyze the main factors affecting the minimum ignition energy. The device can adjust the nitrogen / oxygen / hydrogen ratio, gas nozzle inlet temperature, wind speed and ventilation status in the semi-open chamber, as well as water mist concentration and action time, and link them with the injection and ignition sequence for control. This enables the design and repeated construction of multi-factor operating conditions, providing stable and comparable experimental conditions for regular studies.

[0032] Fourth, this device can help researchers improve their ability to identify ignition results and combustion-detonation transition processes; the high-frequency pressure acquisition mechanism and the high-frequency temperature acquisition mechanism can capture subtle responses caused by weak combustion, and the optical infrared acquisition mechanism can provide intuitive evidence of flame morphology and temperature distribution; by comprehensively analyzing the above information, researchers can more accurately distinguish between different processes such as ignition failure, stable combustion, rapid combustion, and combustion-detonation transition.

[0033] V. This device balances safety and testing efficiency, making it suitable for conducting a series of comparative tests. Explosion-proof fans for ventilation and replacement reduce the risk posed by residual hydrogen. Unified control by the program control system and timing synchronization controller reduces human error and improves the efficiency of repeated tests, thus facilitating the formation of a stable testing process and comparable datasets. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the present invention;

[0035] Figure 2 This is a flowchart of the gas temperature control system of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of the present invention;

[0037] Figure 4 This is a simplified distribution diagram of the hydrogen concentration detector of the present invention in the main view state;

[0038] Figure 5 This is a simplified top-view diagram of the hydrogen concentration detector of the present invention.

[0039] Figure 6 This is a schematic diagram of the installation structure of the three-dimensional adjustable ignition electrode assembly of the present invention;

[0040] In the diagram: 1. Semi-open chamber; 2. Gas cylinder; 3. Premixed tank; 4. Liquid supply tank; 5-1. First high-precision pressure gauge; 5-2. Second high-precision pressure gauge; 6. Atomizing liquid supply pump; 7. Liquid flow meter; 8-1. Liquid solenoid valve; 8-2. Gas solenoid valve; 9. Ultrasonic atomizing device; 10. Pipeline centrifugal pump; 11. Top-mounted grid-type aerosol distributor; 12. Explosion-proof fan; 14. Adjustable louvered grid; 15-1. Positioning suspension bracket; 15-2. Sliding suspension bracket; 15-3. Main suspension rod; 16. High-frequency response dynamic pressure sensor; 17-1. High-frequency response thermocouple; 17-2. Branch thermocouple; 18. Three-dimensional... 19. Adjustable ignition electrode assembly; 20. Telescopic bracket; 21-1. Gas nozzle; 21-2. Jet guide rail; 22-1. Ignition guide rail; 22-2. Bottom guide rail slider seat; 22-2. Middle guide rail slider seat; 23-1. Inerting flow controller; 23-2. High-precision mass flow controller; 24. Sheath-type electric heater; 25. Program control system; 26. Timing synchronization controller; 27. Multi-channel intelligent temperature controller; 28. Adjustable high-voltage ignition device; 29. ​​High-speed camera; 30. Infrared thermal imager; 31. Anemometer; 32. Scale; 33-1. Inerting pipe; 33-2. Gas pipe; 34. Hydrogen concentration detector. Detailed Implementation

[0041] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] In the description of this invention, it should be understood that the terms "left", "right", "front", "back", "up", "down", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Example 1:

[0045] like Figure 1-6As shown, the present invention provides a test device for the minimum ignition energy of hydrogen leakage diffusion non-uniform concentration gradient gas cloud and combustion-detonation conversion experimental device, which includes: a visual semi-open test chamber, a premixing and flow control system, a gas temperature control system, a flow field wind speed control system, an environmental water mist control system, an adjustable high-pressure ignition system, a non-uniform hydrogen injection system, a data acquisition system, a program control system 25, and a timing synchronization controller 26.

[0046] A non-uniform hydrogen injection system is installed in an adjustable position within the semi-open visualization test chamber to inject a mixed gas, which forms a gas cloud within the chamber. A premixing and flow control system supplies the mixed gas to the non-uniform hydrogen injection system, with adjustable flow rate and duration. A gas temperature control system regulates the temperature of the mixed gas entering the system. A flow field and wind speed control system delivers airflow to the semi-open visualization test chamber, with adjustable strength and direction. An environmental water mist control system generates water mist within the chamber. An adjustable high-pressure ignition system is installed in an adjustable position within the chamber for ignition, with adjustable output voltage, discharge duration, and repetition frequency. A data acquisition system collects data such as pressure, temperature, images, and hydrogen concentration within the chamber and uploads this data to the program control system 25 via a timing synchronization controller 26.

[0047] The program control system 25 uses a timing synchronization controller 26 to uniformly control the premixing and flow control system, gas temperature control system, flow field wind speed control system, environmental water mist control system, adjustable high-pressure ignition system, and data acquisition system.

[0048] This device can repeatedly construct hydrogen clouds with non-uniform concentration distribution in a semi-open space. By controlling the parameters of the non-uniform hydrogen injection system through a position-adjustable non-uniform hydrogen injection system and a premixing and flow control system, various cloud morphologies, such as local enrichment or concentration gradients that progress over time, can be formed. The injection position and key parameters can be reproduced, facilitating comparative experiments. At the same time, the device can realize dynamic monitoring of concentration distribution through a data acquisition system. Hydrogen concentration, temperature, pressure, and image data are acquired synchronously and aligned under a unified time reference and coordinate system, thereby helping researchers establish the correspondence between cloud concentration and changes in time and space.

