An experimental apparatus and method for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines.

Abstract

This invention discloses an experimental apparatus and method for studying the leakage diffusion distribution and combustion / explosion response mechanism of buried hydrogen-blended gas pipelines. The apparatus includes a buried pipeline leakage chamber, a hydrogen-blended gas pipeline circulation system, a gas supply system, a pipeline leakage control system, a leak gas tracing system, an environmental wind control system, a sprinkler fire extinguishing system, an adjustable ignition system, a data acquisition system, a safety monitoring and alarm system, a synchronization controller, and a programmable controller. The gas supply system of this experimental apparatus can support research on the leakage diffusion characteristics of combustible gases under different blending ratios; the environmental wind simulation system simulates the impact of the natural environment on the leakage process; this application can comprehensively and accurately reproduce buried combustible gas leakage scenarios, providing reliable experimental support for leakage law research and prevention technology optimization, and improving energy transmission safety.

Description

Technical Field

[0001] This invention relates to an experimental apparatus, and more particularly to an experimental apparatus and method for the influence mechanism of leakage diffusion distribution and combustion explosion response of buried hydrogen-doped gas pipelines. Background Technology

[0002] With the continuous rise in demand for clean energy, buried gas pipelines, as a core infrastructure for energy transmission, have been widely used in various fields such as residential life and industrial production, and their scale and coverage are constantly expanding. However, buried gas pipelines are located in a complex underground environment and are susceptible to soil corrosion, external construction damage, pipeline aging, and other factors, leading to frequent gas leaks. Leaked methane, hydrogen, and other flammable gases can easily form explosive mixtures, which can cause deflagration, explosions, and other catastrophic accidents once they encounter a source of ignition. Therefore, building an experimental system that can accurately simulate buried flammable gas leak scenarios and explore leakage patterns has significant engineering significance and practical value for the prevention, monitoring, and emergency response to leak accidents.

[0003] Currently, buried combustible gas leakage simulation systems used in industrial sectors and research institutions have significant technical shortcomings, making it difficult to meet the needs of comprehensively and accurately investigating leakage patterns. For example, most existing simulation systems adopt a single-use gas supply mode and lack recirculating gas pipelines, resulting in the waste of methane, hydrogen, and other gas resources and hindering long-term stable leakage simulation experiments. Furthermore, most existing systems can only simulate single-component gas leaks, unable to flexibly adjust the methane-to-hydrogen ratio in the gas, making it difficult to explore the leakage diffusion characteristics and safety risks of combustible gases at different concentration ratios. The application of hydrogen-blended natural gas makes research on leaks of gases with different ratios increasingly important. In addition, existing systems lack structures to simulate natural environmental factors such as wind and rainfall, failing to reproduce the impact of natural factors on gas leakage diffusion in actual outdoor environments. This leads to significant deviations between experimental data and actual scenarios, making it difficult to provide accurate scientific evidence for leakage prevention and control, thus limiting in-depth research on the leakage patterns of buried combustible gases and the optimization and upgrading of prevention and control technologies.

[0004] To address the aforementioned technical shortcomings and compensate for the deficiencies of existing simulation systems, this patent proposes an experimental device and method for studying the leakage diffusion distribution and combustion / explosion response mechanisms of buried hydrogen-blended gas pipelines. A recyclable gas pipeline system is constructed to enable the reuse of gas resources and ensure the long-term stability of the experiment. A gas supply system is set up to flexibly adjust the composition and concentration of combustible gas, providing support for the study of the leakage diffusion characteristics of combustible gases under different blending ratios. An environmental wind simulation system is added to simulate the impact of the natural environment on the leakage process, improving the authenticity and practicality of the experimental data. This system can comprehensively and accurately reproduce buried combustible gas leakage scenarios, providing reliable experimental support for leakage law research and prevention technology optimization, and improving the safety of energy transmission. Summary of the Invention

[0005] Purpose of the invention: To provide an experimental apparatus and method for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines, and to solve the problems mentioned in the background art.

[0006] Technical solution: The experimental device for the leakage diffusion distribution and combustion and explosion response influence mechanism of buried hydrogen-blended gas pipeline provided by the present invention includes a buried pipeline leakage box, a hydrogen-blended gas pipeline circulation system, a gas supply system, a pipeline leakage control system, a leak gas tracing system, an ambient wind control system, a sprinkler fire extinguishing system, an adjustable ignition system, a data acquisition system, a safety monitoring and alarm system, a synchronization controller, and a programmable controller.

[0007] The buried pipeline leak box is an open-top box with a visible explosion-proof glass front wall; graduation scales are installed on the front edge of the buried pipeline leak box; and a backfill layer is installed at the bottom inside the buried pipeline leak box.

[0008] The pipeline leak control system, located within the landfill, simulates a damaged buried pipeline. A gas supply system delivers combustible gases of varying proportions to the hydrogen-blended gas pipeline circulation system. The hydrogen-blended gas circulation system circulates combustible gas to the pipeline leak control system while filtering impurities. A leak gas tracing system detects the diffusion trajectory of leaked combustible gas within the landfill. An ambient wind control system generates ambient wind within the buried pipeline leak chamber. An adjustable ignition system ignites the leaking combustible gas. A sprinkler fire suppression system extinguishes fires within the buried pipeline leak chamber. A data acquisition system collects data on gas concentration, temperature, radiant heat, and images within the buried pipeline leak chamber. A safety monitoring and alarm system provides safety alerts.

[0009] The hydrogen-blended gas pipeline circulation system, gas supply system, pipeline leakage control system, leak gas tracing system, ambient air control system, sprinkler fire extinguishing system, adjustable ignition system, data acquisition system, and safety monitoring and alarm system are all electrically connected to the synchronous controller and the program controller. The program controller records the data collected by the data acquisition system.

[0010] Furthermore, the hydrogen-blended gas pipeline circulation system includes nitrogen cylinders, premixed tanks, gas purifiers, gas buffer tanks, and molecular sieve dryers.

[0011] The outlet and return port of the premixed tank are connected by a sealed circulation pipe that penetrates the buried pipeline leak box. A gas purifier, a molecular sieve dryer, a gas buffer tank, and a second high-precision explosion-proof booster pump are connected in series along the circulation pipe from the outlet to the return port of the premixed tank. A pipeline leak control system is connected in series along the circulation pipe between the premixed tank and the gas purifier. A second explosion-proof solenoid valve is connected in series along the circulation pipe between the gas buffer tank and the second high-precision explosion-proof booster pump. A purge line is installed at the outlet of the gas purifier. A fifth explosion-proof solenoid valve is connected in series along the purge line. A first high-precision gas flow meter and a first explosion-proof pressure transmitter, located outside the buried pipeline leak box, are connected in series along the circulation pipes on both sides of the pipeline leak control system. A first explosion-proof solenoid valve is connected in series at the outlet of the premixed tank.

[0012] The nitrogen cylinder is connected to the inlet of the premixed tank via a nitrogen pipeline; a third high-precision explosion-proof booster pump, a second explosion-proof pressure transmitter, a second high-precision gas flow meter, and a ninth explosion-proof solenoid valve are connected in series on the nitrogen pipeline.

[0013] The second high-precision explosion-proof booster pump, the third high-precision explosion-proof booster pump, the first explosion-proof solenoid valve, the second explosion-proof solenoid valve, the fifth explosion-proof solenoid valve, the ninth explosion-proof solenoid valve, the second explosion-proof pressure transmitter, the second high-precision gas flow meter, each of the first high-precision gas flow meters, and each of the first explosion-proof pressure transmitters are all electrically connected to the synchronous controller and the program controller.

[0014] Furthermore, the pipeline leak control system includes two diverters and three leaking pipelines;

[0015] Three leaking pipes are detachably connected in parallel between two distributors; the two distributors are connected in series on the circulation pipe; corrugated flame arresters are connected in series on the circulation pipes on both sides of the pipe leak control system; each leaking pipe is provided with a leak hole, and each leak hole faces a different direction; each leak hole is covered with a sand-blocking and breathable mesh; an eighth explosion-proof solenoid valve is provided at the air inlet end of each leaking pipe; and a detection unit consisting of a pressure sensor, a flow velocity detector, and a flow rate detector is installed at both ends of each leaking pipe.

[0016] Each of the eighth explosion-proof solenoid valves and each detection unit is electrically connected to the synchronization controller and the program controller.

[0017] Furthermore, the gas supply system includes methane cylinders and hydrogen cylinders;

[0018] Methane cylinders and hydrogen cylinders are used to store methane and hydrogen respectively, and both are connected to the inlet of the premixed tank through gas supply pipelines; a third explosion-proof solenoid valve is connected in series on the gas supply pipeline; a fourth explosion-proof solenoid valve, a fifth explosion-proof pressure transmitter, and a fourth high-precision gas flow meter are connected in series in series on the outlet of both the methane cylinder and the hydrogen cylinder; the third explosion-proof solenoid valve, the fourth explosion-proof solenoid valve, the fifth explosion-proof pressure transmitter, and the fourth high-precision gas flow meter are all electrically connected to the synchronous controller and the program controller.

