Experimental device and method for blocking and inhibiting synergistic effect of hydrogen explosion

Abstract

The invention discloses a hydrogen explosion barrier and inhibition synergistic effect experimental device and method, and belongs to the field of combustible gas explosion protection and inhibition. The device comprises a closed circular pipeline system, a porous medium blocking system, an explosion suppression system, a gas distribution system, a high-pressure ignition system, a data acquisition system and a synchronous control system. By analyzing the influence rules of factors such as the length-diameter ratio of a pipeline, the gas equivalence ratio, porous material parameters (thickness, porosity, position and type), explosion suppressant parameters (spraying particle size, spraying angle and type) and the like on the explosion characteristics of combustible gas, the attenuation effect of the porous material on explosion overpressure and the suppression mechanism of flame propagation speed are explored; and the control effect of targeted intervention of the explosion suppressant on explosion flame development is achieved. The invention discloses a hydrogen explosion targeted inhibition mechanism, an adsorption mechanism of a device wall material to active free radical groups and a competitive mechanism of a microporous structure of a porous material to conduction, radiation and convective heat transfer.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydrogen explosion barrier and inhibition synergistic effect experimental device and method, belonging to the field of combustible gas explosion protection and inhibition, particularly relates to a hydrogen explosion barrier and inhibition synergistic effect experimental research. BACKGROUND

[0002] Energy and fuel, as the cornerstone of social progress and industrial development, are self-evident in their importance. In the context of global efforts to achieve carbon peak and carbon neutralization targets, hydrogen energy, with its unique zero-carbon emission, renewable and high-efficiency clean characteristics, has become a strategic choice to promote energy structure transformation and promote green and low-carbon development. Corrosion and hydrogen embrittlement, mechanical damage, construction errors and other reasons may cause pipeline leakage, and the leaked gas may cause severe explosion when encountering a fire source. Pipeline gas explosion is a typical rapid, unsteady fluid dynamics phenomenon, coupling the complex fluid dynamics phenomenon of turbulent flow and combustion reaction. The initial stage of the pipeline flame is mainly laminar flame, with low propagation speed; as the flame propagates along the pipeline, it is affected by flame instability and turbulence, enhancing the combustion reaction rate, accelerating flame propagation, and increasing explosion overpressure. The distortion and instability of the flame front lead to the generation of turbulent flame, the flame propagation speed increases sharply, and the explosion overpressure increases significantly. The cumulative effect of pressure may cause high pressure peaks in local areas, causing significant casualties and property losses. Therefore, it is particularly urgent and important to strengthen the safety protection measures of hydrogen transportation pipelines.

[0003] Explosion barrier technology is a safety protection means that uses fireproof units with micro-porous structure to absorb explosion overpressure, reduce flame propagation speed, and even block the spread of explosion flame, to achieve the purpose of preventing the expansion of explosion hazards. In the industrial field, flame arresters are widely used in combustible gas transportation pipeline systems, and their key role is to effectively prevent the further spread of accidental deflagration or detonation flame, thereby controlling and containing the spread of explosion accidents, and ensuring production safety. Currently, the materials used for gas explosion barrier mainly include metals, ceramics, composite materials, etc. Metal wire mesh is light in weight, high in toughness, not easy to break, cheap, high in hardness, and good in quenching performance, etc. Porous foam materials are widely used in fire prevention, heat insulation, sound absorption and other fields due to their light weight, high porosity, good thermal stability and mechanical properties. By designing a reasonable pore structure and material composition, the barrier performance of porous foam materials can be significantly improved, thereby effectively preventing and reducing the occurrence of gas explosion.