[0049] Furthermore, the visualized semi-open test chamber includes a semi-open chamber body 1 and an adjustable louvered grille 14;

[0050] The semi-open chamber 1 is a cubic container with a transparent observation window on the front side wall and a top opening on the top of the semi-open chamber 1; an adjustable louvered grille 14 is embedded in the middle of the left side wall of the semi-open chamber 1; and a scale 32 is installed on the lower edge and right edge of the front side of the semi-open chamber 1.

[0051] Two graduated scales 32 are placed on the right and lower edges of the front side of the semi-open cabin to facilitate precise positioning during the installation and adjustment of other components and to help conduct comparative experiments under different working conditions; the transparent observation window on the front side facilitates the acquisition of image data and the observation of experimental conditions.

[0052] Furthermore, the non-uniform hydrogen injection system includes three gas nozzles 20; three transverse jet guide rails 21-1 are longitudinally spaced on the bottom surface of the semi-open chamber 1; a bottom guide rail slider seat 22-1 is laterally slidably and adjustablely installed on each jet guide rail 21-1; a jet positioning bolt for positioning is installed on each bottom guide rail slider seat 22-1; the three gas nozzles 20 are respectively installed on the three bottom guide rail slider seats 22-1; gas is delivered to the three gas nozzles 20 by a premixing and flow control system.

[0053] Multiple gas nozzles 20 provide experimental conditions for single-source, multi-source, time-sharing, and zone-sharing injections. The position of the gas nozzles 20 is easily adjusted using the jet guide rail 21-1 and the bottom guide rail slider seat 22-1, and is positioned by the jet positioning bolts. The mixed gas provided by the premixing and flow control system is input into each gas nozzle 20 according to the set flow rate, and the gas nozzles 20 are opened and closed in a set sequence under the control of the timing synchronization controller 26 and the program control system 25. The injection flow rate, injection duration, opening and closing sequence of the gas nozzles 20 and the spatial position of the gas nozzles 20 in the semi-open chamber 1 together determine the gas cloud morphology in the semi-open chamber 1, which can form various gas cloud morphologies such as local enrichment or concentration gradients that advance over time.

[0054] Furthermore, the premixing and flow control system includes three gas cylinders 2 and three premixing tanks 3; the three gas cylinders 2 are used to supply gas to the three premixing tanks 3; the three gas cylinders 2 are respectively used to hold nitrogen, oxygen and hydrogen; a first high-precision pressure gauge 5-1 is installed on each premixing tank 3; the gas outlets of the three premixing tanks 3 are connected to three gas nozzles 20 through gas pipes 33-2, and the part of the gas pipes 33-2 extending into the semi-open chamber 1 is an organ pipe; a high-precision mass flow controller 23-2 and a gas solenoid valve 8-2 are connected in series from the premixing tank 3 to the ignition branch on each gas pipe 33-2; the gas cylinder 2 containing nitrogen is connected to the semi-open chamber 1 through an inerting pipe 33-1; an inerting flow controller 23-1 is connected in series on the inerting pipe 33-1; the inerting flow controller 23-1, each high-precision mass flow controller 23-2 and each gas solenoid valve 8-2 are all electrically connected to the program control system 25 through a timing synchronization controller 26;

[0055] A switch valve is connected in series on the inerting pipe 33-1, each gas pipe 33-2, the mouth of each gas cylinder 2, and the mouth of each premixing tank 3.

[0056] Researchers open and close the valves according to the experimental requirements. Before the experiment, the inerting flow controller 23-1 is controlled by the timing synchronization controller 26 and the program control system 25 to deliver nitrogen from the gas cylinder 2 to the semi-open chamber 1, so as to inertify or dilute the air in the semi-open chamber 1 as a whole, reduce the initial oxygen concentration in the chamber, and provide a safer background atmosphere for subsequent hydrogen injection and ignition experiments. In case of abnormal working conditions or after the experiment, nitrogen can also be quickly replenished into the semi-open chamber 1. In conjunction with the flow field wind speed control system, the dilution and replacement of hydrogen can be accelerated to reduce the concentration of residual combustible gas.

[0057] Three gas cylinders 2 are used to hold nitrogen, oxygen, and hydrogen respectively. These gases are then transported to three premixing tanks 3, where they are mixed in proportion to form a mixed gas, which is then stored to provide a basic gas source for subsequent gas cloud construction. Three high-precision pressure gauges 5-1 are used to monitor the pressure inside the three premixing tanks 3 and record the initial gas supply conditions for easy comparison of operating conditions. High-precision mass flow controllers 23-2 are arranged on each gas pipeline 33-2 to set and stabilize the flow rate of each gas pipeline 33-2. The gas supply intensity and proportion can be adjusted in conjunction with the injection time, thereby affecting the formation and diffusion of the gas cloud. Gas solenoid valves 8-2 are used to quickly open and close gas pipelines 33-2 to determine the start and end times of injection and provide a clear time reference. The program control system 25 records the flow rate setpoint of the high-precision mass flow controllers 23-2 and the valve action time of the gas solenoid valves 8-2, which can be used by researchers to compare with concentration measurement data and help analyze the relationship between injection parameters and concentration distribution evolution.

[0058] Furthermore, the gas temperature control system includes a multi-channel intelligent temperature controller 27, three sheathed electric heaters 24, and three branch thermocouples 17-2; the three sheathed electric heaters 24 are connected in series on three gas pipelines 33-2 respectively; the three branch thermocouples 17-2 are installed on the three gas pipelines 33-2 respectively, and are located on the outlet side of the corresponding sheathed electric heater 24; each sheathed electric heater 24 and each branch thermocouple 17-2 are electrically connected to the multi-channel intelligent temperature controller 27; the multi-channel intelligent temperature controller 27 is electrically connected to the program control system 25 through a timing synchronization controller 26.

