Hydrogen-doped or ammonia-doped fuel jet fire experiment system, combustion diagnosis method and apparatus

Abstract

This invention discloses a hydrogen- or ammonia-blended fuel jet fire experimental system, combustion diagnosis method, and equipment, which can solve problems such as experimental scale distortion, fragmented disaster chain process, and insufficient intelligent control. It realizes integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay, and can obtain experimental data that matches real major accidents. It eliminates the data distortion and blind spots of segmented and isolated experiments, and reduces the control complexity and operational intensity of large-scale complex experiments.

Description

Technical Field

[0001] This application belongs to the field of large-size jet fire, specifically relating to a hydrogen- or ammonia-doped fuel jet fire experimental system, a hydrogen- or ammonia-doped fuel jet fire experimental method, an electronic device, and a computer-readable storage medium. Background Technology

[0002] In the field of hydrogen- or ammonia-blended fuel safety research, existing experimental systems are mostly small-scale laboratory devices, focusing on acquiring basic parameters. Their flame scale and leakage conditions differ significantly from real major accident scenarios, making it impossible to reproduce key physical processes such as strong turbulent mixing and high thermal radiation loads. This results in insufficient extrapolation of experimental results, making it difficult to support the verification of engineering risk assessment models. Furthermore, existing systems lack the ability to simulate the entire dynamic coupling process of leakage, vapor cloud diffusion, ignition, stable combustion, and extinction. Their control methods are mostly time-series program control or manual operation, lacking intelligent regulation, situational awareness, and predictive intervention capabilities for multi-source data. This restricts the experimental safety boundaries and efficiency. Therefore, an intelligent hydrogen- or ammonia-blended fuel jet fire experimental system is urgently needed to solve these problems. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a hydrogen- or ammonia-doped fuel jet fire experimental system that can solve problems such as experimental scale distortion, fragmentation of the disaster chain process, and insufficient intelligent control.

[0004] To achieve the above objectives, a first aspect of the present invention provides a hydrogen- or ammonia-blended fuel jet fire experimental system, comprising: a disaster physics simulation subsystem, and a multi-dimensional synchronous sensing subsystem connected to the disaster physics simulation subsystem; the disaster physics simulation subsystem includes: a gas supply unit, comprising a fuel cylinder group for supplying fuel, an auxiliary cylinder group for supplying hydrogen, a nitrogen cylinder for supplying nitrogen, and a pipeline system connecting each cylinder and equipped with corresponding control valves, flow measurement components, and pressure measurement components for each cylinder; a gas mixing unit, comprising a manifold and a mixing tank, wherein the output of each cylinder in the gas supply unit is collected through the manifold and input into the mixing tank for gas mixing; and a jetting unit. The system comprises: a mixing tank, including an injection pipeline and a nozzle; the outlet of the mixing tank is connected to the nozzle via the injection pipeline, which is equipped with flow measurement and pressure measurement components corresponding to the mixing tank; an ignition unit, located near the nozzle, for igniting the mixed gas ejected from the nozzle; and a multi-dimensional synchronous sensing subsystem including: a combustion diagnostic unit for acquiring the distribution information of OH / CH free radicals in the jet flame generated during the combustion of the mixed gas; a flame morphology unit for acquiring morphological images of the jet flame; a thermal disaster field measurement unit for measuring the thermal radiation and / or heat flow data of the jet flame; and an online laser spectrometer for real-time analysis of the hydrogen or ammonia doping ratio of the gas in the mixing unit and / or injection pipeline.

[0005] In some embodiments, the gas supply unit includes: a fuel cylinder group and a fuel pipeline connected to the fuel cylinder group, the fuel pipeline being equipped with a fuel solenoid valve, and a fuel flow control pipeline and a fuel straight-through pipeline connected in parallel, the fuel flow control pipeline being equipped with a first solenoid valve and a fuel mass flow meter, and the fuel straight-through pipeline being equipped with a second solenoid valve and a fuel pressure sensor; an auxiliary cylinder group and an auxiliary pipeline connected to the auxiliary cylinder group, the auxiliary pipeline being equipped with an auxiliary solenoid valve, and an auxiliary flow control pipeline and an auxiliary straight-through pipeline connected in parallel, the auxiliary flow control pipeline being equipped with a third solenoid valve and an auxiliary mass flow meter, and the auxiliary straight-through pipeline being equipped with a fourth solenoid valve and an auxiliary pressure sensor; and a nitrogen cylinder, i.e., a nitrogen pipeline connected to the nitrogen cylinder, the nitrogen pipeline being equipped with a nitrogen solenoid valve.

[0006] In some embodiments, the mixing unit includes a manifold and a mixing tank; the outputs of the fuel line, the auxiliary line, and the nitrogen line are all connected to the manifold, and the output of the manifold is connected to the inlet of the mixing tank.

[0007] In some embodiments, the injection unit includes: an injection pipeline and a nozzle installed at the end of the injection pipeline; the outlet of the mixing tank is connected to the injection pipeline, and the injection pipeline is provided with an injection pipeline solenoid valve, an injection pipeline flow meter and an injection pipeline pressure sensor.

[0008] In some embodiments, the ignition unit includes: a gas cylinder, a pressure reducing valve, a solenoid valve, an ignition nozzle, an ignition probe, and an ignition coil; the pressure reducing valve is installed on the gas cylinder and connected to the ignition nozzle through a first pipeline, and the ignition coil is connected to a power source and drives the ignition probe to generate an electric spark.

[0009] In some embodiments, the multi-dimensional synchronous sensing subsystem further includes a carbon soot micro-sampling unit, which includes: a telescopic sampling rod with a silicon wafer fixing base at its front end for fixing the sampling substrate; a linear drive mechanism for driving the telescopic sampling rod to move linearly; and a linkage protective cover, which includes a protective cover housing, a drive motor, and a door-shaped sealing structure for covering the silicon wafer fixing base during non-sampling periods.

[0010] In some embodiments, the combustion diagnostic unit includes a first high-speed camera equipped with a narrow-band filter; the flame morphology unit includes a second high-speed camera; and the thermal disaster field measurement unit includes a heat flow meter arranged on the side of the flame and a high-speed acquisition device connected to the heat flow meter.

[0011] According to an embodiment of the present invention, a hydrogen- or ammonia-blended fuel jet fire experimental system includes: a disaster physics simulation subsystem and a multi-dimensional synchronous sensing subsystem connected to the disaster physics simulation subsystem; the disaster physics simulation subsystem includes: a gas supply unit, including a fuel cylinder group for supplying fuel, an auxiliary cylinder group for supplying hydrogen, a nitrogen cylinder for supplying nitrogen, and a pipeline system connecting each cylinder and equipped with control valves, flow measurement components, and pressure measurement components corresponding to each cylinder; a gas mixing unit, including a manifold and a mixing tank, wherein the output of each cylinder in the gas supply unit is collected through the manifold and input into the mixing tank for gas mixing; and a jetting unit, including a jetting pipe. The system includes a mixing tank outlet connected to the nozzle via an injection pipeline, which is equipped with flow and pressure measurement components corresponding to the mixing tank. An ignition unit, located near the nozzle, ignites the mixed gas ejected from the nozzle. A multi-dimensional synchronous sensing subsystem includes: a combustion diagnostic unit for acquiring the distribution information of OH / CH radicals in the jet flame generated during gas combustion; a flame morphology unit for acquiring morphological images of the jet flame; a thermal disaster field measurement unit for measuring the thermal radiation and / or heat flow data of the jet flame; and an online laser spectrometer for real-time analysis of the hydrogen or ammonia doping ratio in the mixing unit and / or injection pipeline. Therefore, this application can solve problems such as experimental scale distortion, fragmented disaster chain processes, and insufficient intelligent control, achieving integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay. It can obtain experimental data matching real major accidents, eliminating data distortion and blind spots in segmented and isolated experiments, and reducing the control complexity and operational intensity of large-scale complex experiments.

[0012] To achieve the above objectives, a second aspect of the present invention provides a method for testing hydrogen- or ammonia-blended fuel jet fires, applicable to a hydrogen- or ammonia-blended fuel jet fire testing system as described above. The method includes: setting a target hydrogen or ammonia blending ratio and a target flow rate or pressure at the nozzle; calculating and controlling the supply of fuel and hydrogen or ammonia in the gas supply unit based on the target hydrogen or ammonia blending ratio and the target flow rate or pressure; opening the solenoid valve of the injection pipeline and starting the ignition unit to ignite the mixed gas ejected from the nozzle to form a jet flame; using an online laser spectral analyzer to monitor the hydrogen or ammonia blending ratio of the gas in the mixing unit and / or injection pipeline in real time, while simultaneously monitoring the actual flow rate or actual pressure of the injection unit; when the monitored hydrogen or ammonia blending ratio is within a preset range, and the actual flow rate is within a preset range or the actual pressure is within a preset range, simultaneously triggering and starting the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit to collect data; after reaching a preset collection time, shutting down the combustion diagnostic unit, flame morphology unit, thermal disaster field measurement unit, gas supply unit, and ignition unit.