[0019] Furthermore, the leak gas tracing system includes a tracer gas cylinder and a non-contact infrared imaging leak detector;

[0020] The tracer gas cylinder is used to store SF6 gas; the tracer gas cylinder is connected to the tracer inlet of the premixed tank through a tracer pipeline; a fourth explosion-proof pressure transmitter, a third high-precision gas flow meter, a seventh explosion-proof solenoid valve, and an electric shut-off valve are connected in series on the tracer pipeline; a non-contact infrared imaging leak detector is located on the front side of the buried pipeline leak box, and is used to collect and monitor the diffusion trajectory image of the combustible gas leaking after mixing with SF6 gas in the landfill layer;

[0021] The non-contact infrared imaging leak detector, the fourth explosion-proof pressure transmitter, the third high-precision gas flow meter, the seventh explosion-proof solenoid valve, and the electric shut-off valve are all electrically connected to the synchronous controller and the program controller.

[0022] Furthermore, the environmental wind control system includes an anemometer, a wind power frequency converter box, and three frequency conversion flow equalization fans;

[0023] A grille ventilation opening is installed on the upper right side wall of the buried pipeline leak box; three variable frequency flow fans are all mounted on the buried pipeline leak box via brackets, with their air outlets facing the grille ventilation opening, and all are electrically connected to the wind power variable frequency control box; an anemometer is installed inside the buried pipeline leak box to detect wind speed; the wind power variable frequency control box and the anemometer are both electrically connected to the synchronous controller and the program controller.

[0024] Furthermore, the sprinkler fire extinguishing system includes an elevated water tank, a Y-type filter, a water pump frequency converter control box, a liquid pressure stabilizing tank, and a liquid recovery tank;

[0025] A parallel pipe is installed at the top opening of the buried pipeline leakage box; multiple pressure nozzles are installed on the parallel pipe; the high-level water tank is connected to the parallel pipe through an inlet pipe; a Y-type filter, a first high-precision explosion-proof booster pump, a pressure relief valve, a third explosion-proof pressure transmitter, and a sixth explosion-proof solenoid valve are connected in series on the inlet pipe; an overflow pipe is installed on the parallel pipe; a venting connector is installed at the end of the overflow pipe; a manual ball valve is connected in series on the overflow pipe; a drainage funnel located below the venting connector is installed on the liquid recovery tank through a recovery pipe; the first high-precision explosion-proof booster pump is electrically connected to the water pump frequency converter control box;

[0026] The water pump frequency converter control box, pressure relief valve, third explosion-proof pressure transmitter and sixth explosion-proof solenoid valve are all electrically connected to the synchronous controller and program controller.

[0027] Furthermore, the data acquisition system includes a gas concentration detection device, a temperature acquisition device, a radiant heat acquisition device, and an image acquisition device that are electrically connected to the synchronization controller and the program controller.

[0028] The gas concentration detection device includes a surface concentration detection unit and a subsurface concentration detection unit; the surface concentration detection unit is used to detect combustible gas concentration data above the landfill layer at multiple points; the subsurface concentration detection unit is used to detect combustible gas concentration data inside the landfill layer at multiple points.

[0029] The temperature acquisition device includes a surface temperature acquisition unit and a subsurface temperature acquisition unit; the surface temperature acquisition unit is used to collect temperature data above the landfill layer at multiple points; the subsurface temperature acquisition unit is used to collect temperature data inside the landfill layer at multiple points.

[0030] The radiant heat acquisition device is used to collect radiant heat data above the landfill layer after combustible gas is ignited at multiple points.

[0031] The image acquisition device is used to acquire infrared image data of the distribution of leaked combustible gas within and above the landfill layer, as well as image data of the flame distribution and impact range after the leaked combustible gas is ignited.

[0032] Furthermore, the adjustable ignition system includes an ignition electrode and an ignition energy regulator; the ignition electrode is installed in an adjustable position inside the buried pipeline leak box and is electrically connected to the synchronization controller and the program controller through the ignition energy regulator.

[0033] Furthermore, the present invention also provides an experimental method for an experimental apparatus for studying the leakage diffusion distribution and combustion and explosion response mechanism of buried hydrogen-doped gas pipelines, comprising the following steps:

[0034] 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 synchronous controller and programmable controller can effectively and accurately control the program and acquire data.

[0035] Step 2: System Adjustment: Adjust each system to the experimental state and debug each system to ensure that each system can work stably and reliably;

[0036] Step 3: Set experimental parameters: Set the corresponding start and stop control program in the program controller, determine the working status and parameters of the gas supply system, leak gas tracing system, ambient wind control system, and adjustable ignition system, fill the landfill layer and adjust the pipeline leak control system according to the experimental requirements.

[0037] Step 4: Conduct the experiment: The synchronous controller and programmable controller work together to control the operation of the gas supply system, hydrogen-blended gas pipeline circulation system, leak gas tracing system, ambient air control system, adjustable ignition system and safety monitoring and alarm system, and control the data acquisition system to collect data such as gas concentration, temperature, radiant heat and images. The programmable controller records the collected data.

[0038] Step 5: Repeat the experiment: After adjusting one experimental parameter according to the experimental requirements, repeat Step 4 until all experiments are completed;

[0039] Step Six: Shutdown of the device: After the experiment is completed, exhaust the gas in the hydrogen-blended gas pipeline circulation system and pipeline leakage control system, shut down all system components, and conduct a comprehensive check to ensure that each system is in a safe shutdown state, confirm that there is no residual pressure, no flammable or other leaks, and ensure that the test environment is safe and stable.

[0040] Step 7: Check and maintain equipment: Check the components of each system for damage and perform maintenance.

[0041] Compared with the prior art, the beneficial effects of this invention are:

[0042] First, it achieves accurate simulation under multiple operating conditions, covering all scenarios of hydrogen-blended gas leakage and explosion. This application can flexibly adjust the gas composition and ratio, leakage mode, leakage orifice diameter and size, and leakage location. At the same time, it can accurately simulate different landfill media (sand, loam, clay), landfill depth, environmental wind conditions, and other operating conditions. It can reproduce various leakage, diffusion, and explosion scenarios that may occur in buried hydrogen-blended gas pipelines in actual engineering, solving the problem of existing devices having single operating conditions and being out of touch with actual engineering. It provides a real and reliable experimental platform for the study of the impact mechanism.

[0043] Second, the measurement parameters are comprehensive and accurate, supporting in-depth analysis of the influencing mechanisms. This application integrates multiple types of monitoring components, including pressure, flow rate, temperature, gas concentration, and thermal radiation, enabling real-time acquisition and synchronous monitoring of various data. It boasts high measurement accuracy and good data synchronization, comprehensively capturing the dynamic evolution of leakage diffusion and combustion-explosion response. This provides precise data support for researching and revealing the intrinsic correlation between various influencing factors (hydrogen doping ratio, soil conditions, leakage parameters, etc.) and experimental results.

[0044] Third, it is easy to operate and highly safe, adaptable to the needs of multivariate comparative tests. This application uses a premixed tank to achieve the proportioning and stable supply of leaked combustible gas, and realizes the automated control of the entire test process through a synchronous controller and a programmable controller, reducing human operation errors; the leaking pipeline can be quickly disassembled and replaced, and the landfill medium can be flexibly laid and reconstructed, facilitating multivariate and multi-group comparative tests and greatly improving test efficiency; at the same time, this application can ensure that the equipment is shut down and there is no residual pressure or combustible gas leakage after the test through a comprehensive inspection, effectively avoiding safety risks during the test process and ensuring the safety of test personnel and the environment.

[0045] Fourth, it boasts strong technological innovation, featuring novel schemes and structural designs, and diverse experimental content. Targeting the unique physicochemical properties of combustible gases (hydrogen is flammable, explosive, and diffuses rapidly), a specially designed control and premixing structure adapted to the hydrogen doping ratio was developed. This combination of a hydrogen-doped gas pipeline circulation system, a gas supply system, a pipeline leak control system, and a leak gas tracing system solves the technical challenge of conventional combustible gas testing devices being unsuitable for hydrogen-doped media. It achieves integrated testing under multiple factors such as landfill media, leak parameters, and environmental conditions, filling the industry gap in dedicated testing devices for the leakage diffusion and explosion response mechanisms of buried hydrogen-doped gas pipelines. This provides crucial experimental technical support for the safety design, leak early warning, and explosion prevention of hydrogen-doped gas pipelines.