[0059] The sheath-type electric heater 24 is used to preheat the mixed gas and reduce temperature fluctuations caused by pipeline heat dissipation, thereby stabilizing the inlet temperature of the gas nozzle 20 and improving the comparability of operating conditions; the branch thermocouple 17-2 is arranged at the outlet of the sheath-type electric heater 24 to measure the gas temperature of each gas pipeline 33-2 in real time; the multi-channel intelligent temperature controller 27 and the branch thermocouple 17-2 automatically adjust the output power of the sheath-type electric heater 24 according to the measured temperature of the branch thermocouple 17-2, so that the gas temperature of each gas pipeline 33-2 can be set independently and maintained within the target range;

[0060] The gas temperature control system process is as follows: A target temperature value is set. Then, the program control system 25 controls the timing synchronization controller 26 to control the three sheathed electric heaters 24 via the multi-channel intelligent temperature controller 27. This causes the three sheathed electric heaters 24 to heat the gas mixture passing through the corresponding gas pipe 33-2. Three branch thermocouples 17-2 detect the temperature of the heated gas mixture in each gas pipe 33-2 and feed back real-time data to the program control system 25 and the multi-channel intelligent temperature controller 27. The program control system 25 then controls the timing synchronization controller 26 to adjust the output power of the three sheathed electric heaters 24 via the multi-channel intelligent temperature controller 27 until the temperature monitored by the branch thermocouples 17-2 reaches the target temperature.

[0061] Furthermore, the flow field wind speed control system includes three explosion-proof fans 12 and three anemometers 31;

[0062] A multi-layer mounting rack is installed on the left side of the semi-open chamber 1; three explosion-proof fans 12 are respectively installed on the three mounting layers of the multi-layer mounting rack, and the air outlets of the three explosion-proof fans 12 all face the adjustable louver grille 14; three anemometers 31 are all installed in the semi-open chamber 1 located to the right of the adjustable louver grille 14, and are used to detect the flow rate of the airflow delivered into the semi-open chamber 1 by the three explosion-proof fans 12; each explosion-proof fan 12 and each anemometer 31 are electrically connected to the program control system 25 through a timing synchronization controller 26.

[0063] The explosion-proof fan 12 is used to deliver directional airflow to the semi-open chamber 1, forming a ventilation flow field with a certain dominant direction within the semi-open chamber 1. The gas undergoes multiple reciprocating flows and renewals within the semi-open chamber 1, and under the impact of jet flow and boundary constraints, local recirculation zones and convective circulations are formed within the chamber, significantly affecting the diffusion, concentration gradient formation, and evolution of the non-uniform hydrogen cloud. The airflow strength can be changed by adjusting the rotational speed of the explosion-proof fan 12, and the airflow direction can be changed by adjusting the adjustable louvered grille 14. The adjustable louvered grille 14, in conjunction with the explosion-proof fan 12, can simulate different ventilation conditions, thereby affecting the hydrogen diffusion rate and the location and duration of the concentration gradient formation. By adjusting the state of the adjustable louvered grille 14 and the fan operation of the explosion-proof fan 12, different dilution rates and flow structures can be obtained, facilitating the comparison of the spatiotemporal evolution differences of the gas cloud. Three anemometers 31 are arranged in the semi-open chamber 1 near the adjustable louvered grille 14 to measure local wind speed and characterize ventilation intensity. The signals are transmitted to the program control system 25 for recording and evaluation.

[0064] Furthermore, the environmental water mist control system includes a liquid supply tank 4, an atomizing liquid supply pump 6, a liquid flow meter 7, a liquid solenoid valve 8-1, an ultrasonic atomizing device 9, a pipeline centrifugal pump 10, and a top grid-type aerosol distributor 11.

[0065] The liquid supply tank 4 is used to store the atomizing liquid; a second high-precision pressure gauge 5-2 is installed on the liquid supply tank 4; the ultrasonic atomizing device 9 is installed on the top of the multi-layer mounting frame; the atomizing liquid supply pump 6 is used to transport the atomizing liquid in the liquid supply tank 4 to the ultrasonic atomizing device 9; the liquid solenoid valve 8-1 is connected in series at the outlet of the atomizing liquid supply pump 6; the liquid flow meter 7 is connected in series between the liquid solenoid valve 8-1 and the atomizing liquid supply pump 6; the top grid-type aerosol distributor 11 is horizontally installed at the top opening of the semi-open chamber 1; the air outlet pipe of the ultrasonic atomizing device 9 is connected to the air inlet of the top grid-type aerosol distributor 11; the pipeline centrifugal pump 10 is connected in series to the air outlet pipe of the ultrasonic atomizing device 9; the atomizing liquid supply pump 6, the liquid flow meter 7, the liquid solenoid valve 8-1, the ultrasonic atomizing device 9, and the pipeline centrifugal pump 10 are all electrically connected to the program control system 25 through the timing synchronization controller 26.

[0066] The pressure inside the liquid supply tank 4 is monitored by a second high-precision pressure gauge 5-2 to ensure stable liquid supply. The atomizing liquid supply pump 6 sends the atomized liquid into the ultrasonic atomizing device 9. The liquid flow meter 7 is used to measure the liquid supply flow rate. The liquid solenoid valve 8-1 is used to quickly open and close under the control of the timing synchronization controller 26. The start and end times of atomization are determined by the program control system 25. The ultrasonic atomizing device 9 works under the control of the timing synchronization controller 26 to atomize the atomized liquid into water mist. The atomization amount and duration are set and controlled by the timing synchronization controller 26 and the program control system 25. The top grid-type aerosol distributor 11 is arranged at the top opening of the semi-open chamber 1. It adopts a porous grid structure to allow water mist to flow out from multiple points. It also has the effect of weakening momentum and buffering high-speed aerosol jets. It can introduce water mist without basically destroying the original non-uniform hydrogen concentration distribution. It is convenient to accurately assess the impact of water mist on minimum ignition energy and deflagration and detonation behavior, and improve the spatial uniformity and repeatability of the cleaning water mist field.