[0013] In some embodiments, the method further includes: if a flow control mode is adopted, opening the first solenoid valve and fuel mass flow meter on the fuel flow control pipeline, and the third solenoid valve and auxiliary mass flow meter on the auxiliary flow control pipeline, and controlling the target flow by adjusting the fuel mass flow meter and the auxiliary mass flow meter; if a pressure control mode is adopted, opening the second solenoid valve and fuel pressure sensor on the fuel straight-through pipeline, and the fourth solenoid valve and auxiliary pressure sensor on the auxiliary straight-through pipeline, and controlling the target pressure by adjusting the opening degree of the fuel solenoid valve corresponding to the fuel cylinder group and the auxiliary solenoid valve corresponding to the auxiliary cylinder group.

[0014] In some embodiments, the method further includes: acquiring multiple frames of original chemiluminescence images of the jet flame at a characteristic wavelength through a combustion diagnostic unit; sequentially cropping, denoising, normalizing brightness, and mirroring the multiple frames of original chemiluminescence images to obtain an axisymmetric two-dimensional average luminescence intensity distribution image; performing an inverse Abel transform on the axisymmetric two-dimensional average luminescence intensity distribution image to invert the one-dimensional distribution of the chemiluminescence intensity of OH / CH radicals along the radial direction of the jet flame.

[0015] In some embodiments, the method further includes: acquiring experimental input parameters; wherein the experimental input parameters include nozzle diameter, target hydrogen or ammonia doping ratio, target flow rate or target pressure; acquiring synchronously collected measured data; wherein the measured data includes jet flame length, jet flame height, thermal radiation value and heat flux value; calculating theoretical data based on the experimental input parameters using a preset physical model; wherein the theoretical data includes theoretical jet flame length, theoretical jet flame height, theoretical thermal radiation value and theoretical heat flux value; constructing a training sample set using normalized input parameters and theoretical data as features and measured data as labels; constructing and training a neural network prediction model that integrates the physical model based on the training sample set; wherein the neural network prediction model takes the experimental input parameters as input, the hard-coded physical model in the neural network prediction model structure serves as a constraint, and the output of the neural network prediction model is the prediction data; wherein the prediction data includes predicted jet flame length, predicted jet flame height, predicted thermal radiation, and predicted heat flux value.

[0016] In some embodiments, the training process of the neural network prediction model includes a first stage and a second stage; the first stage is to minimize the error between the predicted data and the measured data; the second stage is to enhance the consistency between the predicted data and the theoretical data.

[0017] The hydrogen- or ammonia-blended fuel jet fire test method according to embodiments of the present invention is applied to a hydrogen- or ammonia-blended fuel jet fire test system as described above. The method includes: setting a target hydrogen or ammonia blending ratio and a target flow rate or target pressure at the nozzle; calculating and controlling the supply of fuel and hydrogen or ammonia in the gas supply unit according to the target hydrogen or ammonia blending ratio and the target flow rate or target pressure; opening the solenoid valve of the injection pipeline and starting the ignition unit to ignite the mixed gas ejected from the nozzle to form a jet flame; using an online laser spectral analyzer to monitor the hydrogen or ammonia blending ratio of the gas in the mixing unit and / or injection pipeline in real time, while simultaneously monitoring the actual flow rate or actual pressure of the injection unit; when the monitored hydrogen or ammonia blending ratio is within a preset hydrogen or ammonia blending ratio range, and the actual flow rate is within a preset flow rate range or the actual pressure is within a preset pressure range, simultaneously triggering and starting the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit to collect data; after reaching a preset collection time, shutting down the combustion diagnostic unit, flame morphology unit, thermal disaster field measurement unit, gas supply unit, and ignition unit. Therefore, this application can solve problems such as experimental scale distortion, fragmented disaster chain process, and insufficient intelligent control. It realizes integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay, and can obtain experimental data that matches real major accidents. It eliminates the data distortion and blind spots of segmented and isolated experiments, and reduces the control complexity and operational intensity of large-scale complex experiments.

[0018] To achieve the above objectives, a third aspect of the present invention provides an electronic device comprising: a processor and a memory, wherein the memory stores a program or instructions executable on the processor, and the program or instructions, when executed by the processor, implement the steps of the experimental method for hydrogen- or ammonia-blended fuel jet fire as described above.

[0019] The electronic device according to the embodiments of the present invention, by performing the above-described hydrogen- or ammonia-blended fuel jet fire test method, can solve problems such as experimental scale distortion, fragmentation of the disaster chain process, and insufficient intelligent control. It realizes integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay, and can obtain experimental data that matches real major accidents. It eliminates the data distortion and blind spots of segmented and isolated experiments, and reduces the control complexity and operational intensity of large-scale complex experiments.

[0020] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the experimental method for hydrogen- or ammonia-doped fuel jet fire as described above.

[0021] According to the computer-readable storage medium of the present invention, by executing the above-described hydrogen- or ammonia-blended fuel jet fire test method, problems such as experimental scale distortion, fragmented disaster chain process, and insufficient intelligent control can be solved. It realizes the integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay, and can obtain experimental data that matches real major accidents. It eliminates the data distortion and blind spots of segmented and isolated experiments, and reduces the control complexity and operational intensity of large-scale complex experiments.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the structure of a hydrogen- or ammonia-doped fuel jet fire experimental system according to an embodiment of this application; Figure 2 This is a schematic diagram of the overall architecture of a hydrogen- or ammonia-doped fuel jet fire experimental system according to an embodiment of this application; Figure 3 This is a schematic diagram of a carbon soot microsampling unit of a hydrogen- or ammonia-doped fuel jet fire experimental system in an embodiment of this application. Figure 4This is a schematic flowchart of an experimental method for a hydrogen- or ammonia-doped fuel jet fire in an embodiment of this application. Figure 5 This is a schematic diagram of the process for obtaining OH / CH radicals in an experimental method for a hydrogen- or ammonia-doped fuel jet fire according to an embodiment of this application. Figure 6 This is a schematic flowchart illustrating the fire situation prediction process of a hydrogen- or ammonia-doped fuel jet fire experimental method in an embodiment of this application. Figure 7 This is a schematic diagram of the structure of an electronic device according to an embodiment of this application.

[0025] Figure reference numerals: 100 Hydrogen- or Ammonia-blended fuel jet fire experimental system; 200 Disaster physics simulation subsystem; 300 Multi-dimensional synchronous sensing subsystem; 201 Gas supply unit; 202 Gas mixing unit; 203 Injection unit; 204 Ignition unit; 301 Combustion diagnosis unit; 302 Flame morphology unit; 303 Thermal disaster field measurement unit; 304 Carbon soot micro-sampling unit; 1 Fuel cylinder group; 2 Fuel pipeline; 3 Fuel solenoid valve; 4 Fuel flow control pipeline; 5 Fuel straight-through pipeline; 6 First solenoid valve; 7 Fuel mass flow meter; 8 Second solenoid valve; 9 Fuel pressure sensor; 10 Auxiliary cylinder group; 11 Auxiliary pipeline; 12 Auxiliary flow control pipeline; 13 Auxiliary straight-through pipeline; 14 Third solenoid valve; 15 Auxiliary mass flow meter; 16 Fourth solenoid valve; 17 Auxiliary pressure sensor; 18 Nitrogen cylinder; 19 Nitrogen pipeline; 20 Nitrogen solenoid valve; 21 22. Manifold 23. Mixing tank 24. Injection pipe 25. Nozzle 26. Injection pipe solenoid valve 27. Injection pipe flow meter 28. Injection pipe pressure sensor 29. Gas cylinder 20. Pressure reducing valve 31. Solenoid valve 32. Ignition nozzle 33. Ignition probe 34. Ignition coil 35. First pipe 36. Power supply 37. Telescopic sampling support rod 38. Silicon wafer fixing base 39. Linked protective cover 40. Protective cover housing 40. Drive motor 41. Door-type sealing structure 42. Protective cover bracket 43. Second motor 44. Drive shaft 45. Connecting rod 46. Drive mechanism bracket 47. Circular card seat 48. Linear card slot 49. Filter 50. First high-speed camera 51. Second high-speed camera 52. Heat flow meter 53. High-speed acquisition device 54. Online laser spectrometer 55. Processor 710. Memory 720. Input / output interface 730. Communication interface 740. Bus 750. Detailed Implementation

[0026] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0027] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.