[0046] Fifth, it is highly practical, with a wide range of applications and significant value. This application can not only be used for basic research on the leakage diffusion and combustion explosion response mechanisms of buried hydrogen-blended gas pipelines, but also for the verification and optimization of leakage detection technology and combustion explosion prevention measures for hydrogen-blended gas pipelines, providing a scientific basis for the laying, operation, maintenance, and safety management of buried hydrogen-blended gas pipelines in engineering practice. The application has a reasonable structural design and strong versatility, allowing for flexible adjustment of operating parameters according to experimental needs, adapting to the experimental requirements of combustible gases with different hydrogen blending ratios, and possesses broad engineering application value and promising prospects for promotion. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the present invention;

[0048] Figure 2 This is an enlarged view of region A of the present invention;

[0049] Figure 3 This is an enlarged view of region B of the present invention;

[0050] Figure 4 This is a cross-sectional view (CC) of the present invention.

[0051] Figure 5 This is a schematic diagram of the slide rail for the buried pipeline leakage box of the present invention;

[0052] Figure 6 This is a graph showing the horizontal diffusion radius curves of methane at HBR=0% and HBR=20% according to the present invention;

[0053] In the diagram: 1. Buried pipeline leakage box; 2. Premixed tank; 3-1. First explosion-proof pressure transmitter; 3-2. Second explosion-proof pressure transmitter; 3-3. Third explosion-proof pressure transmitter; 3-4. Fourth explosion-proof pressure transmitter; 3-5. Fifth explosion-proof pressure transmitter; 4-1. First explosion-proof solenoid valve; 4-2. Second explosion-proof solenoid valve; 4-3. Third explosion-proof solenoid valve; 4-4. Fourth explosion-proof solenoid valve; 4-5. Fifth explosion-proof solenoid valve; 4-6. Sixth explosion-proof solenoid valve; 4-7. Seventh explosion-proof solenoid valve; 4-8. Eighth explosion-proof solenoid valve; 4-9. Ninth explosion-proof solenoid valve; 5-1. First high-precision gas flow meter; 5-2. Second high-precision gas flow meter; High-precision gas flow meter; 5-3, Third high-precision gas flow meter; 5-4, Fourth high-precision gas flow meter; 6-1, First spring-loaded check valve; 6-2, Second spring-loaded check valve; 6-4, Fourth spring-loaded check valve; 6-6, Sixth spring-loaded check valve; 6-7, Seventh spring-loaded check valve; 6-8, Eighth spring-loaded check valve; 7, Electric shut-off valve; 8, Pipe support; 9, Corrugated flame arrester; 10, Rubber sealing ring; 11, Diverter; 12, Sand-blocking and breathable mesh cover; 13, Tracer gas cylinder; 14, Methane cylinder; 15, Hydrogen cylinder; 16, High-level water tank; 17, Y-type filter; 18-1, First high-precision explosion-proof booster pump; 18-2, Second high-precision explosion-proof booster pump; 18-3, Third high-precision explosion-proof booster pump; 19, Liquid pressure stabilizing tank; 20-1, Water pump frequency converter control box; 20-2, Wind power frequency converter control box; 21, Ignition electrode; 22, Pressure relief valve; 23, High-speed infrared thermal imager; 24, High-speed camera; 25, Non-contact infrared imaging leak detector; 26, Programmable controller; 27, Audible and visual alarm; 28, Buried gas concentration detector; 29, Surface gas concentration detector; 30, Synchronization controller; 31, Ignition energy regulator; 32, Variable frequency flow equalization fan; 33, Wind speed tester; 34, Gas purifier; 35, Gas buffer tank; 36, ... 37. Sieve dryer; 38. Manual ball valve; 39. Vent connector; 40. Drain funnel; 41. Liquid recovery tank; 42. Anti-static grounding device; 43. Pressure nozzle; 44. High-temperature thermocouple; 45. Radiant heat flow meter; 45-1. First gas concentration detector; 45-2. Second gas concentration detector; 46. High-frequency temperature transmitter; 47. Sand; 48. Loam; 49. Clay; 50. Nitrogen cylinder; 51. Leakage pipe; 52. Adjusting track frame; 53. Adjusting vertical rod; 54. Adjusting longitudinal rod; 55. Vertical rod sliding seat; 56. Longitudinal rod sliding seat; 57. Positioning mounting seat; 58. Rigid support rod; 59. Sliding rod. Detailed Implementation

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Example 1:

[0058] like Figure 1-6 As shown, the experimental device for the leakage diffusion distribution and combustion and explosion response influence mechanism of buried hydrogen-doped gas pipeline provided by the present invention includes: buried pipeline leakage box 1, hydrogen-doped gas pipeline circulation system, gas supply system, pipeline leakage control system, leakage gas tracing system, ambient wind control system, sprinkler fire extinguishing system, adjustable ignition system, data acquisition system, safety monitoring and alarm system, synchronous controller 30 and program controller 26.

[0059] The buried pipeline leakage box 1 is an open-top box structure, and the front side wall of the buried pipeline leakage box 1 is made of visible explosion-proof glass; universal wheels are installed at the four top corners of the bottom surface of the buried pipeline leakage box 1; scales are installed on the left, right and lower edges of the front side of the buried pipeline leakage box 1; and a backfill layer is installed at the bottom inside the buried pipeline leakage box 1.

[0060] The pipeline leak control system is located within the landfill layer and is used to simulate a damaged buried pipeline; the gas supply system is used to deliver combustible gases with different component ratios to the hydrogen-blended gas pipeline circulation system; the hydrogen-blended gas pipeline circulation system circulates combustible gases to the pipeline leak control system and filters impurities; the leak gas tracing system is used to detect the diffusion trajectory of leaked combustible gases in the landfill layer; the ambient wind control system is used to generate ambient wind within the buried pipeline leak box 1; the adjustable ignition system is used to ignite the leaked combustible gases; the sprinkler fire extinguishing system is used to spray and extinguish fires within the buried pipeline leak box 1; the data acquisition system is used to collect data such as gas concentration, temperature, radiant heat, and images within the buried pipeline leak box 1; and the safety monitoring and alarm system is used to issue safety alarms.

[0061] The hydrogen-blended gas pipeline circulation system, gas supply system, pipeline leakage control system, leak gas tracing system, ambient air control system, sprinkler fire extinguishing system, adjustable ignition system, and data acquisition system are all electrically connected to the synchronous controller 30 and the program controller 26, and the program controller 26 records the data collected by the data acquisition system.

[0062] The safety monitoring and alarm system includes an anti-static grounding device 41, an audible and visual alarm 27, multiple buried gas concentration detectors 28, and multiple surface gas concentration detectors 29.

[0063] The audible and visual alarm 27, the gas concentration detectors 28 in each buried layer, and the gas concentration detectors 29 on the surface are all electrically connected to the synchronous controller 30 and the program controller 26; the anti-static grounding device 41 is used to ground the components for protection.

[0064] This application establishes a recyclable loop through a hydrogen-blended gas pipeline circulation system, a gas supply system, and a pipeline leakage control system, enabling the reuse of combustible gas and ensuring the long-term stable operation of experiments. The gas supply system allows for flexible adjustment of the gas composition and concentration, providing support for research on the leakage and diffusion characteristics of combustible gases under different blending ratios. An environmental wind simulation system is used to recreate the impact of the natural environment on the leakage process, improving the authenticity and practicality of experimental data. This application can comprehensively and accurately reproduce buried combustible gas leakage scenarios, providing reliable experimental support for leakage law research and prevention technology optimization, and improving the safety of energy transmission.

[0065] Using landfill layers to simulate underground conditions, researchers can simulate and analyze the leakage of combustible gases at the surface and underground. The landfill layer consists of three media: sand (47), loam (48), and clay (49). Landfill layer parameters, such as the type of media, the order of media placement, the thickness of each layer, and the degree of media mixing, can be adjusted according to experimental needs. By adjusting these parameters, the overall porosity of the landfill layer can be changed, allowing for the study of the relationship between the overall porosity and the gas leakage rate. Based on this, Formula I is proposed to analyze the correlation between the gas leakage rate and the landfill layer parameters:

[0066] Ⅰ

[0067] In the formula: The gas mass leakage rate associated with the landfill medium; The pressure of the flammable gas inside the leaking pipe 51; This refers to the thickness of the landfill layer; The comprehensive porosity of the landfill layer.

[0068] Furthermore, the hydrogen-blended gas pipeline circulation system includes a nitrogen cylinder 50, a premixed tank 2, a gas purifier 34, a gas buffer tank 35, and a molecular sieve dryer 36.