[0067] Furthermore, the adjustable high-voltage ignition system includes an adjustable high-voltage ignition device 28, a three-dimensional adjustable ignition electrode assembly 18, and a telescopic bracket 19.

[0068] A vertical guide rail is vertically installed on the inner right side of the semi-open cabin 1; an ignition rail 21-2 is vertically slidably mounted on the vertical guide rail via a vertical guide rail slider seat; a vertical positioning bolt for positioning is installed on the vertical guide rail slider seat; a middle guide rail slider seat 22-2 is longitudinally slidably and adjustablely mounted on the ignition rail 21-2; a longitudinal positioning bolt for positioning is installed on the middle guide rail slider seat 22-2; a telescopic bracket 19 is mounted on the middle guide rail slider seat 22-2; a three-dimensional adjustable ignition electrode assembly 18 is mounted on the end of the telescopic bracket 19 and is electrically connected to an adjustable high-voltage ignition device 28; the adjustable high-voltage ignition device 28 is electrically connected to a program control system 25 via a timing synchronization controller 26.

[0069] By utilizing the cooperation between the vertical guide rail and the vertical guide rail slider seat, the cooperation between the ignition guide rail 21-2 and the middle guide rail slider seat 22-2, and the telescopic bracket 19, the vertical, longitudinal, and lateral positions of the three-dimensional adjustable ignition electrode assembly 18 can be adjusted, allowing the three-dimensional adjustable ignition electrode assembly 18 to be aligned with a local area of ​​the non-uniform hydrogen cloud; the adjustable high-pressure ignition device 28 is electrically connected to the three-dimensional adjustable ignition electrode assembly 18, and its output voltage, discharge duration, and repetition frequency can be set according to experimental needs to form a continuous or graded ignition energy sequence. The ignition energy can be adjusted from low to high in stages to determine the ignition threshold under different operating conditions. The ignition discharge energy calculation formula and energy grading sequence are executed according to the following formulas I and II; the MIE of the hydrogen-air mixture at ambient temperature is as follows: Figure 5 As shown;

[0070] Ⅰ

[0071] In the formula: U(t) is the output voltage of the adjustable high-voltage ignition device 28, I(t) is the discharge current, to and t1 are the start and end times of discharge, and E is the energy of a single discharge.

[0072] II

[0073] In the formula: E k Let E be the ignition energy of the k-th stage, and ΔE be the stage step size. mim The initial energy is used to determine the threshold range between ignition failure and ignition success.

[0074] Furthermore, the data acquisition system includes a hydrogen concentration detection mechanism, an optical infrared acquisition mechanism, a high-frequency pressure acquisition mechanism, and a high-frequency temperature acquisition mechanism.

[0075] The hydrogen concentration detection mechanism includes three sliding suspension brackets 15-2 and several hydrogen concentration detectors 34; two positioning suspension brackets 15-1 are horizontally fixed on the upper side inside the semi-open chamber 1; the two ends of the three sliding suspension brackets 15-2 are respectively supported on the two positioning suspension brackets 15-1; three main suspension rods 15-3 are fixed at intervals on the lower edge of each sliding suspension bracket 15-2; each hydrogen concentration detector 34 is in a group of three, and each group of hydrogen concentration detectors 34 is installed on each main suspension rod 15-3; the three hydrogen concentration detectors 34 in the same group are respectively set on the upper, middle and lower parts of the corresponding main suspension rods 15-3; each hydrogen concentration detector 34 is electrically connected to the program control system 25 through a timing synchronization controller 26;

[0076] The optical infrared acquisition mechanism includes a high-speed camera 29 and an infrared thermal imager 30;

[0077] Both the high-speed camera 29 and the infrared thermal imager 30 are located on the front side of the semi-open cabin 1, and their acquisition ends face the transparent observation window of the semi-open cabin 1; both the high-speed camera 29 and the infrared thermal imager 30 are electrically connected to the program control system 25 through the timing synchronization controller 26.

[0078] The high-frequency pressure acquisition mechanism includes three high-frequency response dynamic pressure sensors 16; the high-frequency temperature acquisition mechanism includes three high-frequency response thermocouples 17-1.

[0079] Two branch suspension rods 15-4 are fixed on the lower edge of the sliding suspension bracket 15-2 in the middle; three high-frequency response dynamic pressure sensors 16 are respectively installed on the upper, middle and lower parts of the branch suspension rods 15-4; three high-frequency response thermocouples 17-1 are respectively installed on the upper, middle and lower parts of another branch suspension rod 15-4.

[0080] The three high-frequency response dynamic pressure sensors 16 and the three high-frequency response thermocouples 17-1 are all electrically connected to the program control system 25 through the timing synchronization controller 26.

[0081] Each hydrogen concentration detector 34 is arranged at different heights and planar positions within the semi-open chamber 1, and is installed via a positioning suspension bracket 15-1 and a sliding suspension bracket 15-2, allowing for rapid adjustment of the measurement point position and easy repositioning. The hydrogen concentration detector 34 measures the local hydrogen gas integral, and multi-point synchronous data measurement can obtain the change of concentration at each location over time, which can be used to characterize the spatial distribution of the gas cloud and the evolution of the concentration gradient. The signals from each hydrogen concentration detector 34 are uniformly connected to the program control system 25 for display and recording. Researchers can combine the injection start and stop, fan operation conditions and atomization conditions to compare the concentration process in segments, and provide a basis for ignition window selection.