[0028] As described in the background section, driven by the "dual-carbon" strategic goal, accelerating the construction of a clean, low-carbon, safe, and efficient energy system is the main direction of the energy revolution. Hydrogen energy, as a zero-carbon energy carrier, is a key pathway to achieving deep decarbonization through its large-scale energy utilization (such as power generation and industrial heating). Therefore, the storage, transportation, and safe utilization of hydrogen- or ammonia-blended natural gas is a core approach to overcoming the bottlenecks in the large-scale development of the hydrogen energy industry. However, the physical properties of hydrogen or ammonia (such as high diffusion coefficient, wide explosion limits, and low ignition energy) differ significantly from those of natural gas, making leaks in hydrogen- or ammonia-blended natural gas pipelines prone to jet fires or explosions. Especially in the low-pressure, low-oxygen environment of high-altitude areas, this further alters combustion and flow characteristics, significantly increasing the risk of accidents.

[0029] Diffusion jet fires caused by leaks in high-pressure, large-diameter hydrogen- or ammonia-blended fuel trunk pipelines have become a major safety risk. Currently, the relevant technologies in the field of hydrogen- or ammonia-blended fuel safety research are mainly conducted using small-scale laboratory experimental systems. These systems simulate stable jet fires under different hydrogen or ammonia blending ratios and pressures using small gas supply units and injection units. The experimental process is controlled by timing programs or manual operation, and single-dimensional data such as flame morphology and basic combustion parameters are collected and analyzed.

[0030] The relevant technologies suffer from defects such as a serious disconnect between the experimental scale and real engineering accident scenarios, and a fragmented disaster chain simulation process. The leakage aperture, flow rate, and flame scale of small-scale devices differ too much from real high-pressure, large-diameter pipeline accident scenarios, making it impossible to reproduce key physical processes unique to large-scale leaks, such as strong turbulent mixing, strong buoyancy entrainment, large-scale vapor cloud diffusion, and high thermal radiation load. Experimental results are difficult to directly use to verify engineering risk assessment models, and extrapolation is severely insufficient. Existing systems lack the ability to reproduce the entire dynamic coupling evolution from high-pressure gas leakage to the formation and diffusion of combustible vapor clouds on a unified physical platform, and cannot achieve high-precision dynamic control of large-flow-rate gases or seamless switching between multiple disaster modes.

[0031] To address the aforementioned problems, the hydrogen- or ammonia-blended fuel jet fire experimental system of this invention will study the combustion mechanism of hydrogen- or ammonia-blended fuel diffusion jet flames, reveal the influence mechanism of hydrogen or ammonia coupling on the entrainment characteristics, flow field structure, and combustion behavior (morphology, stability, and thermal radiation) of the fire plume, and establish an evolution and stability prediction model for the characteristic parameters of hydrogen- or ammonia-blended fuel diffusion jet fire plumes. This system solves problems such as experimental scale distortion, fragmented disaster chain processes, and insufficient intelligent control, achieving integrated simulation of the entire chain of high-pressure, high-flow-rate hydrogen- or ammonia-blended fuel leak fires, simultaneous acquisition of multi-dimensional parameters, and intelligent predictive control. It can obtain experimental data comparable to real major accidents in terms of geometric scale and thermodynamic characteristics, thus enhancing the reference value of the experimental results.

[0032] The following is for reference. Figures 1-3 This application describes an experimental system for hydrogen- or ammonia-doped fuel jet fire, as provided in an embodiment.

[0033] like Figure 1 The diagram shows a structural schematic of a hydrogen- or ammonia-blended fuel jet fire experimental system according to an embodiment of this application. The hydrogen- or ammonia-blended fuel jet fire experimental system 100 includes: a disaster physics simulation subsystem 200, and a multi-dimensional synchronous sensing subsystem 300 connected to the disaster physics simulation subsystem 200 via signal transmission. The disaster physics simulation subsystem 200 includes: a gas supply unit 201, comprising a fuel cylinder group 1 for supplying fuel, an auxiliary gas cylinder group 10 for supplying hydrogen, a nitrogen cylinder 19 for supplying nitrogen, and a pipeline system connecting each cylinder and equipped with corresponding control valves, flow measurement components, and pressure measurement components; a gas mixing unit 202, comprising a manifold 22 and a gas mixing tank 23, wherein the output of each cylinder in the gas supply unit 201 is collected through the manifold 22 and input into the gas mixing tank 23 for gas mixing; spray... The injection unit 203 includes an injection pipe 24 and a nozzle 25. The outlet of the mixing tank 23 is connected to the nozzle 25 through the injection pipe 24. The injection pipe 24 is equipped with a flow measurement component and a pressure measurement component corresponding to the mixing tank 23. The ignition unit 204 is located near the nozzle 25 and is used to ignite the mixed gas ejected from the nozzle 25. The multi-dimensional synchronous sensing subsystem 300 includes: a combustion diagnosis unit 301, used to acquire the distribution information of OH / CH free radicals in the jet flame generated during the combustion of the mixed gas; a flame morphology unit 302, used to acquire the morphology image of the jet flame; a thermal disaster field measurement unit 303, used to measure the thermal radiation and / or heat flow data of the jet flame; and an online laser spectrometer 55, used to analyze the hydrogen or ammonia doping ratio of the gas in the mixing unit 202 and / or the injection pipe 24 in real time.

[0034] Specifically, refer to Figure 2This is a schematic diagram of the overall architecture of a hydrogen- or ammonia-blended fuel jet fire experimental system according to an embodiment of this application. The system consists of a modular gas cylinder group (fuel cylinder group 1, auxiliary gas cylinder group 10, and nitrogen cylinder 19) with control valves, flow and pressure measuring components. This modular group regulates the output of fuel, hydrogen or ammonia, and nitrogen, providing a gas source to the manifold 22. The manifold 22 collects multiple gas streams and sends them to the mixing tank 23 for thorough mixing, avoiding experimental deviations caused by uneven composition. This ensures that the injection pipeline 24 receives a stable supply of hydrogen- or ammonia-blended fuel. Based on the high-pressure injection pipeline 24, the nozzle 25, and the pipeline's built-in flow meter and pressure measuring components, the system simulates a high-pressure, large-diameter pipeline leakage scenario, generating a jet that matches a real accident. The flame and the ignition unit 204 near the nozzle 25 are synchronously triggered to ignite, fully initiating the disaster chain evolution from leakage and the formation of combustible vapor cloud to stable combustion. The online laser spectrometer 55 monitors the hydrogen or ammonia ratio in the mixing unit 202 and the injection pipeline 24 in real time, and feeds the data back to the gas supply unit 201. The gas ratio is corrected by adjusting the pipeline control valve and the parameters of the measuring components to maintain stable experimental conditions. The first high-speed camera 51 captures the distribution information of OH / CH free radicals in the jet flame, and the second high-speed camera 52 acquires flame morphology images. The heat flow meter 53 and the high-speed acquisition device 54 simultaneously measure thermal radiation and heat flow data. These data together realize the full-chain simulation of hydrogen or ammonia fuel leakage fire on an engineering scale.

[0035] It should be noted that these are key markers of the combustion process and characteristics of OH / CH radicals. OH radicals are important carriers of combustion chain reactions. Their spatial distribution reflects the location of the flame reaction zone, the intensity of combustion, and the oxidation efficiency of hydrogen- or ammonia-blended fuels. Ammonia-blended fuels can replace some hydrocarbon fuels to reduce carbon emissions during combustion. However, their lower combustion rate compared to hydrogen, lower flame temperature, and lack of carbon significantly alter the flame reaction atmosphere and the evolution of free radicals. During combustion, ammonia-blended fuels undergo a series of oxidation processes that consume OH radicals in the flame, leading to changes in the concentration distribution and reaction zone range of OH radicals. CH radicals are mainly concentrated in the combustion front region of the flame and are the hallmark free radicals of hydrocarbon fuel combustion. Their concentration and distribution directly reflect the impact of hydrogen or ammonia blending ratio on the combustion process and flame structure. Ammonia-blended fuels do not contain carbon and do not directly generate CH radicals. The addition of ammonia-blended fuels dilutes the concentration of hydrocarbon fuels and changes the flame temperature and reaction environment, resulting in a decrease in the concentration of CH radicals and a shift in the combustion front region. In contrast, hydrogen-blended fuels do not dilute the concentration of hydrocarbon fuels and increase combustion activity, indirectly affecting the distribution range of CH radicals.