[0069] The outlet and return port of the premix tank 2 are connected by a circulation pipe; multiple pipe supports 8 are provided on the circulation pipe for support; a gas purifier 34, a molecular sieve dryer 36, a gas buffer tank 35 and a second high-precision explosion-proof booster pump 18-2 are connected in series from the outlet to the return port of the premix tank 2 on the circulation pipe; a pipeline leakage control system is connected in series on the circulation pipe between the premix tank 2 and the gas purifier 34; the circulation pipe horizontally penetrates the lower side of the left and right side walls of the buried pipeline leakage box 1, and a rubber sealing ring 10 is sealed between the penetration point of the circulation pipe and the buried pipeline leakage box 1;

[0070] A second explosion-proof solenoid valve 4-2 is connected in series on the circulation pipeline between the gas buffer tank 35 and the second high-precision explosion-proof booster pump 18-2; a second spring check valve 6-2 is connected in series on the circulation pipeline between the second high-precision explosion-proof booster pump 18-2 and the premix tank 2; a purging pipeline is provided at the outlet of the gas purifier 34; a fifth explosion-proof solenoid valve 4-5 is connected in series on the purging pipeline;

[0071] Two first spring-loaded check valves 6-1 are connected in series on the circulation pipe between the premix tank 2 and the gas purifier 34, and the buried pipeline leakage box 1 is located between the two first spring-loaded check valves 6-1; a first high-precision gas flow meter 5-1 and a first explosion-proof pressure transmitter 3-1 are connected in series on the circulation pipes on both sides of the buried pipeline leakage box 1; a first explosion-proof solenoid valve 4-1 is connected in series on the circulation pipe between the first high-precision gas flow meter 5-1 and the first explosion-proof pressure transmitter 3-1 on the gas outlet side of the premix tank 2;

[0072] Nitrogen cylinder 50 is connected to the inlet of premix tank 2 via nitrogen pipeline; the nitrogen pipeline is connected in series with the third high-precision explosion-proof booster pump 18-3, the second explosion-proof pressure transmitter 3-2, the second high-precision gas flow meter 5-2, the eighth spring check valve 6-8 and the ninth explosion-proof solenoid valve 4-9.

[0073] The second high-precision explosion-proof booster pump 18-2, the third high-precision explosion-proof booster pump 18-3, the first explosion-proof solenoid valve 4-1, the second explosion-proof solenoid valve 4-2, the fifth explosion-proof solenoid valve 4-5, the ninth explosion-proof solenoid valve 4-9, the second explosion-proof pressure transmitter 3-2, the second high-precision gas flow meter 5-2, each of the first high-precision gas flow meters 5-1, and each of the first explosion-proof pressure transmitters 3-1 are all electrically connected to the synchronous controller 30 and the program controller 26.

[0074] The first explosion-proof pressure transmitter 3-1 on the outlet side of the premixed tank 2 helps the synchronous controller 30 and the program controller 26 monitor the pressure of the mixed gas inside the premixed tank 2. The first high-precision gas flow meter 5-1 on the outlet side of the premixed tank 2 helps the synchronous controller 30 and the program controller 26 monitor and control the mass flow rate of the combustible gas before it leaks through the pipeline control system. The first explosion-proof pressure transmitter 3-1 and the first high-precision gas flow meter 5-1 on the inlet side of the gas purifier 34 help the synchronous controller 30 and the program controller 26 monitor the pressure and mass flow rate of the combustible gas after it leaks through the pipeline control system. Two first spring-loaded check valves 6-1 are used to prevent the combustible gas from flowing back.

[0075] The combustible gas in the circulation pipeline is filtered, dried, and recovered using a gas purifier 34, a molecular sieve dryer 36, and a gas buffer tank 35 to ensure its purity. Any unleashed combustible gas is filtered, dried, and recovered into the gas buffer tank 35, where it can be mixed with nitrogen from the nitrogen cylinder 50 at a set concentration ratio and reused. This recycling scheme is safe, stable, and feasible, enabling the recycling of experimental gases and energy conservation and emission reduction. After the experiment, the fifth explosion-proof solenoid valve 4-5 is used to open the purge line and release the mixed gas in the circulation pipeline.

[0076] The program controller 26 records the data collected by the second high-precision explosion-proof booster pump 18-2, the third high-precision explosion-proof booster pump 18-3, the second explosion-proof pressure transmitter 3-2, the second high-precision gas flow meter 5-2, each of the first high-precision gas flow meters 5-1, and each of the first explosion-proof pressure transmitters 3-1.

[0077] Furthermore, the pipeline leakage control system includes two diverters 11 and three leakage pipelines 51;

[0078] Three leaking pipes 51 are detachably connected in parallel between two diverters 11; the two diverters 11 are connected in series on the circulation pipe; corrugated flame arresters 9 located inside the buried pipeline leak box 1 are connected in series on the circulation pipes on both sides of the pipeline leak control system; each leaking pipe 51 is provided with a leak hole, and each leak hole faces a different direction; each leak hole is covered with a sand-blocking and breathable mesh 12; an eighth explosion-proof solenoid valve 4-8 is provided at the air inlet end of each leaking pipe 51.

[0079] At both ends of each leaking pipe 51, a detection unit consisting of a pressure sensor, a flow velocity detector, and a flow rate detector is installed.

[0080] Each of the eighth explosion-proof solenoid valves 4-8 and each detection unit is electrically connected to the synchronization controller 30 and the program controller 26.

[0081] A sand-blocking and breathable covering net 12 is used to prevent landfill soil from entering the leaking pipe 51 and contaminating the combustible gas; a corrugated flame arrester 9 is used to prevent the leaked combustible gas from being ignited and exploding, causing combustion inside the leaking pipe 51 to spread into the circulation pipe; a synchronous controller 30 and a programmable controller 26 can achieve separate conduction control of the three leaking pipes 51 through three eighth explosion-proof solenoid valves 4-8, allowing combustible gas to leak in different directions through corresponding leak holes by opening different leaking pipes 51, thus realizing the leakage test of combustible gas in different directions in the landfill; the pressure, flow velocity, and flow rate data inside the leaking pipe 51 are measured by a detection unit, and the data are recorded by the programmable controller 26. According to the design, the leakage pipe 51 is a single-variable controllable design, comprising multiple sets of experimental pipes with only one leakage pipe parameter changed. These parameters include the leakage orifice diameter, leakage location, and leakage orifice shape. Only one leakage pipe parameter differs between each set of pipes, enabling multi-condition comparative experiments on the diffusion of buried hydrogen-blended gas leaks. By replacing the leakage pipe 51, the influence of different leakage orifice diameters, orifice shapes, and leakage directions on the leakage rate can be measured, thereby analyzing the mechanism by which the shape, direction, and size of the leakage orifice affect flammable gas leakage. Based on this, Formula II is proposed to analyze the correlation between the gas leakage rate and leakage pipe parameters such as leakage orifice diameter, orifice shape, and leakage direction.

[0082] II

[0083] In the formula: The gas quality leakage rate is related to the parameters of the leaking pipeline. The diameter of the leakage hole; This is a correction factor for the shape of the leakage hole; This is the correction factor for the direction of the leakage hole.

[0084] Furthermore, the gas supply system includes a methane cylinder 14 and a hydrogen cylinder 15;

[0085] Methane cylinder 14 and hydrogen cylinder 15 are used to store methane and hydrogen, respectively. Both methane cylinder 14 and hydrogen cylinder 15 are connected to the inlet of premixed tank 2 through gas supply pipelines. A third explosion-proof solenoid valve 4-3 is connected in series on the gas supply pipeline. A fourth explosion-proof solenoid valve 4-4, a fifth explosion-proof pressure transmitter 3-5, a fourth high-precision gas flow meter 5-4, and a fourth spring-loaded check valve 6-4 are connected in series on the outlet of both methane cylinder 14 and hydrogen cylinder 15. The third explosion-proof solenoid valve 4-3, the fourth explosion-proof solenoid valve 4-4, the fifth explosion-proof pressure transmitter 3-5, and the fourth high-precision gas flow meter 5-4 are all electrically connected to the synchronous controller 30 and the program controller 26.

[0086] Methane cylinder 14 and hydrogen cylinder 15 are used to supply gas to the premixing tank 2. Synchronous controller 30 and programmable controller 26 control the opening and closing of methane cylinder 14 and hydrogen cylinder 15 respectively via fourth explosion-proof solenoid valves 4-4 installed at their respective outlets. Two fifth explosion-proof pressure transmitters 3-5 monitor and record the delivery pressure of methane and hydrogen respectively. Two fourth high-precision gas flow meters 5-4 monitor, record, and adjust the flow rates of methane and hydrogen, thereby controlling the ratio of methane to hydrogen. This facilitates experiments mixing combustible gases of different components and ratios. The fourth spring-type check valve 6-4 is used to prevent the backflow of combustible gas in the premixed tank 2; the pressure in the premixed tank 2 can be controlled by controlling the flow rates of the methane cylinder 14 and the hydrogen cylinder 15, thereby controlling the leakage rate of the leakage pipeline 51; furthermore, the relationship between the gas leakage rate and factors such as the flow rate, pressure, and hydrogen blending ratio of the combustible gas are analyzed under the same leakage orifice diameter, leakage orifice shape, and leakage direction; based on this, Formula III is proposed to analyze the correlation between the gas leakage rate and the circulation pipeline parameters such as the flow rate, pressure, and hydrogen blending ratio of the combustible gas in the leakage pipeline 51.

[0087] III

[0088] In the formula: The gas quality leakage rate is related to the parameters of the circulation pipeline. The velocity of the combustible gas inside the leaking pipe 51; The pressure of the flammable gas inside the leaking pipe 51; This refers to the hydrogen blending ratio of the fuel gas.