[0004] In the process of hydrogen production, hydrogen storage, hydrogen transportation and hydrogen utilization, hydrogen is often inevitably present in long pipelines. Once the pipeline leaks or catches fire, the flame and overpressure along the pipeline will cause more extensive damage. It is worth emphasizing that the flame instability and strong turbulent coupling caused by the long length-diameter ratio and obstacles of long hydrogen pipeline will inevitably lead to higher explosion overpressure and faster flame propagation speed. Meanwhile, the hydrogen explosion and combustion speed is relatively high. Under the constraint of limited explosion barrier, it is difficult to cut off the hydrogen pipeline explosion propagation by relying solely on passive explosion protection of explosion barrier. The hydrogen pipeline flame will inevitably continue to accelerate and even completely detonate, thereby causing dangerous accident consequences. Therefore, it is urgent to develop safety protection technology suitable for hydrogen pipeline explosion, which is crucial for improving the safety of hydrogen pipeline transportation and optimizing explosion-proof design. SUMMARY

[0005] The purpose of the present application is to provide a hydrogen explosion barrier and inhibition synergistic experimental device and method. Through experiments, the influence of factors such as pipeline length-diameter ratio, fuel gas equivalence ratio, porous material parameters (thickness, porosity, position, type) and explosion inhibitor parameters (spray particle size, spray angle, type) on the explosion characteristics of combustible gas can be analyzed. The attenuation effect of porous materials on explosion overpressure and the inhibition mechanism of flame propagation speed, as well as the control effect of explosion inhibitor targeted intervention on explosion flame development are explored. The targeted inhibition mechanism of hydrogen explosion, the adsorption mechanism of active free radicals on the wall material, and the competition mechanism of conduction, radiation and convection heat on the micro-porous structure of porous materials are revealed, providing ideas and methods for experimental research on the synergistic effect of hydrogen explosion barrier and inhibition.

[0006] The technical solutions adopted by the present application are as follows: an experimental device for the synergistic effect of hydrogen explosion barrier and inhibition, comprising a closed circular pipeline system, a porous medium barrier system, an explosion suppression system, a gas distribution system, a data acquisition system, a high-pressure ignition system and a synchronous control system.

[0007] The closed circular pipeline system comprises three sections of circular pipelines with the same volume. Pressure sensors and explosion suppression tanks are installed on the upper wall of the circular pipeline. Photodiodes and gas inlet pipes are installed on the lower wall. An ignition electrode is installed on the left end flange of the closed circular pipeline system.

[0008] The porous medium barrier system comprises two fireproof segments, porous materials and a fixing sleeve. The fireproof segments are connected to the flanges of the circular pipelines by bolts. The three sections of circular pipelines are arranged alternately with the two fireproof segments.

[0009] The explosion suppression system comprises explosion suppression tanks, electromagnetic valves and nozzles with different hole diameters and spray angles. The explosion suppression tanks are provided with gas inlets and water inlets. The lower end of the explosion suppression tank is provided with an electromagnetic valve, a fixing ring and a nozzle. The explosion suppression tank is arranged above the circular pipeline through the fixing ring, and the nozzle is inserted into the circular pipeline.

[0010] The synchronous control system includes a timing controller, an ignition electrode, a photodiode, a solenoid valve, and a data acquisition instrument. The timing controller controls the ignition. After the first photodiode at the rear end of the flame arrestor receives the light signal, it converts the light signal into an electrical signal and sends it to the timing controller. The timing controller then controls the solenoid valve to open, thereby spraying the flame suppressant and extinguishing the flame.

[0011] Furthermore, the gas distribution system includes a gas cylinder, an air cylinder, a premix tank, a pressure reducing valve, a pipeline needle valve, a pressure gauge, a vacuum pump, and a PU gas pipe;

[0012] The data acquisition system includes a piezoelectric pressure sensor, a sensor power supply box, a photodiode, and a data acquisition instrument. The pressure sensor converts the pressure signal into an electrical signal, the photodiode converts the optical signal into an electrical signal, and the data acquisition instrument records the signal according to a certain sampling frequency and time length.

[0013] The high-voltage ignition system includes an ignition electrode, a high-voltage ignition coil, and a timing controller. The high-voltage ignition system activates the timing controller via a low-voltage electrical push-button switch, which simultaneously triggers the data acquisition instrument and the explosion suppression canister to spray. Then, it controls the high-voltage ignition coil to output a high-voltage current, generating an electric arc at the tip of the ignition electrode to ignite the combustible gas.

[0014] The synchronous control system includes a timing controller that controls the start time and duration of spraying from the explosion suppression tank, controls the triggering of the data acquisition instrument, and controls ignition.

[0015] Furthermore, the pressure sensor is fixed in a hollow pressure sensor fixing bolt, the photodiode is fixed in a hollow photodiode fixing bolt, and quartz glass is filled at the bottom of the photodiode fixing bolt to assist in bearing pressure.