[0036] As an optional embodiment, the gas supply unit 201 includes: a fuel cylinder group 1 and a fuel pipeline 2 connected to the fuel cylinder group 1, the fuel pipeline 2 being equipped with a fuel solenoid valve 3, and a fuel flow control pipeline 4 and a fuel straight-through pipeline 5 connected in parallel, the fuel flow control pipeline 4 being equipped with a first solenoid valve 6 and a fuel mass flow meter 7, and the fuel straight-through pipeline 5 being equipped with a second solenoid valve 8 and a fuel pressure sensor 9; an auxiliary cylinder group 10 and an auxiliary pipeline 11 connected to the auxiliary cylinder group 10, the auxiliary pipeline 11 being equipped with an auxiliary solenoid valve 12, and an auxiliary flow control pipeline 13 and an auxiliary straight-through pipeline 14 connected in parallel, the auxiliary flow control pipeline 13 being equipped with a third solenoid valve 15 and an auxiliary mass flow meter 16, and the auxiliary straight-through pipeline 14 being equipped with a fourth solenoid valve 17 and an auxiliary pressure sensor 18; a nitrogen cylinder 19 and a nitrogen pipeline 20 connected to the nitrogen cylinder 19, the nitrogen pipeline being equipped with a nitrogen solenoid valve 21.

[0037] Specifically, fuel cylinder group 1 delivers fuel through fuel pipeline 2. Fuel solenoid valve 3 controls the opening and closing of fuel pipeline 2. The parallel fuel flow control pipeline 4 and fuel direct pipeline 5 can adapt to different experimental conditions and flexibly switch between flow and pressure control modes. The first solenoid valve 6 on fuel flow control pipeline 4 controls the pipeline's start and stop, and combined with fuel mass flow meter 7, it realizes the metering and regulation of fuel delivery in low-flow scenarios. Fuel direct pipeline 5, through the second solenoid valve 8 and fuel pressure sensor 9, realizes fuel delivery and real-time pressure monitoring under high-flow and high-pressure conditions. Auxiliary cylinder group 10 delivers hydrogen through auxiliary pipeline 11, and auxiliary solenoid valve 12 controls the opening and closing of auxiliary pipeline 11. The auxiliary flow control pipeline 13 and the auxiliary straight-through pipeline 14 form a symmetrical control structure. The third solenoid valve 15 and the auxiliary mass flow meter 16 control the small flow rate of hydrogen. The fourth solenoid valve 17 and the auxiliary pressure sensor 18 are adapted to the large flow rate and high pressure of hydrogen or ammonia and pressure feedback, ensuring that the mixing ratio of fuel with hydrogen or ammonia can be adjusted as needed. The nitrogen cylinder 19 delivers inert gas through the nitrogen pipeline 20. The nitrogen solenoid valve 21 controls the opening and closing of the nitrogen pipeline 20. Nitrogen or ammonia fuel concentration can be adjusted by connecting nitrogen according to experimental requirements. The pipeline and the manifold 22 and mixing tank 23 of the subsequent mixing unit are purged before and after the experiment to avoid residual gas affecting the experimental accuracy.

[0038] It should be noted that the low-flow-rate scenario is mainly used for basic combustion characteristic research in the laboratory. It can adjust the mixing ratio of fuel with hydrogen or ammonia to obtain basic data such as OH / CH free radical distribution and flame microstructure. The high-flow-rate scenario is used to simulate engineering-level leakage scenarios of complete rupture of large-diameter pipelines with diameters of DN500 and above, and to reproduce physical processes such as strong turbulent mixing, strong buoyancy entrainment, and high thermal radiation load in real accidents.

[0039] Large-diameter pipelines of DN500 and above refer to high-pressure hydrogen or ammonia blended fuel trunk transmission pipelines with a diameter of not less than 500mm. They are the core facilities of urban gas pipeline networks and industrial hydrogen or ammonia blended fuel distribution systems. They mainly undertake the task of large-scale, high-pressure long-distance transmission of hydrogen or ammonia blended fuels. Once a full-diameter rupture and leak occurs in this type of pipeline, a large flow of flammable gas mixture will be released instantly, making it the highest-risk scenario in the application of hydrogen or ammonia blended fuels.

[0040] As an optional embodiment, the mixing unit 202 includes: a manifold 22 and a mixing tank 23; the output ends of the fuel line 2, the auxiliary line 11 and the nitrogen line 20 are all connected to the manifold 22, and the output end of the manifold 22 is connected to the inlet of the mixing tank 23.

[0041] Specifically, the manifold 22 integrates the fuel transported by the fuel pipeline 2, the hydrogen or ammonia transported by the auxiliary pipeline 11, and the nitrogen transported by the nitrogen pipeline 20 in an orderly manner, avoiding problems such as pipeline interference and airflow impact when multiple gases are transported in parallel. The output mixed gas flow is connected to the mixing tank 23. The mixing tank 23 is equipped with a turbulence structure to enhance the turbulent mixing of the gas, ensuring that the component concentration and the proportion of hydrogen or ammonia added to the output gas remain stable and consistent.

[0042] It should be noted that the turbulence structure is a component inside the mixing tank 23 used to break the laminar flow of gas and enhance the turbulent mixing of multiple gas streams. It can take the form of baffles, deflectors, spiral guide vanes, etc. These structures repeatedly block, split, and swirl, allowing fuel, hydrogen or ammonia, and nitrogen to collide fully, so that different gas molecules can be fully mixed, avoiding stratification or uneven local concentration of gas due to differences in density and flow rate.

[0043] As an optional embodiment, the injection unit 203 includes: an injection pipeline 24 and a nozzle 25 installed at the end of the injection pipeline 24; the outlet of the mixing tank 23 is connected to the injection pipeline 24, and the injection pipeline 24 is provided with an injection pipeline solenoid valve 26, an injection pipeline flow meter 27 and an injection pipeline pressure sensor 28.

[0044] Specifically, the injection pipeline 24 receives a homogeneous hydrogen-blended gas source or an ammonia-blended gas source output from the mixing tank 23. The injection pipeline solenoid 26 rapidly opens and closes the injection pipeline 24 according to the experimental sequence, controlling the injection start and stop nodes. The injection pipeline flow meter 27 and the injection pipeline pressure sensor 28 synchronously collect gas flow and pressure data in the pipeline. These data are fed back to the fuel mass flow meter 7, the auxiliary mass flow meter 16, and various solenoid valves to dynamically correct the gas source output parameters. The nozzle 25 adopts a large-diameter, high-flow-rate design, which can simulate the scenario of a complete rupture of a large-diameter pipeline network of DN500 or above, and reproduce the physical processes such as strong turbulent mixing and strong buoyancy entrainment in real accidents.

[0045] As an optional embodiment, the ignition unit 204 includes: a gas cylinder 29, a pressure reducing valve 30, a solenoid valve 31, an ignition nozzle 32, an ignition probe 33, and an ignition coil 34; the pressure reducing valve 30 is installed on the gas cylinder 29 and connected to the ignition nozzle 32 through a first pipeline 35; the ignition coil 34 is connected to a power supply 36 and drives the ignition probe 33 to generate an electric spark.

[0046] Specifically, cylinder 29 provides the methane gas required for ignition, pressure reducing valve 30 regulates the output pressure to prevent ignition failure due to excessively high or low pressure. The stabilized methane is delivered to ignition nozzle 32 via first pipeline 35. Solenoid valve 31 and injection pipeline solenoid valve 26 open and close synchronously according to the experimental preset sequence, supplying gas in time at the moment when hydrogen- or ammonia-mixed gas is ejected from nozzle 25 to prepare for ignition. Ignition coil 34 is connected to power supply 36 to obtain stable electrical energy, driving ignition probe 33 to generate a high-intensity electric spark near the outlet of ignition nozzle 32, igniting the ejected methane and hydrogen- or ammonia-mixed gas.

[0047] As an optional embodiment, the multi-dimensional synchronous sensing subsystem 300 further includes a carbon soot micro-sampling unit 304, which includes: a telescopic sampling rod 37, the front end of which is provided with a silicon wafer fixing base 38 for fixing the sampling substrate; a linear drive mechanism for driving the telescopic sampling rod 37 to move linearly; and a linkage protective cover 39, which includes a protective cover housing 40, a drive motor 41, and a door-shaped sealing structure 42 for covering the silicon wafer fixing base 38 during non-sampling periods.