[0089] Furthermore, the leak gas tracing system includes a tracer gas cylinder 13 and a non-contact infrared imaging leak detector 25;

[0090] The tracer cylinder 13 is used to store SF6 gas and is connected to the tracer inlet of the premixed tank 2 through a tracer pipeline; the tracer pipeline from the tracer cylinder 13 to the premixed tank 2 is connected in series with the fourth explosion-proof pressure transmitter 3-4, the third high-precision gas flow meter 5-3, the seventh spring check valve 6-7, the seventh explosion-proof solenoid valve 4-7 and the electric shut-off valve 7.

[0091] The non-contact infrared imaging leak detector 25 is located on the front side of the buried pipeline leak box 1 and is used to collect images of the diffusion trajectory of the combustible gas leaking after mixing with SF6 gas in the landfill layer.

[0092] The non-contact infrared imaging leak detector 25, the fourth explosion-proof pressure transmitter 3-4, the third high-precision gas flow meter 5-3, the seventh explosion-proof solenoid valve 4-7, and the electric shut-off valve 7 are all electrically connected to the synchronous controller 30 and the program controller 26.

[0093] The synchronous controller 30 and the program controller 26 monitor and record the pipeline pressure of the tracer pipeline through the fourth explosion-proof pressure transmitter 3-4, monitor, record and control the flow rate of SF6 gas in the tracer pipeline through the third high-precision gas flow meter 5-3, thereby controlling the amount of SF6 gas added proportionally, realize the opening or closing of the tracer pipeline through the seventh explosion-proof solenoid valve 4-7, ensure the final delivery state of the tracer pipeline through the electric shut-off valve 7, and collect and record the diffusion trajectory image of the leaked combustible gas mixed with SF6 gas in the landfill layer through the non-contact infrared imaging leak detector 25, thereby obtaining a more accurate diffusion trajectory map of the leaked combustible gas.

[0094] Furthermore, the environmental wind control system includes an anemometer 33, a wind power frequency converter control box 20-2, and three frequency conversion flow equalization fans 32;

[0095] A grille ventilation opening is provided on the upper right side wall of the buried pipeline leakage box 1; three variable frequency flow equalizing fans 32 are all mounted on the buried pipeline leakage box 1 by brackets, and the air outlets are all facing the grille ventilation opening. The three variable frequency flow equalizing fans 32 are all electrically connected to the wind power variable frequency control box 20-2; an anemometer 33 is installed inside the buried pipeline leakage box 1 to detect wind speed; the wind power variable frequency control box 20-2 and the anemometer 33 are all electrically connected to the synchronous controller 30 and the program controller 26.

[0096] When the experiment needs to analyze the influence of environmental factors, namely wind speed, on the diffusion of leaked combustible gas above the landfill layer, the synchronous controller 30 and the program controller 26 control the output wind speed of the three variable frequency flow equalizing fans 32 through the wind power variable frequency control box 20-2, and further adjust the output wind speed of the three variable frequency flow equalizing fans 32 by monitoring and recording the feedback data through the anemometer 33 until the wind speed detected by the anemometer 33 reaches the set value, thereby simulating the environmental wind speed.

[0097] Furthermore, the sprinkler fire extinguishing system includes an elevated water tank 16, a Y-type filter 17, a water pump frequency conversion control box 20-1, a liquid pressure stabilizing tank 19, and a liquid recovery tank 40;

[0098] At the top opening of the buried pipeline leakage box body 1, there is a parallel pipe in a shape like a Chinese character 'Ri' in the top view state; three pressure spray nozzles 42 are arranged at intervals on the three parallel branches of the parallel pipe; the high-level water tank 16 is connected to the parallel pipe through a water inlet pipe; from the high-level water tank 16 to the parallel pipe on the water inlet pipe, a Y-type filter 17, a first high-precision explosion-proof booster pump 18-1, a sixth spring-type check valve 6-6, a pressure relief valve 22, a third explosion-proof pressure transmitter 3-3, and a sixth explosion-proof solenoid valve 4-6 are connected in series in sequence; a drain overflow pipe is arranged on the parallel pipe; a drain joint 38 is arranged at the end of the drain overflow pipe; a manual ball valve 37 is connected in series on the drain overflow pipe; a recovery pipe is connected and installed on the liquid recovery tank 40; a drain funnel 39 is installed at the upper end of the recovery pipe, and the drain funnel 39 is used to receive the water discharged from the drain joint 38;

[0099] The first high-precision explosion-proof booster pump 18-1 is electrically connected to the water pump frequency conversion control box 20-1; the water pump frequency conversion control box 20-1, the pressure relief valve 22, the third explosion-proof pressure transmitter 3-3, and the sixth explosion-proof solenoid valve 4-6 are all electrically connected to the synchronous controller 30 and the program controller 26.

[0100] The synchronous controller 30 and the program controller 26 control the output power of the first high-precision explosion-proof booster pump 18-1 through the water pump frequency conversion control box 20-1, and then control the water outlet pressure of the pressure spray nozzle 42. Pressure monitoring, recording and feedback are carried out through the third explosion-proof pressure transmitter 3-3, and then the output power of the first high-precision explosion-proof booster pump 18-1 is adjusted through the water pump frequency conversion control box 20-1 until the pressure monitored by the third explosion-proof pressure transmitter 3-3 reaches the set value, so as to adjust the output efficiency of the pressure spray nozzle 42; the water in the high-level water tank 16 is pressurized by the first high-precision explosion-proof booster pump 18-1, and then the water pressure is made constant by the liquid pressure stabilizing tank 19. The excessive pressure in the water inlet pipe is discharged through the pressure relief valve 22; the array installation of each pressure spray nozzle 42 can achieve efficient fire extinguishing; the manual ball valve 37 and the drain joint 38 are used to empty the parallel pipe when the spraying work stops, and the drain funnel 39 is used to recover the water discharged from the drain joint 38, and the discharged water is recovered by the liquid recovery tank 40.

[0101] Furthermore, the data acquisition system includes a gas concentration detection device, a temperature acquisition device, a radiant heat acquisition device, and an image acquisition device;

[0102] Two adjusting brackets are installed in the buried pipeline leakage box body 1; the adjusting bracket includes an adjusting track frame 52, three adjusting longitudinal rods 54, and four adjusting vertical rods 53;

[0103] The adjusting track frames 52 of the two adjusting brackets are respectively installed on the inner walls of the left and right sides of the buried pipeline leakage box 1; the front and rear ends of each adjusting longitudinal rod 54 are respectively vertically slidably installed on the front and rear side frames of the adjusting track frame 52 through the longitudinal rod sliding seat 56; the upper and lower ends of each adjusting vertical rod 53 are respectively vertically slidably installed on the upper and lower side frames of the adjusting track frame 52 through the vertical rod sliding seat 55; three positioning mounting seats 57 are vertically adjustable on each adjusting vertical rod 53, and the three positioning mounting seats 57 on each adjusting vertical rod 53 are respectively vertically adjustable on the three adjusting longitudinal rods 54; a rigid support rod 58 is horizontally installed on each positioning mounting seat 57;

[0104] The gas concentration detection device includes a surface concentration detection unit and a subsurface concentration detection unit;

[0105] The surface detection unit includes multiple first gas concentration detectors 45-1; the underground detection unit includes multiple second gas concentration detectors 45-2.

[0106] The first gas concentration detector 45-1 is arranged in pairs, and each pair of first gas concentration detectors 45-1 is slidably and adjustablely installed on each rigid support rod 58.

[0107] Three sliding rods 59 are fixed between the left and right side walls of the buried pipeline leakage box 1; each sliding rod 59 is located in the landfill layer above the pipeline leakage control system; the second gas concentration detectors 45-2 are grouped into groups of three, and each group of second gas concentration detectors 45-2 is slidably and adjustablely installed on each sliding rod 59; each first gas concentration detector 45-1 and each second gas concentration detector 45-2 are electrically connected to the synchronous controller 30 and the program controller 26.

[0108] The temperature acquisition device includes a surface temperature acquisition unit and a subsurface temperature acquisition unit;

[0109] The surface temperature acquisition unit includes multiple high-temperature thermocouples 43; the underground temperature acquisition unit includes multiple high-frequency temperature transmitters 46; a three-pronged support is installed at the ends of the two rigid support rods 58 in the middle of each adjustment bracket; each high-temperature thermocouple 43 is installed at the ends of each branch rod of each three-pronged support; each high-frequency temperature transmitter 46 is installed in the middle of each slide rod 59; each high-temperature thermocouple 43 and each high-frequency temperature transmitter 46 are electrically connected to the synchronous controller 30 and the program controller 26.

[0110] The radiative heat acquisition device includes multiple radiative heat flow meters 44; each radiative heat flow meter 44 is respectively installed on a rigid support rod 58 located at the edge, and is electrically connected to the synchronous controller 30 and the program controller 26.