[0082] The high-speed camera 29 covers the main distribution area of ​​the non-uniform hydrogen cloud and the ignition area, and is used to record the changes in the cloud morphology and the ignition, propagation and evolution of the flame after ignition. The infrared thermal imager 30 obtains the temperature field distribution before and after ignition through the observation window, focusing on reflecting the temperature changes in the ignition area and its surroundings, which is used to help interpret the differences in ignition and analyze the thermal characteristics of the transition from combustion to explosion. Both the high-speed camera 29 and the infrared thermal imager 30 are triggered by the timing synchronization controller 26. The program control system 25 is used to set the frame rate, exposure and recording duration, and to complete data transmission and storage. Two scales 32 are used for image spatial calibration.

[0083] A high-frequency response dynamic pressure sensor 16 is mounted on a sliding suspension bracket 15-2, enabling rapid adjustment and repeated positioning in different experiments. The sensor monitors pressure at different points within the semi-open chamber 1, recording pressure changes during the cloud formation phase and focusing on the transient pressure response after ignition. The signal from the high-frequency response dynamic pressure sensor 16 is input to the program control system 25 for display and storage, helping researchers establish pressure curves. These curves allow researchers to determine ignition success and characterize combustion intensity: near the minimum ignition energy, pressure rise is often small and gradual; when combustion intensifies or a combustion explosion trend occurs, researchers can extract indicators such as peak pressure, pressure rise rate, and duration. Combined with concentration gradients, airflow, and humidity conditions, the sensor helps researchers analyze the changing patterns of the combustion explosion threshold.

[0084] Three high-frequency response thermocouples 17-1 are mounted on a sliding suspension bracket 15-2, allowing for adjustment of the monitoring point position and facilitating repeated positioning. The high-frequency response thermocouples 17-1 are used to monitor the temperature at different points within the semi-open chamber 1, thereby recording the background gas temperature during the gas cloud formation stage and the rapid temperature changes in the local area after ignition. The signals from the high-frequency response thermocouples 17-1 are input to the program control system 25 for display and storage. The temperature time history helps researchers assess the initial temperature level and fluctuation range, and verify it against the inlet temperature setpoint. Upon successful ignition, researchers can extract the heating rate and peak temperature and observe the cooling process to characterize combustion intensity and distinguish between weak and stronger combustion. Combining pressure, concentration, and visible and infrared images helps researchers analyze the correlation between temperature changes and ignition behavior and combustion-detonation transition characteristics.

[0085] Furthermore, the present invention also provides an experimental method for testing the minimum ignition energy of a hydrogen leakage diffusion non-uniform concentration gradient gas cloud and for experimental apparatus for combustion-detonation conversion, comprising the following steps:

[0086] Step 1: Instrument Inspection: Check and confirm that the connections of each system are intact; check and confirm that the components in each system are working properly; check and ensure that the timing synchronization controller 26 and the program control system 25 can effectively and accurately control the program and acquire data.

[0087] Step 2: Adjust the monitoring location and data acquisition frequency of the data acquisition system;

[0088] Adjust the positions of the high-speed camera 29 and the infrared thermal imager 30 to ensure that their fields of view cover the main distribution area of ​​the gas cloud and the ignition area inside the semi-open cabin 1, ensuring clear images; use two scale rulers 32 to complete the image scale calibration so that the image position corresponds to the coordinates inside the semi-open cabin 1; set and adjust the acquisition frequency, exposure time and recording duration of the high-speed camera 29 and the infrared thermal imager 30 through the program control system 25.

[0089] The sampling frequencies of the hydrogen concentration detector 34, the high-frequency response dynamic pressure sensor 16, and the high-frequency response thermocouple 17-1 are set by the program control system 25.

[0090] Step 3: Gas Configuration and Temperature Setting: According to the experimental requirements, open the three gas cylinders 2 to mix nitrogen, oxygen, and hydrogen in the three premixing tanks 3 according to the specified ratio to form a mixed gas; read the pressure values ​​of the three first high-precision pressure gauges 5-1 to confirm that the gas supply is stable and meets the settings; set the target flow rate of each high-precision mass flow controller 23-2 through the program control system 25, and control the opening and closing of the corresponding gas pipelines 33-2 through the three gas solenoid valves 8-2; then the program control system 25 and the timing synchronization controller 26 start each sleeve-type electric heater 24 through the multi-channel intelligent temperature controller 27 and set the target temperature, and adjust the mixed gas delivered by each gas pipeline 33-2 to the target temperature through the gas temperature control system process; after the inlet temperature of the gas nozzle 20 stabilizes, proceed to the next step;

[0091] Step 4: Setting up the flow field and ambient water mist conditions: According to the test requirements, the start and stop times and speed of the explosion-proof fan 12 are set through the program control system 25 and the timing synchronization controller 26, and the opening of the adjustable louver grille 14 is adjusted to set the ventilation state and form a ventilation flow field; the wind speed data of the anemometer 31 is read to confirm that the airflow intensity of the ventilation flow field has reached the target level.

[0092] When water mist or humidity conditions are required, the atomizing liquid supply pump 6 is turned on and the liquid supply flow is confirmed by the liquid flow meter 7; the liquid solenoid valve 8-1 is opened and closed by the program control system 25 and the timing synchronization controller 26, thereby controlling the start and stop of the liquid supply, triggering the ultrasonic atomizing device 9 to generate water mist, the water mist is transported to the top grid-type aerosol distributor 11 by the pipeline centrifugal pump 10, and a water mist field of a set concentration is formed in the semi-open chamber 1.