[0048] Specifically, such as Figure 3 The diagram shows a carbon soot microsampling unit of a hydrogen- or ammonia-doped fuel jet fire experimental system in an embodiment of this application. When the jet flame enters the stable combustion stage, the second motor 44 starts and drives the transmission shaft 45 to rotate. The circular seat 48 at the end of the transmission shaft 45 is embedded in the linear slot 49 of the connecting rod 46, converting the rotational motion into the swing of the connecting rod 46, which pushes the retractable sampling support rod 37 to move linearly along the drive mechanism bracket 47. The drive motor 41 drives the gate-type sealing structure 42 to rotate and open the hole on the end face of the protective cover housing 40. The standard SEM silicon wafer on the silicon wafer fixing base 38 at the front end of the retractable sampling support rod 37 just extends out of the hole and into the core area of ​​the jet flame ejected by the nozzle 25 to complete the carbon soot particle deposition sampling. After the sampling is completed, the drive motor 41 reverses to make the gate-type sealing structure 42 return to its original position to seal the hole, protecting the silicon wafer from the influence of flame heat radiation and environmental impurities.

[0049] As an optional embodiment, the combustion diagnostic unit 305 includes a first high-speed camera 51 equipped with a narrow-band filter 50; the flame morphology unit 600 includes a second high-speed camera 52; and the thermal disaster field measurement unit 700 includes a heat flow meter 53 arranged on the side of the flame and a high-speed acquisition device 54 connected to the heat flow meter 53.

[0050] Specifically, please refer to Figure 2 When the ignition unit 204 triggers the hydrogen- or ammonia-doped mixed gas ejected from the nozzle 25 to ignite, the first high-speed camera 51 captures the specific wavelength signal of OH / CH free radicals in the jet flame through the narrow-band filter 50. The second high-speed camera 52 simultaneously acquires images of the macroscopic morphological evolution of the flame. By using timestamps and the free radical distribution data of the first high-speed camera 51 to form a spatial mapping, the correspondence between the core reaction zone of the flame and the macroscopic morphology is clarified. The heat flow meter 53 is arranged at a preset monitoring point on the side of the flame. The heat radiation data it collects is simultaneously recorded by the high-speed acquisition device 54. The dynamic response of the heat flow intensity is analyzed by the flame length and swing amplitude.

[0051] In summary, the hydrogen- or ammonia-blended fuel jet fire experimental system provided according to the embodiments of this application includes: a disaster physics simulation subsystem and a multi-dimensional synchronous sensing subsystem connected to the disaster physics simulation subsystem; the disaster physics simulation subsystem includes: a gas supply unit, including a fuel cylinder group for supplying fuel, an auxiliary cylinder group for supplying hydrogen, a nitrogen cylinder for supplying nitrogen, and a pipeline system connecting each cylinder and equipped with corresponding control valves, flow measurement components, and pressure measurement components for each cylinder; a gas mixing unit, including a manifold and a gas mixing tank, wherein the output of each cylinder in the gas supply unit is collected through the manifold and input into the gas mixing tank for gas mixing; and an injection unit, including... The system includes an injection pipeline and nozzle; the outlet of the mixing tank is connected to the nozzle via the injection pipeline, which is equipped with flow measurement and pressure measurement components corresponding to those of the mixing tank; an ignition unit, located near the nozzle, is used to ignite the mixed gas ejected from the nozzle; and a multi-dimensional synchronous sensing subsystem includes: a combustion diagnostic unit for acquiring the distribution information of OH / CH radicals in the jet flame generated during the combustion of the mixed gas; a flame morphology unit for acquiring morphological images of the jet flame; a thermal disaster field measurement unit for measuring the thermal radiation and / or heat flow data of the jet flame; and an online laser spectrometer for real-time analysis of the hydrogen or ammonia doping ratio of the gas in the mixing unit and / or injection pipeline. Therefore, this application can solve problems such as experimental scale distortion, fragmented disaster chain processes, and insufficient intelligent control, achieving integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay. It can obtain experimental data matching real major accidents, eliminating data distortion and blind spots in segmented and isolated experiments, and reducing the control complexity and operational intensity of large-scale complex experiments.

[0052] refer to Figure 4 The diagram below illustrates a process flow diagram of a hydrogen- or ammonia-doped fuel jet fire testing method according to an embodiment of this application. The hydrogen- or ammonia-doped fuel jet fire testing method according to an embodiment of this application may include the following steps: Step S401: Set the target hydrogen or ammonia doping ratio and the target flow rate or target pressure at the nozzle.

[0053] Specifically, the target hydrogen or ammonia doping ratio α is determined. If the flow control mode is used, the target flow rate Q is set. If the pressure control mode is used, the target pressure is set. At the same time, the flow stability judgment threshold ±a, the pressure stability judgment threshold ±d, and the blending ratio stability judgment threshold ±b are preset.

[0054] Step S402: Calculate and control the supply of fuel and hydrogen or ammonia in the gas supply unit based on the target hydrogen or ammonia blending ratio and the target flow rate or target pressure.

[0055] As an optional embodiment, the method further includes: if a flow control mode is adopted, opening the first solenoid valve and fuel mass flow meter on the fuel flow control pipeline, and the third solenoid valve and auxiliary mass flow meter on the auxiliary flow control pipeline, and controlling the target flow by adjusting the fuel mass flow meter and the auxiliary mass flow meter; if a pressure control mode is adopted, opening the second solenoid valve and fuel pressure sensor on the fuel straight-through pipeline, and the fourth solenoid valve and auxiliary pressure sensor on the auxiliary straight-through pipeline, and controlling the target pressure by adjusting the opening degree of the fuel solenoid valve corresponding to the fuel cylinder group and the auxiliary solenoid valve corresponding to the auxiliary cylinder group.

[0056] Specifically, if a flow control mode is adopted, the target hydrogen or ammonia doping ratio is set accordingly. and target traffic Through formula Calculate the required flow rate of fuel gas cylinder bank. Through formula Calculate the required flow rate of the auxiliary gas cylinder group. A flow stability threshold of ±a is preset, meaning the flow reading fluctuation is within ±a range, for subsequent flow stability verification. If pressure control mode is used, the target hydrogen or ammonia doping ratio is set accordingly. And target pressure, through formula Calculate the initial pressure value that needs to be set for the fuel cylinder group. Through formula Calculate the initial pressure value that needs to be set for the fuel cylinder group. The preset pressure stability judgment threshold ±d is adapted to the verification requirements of subsequent pressure conditions. Both of the above control modes need to specify the blending ratio stability judgment threshold ±b, which is directly related to the monitoring results of the online laser spectrometer.

[0057] Step S403: Open the solenoid valve of the injection pipeline and start the ignition unit to ignite the mixed gas ejected from the nozzle to form a jet flame.

[0058] Specifically, the solenoid valve of the injection pipeline is opened, allowing the hydrogen- or ammonia-mixed gas to be smoothly delivered to the nozzle along the injection pipeline and continuously sprayed outward. The ignition unit is activated, and the gas cylinder adjusts the output pressure through the pressure reducing valve to avoid abnormal pressure affecting the ignition effect. The solenoid valve opens synchronously according to a preset sequence, delivering stable pressure methane gas to the ignition nozzle through the first pipeline. The ignition coil is connected to the power supply to obtain stable electrical energy, driving the ignition probe to generate a high-intensity electric spark near the outlet of the ignition nozzle, igniting the hydrogen- or ammonia-mixed gas sprayed from the nozzle to form a stable jet flame.

[0059] It should be noted that in the embodiments of this application, the gas cylinder uses hydrogen-blended methane. In specific implementations, the gas cylinder may also use pure hydrogen, pure ammonia, hydrogen-blended fuel, ammonia-blended fuel, or a mixture of hydrogen and ammonia.

[0060] Step S404: Use an online laser spectroscopy analyzer to monitor the hydrogen or ammonia ratio of the gas in the mixing unit and / or injection pipeline in real time, while monitoring the actual flow rate or actual pressure of the injection unit.

[0061] Specifically, when the online laser spectrometer starts working, its built-in laser emits infrared laser of a specific wavelength. After the laser is absorbed by the hydrogen- or ammonia-doped mixed gas, the light intensity is attenuated. The detector receives the attenuated light intensity signal and completes the analysis, outputting the actual hydrogen or ammonia doping ratio of the mixed gas. If it is in flow control mode, the actual gas flow rate in the injection pipeline is collected in real time by the flow meter in the injection pipeline. If it is in pressure control mode, the actual gas pressure in the injection pipeline is collected in real time by the pressure sensor in the injection pipeline.

[0062] Step S405: When the monitored hydrogen or ammonia doping ratio is within the preset hydrogen or ammonia doping ratio range, and the actual flow rate is within the preset flow rate range or the actual pressure is within the preset pressure range, the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit are simultaneously triggered and started to collect data.