[0111] The image acquisition device includes a high-speed infrared thermal imager 23 and a high-speed camera 24; both the high-speed infrared thermal imager 23 and the high-speed camera 24 are installed on the front side of the buried pipeline leakage box 1, and are electrically connected to the synchronous controller 30 and the program controller 26.

[0112] Synchronous controller 30 and program controller 26 monitor and record the concentration of combustible gas above and inside the landfill layer via second gas concentration detector 45-2 and first gas concentration detector 45-1, respectively. Each second gas concentration detector 45-2 and each first gas concentration detector 45-1 is located at a different detection position, enabling multi-dimensional data acquisition. This helps researchers analyze the differences in the horizontal diffusion radius of methane reaching the lower explosive limit under different hydrogen doping ratios in HBR operation. Figure 6 As shown, it clearly reveals the characteristics of the horizontal diffusion radius of methane reaching the lower explosion limit over time under the conditions of hydrogen doping ratio HBR=0% and HBR=20%, providing intuitive data support for researchers to quantitatively analyze the impact of hydrogen doping ratio on the diffusion range of flammable gas leaking from leaking pipeline 51 and the explosion risk boundary.

[0113] Synchronous controller 30 and program controller 26 monitor and record the temperature at different locations above the middle of the landfill after the leaked combustible gas is ignited, as well as the temperature signals at different depths inside the landfill after the leaked combustible gas is ignited, through high-temperature thermocouple 43 and high-frequency temperature transmitter 46, respectively.

[0114] The synchronous controller 30 and the program controller 26 monitor and record the radiant heat at different locations above the landfill after the leaked combustible gas is ignited by the radiant heat flow meter 44, collect and record infrared images of the distribution of the leaked combustible gas inside and above the landfill by the high-speed infrared thermal imager 23, and collect and record images of the flame distribution and the range of influence after the leaked combustible gas is ignited by the high-speed camera 24 to help researchers conduct subsequent data analysis.

[0115] When the second gas concentration detector 45-2 or the first gas concentration detector 45-1 detects that the concentration of the leaked combustible gas has reached the critical value of the explosion limit, the synchronous controller 30 and the program controller 26 control the audible and visual alarm 27 to issue an audible and visual alarm signal. Through the early warning measures of the audible and visual alarm, researchers are reminded to carry out adjustment and shutdown operations, realize safety warning and protection operations in the experimental process, and ensure the safety of the buried hydrogen-doped gas leakage and explosion experiment.

[0116] Each buried layer gas concentration detection lamp 28 corresponds to each second gas concentration detector 45-2. When any second gas concentration detector 45-2 detects leaked combustible gas, the synchronization controller 30 and the program controller 26 control the corresponding buried layer gas concentration detection lamp 28 to light up and emit a light signal, which serves as a more visual signal to indicate the diffusion of leaked gas in the landfill layer.

[0117] Each surface gas concentration detection lamp 29 corresponds to a first gas concentration detector 45-1. When any first gas concentration detector 45-1 detects leaked combustible gas, the synchronization controller 30 and the program controller 26 control the corresponding surface gas concentration detection lamp 29 to light up and emit a light signal, which serves as a more visual signal to indicate the diffusion of leaked gas above the landfill layer. At the same time, researchers can use the lighting status of the surface gas concentration detection lamp 29 as the ignition signal of the ignition electrode 21 as needed.

[0118] The anti-static grounding device 41 is used to guide static electricity to the ground, ensuring the safety of experimental operations and researchers in the event of static electricity generation or potential for dangerous accidents.

[0119] Furthermore, the adjustable ignition system includes an ignition electrode 21 and an ignition energy regulator 31; ignition sliding seats are vertically adjustable and mounted on the lower sides of the front and rear side frames of one of the adjustment track frames 52; ignition longitudinal rods are connected and fixed to the two ignition sliding seats, and the ignition longitudinal rods, adjustment longitudinal rods 54 and adjustment vertical rods 53 are located on different longitudinal planes; an ignition mounting base is vertically adjustable and mounted on the ignition longitudinal rod; an ignition adjustment rod is horizontally mounted on the ignition mounting base; the ignition electrode 21 is horizontally adjustable and mounted on the ignition adjustment rod, and is electrically connected to the synchronization controller 30 and the program controller 26 through the ignition energy regulator 31.

[0120] The synchronous controller 30 and the program controller 26 control the opening and closing of the ignition electrode 21 and the magnitude of the ignition energy through the ignition energy regulator 31. This allows for the investigation of the ignition effect of different ignition energies and ignition positions on the ignition of combustible gases of different concentrations, helping researchers establish the correspondence between the minimum ignition energy required to ignite combustible gases of different concentrations and their ignition positions. In addition, researchers can use the lighting status of each LED of the surface gas concentration detector 29 as a basis for judging the ignition timing, and ignite at the required time according to the needs.

[0121] By adjusting the ignition position and ignition energy, the ignition effect of different ignition energies and their ignition positions on leaked combustible gases of different concentrations can be investigated. The correspondence between the minimum ignition energy that can ignite leaked combustible gases of different concentrations and their ignition positions can be established. Furthermore, the correspondence between parameters such as the comprehensive porosity of different landfill layers, the flow velocity of combustible gases, the pressure of combustible gases, the hydrogen doping ratio of the gas, the diameter of the leaking hole, the shape of the leaking hole, and the direction of the leak and the minimum ignition energy of the leaked combustible gas at different ignition positions can be studied.

[0122] Based on this, Equation IV is proposed to establish the corresponding relationship between the minimum ignition energy and parameters such as the overall porosity of different landfill layers, the flow velocity of combustible gas, the pressure of combustible gas, the hydrogen doping ratio of the gas, the leakage orifice diameter, the leakage orifice shape, and the leakage direction:

[0123] IV

[0124] In the formula: The minimum ignition energy related to the properties of combustible gases and the landfill medium; The overall porosity of the landfill layer; The velocity of the combustible gas in the leaking pipe 51; The pressure of the combustible gas inside the leaking pipe 51; The hydrogen blending ratio of the fuel gas;

[0125] Formula V is proposed to establish the correspondence between the minimum ignition energy and the parameters of the leakage orifice diameter, leakage orifice shape, and leakage direction:

[0126] V

[0127] In the formula: The minimum ignition energy related to parameter 51 of the leaking pipeline; The diameter of the leakage hole; This is a correction factor for the shape of the leakage hole; This is the correction factor for the direction of the leakage hole.

[0128] Furthermore, the present invention also provides an experimental method for an experimental apparatus for studying the leakage diffusion distribution and combustion and explosion response mechanism of buried hydrogen-doped gas pipelines, comprising the following steps:

[0129] 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 synchronous controller 30 and the program controller 26 can effectively and accurately control the program and acquire data.

[0130] Step 2: System Adjustment: Adjust each system to the experimental state and debug each system to ensure that each system can work stably and reliably;

[0131] Step 3: Set experimental parameters: Set the corresponding start-stop control program in the program controller 26, determine the composition and ratio of the combustible gas provided by the gas supply system, the ratio of SF6 gas and combustible gas provided by the leak gas tracing system, the ambient wind speed generated by the ambient wind control system, the ignition energy and ignition position of the adjustable ignition system, adjust the type of landfill medium, the landfill sequence and the thickness of each landfill medium according to the experimental requirements, adjust the pipeline leakage control system, that is, replace the leakage pipeline 51 with different leakage hole diameters and leakage hole shapes according to the experimental requirements; adjust the longitudinal and vertical positions of each rigid support rod 58, and adjust the lateral positions of each first gas concentration detector 45-1 and each second gas concentration detector 45-2.

[0132] Step 4: Conduct the experiment: The synchronous controller 30 and the program controller 26 work together to control the operation of the gas supply system, the hydrogen-blended gas pipeline circulation system, the leak gas tracing system, the ambient wind control system, the adjustable ignition system, and the safety monitoring and alarm system, and control the data acquisition system to collect data such as gas concentration, temperature, radiant heat, and images. The program controller 26 records the collected data.

[0133] The gas supply system is configured with combustible gas according to experimental requirements and delivered to the premixing tank 2; the synchronous controller 30 and the program controller 26 open the methane cylinder 14 and the hydrogen cylinder 15 through two fourth explosion-proof solenoid valves 4-4, and open the third explosion-proof solenoid valve 4-3, and control the flow rate of methane and hydrogen entering the premixing tank 2 through two fourth high-precision gas flow meters 5-4, thereby realizing the premixing of combustible gases with different components and ratios;

[0134] Synchronous controller 30 and program controller 26 control the operation of the hydrogen-blended gas pipeline circulation system, so that the combustible gas in the premixed tank 2 reaches the pipeline leakage control system, that is, the first explosion-proof solenoid valve 4-1 is opened, the second explosion-proof solenoid valve 4-2 and the fifth explosion-proof solenoid valve 4-5 are closed, and the combustible gas output flow rate of the premixed tank 2 is controlled by the first high-precision gas flow meter 5-1. According to the test requirements of the leakage direction, the corresponding leakage pipeline 51 is selected and opened by the corresponding eighth explosion-proof solenoid valve 4-8. The combustible gas that has not completely leaked is filtered and dried by the gas purifier 34 and the molecular sieve dryer 36 and then enters the gas buffer tank 35 for storage, waiting to be mixed with nitrogen provided by the nitrogen cylinder 50 at the set concentration ratio and then put back into circulation for reuse.