[0016] Furthermore, the device includes three sections of circular pipe, two flame arrestor sections, and three explosion suppression containers. Two pressure sensors are installed on the upper wall of each circular pipe section at 60mm and 740mm from the left flange end face to monitor the explosion pressure before and after the wire mesh. Four photodiodes are symmetrically placed on the lower wall at 100mm, 300mm, 500mm, and 700mm from the left flange end face to measure the average flame velocity in the pipe. The flanges on both sides of the flame arrestor section can be removed after the threads are unscrewed to facilitate the replacement of porous materials with different porosities and thicknesses, enabling experimental research on the overpressure variation law of combustible gas explosion in sealed pipes under different porosities and thicknesses and the effect of explosion isolation. Sealing rings / gaskets are provided at the connection between the circular pipe and the flame arrestor section.

[0017] The experimental method of the experimental setup includes the following steps:

[0018] Step (1): According to the experimental plan, install the porous media flame arrestor section with specified porosity and thickness, connect the circular pipe flanges on both sides of the flame arrestor section with bolts, fix the porous media flame arrestor section, install pressure sensor and photodiode at the specified position, and place sealing rubber ring / gasket at the flange connection to build the explosion suppression system, connect the output end of the high-pressure ignition system to the specified ignition electrode, and connect the timing controller to the high-pressure ignition pack, data acquisition instrument and explosion suppression tank solenoid valve respectively;

[0019] Step (2): Start the vacuum pump and evacuate the premix tank to a vacuum level of <1.0 kPa, then check the airtightness;

[0020] Step (3): According to Dalton's law of partial pressure, configure the required concentration of combustible gas and air in the premixed system for the specified gas equivalence ratio, and after the pressure gauge reading stabilizes, let it stand to allow the premixed gas inside the premix tank to mix evenly.

[0021] Step (4): Start the vacuum pump and evacuate the sealed circular pipe to a low vacuum level of <1.0 kPa, then check the airtightness;

[0022] Step (5): According to Dalton's law of partial pressure, the premixed gas in the premix tank is configured to the pressure required for the experimental conditions, and after the pressure gauge reading stabilizes, it is left to stand so that the premixed gas inside the closed circular pipe is mixed evenly.

[0023] Step (6): Press the low-voltage electrical push-button switch to complete the triggering and ignition operations and the spraying of the explosion suppressant in sequence according to the preset timing controller.

[0024] Step (7): Save the pressure data and photodiode data from the data acquisition instrument.

[0025] Furthermore, in step (6), before pressing the low-voltage electrical push-button switch, it is necessary to check that the signal transmission and data acquisition lines of the pressure sensor, photodiode, solenoid valve, and ignition electrode are correctly connected, and adjust the data acquisition instrument to the ready-to-trigger state.

[0026] Furthermore, the gas distribution system first evacuates the premixed tank to a low vacuum level using a vacuum pump. Then, based on Dalton's law of partial pressure, it controls the concentration of a specified gas mixture within the premixed tank by switching the needle valve on the pipeline and monitoring the pressure gauge readings. After evacuating the sealed circular pipeline to a low vacuum level using a vacuum pump, it controls the distribution of a specified pressure gas mixture from the premixed tank into the sealed circular pipeline by switching the needle valve on the pipeline and monitoring the pressure gauge readings. This allows for experiments on the synergistic effect of hydrogen explosion blocking and suppression under different gas equivalence ratios. Each of the three sections of the circular pipeline has a gas distribution pipeline inlet at its bottom and at the top of the premixed tank to ensure uniform gas concentration throughout the pipeline system.

[0027] Furthermore, the high-pressure ignition system is equipped with an ignition electrode at the center of the flange on the left side of the first section of the circular pipe. Changing the output current and voltage of the high-pressure ignition pack can generate different ignition energies, and experiments are conducted to investigate the synergistic effect of different ignition positions and ignition energies on the blocking and suppression of hydrogen explosions.