[0063] Specifically, when the actual hydrogen or ammonia doping ratio monitored by the online laser spectrometer is stable within the preset target hydrogen or ammonia doping ratio ±b, and the actual flow rate collected by the jet pipeline flow meter in flow control mode is stable within the ±a range, or the actual pressure collected by the jet pipeline pressure sensor in pressure control mode is stable within the ±d range, the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit are immediately triggered and started. The first high-speed camera of the combustion diagnostic unit captures the specific wavelength signal of OH / CH free radicals in the jet flame through the equipped narrow-band filter, and records the dynamic changes of the microscopic active region of combustion in real time. The second high-speed camera of the flame morphology unit synchronously collects the macroscopic morphological evolution image of the flame, forming a precise temporal and spatial mapping with the free radical distribution data of the first high-speed camera. The thermal disaster field measurement unit collects thermal radiation data through the heat flow meter on the side of the flame, and records it synchronously at high speed through the high-speed acquisition equipment.

[0064] Step S406: After the preset acquisition time is reached, shut down the combustion diagnostic unit, flame morphology unit, thermal disaster field measurement unit, gas supply unit, and ignition unit.

[0065] Specifically, when the acquisition duration meets the preset value c, the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit are shut down, and the image acquisition of the first high-speed camera and the second high-speed camera and the data recording of the heat flow meter are stopped. If it is a flow control mode, the readings of the fuel mass flow meter and the auxiliary mass flow meter are reset to zero, and then the fuel solenoid valve and the auxiliary solenoid valve are closed. Finally, the injection pipeline solenoid valve, the injection pipeline flow meter, and the first and third solenoid valves are closed. If it is a pressure control mode, the fuel solenoid valve, the auxiliary solenoid valve, the injection pipeline solenoid valve, the injection pipeline pressure sensor, and the second and fourth solenoid valves are closed directly. At the same time, the ignition unit is shut down, the power supply to the ignition coil is cut off, and the solenoid valves are closed to ensure that the jet flame is completely extinguished.

[0066] refer to Figure 5 This is a schematic diagram of the process for obtaining OH / CH radicals in a hydrogen- or ammonia-doped fuel jet fire test method according to an embodiment of this application. The obtaining of OH / CH radicals is carried out according to the following steps, which may include: Step S501: Obtain multiple frames of raw chemiluminescence images of the jet flame at characteristic wavelengths through the combustion diagnostic unit.

[0067] Specifically, narrowband filters can be used to screen out the characteristic emission spectra of OH / CH radicals (OH radicals at 306.4 nm or CH radicals at 431.5 nm), eliminating interference from background light and ambient stray light. The first high-speed camera is adapted to the time resolution required for the transient characteristics of jet fires and operates at high speed, dynamically capturing the real-time changes of the flame. Multiple frames of original chemiluminescence images are continuously captured under the same experimental conditions, and each image completely records the original luminescence signal of the flame area.

[0068] Step S502: The original chemiluminescence images of multiple frames are cropped, averaged and denoised, normalized and mirrored to obtain an axisymmetric two-dimensional average luminescence intensity distribution image.

[0069] Specifically, each original image is cropped to remove non-flame areas such as the background and device borders, retaining only the core flame area to reduce interference from irrelevant data in subsequent processing. Pixel-level multi-frame averaging denoising is performed on all cropped images under the same operating condition. The average image under that condition is obtained by averaging the brightness value of n images at the same pixel location, eliminating brightness fluctuations caused by flame fluctuations and camera noise. Combined with the transmittance T of the narrowband filter, the brightness value B of each pixel in the average image is normalized, as shown in the following formula:

[0070] in, The normalized brightness value is used to eliminate systematic errors caused by image intensifier gain and filter transmittance, so that the normalized brightness value can accurately reflect the chemiluminescence intensity of free radicals. Due to the axisymmetric characteristics of the free radical distribution in the hydrogen- or ammonia-doped fuel diffusion jet flame (with the jet center axis as the axis of symmetry), the normalized average image is mirrored (with the jet center axis as the reference, the pixel values ​​on one side of the image are mirrored to the other side) to form a complete axisymmetric two-dimensional average luminescence intensity distribution image, ensuring that the image meets the prerequisite requirement of "axisymmetric distribution" for subsequent Abel inverse transform.

[0071] It should be noted that the inverse Abel transform is a mathematical transformation method for axisymmetric distributions. It inverts the line integral signal along the line of sight into a radial point distribution signal. The original chemiluminescence image captured by the camera is the result of integration along the line of sight, that is, the brightness of each pixel is the accumulation of the luminescence intensity of all radial positions along that line of sight. It cannot directly reflect the true concentration of free radicals at a single radial position. The point distribution signal after inversion by the inverse Abel transform can remove the interference of the line of sight integration and present the free radical chemiluminescence intensity of each radial position of the flame from the central axis to the edge.

[0072] Step S503: Perform an inverse Abel transform on the axisymmetric two-dimensional average luminescence intensity distribution image to obtain the one-dimensional distribution of the chemiluminescence intensity of OH / CH radicals along the radial direction of the jet flame.

[0073] Specifically, first read the axisymmetric image output in step S502 above, and extract the integral value of the free radical chemiluminescence intensity along the line of sight (y-axis), where... For the image The cumulative luminous intensity at all radial positions along the line of sight, i.e., the raw signal captured by the camera, reflects the overall superposition effect along the line of sight rather than the true signal at a single radial position. For each radial coordinate in the image... ( , R The radical chemiluminescence intensity at that radial position (where the flame's maximum radial dimension) is obtained by inversion using the Abel inverse transform formula. The formula is:

[0074] in, The derivative of the integral value along the line of sight. As a geometric factor, this formula can eliminate the integral effect along the line of sight, thus transforming the "line integral signal" into a geometrically integrated signal. Converted into a "point distribution signal" Finally, the one-dimensional distribution of the chemiluminescence intensity of OH / CH radicals along the radial direction of the jet flame was obtained, with the abscissa representing the radial coordinate. r The vertical axis represents the radial position of the flame from the central axis to the edge, and the vertical axis represents the intensity of free radical chemiluminescence. The corresponding radial position corresponds to the concentration of OH / CH free radicals (luminescence intensity is positively correlated with free radical concentration).

[0075] refer to Figure 6 This is a flowchart illustrating the fire situation prediction process for a hydrogen- or ammonia-doped fuel jet fire test method according to an embodiment of this application. The fire situation prediction is performed according to the following steps, which may include: Step S601: Obtain experimental input parameters; wherein, the experimental input parameters include nozzle diameter, target hydrogen or ammonia doping ratio, target flow rate or target pressure.

[0076] Step S602: Obtain synchronously collected measured data; wherein, the measured data includes jet flame length, jet flame height, thermal radiation value and heat flux value.

[0077] Specifically, measured data is acquired synchronously through multiple devices. The flame videos captured by high-speed cameras are edited to obtain the required flame video segments. Each frame is converted to grayscale image, and the Otsu algorithm is used to binarize each frame to generate binary flame video segments. The binarized flame video segments are then superimposed to output an average probability distribution cloud map of the flame. This cloud map is then combined with the ratio between the video capture and the actual scene to obtain the average probability distribution cloud map of the flame, and the measured flame length is further extracted. Measured flame height The measured thermal radiation was obtained by time averaging the flame radiation and heat flow data collected during time segment c. Measured heat flux value .

[0078] It should be noted that the Otsu algorithm is an adaptive image thresholding segmentation algorithm that can automatically determine the optimal binarization threshold for grayscale images without manual intervention. Based on the criterion of maximizing inter-class variance, it divides image pixels into two classes: foreground (target region) and background (non-target region). It traverses all possible thresholds and calculates the inter-class variance of the corresponding two classes of pixels, and selects the threshold that maximizes the inter-class variance as the optimal segmentation threshold, thus achieving accurate separation of foreground and background.

[0079] Step S603: Based on the experimental input parameters, theoretical data are calculated using a preset physical model; the theoretical data includes theoretical jet flame length, theoretical jet flame height, theoretical thermal radiation value, and theoretical heat flux value.

[0080] Specifically, based on the nozzle diameter, the ratio of hydrogen or ammonia doping, and the gas pressure / flow rate in the injection pipeline, combined with the combustion physics of hydrogen- or ammonia-doped jet flames, a physical model of the flame length is obtained. Flame Height Physical Model Thermal radiation physical model Heat flow physical model Pressure, nozzle diameter, and hydrogen or ammonia doping ratio are used as model input parameters. These original parameters are normalized and scaled to the [0,1] interval to eliminate dimensional differences. The measured flame length is then used as the model input parameter. Flame height Radiation value Heat flux value Using these as experimental labels, and based on the four previously constructed physical models, the theoretical flame length for each set of data was calculated. Theoretical flame height Theoretical thermal radiation value Theoretical heat flux .