[0135] Synchronous controller 30 and program controller 26 control the seventh explosion-proof solenoid valve 4-7 to open for a period of time, and control the flow rate of SF6 gas entering the premix tank 2 through the third high-precision gas flow meter 5-3, so as to input a certain amount of SF6 gas into the premix tank 2 according to the experimental requirements, so that the SF6 gas mixes with the combustible gas, and control the non-contact infrared imaging leak detector 25 to acquire and store images.

[0136] Synchronous controller 30 and program controller 26 control the output power of three variable frequency flow equalizing fans 32 through wind power variable frequency control box 20-2, and further adjust the output wind speed of the three variable frequency flow equalizing fans 32 through feedback data monitored and recorded by wind speed tester 33, until the wind speed detected by wind speed tester 33 reaches the set value.

[0137] The synchronous controller 30 and the program controller 26 collect gas concentration data from the gas concentration detection device, control the operation of the safety monitoring and alarm system, observe the lighting status of each surface gas concentration detection lamp 29, and control the ignition electrode 21 to ignite at the corresponding time according to the test requirements; the synchronous controller 30 and the program controller 26 control the temperature acquisition device, the radiant heat acquisition device and the image acquisition device to collect and store the corresponding data.

[0138] Step 5: Repeat the experiment: Adjust one of the following parameters according to the test requirements: landfill medium type, landfill sequence, thickness of each layer of landfill medium, leakage hole diameter, leakage hole shape, leakage direction, flow rate of combustible gas, pressure of combustible gas, hydrogen blending ratio of combustible gas, etc., and repeat Step 4 until all experiments are completed.

[0139] Step Six: Shutdown: After the experiment, exhaust the gas in the hydrogen-blended gas pipeline circulation system and pipeline leakage control system. Synchronous controller 30 and program controller 26 close the second explosion-proof solenoid valve 4-2, the third explosion-proof solenoid valve 4-3 and the seventh explosion-proof solenoid valve 4-7, and open the first explosion-proof solenoid valve 4-1, the fifth explosion-proof solenoid valve 4-5, the ninth explosion-proof solenoid valve 4-9 and each of the eighth explosion-proof solenoid valves 4-8. Control the third high-precision explosion-proof booster pump 18-3 to operate, so that nitrogen enters the pipeline leakage control system and purging pipeline through the circulation pipeline for purging of combustible gas. After purging for a period of time, shut down all system components and conduct a comprehensive check to ensure that all systems are in a safe shutdown state, confirm that there is no residual pressure and no other flammable leaks, and ensure that the test environment is safe and stable.

[0140] Step 7: Check and maintain equipment: Check the components of each system for damage and perform maintenance.

[0141] In the experimental apparatus for the leakage diffusion distribution and explosion response influence mechanism of buried hydrogen-doped gas pipelines provided by this invention, the synchronous controller adopts an existing synchronous controller; the program controller 26 adopts an existing program controller; the first explosion-proof pressure transmitter 3-1, the second explosion-proof pressure transmitter 3-2, the third explosion-proof pressure transmitter 3-3, the fourth explosion-proof pressure transmitter 3-4, and the fifth explosion-proof pressure transmitter 3-5 all adopt existing explosion-proof pressure transmitters; the first explosion-proof solenoid valve 4-1, the second explosion-proof solenoid valve 4-2, the third explosion-proof solenoid valve 4-3, the fourth explosion-proof solenoid valve 4-4, the fifth explosion-proof solenoid valve 4-5, the sixth explosion-proof solenoid valve 4-6, the seventh explosion-proof solenoid valve 4-7, and the eighth explosion-proof solenoid valve 4-8 -8 and the ninth explosion-proof solenoid valve 4-9 both use existing explosion-proof solenoid valves; the first high-precision gas flow meter 5-1, the second high-precision gas flow meter 5-2, the third high-precision gas flow meter 5-3, and the fourth high-precision gas flow meter 5-4 all use existing high-precision gas flow meters; the first spring check valve 6-1, the second spring check valve 6-2, the fourth spring check valve 6-4, the sixth spring check valve 6-6, the seventh spring check valve 6-7, and the eighth spring check valve 6-8 all use existing spring check valves; the electric shut-off valve 7 uses existing electric shut-off valves; the corrugated flame arrester 9 uses existing corrugated flame arresters; the diverter uses existing diverters; the Y-type filter 17. Existing Y-type filters are used; the first high-precision explosion-proof booster pump 18-1 is an existing high-precision explosion-proof booster water pump, and the water pump frequency converter control box 20-1 is a corresponding water pump frequency converter control box; the second high-precision explosion-proof booster pump 18-2 and the third high-precision explosion-proof booster pump 18-3 are both existing high-precision explosion-proof booster air pumps; the liquid pressure stabilizing tank 19 is an existing pressure stabilizing tank; the ignition electrode 21 is an existing ignition electrode, and the ignition energy regulator 31 is a corresponding ignition energy regulator; the high-speed infrared thermal imager 23 is an existing high-speed infrared thermal imager; the high-speed camera 24 is an existing high-speed camera; and the non-contact infrared imaging leak detector 25 is an existing non-contact infrared imaging leak detector. The audible and visual alarm 27 uses an existing audible and visual alarm; the variable frequency flow equalization fan 32 uses an existing variable frequency flow equalization fan; the wind power variable frequency control box 20-2 uses a corresponding wind power frequency control box; the gas purifier 34 uses an existing gas purifier; the gas buffer tank 35 uses an existing gas buffer tank; the molecular sieve dryer 36 uses an existing molecular sieve dryer; the manual ball valve 37 uses an existing manual ball valve; the high-temperature thermocouple 43 uses an existing high-temperature thermocouple; the radiation heat flow meter 44 uses an existing radiation heat flow meter; the first gas concentration detector 45-1 and the second gas concentration detector 45-2 both use existing gas concentration detectors; the high-frequency temperature transmitter 46 uses an existing high-frequency temperature transmitter.

[0142] The wiring methods of the various components in this invention are common knowledge in the field, and the appropriate model of each component can be selected according to actual use.

[0143] 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. An experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines, characterized in that: It includes a buried pipeline leak box (1), a hydrogen-blended gas pipeline circulation system, a gas supply system, a pipeline leak control system, a leak gas tracing system, an ambient wind control system, a sprinkler fire extinguishing system, an adjustable ignition system, a data acquisition system, a safety monitoring and alarm system, a synchronization controller (30), and a programmable controller (26). The buried pipeline leakage box (1) is an open box with a visible explosion-proof glass front wall; a scale is provided on the front edge of the buried pipeline leakage box (1); a landfill layer is provided at the bottom inside the buried pipeline leakage box (1). The pipeline leakage control system is located within the landfill layer and is used to simulate a damaged buried pipeline; the gas supply system is used to supply combustible gases with different component ratios to the hydrogen-blended gas pipeline circulation system; the hydrogen-blended gas pipeline circulation system circulates combustible gases to the pipeline leakage control system and filters impurities; the leak gas tracing system is used to detect the diffusion trajectory of leaked combustible gases in the landfill layer; the environmental wind control system is used to create environmental wind within the buried pipeline leakage box (1); the adjustable ignition system is used to ignite the leaked combustible gases; the sprinkler fire extinguishing system is used to spray and extinguish fires in the buried pipeline leakage box (1); the data acquisition system is used to collect data such as gas concentration, temperature, radiant heat, and images within the buried pipeline leakage box (1); and the safety monitoring and alarm system is used to issue safety alarms. The hydrogen-blended gas pipeline circulation system, gas supply system, pipeline leakage control system, leak gas tracing system, ambient wind control system, sprinkler fire extinguishing system, adjustable ignition system, data acquisition system, and safety monitoring and alarm system are all electrically connected to the synchronous controller (30) and the program controller (26), and the program controller (26) records the data collected by the data acquisition system.

2. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The hydrogen-blended gas pipeline circulation system includes a nitrogen cylinder (50), a premixed tank (2), a gas purifier (34), a gas buffer tank (35), and a molecular sieve dryer (36). The outlet and return port of the premixing tank (2) are connected to the circulation pipe of the sealed underground pipeline leakage box (1); a gas purifier (34), a molecular sieve dryer (36), a gas buffer tank (35), and a second high-precision explosion-proof booster pump (18-2) are connected in series from the outlet to the return port of the premixing tank (2) on the circulation pipe; the pipeline leakage control system is connected in series on the circulation pipe between the premixing tank (2) and the gas purifier (34); the gas buffer tank (35) and the second high-precision explosion-proof booster pump (18-2) are connected in series on the circulation pipe. A second explosion-proof solenoid valve (4-2) is connected in series on the circulation pipeline between the pressure pumps (18-2); a purging pipeline is provided at the outlet of the gas purifier (34); a fifth explosion-proof solenoid valve (4-5) is connected in series on the purging pipeline; a first high-precision gas flow meter (5-1) and a first explosion-proof pressure transmitter (3-1) located outside the buried pipeline leakage box (1) are connected in series on the circulation pipelines on both sides of the pipeline leakage control system; a first explosion-proof solenoid valve (4-1) is connected in series at the outlet of the premix tank (2); The nitrogen cylinder (50) is connected to the inlet of the premixed tank (2) through a nitrogen pipeline; the nitrogen pipeline is connected in series with the third high-precision explosion-proof booster pump (18-3), the second explosion-proof pressure transmitter (3-2), the second high-precision gas flow meter (5-2) and the ninth explosion-proof solenoid valve (4-9). The second high-precision explosion-proof booster pump (18-2), the third high-precision explosion-proof booster pump (18-3), the first explosion-proof solenoid valve (4-1), the second explosion-proof solenoid valve (4-2), the fifth explosion-proof solenoid valve (4-5), the ninth explosion-proof solenoid valve (4-9), the second explosion-proof pressure transmitter (3-2), the second high-precision gas flow meter (5-2), each of the first high-precision gas flow meters (5-1) and each of the first explosion-proof pressure transmitters (3-1) are all electrically connected to the synchronous controller (30) and the program controller (26).

3. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The pipeline leakage control system includes two diverters (11) and three leakage pipes (51). Three leak pipes (51) are detachably connected in parallel between two distributors (11); the two distributors (11) are connected in series on the circulation pipe; corrugated flame arresters (9) are connected in series on the circulation pipes on both sides of the pipe leak control system; each leak pipe (51) is provided with a leak hole, and each leak hole faces a different direction; each leak hole is covered with a sand-blocking and breathable mesh (12); an eighth explosion-proof solenoid valve (4-8) is provided at the air inlet end of each leak pipe (51); a detection unit consisting of a pressure sensor, a flow velocity detector, and a flow rate detector is installed at both ends of each leak pipe (51); Each of the eighth explosion-proof solenoid valves (4-8) and each detection unit is electrically connected to the synchronization controller (30) and the program controller (26).

4. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The gas supply system includes a methane cylinder (14) and a hydrogen cylinder (15). Methane cylinder (14) and hydrogen cylinder (15) are used to store methane and hydrogen respectively, and are connected to the inlet of the premixed tank (2) through gas supply pipelines; a third explosion-proof solenoid valve (4-3) is connected in series on the gas supply pipeline; a fourth explosion-proof solenoid valve (4-4), a fifth explosion-proof pressure transmitter (3-5) and a fourth high-precision gas flow meter (5-4) are connected in series on the outlet of methane cylinder (14) and hydrogen cylinder (15); the third explosion-proof solenoid valve (4-3), the fourth explosion-proof solenoid valve (4-4), the fifth explosion-proof pressure transmitter (3-5) and the fourth high-precision gas flow meter (5-4) are all electrically connected to the synchronous controller (30) and the program controller (26).

5. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The leak gas tracing system includes a tracing gas cylinder (13) and a non-contact infrared imaging leak detector (25). The tracer cylinder (13) is used to store SF6 gas; the tracer cylinder (13) is connected to the tracer inlet of the premixed tank (2) through the tracer pipe; the fourth explosion-proof pressure transmitter (3-4), the third high-precision gas flow meter (5-3), the seventh explosion-proof solenoid valve (4-7) and the electric shut-off valve (7) are connected in series on the tracer pipe; the non-contact infrared imaging leak detector (25) is located on the front side of the buried pipeline leak box (1) and is used to collect and monitor the diffusion trajectory image of the combustible gas leaked after mixing with SF6 gas in the landfill layer; The non-contact infrared imaging leak detector (25), the fourth explosion-proof pressure transmitter (3-4), the third high-precision gas flow meter (5-3), the seventh explosion-proof solenoid valve (4-7), and the electric shut-off valve (7) are all electrically connected to the synchronous controller (30) and the program controller (26).

6. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The environmental wind control system includes an anemometer (33), a wind power frequency converter box (20-2), and three frequency converter flow equalization fans (32). A grille ventilation opening is provided on the upper side of the right wall of the buried pipeline leakage box (1); three variable frequency flow fans (32) are all installed on the buried pipeline leakage box (1) by brackets, and the air outlets are all facing the grille ventilation opening, and are all electrically connected to the wind power variable frequency control box (20-2); the wind speed tester (33) is installed inside the buried pipeline leakage box (1) to detect the wind speed; the wind power variable frequency control box (20-2) and the wind speed tester (33) are all electrically connected to the synchronous controller (30) and the program controller (26).

7. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The sprinkler fire extinguishing system includes an elevated water tank (16), a Y-type filter (17), a water pump frequency converter control box (20-1), a liquid pressure stabilizing tank (19), and a liquid recovery tank (40). A parallel pipe is installed at the top opening of the buried pipeline leakage box (1); multiple pressure nozzles (42) are installed on the parallel pipe; the high-level water tank (16) is connected to the parallel pipe through an inlet pipe; a Y-type filter (17), a first high-precision explosion-proof booster pump (18-1), a pressure relief valve (22), a third explosion-proof pressure transmitter (3-3) and a sixth explosion-proof solenoid valve (4-6) are connected in series on the inlet pipe; an overflow pipe is installed on the parallel pipe; a venting connector (38) is installed at the end of the overflow pipe; a manual ball valve (37) is connected in series on the overflow pipe; a drainage funnel (39) located below the venting connector (38) is installed on the liquid recovery tank (40) through the recovery pipe; the first high-precision explosion-proof booster pump (18-1) is electrically connected to the water pump frequency conversion control box (20-1); The pump frequency converter control box (20-1), pressure relief valve (22), third explosion-proof pressure transmitter (3-3) and sixth explosion-proof solenoid valve (4-6) are all electrically connected to the synchronous controller (30) and the program controller (26).

8. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The data acquisition system includes a gas concentration detection device, a temperature acquisition device, a radiant heat acquisition device, and an image acquisition device that are electrically connected to a synchronization controller (30) and a program controller (26); The gas concentration detection device includes a surface concentration detection unit and a subsurface concentration detection unit; the surface concentration detection unit is used to detect combustible gas concentration data above the landfill layer at multiple points; the subsurface concentration detection unit is used to detect combustible gas concentration data inside the landfill layer at multiple points. The temperature acquisition device includes a surface temperature acquisition unit and a subsurface temperature acquisition unit; The surface temperature acquisition unit is used to collect temperature data above the landfill layer at multiple points. The underground temperature acquisition unit is used to collect temperature data from multiple points inside the landfill layer; The radiant heat acquisition device is used to collect radiant heat data above the landfill layer after combustible gas is ignited at multiple points. The image acquisition device is used to acquire infrared image data of the distribution of leaked combustible gas within and above the landfill layer, as well as image data of the flame distribution and impact range after the leaked combustible gas is ignited.

9. The experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that: The adjustable ignition system includes an ignition electrode (21) and an ignition energy regulator (31); the ignition electrode (21) is installed in the buried pipeline leakage box (1) in an adjustable position, and is electrically connected to the synchronization controller (30) and the program controller (26) through the ignition energy regulator (31).

10. The experimental method of the experimental apparatus for the influence mechanism of leakage diffusion distribution and combustion and explosion response of buried hydrogen-doped gas pipelines according to claim 1, characterized in that, Includes 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 synchronous controller (30) and the program controller (26) can effectively and accurately control the program and acquire data; Step 2: System Adjustment: Adjust each system to the experimental state and debug each system to ensure that each system can work stably and reliably; Step 3: Set experimental parameters: Set the corresponding start and stop control program in the program controller (26), determine the working status and parameters of the gas supply system, leak gas tracing system, ambient wind control system and adjustable ignition system, fill the landfill layer and adjust the pipeline leakage control system according to the experimental requirements. Step 4: Conduct the experiment: The synchronous controller (30) and the program controller (26) work together to control the operation of the gas supply system, the hydrogen-blended gas pipeline circulation system, the leak gas tracing system, the ambient wind control system, the adjustable ignition system and the safety monitoring and alarm system, and control the data acquisition system to collect data such as gas concentration, temperature, radiant heat and images. The program controller (26) records the collected data. Step 5: Repeat the experiment: After adjusting one experimental parameter according to the experimental requirements, repeat Step 4 until all experiments are completed; Step Six: Shutdown of the device: After the experiment is completed, exhaust the gas in the hydrogen-blended gas pipeline circulation system and pipeline leakage control system, shut down all system components, and conduct a comprehensive check to ensure that each system is in a safe shutdown state, confirm that there is no residual pressure, no flammable or other leaks, and ensure that the test environment is safe and stable. Step 7: Check and maintain equipment: Check the components of each system for damage and perform maintenance.

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