[0028] Furthermore, after the twelve photodiodes distributed on the three sections of the circular pipe successively capture the light signal, the average propagation speed of the flame in the pipe is calculated based on the distance / time. Experiments are conducted to investigate the effects of different gas equivalence ratios, different porosities of porous media, different thicknesses of porous media, and different materials of porous media on the propagation speed of combustible gas flames before and after passing through the flame arrestor section in the sealed pipe.

[0029] Specifically, the experimental apparatus includes a closed circular pipeline system, a porous media barrier system, an explosion suppression system, a gas distribution system, a data acquisition system, a high-pressure ignition system, and a synchronous control system. The closed circular pipeline system comprises three sections of circular pipes with the same volume. A pressure sensor and an explosion suppression canister are installed on the upper wall of the circular pipes. The pressure sensor is fixed in a hollow pressure sensor fixing bolt. A photodiode and a gas distribution pipeline inlet are installed on the lower wall. The photodiode is fixed in a hollow photodiode fixing bolt to assist in pressure bearing. An ignition electrode is installed on the flange at the left end of the first pipe. The porous media barrier system includes two flame-arresting sections, porous materials with different porosities and thicknesses, and several fixing sleeves of different lengths. The flanges at both ends of the circular pipes are bolted to the experimental system. The explosion suppression system includes an explosion suppression canister, a solenoid valve, and nozzles with different orifice diameters and nozzle angles. An air inlet and a water inlet are installed on the upper wall of the explosion suppression canister, and an air inlet is installed on the side wall of the explosion suppression canister. The solenoid valve and nozzles are installed at the lower end of the explosion suppression canister. The gas distribution system includes a gas cylinder, an air cylinder, a premixing tank, a pressure reducing valve, a pipeline needle valve, a pressure gauge, a vacuum pump, and a PU gas tubing. The data acquisition system includes a pressure sensor, a sensor power supply box, a photodiode, and a data acquisition instrument. The pressure sensor converts pressure signals into electrical signals, the photodiode converts light signals into electrical signals, and the data acquisition instrument records these signals at a certain sampling frequency and duration. The high-pressure ignition system includes an ignition electrode, a high-pressure ignition coil, and a timing controller. The high-pressure ignition system activates the timing controller via a low-pressure electrical push-button switch, synchronously triggering the data acquisition instrument and the explosion suppression tank to spray. It then controls the high-pressure ignition coil to output a high-pressure current, generating an electric arc at the tip of the ignition electrode to ignite the combustible gas. The synchronous control system includes a timing controller that controls the start time and duration of the explosion suppression tank spraying, controls the triggering of the data acquisition instrument, and controls ignition.

[0030] The three circular pipe sections, two flame arrestor sections, and three explosion suppression containers exhibit high overall explosion resistance and pressure bearing capacity. Pressure sensors are installed at the rear end of the upper wall of each circular pipe section to monitor the explosion pressure before and after the wire mesh. Four photodiodes are symmetrically placed at intervals at the center of the lower wall to measure the average flame velocity within the pipe. The flanges on both sides of the flame arrestor section can be removed after disassembly to facilitate the replacement of porous media with different porosities and thicknesses, enabling experimental research on the overpressure variation law of combustible gas explosions in closed pipes under different porosities and thicknesses and the influence of explosion containment. Sealing rings / gaskets are provided at the connections between the circular pipes and the flame arrestor sections, and all threads are wrapped with PTFE tape before installation to fully ensure the overall airtightness of the device.

[0031] After the twelve photodiodes distributed on the three sections of the circular pipe capture the light signal in succession, the average speed of the flame propagation in the pipe can be calculated based on the "distance / time" ratio. This allows for the study of the influence of different gas equivalence ratios, different porosities of porous media, different thicknesses of porous media, and different materials of porous media on the propagation speed of combustible gas flames before and after passing through the flame arrestor section in a sealed pipe.

[0032] The porous media barrier system includes two fire-resistant sections, each equipped with several sleeves for fixing porous media, with a sealing ring at the front end of the sleeve, and porous materials of different thicknesses, different porosities, and different materials.

[0033] The explosion suppression system includes three explosion suppression tanks, each equipped with two air inlets and outlets, one water inlet, one solenoid valve, and nozzles with different orifice diameters and spray angles. The explosion suppression tanks are connected to the pipes via a retaining ring and threads on the pipes.