[0081] It should be noted that the physical model is an empirical formula based on classical combustion theory, and the hard-coded constraints are implemented by adding a regularization term of the physical model calculation results to the neural network loss function.

[0082] Step S604: Using the normalized input parameters and theoretical data as features, and the measured data as labels, construct a training sample set.

[0083] Specifically, based on the normalized nozzle diameter, hydrogen or ammonia doping ratio, and pressure, combined with the theoretical flame length... Theoretical flame height Theoretical thermal radiation value Theoretical heat flux To form a complete feature dimension, based on the measured flame length Measured flame height Measured radiation values Measured heat flux value As the corresponding label dimension, the features and label data of each working condition are matched and integrated, and multiple sets of matched samples together constitute a standardized training sample set.

[0084] Step S605: Construct and train a neural network prediction model that integrates the physical model based on the training sample set; wherein, the neural network prediction model takes the experimental input parameters as input, the hard-coded physical model in the structure of the neural network prediction model is used as a constraint, and the output of the neural network prediction model is the prediction data; wherein, the prediction data includes the predicted jet flame length, the predicted jet flame height, the predicted thermal radiation, and the predicted heat flux value.

[0085] As an optional embodiment, the training process of the neural network prediction model includes a first stage and a second stage; the first stage is to minimize the error between the predicted data and the measured data; the second stage is to enhance the consistency between the predicted data and the theoretical data.

[0086] Specifically, the constructed neural network prediction model adopts a hierarchical architecture design. The input layer has three nodes (corresponding to the normalized nozzle diameter, hydrogen or ammonia doping ratio, and pressure), and a physical constraint layer is added in the middle to incorporate the physical model of the flame length. Flame Height Physical Model Thermal radiation physical model Heat flow physical model Hard-coded embedding is used, with a hidden layer configured with 3 layers × 32 neurons. Complex nonlinear operations are used to simulate the complex relationship between experimental parameters and flame characteristics. The output layer has 4 nodes (predicting flame length, height, thermal radiation value, and heat flux value). Model training adopts a phased strategy with a dynamic weight adjustment mechanism. The first phase is basic fitting, which minimizes the mean square error between predicted and measured values ​​to make the predicted values ​​close to the measured values. The initial data loss weight is set to 1.0 and the physical loss weight is set to 0.3 to ensure data fitting accuracy. The second phase is physical constraint reinforcement, which adds physical consistency constraints to the loss function to ensure that the relative error between the predicted value and the theoretical model value is less than a preset threshold e. As the training progresses, the physical loss weight is gradually increased to 1.0. After the model is trained, it is tested using new data that was not used in the training. The average error between the predicted value and the measured value is calculated to verify physical consistency. The trained model is embedded into the console computer. In subsequent runs, if the prediction error of a new experiment exceeds the threshold f, the corresponding working condition parameters and measured values ​​are recorded. After accumulating g sets of new data, incremental training is started to continuously optimize the model's adaptability and prediction accuracy.

[0087] It should be noted that this system can improve the control accuracy of the hydrogen or ammonia doping ratio from ±5% of the traditional open-loop control to within ±1.5%; the time deviation of multi-sensor synchronous acquisition is less than 1 millisecond; and the prediction error of flame length based on the neural network model that integrates physical information is reduced by about 30% compared with the pure data-driven model.

[0088] In summary, the hydrogen- or ammonia-blended fuel jet fire test method of this invention is applied to a hydrogen- or ammonia-blended fuel jet fire test system as described above. The method includes: setting a target hydrogen or ammonia blending ratio and a target flow rate or target pressure at the nozzle; calculating and controlling the supply of fuel and hydrogen or ammonia in the gas supply unit according to the target hydrogen or ammonia blending ratio and the target flow rate or target pressure; opening the solenoid valve of the injection pipeline and starting the ignition unit to ignite the mixed gas ejected from the nozzle to form a jet flame; using an online laser spectral analyzer to monitor the hydrogen or ammonia blending ratio of the gas in the mixing unit and / or injection pipeline in real time, while simultaneously monitoring the actual flow rate or actual pressure of the injection unit; when the monitored hydrogen or ammonia blending ratio is within the preset hydrogen or ammonia blending ratio range, and the actual flow rate is within the preset flow rate range or the actual pressure is within the preset pressure range, simultaneously triggering and starting the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit to collect data; after reaching the preset acquisition time, shutting down the combustion diagnostic unit, flame morphology unit, thermal disaster field measurement unit, gas supply unit, and ignition unit. Therefore, this application can solve problems such as experimental scale distortion, fragmented disaster chain processes, and insufficient intelligent control, realizing integrated simulation of the entire chain from leakage and vapor cloud diffusion to fire decay. It can obtain experimental data that matches real major accidents, eliminating the data distortion and blind spots of segmented and isolated experiments, and reducing the management complexity and operational intensity of large-scale complex experiments.

[0089] It should be noted that the method of this embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this embodiment, and the multiple devices will interact with each other to complete the above method.

[0090] It should be noted that the above description describes some embodiments of the present invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than that shown in the above embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0091] refer to Figure 7 The diagram below is a block diagram of an electronic device according to some embodiments of the present invention. It illustrates a more specific hardware structure of an electronic device provided in this application embodiment. The device may include: a processor 710, a memory 720, an input / output interface 730, a communication interface 740, and a bus 750. The processor 710, memory 720, input / output interface 730, and communication interface 740 are internally connected to each other via the bus 750.

[0092] The processor 710 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0093] The memory 720 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 720 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 720 and is called and executed by the processor 710.

[0094] The input / output interface 730 is used to connect input / output modules to enable information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0095] The communication interface 740 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0096] Bus 750 includes a pathway for transmitting information between various components of the device, such as processor 710, memory 720, input / output interface 730, and communication interface 740.

[0097] It should be noted that although the above-described device only shows the processor 710, memory 720, input / output interface 730, communication interface 740, and bus 750, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0098] The electronic equipment described above is used to implement the corresponding hydrogen- or ammonia-doped fuel jet fire test method in any of the foregoing embodiments, and has the beneficial effects of the corresponding hydrogen- or ammonia-doped fuel jet fire test method embodiments, which will not be repeated here.

[0099] Based on the same concept, corresponding to the hydrogen- or ammonia-doped fuel jet fire test method provided in any of the above embodiments, this application also provides a computer-readable storage medium storing a program or instructions, which, when executed by a processor, implements the hydrogen- or ammonia-doped fuel jet fire test method as described above.

[0100] The aforementioned computer-readable storage medium can be any available medium or data storage device that a computer can access, including but not limited to magnetic storage (e.g., floppy disks, hard disks, magnetic tapes, magneto-optical disks (MOs), etc.), optical storage (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (e.g., ROMs, EPROMs, EEPROMs, non-volatile memory (NAND flash), solid-state drives (SSDs)).

[0101] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the corresponding hydrogen- or ammonia-doped fuel jet fire test method in any of the foregoing embodiments, and have the beneficial effects of the corresponding hydrogen- or ammonia-doped fuel jet fire test method embodiments, which will not be repeated here.

[0102] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0103] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0104] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A hydrogen- or ammonia-doped fuel jet fire experimental system, characterized in that, include: A disaster physical simulation subsystem (200), and a multi-dimensional synchronous sensing subsystem (300) connected to the disaster physical simulation subsystem (200) via signal connection; The disaster physics simulation subsystem (200) includes: The gas supply unit (201) includes a fuel cylinder group (1) for supplying fuel, an auxiliary cylinder group (10) for supplying hydrogen or ammonia, a nitrogen cylinder (19) for supplying nitrogen, and a pipeline system that connects each cylinder and is equipped with a control valve, flow measuring component and pressure measuring component corresponding to each cylinder. The gas mixing unit (202) includes a manifold (22) and a gas mixing tank (23). The output of each gas cylinder in the gas supply unit (201) is collected through the manifold (22) and input into the gas mixing tank (23) for gas mixing. The injection unit (203) includes an injection pipe (24) and a nozzle (25). The outlet of the mixing tank (23) is connected to the nozzle (25) through the injection pipe (24). The injection pipe (24) is provided with a flow measurement component and a pressure measurement component corresponding to the mixing tank (23). An ignition unit (204) is disposed near the nozzle (25) for igniting the mixed gas ejected from the nozzle (25); The multi-dimensional synchronous sensing subsystem (300) includes: Combustion diagnostic unit (301) is used to acquire the distribution information of OH / CH free radicals in the jet flame generated during the combustion of the mixed gas; Flame morphology unit (302) is used to acquire morphological images of the jet flame; Thermal disaster field measurement unit (303) is used to measure the thermal radiation and / or heat flow data of the jet flame; An online laser spectrometer (55) is used to analyze the hydrogen doping ratio of the gas in the gas mixing unit (202) and / or the injection line (24) in real time.