[0093] The aforementioned ventilation flow field and water mist field conditions need to be kept stable before ignition;

[0094] Step 5: Construction of a non-uniform hydrogen cloud: According to the experimental requirements, before starting Step 3, adjust the positions of the three bottom guide rail slider seats 22-1 so that the three gas nozzles 20 are in the required positions respectively; control the premixing and flow control system according to the settings in Step 3 through the program control system 25 and the timing synchronization controller 26 to supply gas and inject the mixed gas, thereby establishing a gas cloud;

[0095] Step Six: Ignition Condition Setting and Minimum Ignition Energy Test: According to the test requirements, before starting Step Three, adjust the position of the vertical guide rail slider seat, the position of the middle guide rail slider seat 22-2, and the telescopic length of the telescopic bracket 19; control the adjustable high-voltage ignition device 28 through the program control system 25 and the timing synchronization controller 26 to set the discharge parameters of the adjustable high-voltage ignition device 28.

[0096] The adjustable high-voltage ignition device 28 is ignited by the program control system 25 and the timing synchronization controller 26.

[0097] During steps three through six, the program control system and the timing synchronization controller continuously control the data acquisition system to collect and detect data such as pressure, temperature, image, and hydrogen concentration, and the data is recorded by the program control system.

[0098] The ignition energy was gradually adjusted in a stepwise or continuous manner, and the boundary conditions for ignition failure and ignition success were recorded respectively. The energy that "just enough to initiate stable combustion or a significant pressure rise" was taken as the minimum ignition energy under the concentration gradient state at that position and time.

[0099] Step 7: After each test, according to the requirements of the next test, the flow field wind speed control system and the inerting flow controller 23-1 are controlled by the program control system 25 and the timing synchronization controller 26 to replace the gas in the semi-open chamber 1 and introduce nitrogen into the semi-open chamber 1 to inertate or dilute the air in the semi-open chamber 1 as a whole, reduce the initial oxygen concentration in the chamber, and provide a safer background atmosphere for subsequent tests. Adjust one of the following parameters: the ignition position of the adjustable high-pressure ignition system, the injection position of the non-uniform hydrogen injection system, the strength of the airflow generated by the flow field wind speed control system, and the concentration of water mist generated by the environmental water mist control system. Comparative experiments are conducted, and steps 3 to 6 are repeated until all experiments are completed. This helps to establish the correspondence between "concentration gradient spatiotemporal evolution - ignition position - minimum ignition energy".

[0100] Step 8: Clean and shut down the device: After the experiment is completed, the program control system 25 and the timing synchronization controller 26 first shut down the adjustable high-pressure ignition system, then control the flow field wind speed regulation system to continuously generate airflow, so that the hydrogen concentration in the semi-open test chamber is lower than the preset safety threshold, control the inerting flow controller 23-1 to replenish nitrogen into the semi-open chamber 1, accelerate the dilution and replacement of hydrogen, and reduce the concentration of residual combustible gas; clean and empty the environmental water mist regulation system; finally shut down all system components.

[0101] Step Nine: Check and maintain equipment: Check the components of each system for damage and perform maintenance accordingly;

[0102] Step 10: Summarize and organize the various data collected by the program control system 25.

[0103] In the hydrogen leakage diffusion non-uniform concentration gradient gas cloud minimum ignition energy test and combustion-detonation conversion experimental device provided by the present invention, the program control system 25 adopts an existing program control system; the timing synchronization controller 26 adopts an existing timing synchronization controller; the multi-channel intelligent temperature controller 27 adopts an existing multi-channel intelligent temperature controller; the adjustable high-pressure ignition device 28 adopts an existing adjustable high-pressure igniter, and the three-dimensional adjustable ignition electrode assembly 18 adopts the corresponding ignition electrode; the high-speed camera 29 adopts an existing high-speed camera; the infrared thermal imager 30 adopts an existing infrared thermal imager; the anemometer 31 adopts an existing anemometer; the hydrogen concentration detector 34 adopts an existing hydrogen concentration detector; the first high-precision pressure gauge 5-1 and the second high-precision pressure gauge 5-2 both adopt existing high-precision pressure gauges; and the atomizing liquid supply pump... 6 and the pipeline centrifugal pump 10 both use existing pump bodies; the liquid flow meter 7 uses existing liquid flow meters; the liquid solenoid valve 8-1 and the gas solenoid valve 8-2 use existing liquid solenoid valves and gas solenoid valves respectively; the ultrasonic atomizing device 9 uses existing ultrasonic atomizing devices; the top grid-type aerosol distributor 11 uses existing grid-type distributors; the explosion-proof fan 12 uses existing fans; the high-frequency response dynamic pressure sensor 16 uses existing high-frequency response dynamic pressure sensors; the high-frequency response thermocouple 17-1 and the branch thermocouple 17-2 both use existing high-frequency response thermocouples; the inerting flow controller 23-1 and the high-precision mass flow controller 23-2 both use existing high-precision mass flow controllers; the sheath-type electric heater 24 uses existing sheath-type electric heaters.

[0104] The beneficial effects of this invention are:

[0105] I. This device can repeatedly construct hydrogen gas clouds with non-uniform concentration distribution in a semi-open space. Through the injection of multiple gas nozzles 20, the adjustable position of the gas nozzles 20, and the control of the injection flow rate, various gas cloud morphologies such as local enrichment or concentration gradients that advance over time can be formed. The injection position and key parameters can be reproduced, facilitating comparative experiments. At the same time, the device can realize dynamic monitoring of concentration distribution through a data acquisition system. Multi-point hydrogen concentration data, along with data such as wind speed, temperature, pressure, and visible light and infrared images, are collected synchronously and aligned under a unified time reference and coordinate calibration, thereby helping researchers establish the correspondence between gas cloud concentration and changes in time and space.