2. The hydrogen- or ammonia-doped fuel jet fire experimental system according to claim 1, characterized in that, The gas supply unit (201) includes: A fuel cylinder assembly (1) and a fuel pipeline (2) connected to the fuel cylinder assembly (1), wherein a fuel solenoid valve (3) is provided on the fuel pipeline (2), and a fuel flow control pipeline (4) and a fuel direct pipeline (5) are provided in parallel. A first solenoid valve (6) and a fuel mass flow meter (7) are provided on the fuel flow control pipeline (4), and a second solenoid valve (8) and a fuel pressure sensor (9) are provided on the fuel direct pipeline (5). An auxiliary gas cylinder group (10) and an auxiliary pipeline (11) connected to the auxiliary gas cylinder group (10) are provided with an auxiliary solenoid valve (12), and an auxiliary flow control pipeline (13) and an auxiliary straight-through pipeline (14) are provided in parallel. The auxiliary flow control pipeline (13) is provided with a third solenoid valve (15) and an auxiliary mass flow meter (16), and the auxiliary straight-through pipeline (14) is provided with a fourth solenoid valve (17) and an auxiliary pressure sensor (18). The nitrogen cylinder (19) is the nitrogen pipeline (20) connected to the nitrogen cylinder (19), and the nitrogen pipeline is equipped with a nitrogen solenoid valve (21).

3. The hydrogen- or ammonia-doped fuel jet fire experimental system according to claim 2, characterized in that, The gas mixing unit (202) includes: Manifold (22) and mixing tank (23); The output ends of the fuel line (2), the auxiliary line (11) and the nitrogen line (20) are all connected to the manifold (22), and the output end of the manifold (22) is connected to the inlet of the mixing tank (23).

4. The hydrogen- or ammonia-blended fuel jet fire experimental system according to claim 3, characterized in that, The injection unit (203) includes: The injection pipe (24) and the nozzle (25) installed at the end of the injection pipe (24); The outlet of the mixing tank (23) is connected to the injection pipeline (24), and the injection pipeline (24) is equipped with an injection pipeline solenoid valve (26), an injection pipeline flow meter (27), and an injection pipeline pressure sensor (28).

5. The hydrogen- or ammonia-blended fuel jet fire experimental system according to claim 4, characterized in that, The ignition unit (204) includes: Gas cylinder (29), pressure reducing valve (30), solenoid valve (31), ignition nozzle (32), ignition probe (33) and ignition coil (34); The pressure reducing valve (30) is installed on the gas cylinder (29) and connected to the ignition nozzle (32) through the first pipeline (35). The ignition coil (34) is connected to the power supply (36) and drives the ignition probe (33) to generate an electric spark.

6. The hydrogen- or ammonia-doped fuel jet fire experimental system according to claim 1, characterized in that, The multi-dimensional synchronous sensing subsystem (300) further includes a carbon soot micro-sampling unit (304), which includes: A retractable sampling rod (37) is provided at its front end with a silicon wafer fixing base (38) for fixing the sampling substrate; A linear drive mechanism is used to drive the retractable sampling rod (37) to move linearly; The linkage protective cover (39) includes a protective cover housing (40), a drive motor (41), and a door-shaped sealing structure (42), which is used to cover the silicon wafer fixing base (38) during non-sampling periods.

7. The hydrogen- or ammonia-blended fuel jet fire experimental system according to claim 6, characterized in that, The combustion diagnostic unit (305) includes a first high-speed camera (51) equipped with a narrow-band filter (50); the flame morphology unit (600) includes a second high-speed camera (52); and the thermal disaster field measurement unit (700) includes a heat flow meter (53) arranged on the side of the flame and a high-speed acquisition device (54) connected to the heat flow meter (53).

8. A method for testing hydrogen- or ammonia-doped fuel jet fires, characterized in that, The method, applied to the hydrogen- or ammonia-blended fuel jet fire experimental system as described in any one of claims 1-7, comprises: Set the target hydrogen or ammonia doping ratio and the target flow rate or target pressure at the nozzle; Based on the target hydrogen or ammonia blending ratio and the target flow rate or target pressure, calculate and control the supply of fuel and hydrogen or ammonia in the gas supply unit. Open the solenoid valve of the injection pipeline and start the ignition unit to ignite the mixed gas ejected from the nozzle to form a jet flame; The proportion of hydrogen or ammonia added to the gas in the mixing unit and / or injection pipeline is monitored in real time using a laser spectrometer, while the actual flow rate or actual pressure of the injection unit is also monitored. When the monitored hydrogen or ammonia doping ratio is within the preset hydrogen or ammonia doping ratio range, and the actual flow rate is within the preset flow rate range or the actual pressure is within the preset pressure range, the combustion diagnostic unit, flame morphology unit, and thermal disaster field measurement unit are simultaneously triggered and started to collect data. After the preset data collection time is reached, the combustion diagnostic unit, the flame morphology unit, the thermal disaster field measurement unit, the gas supply unit, and the ignition unit are shut down.

9. The experimental method for hydrogen- or ammonia-doped fuel jet fire according to claim 8, characterized in that, The method further includes: If the flow control mode is adopted, the first solenoid valve and fuel mass flow meter on the fuel flow control pipeline, as well as the third solenoid valve and auxiliary mass flow meter on the auxiliary flow control pipeline, are opened, and the target flow is controlled by adjusting the fuel mass flow meter and the auxiliary mass flow meter. If the pressure control mode is adopted, the second solenoid valve and fuel pressure sensor on the fuel direct line, as well as the fourth solenoid valve and auxiliary pressure sensor on the auxiliary direct line, are opened. The target pressure is controlled by adjusting the opening degree of the fuel solenoid valve corresponding to the fuel cylinder group and the auxiliary solenoid valve corresponding to the auxiliary cylinder group through feedback.

10. The experimental method for hydrogen- or ammonia-doped fuel jet fire according to claim 9, characterized in that, The method further includes: The combustion diagnostic unit acquires multiple frames of raw chemiluminescence images of the jet flame at characteristic wavelengths. The original chemiluminescence images of the multiple frames are cropped, multi-frame average denoising is performed, brightness is normalized and mirror symmetry is applied in sequence to obtain an axisymmetric two-dimensional average luminescence intensity distribution image. An inverse Abel transform is performed on the axisymmetric two-dimensional average luminescence intensity distribution image to obtain the one-dimensional distribution of the chemiluminescence intensity of OH / CH radicals along the radial direction of the jet flame.

11. The experimental method for hydrogen- or ammonia-doped fuel jet fire according to claim 10, characterized in that, The method further includes: Obtain experimental input parameters; wherein, the experimental input parameters include nozzle diameter, target hydrogen or ammonia doping ratio, target flow rate or target pressure; Acquire synchronously collected measured data; wherein, the measured data includes jet flame length, jet flame height, thermal radiation value, and heat flux value; Based on the experimental input parameters, theoretical data are calculated using a preset physical model; wherein, the theoretical data includes theoretical jet flame length, theoretical jet flame height, theoretical thermal radiation value, and theoretical heat flux value; A training sample set is constructed using the normalized input parameters and the theoretical data as features, and the measured data as labels. A neural network prediction model is constructed and trained based on the training sample set and fused with the physical model; wherein the neural network prediction model takes the experimental input parameters as input, the physical model is used as a constraint in the hard coding of the neural network prediction model structure, and the output of the neural network prediction model is prediction data; wherein the prediction data includes predicted jet flame length, predicted jet flame height, predicted thermal radiation, and predicted heat flux value.

12. The experimental method for hydrogen- or ammonia-doped fuel jet fire according to claim 11, characterized in that, The training process of the neural network prediction model includes a first stage and a second stage; The first stage is to minimize the error between the predicted data and the measured data; The second stage is to enhance the consistency between the predicted data and the theoretical data.

13. An electronic device, characterized in that, include: A processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the experimental method for hydrogen- or ammonia-blended fuel jet fire as described in any one of claims 8 to 12.

14. A computer-readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the experimental method for hydrogen- or ammonia-blended fuel jet fire as described in any one of claims 8 to 12.

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