[0106] Second, the ignition position of this device supports three-dimensional adjustment and is easy to repeat positioning, enabling zoned and layered ignition tests; the adjustable installation of the three-dimensional adjustable ignition electrode assembly 18 can be continuously adjusted in the horizontal, vertical and insertion depth directions, and can be locked in a specified position, so that the ignition point can be accurately set and stably reproduced; at the same time, the ignition energy can be continuously adjusted or adjusted in stages according to the level, and gradually searched and finely determined under the condition of synchronously collecting response data such as pressure, temperature, concentration and images, thereby improving the resolution and reliability of minimum ignition energy determination.

[0107] Third, this device supports the combined setting of multiple parameter conditions, which helps researchers analyze the main factors affecting the minimum ignition energy. The device can adjust the nitrogen / oxygen / hydrogen ratio, the inlet temperature of the gas nozzle 20, the wind speed and ventilation status in the semi-open chamber 1, as well as the water mist concentration and action time, and link them with the injection and ignition sequence for control. This enables the design and repeated construction of multi-factor conditions, providing stable and comparable experimental conditions for regular studies.

[0108] Fourth, this device can help researchers improve their ability to identify ignition results and combustion-detonation transition processes; the high-frequency pressure acquisition mechanism and the high-frequency temperature acquisition mechanism can capture subtle responses caused by weak combustion, and the optical infrared acquisition mechanism can provide intuitive evidence of flame morphology and temperature distribution; by comprehensively analyzing the above information, researchers can more accurately distinguish between different processes such as ignition failure, stable combustion, rapid combustion, and combustion-detonation transition.

[0109] V. This device balances safety and testing efficiency, making it suitable for conducting a series of comparative tests. The explosion-proof fan 12 reduces the risk posed by residual hydrogen through ventilation and replacement. The unified control of the program control system 25 and the timing synchronization controller 26 reduces human error and improves the efficiency of repeated tests, thereby facilitating the formation of a stable testing process and comparable datasets.

[0110] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A test apparatus for the minimum ignition energy of hydrogen leakage diffusion non-uniform concentration gradient gas cloud and for combustion-detonation conversion, characterized in that: It includes a visual semi-open test chamber, a premixing and flow control system, a gas temperature control system, a flow field wind speed control system, an environmental water mist control system, an adjustable high-pressure ignition system, a non-uniform hydrogen injection system, a data acquisition system, a program control system (25), and a timing synchronization controller (26). The non-uniform hydrogen injection system is installed in an adjustable position inside the visualized semi-open test chamber to inject a mixed gas, which forms a gas cloud inside the visualized semi-open test chamber. The premixing and flow control system is used to supply mixed gas to the non-uniform hydrogen injection system, and the gas supply flow rate and supply duration are adjustable; the gas temperature control system is used to regulate the temperature of the mixed gas entering the non-uniform hydrogen injection system. The flow field wind speed control system is used to deliver airflow to the visual semi-open test chamber, and the airflow strength and direction are adjustable; the environmental water mist control system is used to generate water mist in the visual semi-open test chamber, and the water mist concentration is adjustable; the adjustable high-pressure ignition system is installed in the visual semi-open test chamber for ignition, and the output voltage, discharge duration and repetition frequency and other discharge parameters are adjustable; the data acquisition system is used to collect data such as pressure, temperature, image and hydrogen concentration in the visual semi-open test chamber, and uploads the data to the program control system (25) through the timing synchronization controller (26); the program control system (25) performs unified control of the premixing and flow control system, gas temperature control system, flow field wind speed control system, environmental water mist control system, adjustable high-pressure ignition system and data acquisition system through the timing synchronization controller (26).

2. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The semi-open test chamber includes a semi-open chamber (1) and an adjustable louvered grid (14); the semi-open chamber (1) is a cubic container and the front side wall is set as a transparent observation window; a top opening is provided at the top of the semi-open chamber (1); the adjustable louvered grid (14) is embedded in the middle of the left side wall of the semi-open chamber (1); a scale (32) is installed on the lower edge and the right edge of the front side of the semi-open chamber (1).

3. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The non-uniform hydrogen injection system includes three gas nozzles (20); three transverse jet guides (21-1) are installed on the inner bottom surface of the visualization semi-open test chamber; the three gas nozzles (20) are laterally and adjustablely mounted on the three transverse jet guides (21-1) via bottom guide slider seats (22-1); gas is delivered to the three gas nozzles (20) by a premixing and flow control system.

4. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The premixing and flow control system includes three gas cylinders (2) and three premixing tanks (3); the three gas cylinders (2) are used to supply gas to the three premixing tanks (3); the three premixing tanks (3) are connected to three gas nozzles (20) through gas pipelines (33-2); a high-precision mass flow controller (23-2) and a gas solenoid valve (8-2) are connected in series on each gas pipeline (33-2); each high-precision mass flow controller (23-2) and each gas solenoid valve (8-2) are electrically connected to the program control system (25) through a timing synchronization controller (26).

5. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 4, characterized in that: The gas temperature control system includes a multi-channel intelligent temperature controller (27), three sheath-type electric heaters (24), and three branch thermocouples (17-2); the three sheath-type electric heaters (24) are connected in series on three gas pipelines (33-2); the three branch thermocouples (17-2) are installed on the three gas pipelines (33-2) respectively, and are located on the gas outlet side of the corresponding sheath-type electric heater (24); each sheath-type electric heater (24) and each branch thermocouple (17-2) are electrically connected to the multi-channel intelligent temperature controller (27); the multi-channel intelligent temperature controller (27) is electrically connected to the program control system (25) through a timing synchronization controller (26).

6. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The flow field wind speed control system includes three explosion-proof fans (12) and three anemometers (31); a multi-layer mounting rack is installed on the left side of the semi-open chamber (1); the three explosion-proof fans (12) are installed on the multi-layer mounting rack, and the air outlets are all facing the adjustable louver grille (14); the three anemometers (31) are all installed inside the semi-open chamber (1) and are used to detect the flow rate of the airflow delivered by the three explosion-proof fans (12) into the semi-open chamber (1); each explosion-proof fan (12) and each anemometer (31) are electrically connected to the program control system (25) through a timing synchronization controller (26).

7. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The environmental water mist control system includes a liquid supply tank (4), an atomizing liquid supply pump (6), a liquid flow meter (7), a liquid solenoid valve (8-1), an ultrasonic atomizing device (9), a pipeline centrifugal pump (10), and a top-grid aerosol distributor (11). The liquid supply tank (4) is used to store the atomizing liquid. The atomizing liquid supply pump (6) is used to transport the atomizing liquid in the liquid supply tank (4) to the ultrasonic atomizing device (9). The liquid flow meter (7) and the liquid solenoid valve (8-1) are connected in series with the atomizing liquid supply pump (6). The liquid outlet of the semi-open chamber (1) is located at the top of the liquid outlet; the top grid-type aerosol distributor (11) is horizontally installed at the top opening of the semi-open chamber (1); the ultrasonic atomizing device (9) is used to atomize the atomized liquid and is connected to the grid-type paint mist distributor (11) through the pipeline centrifugal pump (10); the atomizing liquid supply pump (6), the liquid flow meter (7), the liquid solenoid valve (8-1), the ultrasonic atomizing device (9) and the pipeline centrifugal pump (10) are all electrically connected to the program control system (25) through the timing synchronization controller (26).

8. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The adjustable high-voltage ignition system includes an adjustable high-voltage ignition device (28), a three-dimensional adjustable ignition electrode assembly (18), and a telescopic bracket (19); the telescopic bracket (19) is installed laterally in the semi-open cabin (1) with adjustable position; the three-dimensional adjustable ignition electrode assembly (18) is installed on the end of the telescopic bracket (19) and is electrically connected to the adjustable high-voltage ignition device (28); the adjustable high-voltage ignition device (28) is electrically connected to the program control system (25) through a timing synchronization controller (26).

9. The experimental apparatus for testing the minimum ignition energy and combustion-detonation transition of hydrogen leakage diffusion non-uniform concentration gradient gas cloud according to claim 1, characterized in that: The data acquisition system includes a hydrogen concentration detection mechanism, an optical infrared acquisition mechanism, a high-frequency pressure acquisition mechanism, and a high-frequency temperature acquisition mechanism. The hydrogen concentration detection mechanism is used to acquire the hydrogen concentration at different points inside the semi-open chamber (1). The optical infrared acquisition mechanism is used to record dynamic images inside the semi-open chamber (1) and acquire temperature field distribution images. The high-frequency pressure acquisition mechanism and the high-frequency temperature acquisition mechanism are used to acquire the pressure and temperature at different points inside the semi-open chamber (1), respectively. The hydrogen concentration detection mechanism, the optical infrared acquisition mechanism, the high-frequency pressure acquisition mechanism, and the high-frequency temperature acquisition mechanism are all electrically connected to the program control system (25) through a timing synchronization controller (26).

10. The experimental method for testing the minimum ignition energy of a non-uniform concentration gradient gas cloud and the combustion-detonation conversion experimental device for hydrogen leakage diffusion according to claim 1, comprising the following steps: Step 1: Instrument check: Check to ensure that the connections of each system are intact; check to ensure that the components in each system are working properly; check to ensure that the timing synchronization controller (26) and the program control system (25) can effectively and accurately control the program and acquire data; Step 2: Adjust the monitoring location and data acquisition frequency of the data acquisition system; Step 3: Gas configuration and temperature condition setting: According to the test requirements, the mixed gas is configured through the premixing and flow control system, and the gas supply flow rate and supply duration of the premixing and flow control system to the non-uniform hydrogen injection system are adjusted through the program control system (25) and the timing synchronization controller (26). The gas temperature control system is controlled to adjust the temperature of the mixed gas entering the non-uniform hydrogen injection system. Step 4: Setting up flow field and environmental water mist conditions: According to the test requirements, adjust the airflow intensity of the flow field wind speed control system to deliver airflow to the visual semi-open test chamber and the water mist concentration generated by the environmental water mist control system through the program control system (25) and the timing synchronization controller (26). Step 5: Construction of a non-uniform hydrogen cloud: Adjust the position of the non-uniform hydrogen injection system according to experimental requirements; Step 6: Ignition condition setting and minimum ignition energy test: According to the test requirements, adjust the position of the adjustable high-voltage ignition system, and adjust the discharge parameters of the adjustable high-voltage ignition system through the program control system (25) and the timing synchronization controller (26); The adjustable high-voltage ignition system is ignited by the program control system (25) and the timing synchronization controller 26. During steps three to six, the program control system (25) and the timing synchronization controller (26) continuously control the data acquisition system to collect and detect data such as pressure, temperature, image, and hydrogen concentration, and the data is recorded by the program control system (25). Step 7: Adjust one of the following parameters: the ignition position of the adjustable high-pressure ignition system, the injection position of the non-uniform hydrogen injection system, the strength of the airflow generated by the flow field wind speed control system, and the concentration of the water mist generated by the environmental water mist control system. Repeat steps 3 to 6 until all experiments are completed. Step 8: Clean and shut down the device: After the experiment is completed, the program control system (25) and the timing synchronization controller (26) first shut down the adjustable high-pressure ignition system, and then control the flow field wind speed regulation system to continuously generate airflow so that the hydrogen concentration in the visualized semi-open test chamber is lower than the preset safety threshold; clean and drain the environmental water mist regulation system; and finally shut down all system components. Step Nine: Check and maintain equipment: Check the components of each system for damage and perform maintenance accordingly; Step 10: Summarize and organize the data collected by the program control system (25).

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