[0034] The gas distribution system first evacuates the premixed tank to a low vacuum level using a vacuum pump. Then, based on Dalton's law of partial pressure, it controls the concentration of a specified gas mixture within the premixed tank by switching the needle valve on the pipeline and monitoring the pressure gauge readings. After evacuating the sealed circular pipeline to a low vacuum level using a vacuum pump, it controls the distribution of a specified pressure gas mixture from the premixed tank into the sealed circular pipeline by switching the needle valve on the pipeline and monitoring the pressure gauge readings. This allows for experimental research on the synergistic effect of hydrogen explosion blocking and suppression under different gas equivalence ratios. Each of the three sections of the circular pipeline has a gas distribution pipeline inlet at its bottom and at the top of the premixed tank to ensure uniform gas concentration throughout the pipeline system.

[0035] The pressure sensor in the data acquisition system is installed on the upper wall of the three-section circular pipe to measure the overpressure of the explosion as the combustible gas explosion flame propagates in the explosion barrier pipe.

[0036] The high-pressure ignition system is equipped with an ignition electrode at the center of the flange on the left side of the first section of the circular pipe. Changing the output current and voltage of the high-pressure ignition pack can generate different ignition energies, so as to conduct experimental research on the synergistic effect of different ignition positions and ignition energies on the blocking and suppression of hydrogen explosions.

[0037] The synchronous control system controls ignition, triggering of the data acquisition instrument, and spraying of the explosion suppression tank through a timing controller.

[0038] The aforementioned experiment on the synergistic effect of hydrogen explosion prevention and suppression includes the following steps:

[0039] Step (1): According to the experimental plan, install the porous media flame arrestor section with specified porosity and thickness, connect the circular pipe flanges on both sides of the flame arrestor section with bolts, fix the porous media flame arrestor section, install the porous media flame arrestor material, pressure sensor, and photodiode at the specified position, place sealing rubber rings / gaskets at the flange connection, wrap the threaded connection with PTFE tape to ensure good air tightness, build the explosion suppression system, connect the output end of the high-pressure ignition system to the specified ignition electrode pair, and connect the timing controller to the high-pressure ignition pack, data acquisition instrument and explosion suppression tank solenoid valve respectively;

[0040] Step (2): Start the vacuum pump, evacuate the premix tank to a low vacuum (<1.0 kPa), and observe the pressure gauge reading fluctuation after a short period of stillness (about 2 minutes) to check if the airtightness is good. If the pressure value rises significantly in a short time, it indicates that the airtightness is poor. It is necessary to check the location of the incompletely sealed parts and reseal them before checking the airtightness again. If the pressure value does not rise significantly, it indicates that the airtightness is good and gas mixing can proceed.

[0041] Step (3): According to Dalton's law of partial pressure, configure the required concentration of combustible gas and air in the premixed system for the specified gas equivalence ratio, and after the pressure gauge reading stabilizes, let it stand for 24 hours to ensure that the premixed gas inside the premix tank is mixed evenly.

[0042] Step (4): Start the vacuum pump and evacuate the sealed circular pipe to a low vacuum level (<1.0 kPa). After a short period of stillness (about 2 minutes), observe the fluctuation range of the pressure gauge reading to check whether the air tightness is good. If the pressure value rises significantly in a short time, it indicates that the air tightness is not good. It is necessary to check the location of the incompletely sealed parts and reseal them before checking the air tightness again. If the pressure value does not rise significantly, it indicates that the air tightness is good and gas mixing can be carried out.

[0043] Step (5): According to Dalton's law of partial pressure, the premixed gas in the premix tank is configured to the pressure required for the experimental conditions, and after the pressure gauge reading stabilizes, it is left to stand for 5 minutes to ensure that the premixed gas inside the closed circular pipe is mixed evenly.

[0044] Step (6): Check that the signal transmission and data acquisition lines of the pressure sensor, photodiode, solenoid valve, and ignition electrode are correctly connected. After adjusting the data acquisition instrument to the ready-to-trigger state, press the low-voltage electrical push-button switch and complete the triggering and ignition operations in sequence according to the preset timing controller.

[0045] Step (7): Save the pressure data and photodiode data from the data acquisition instrument.

[0046] An experimental method for studying the synergistic effect of hydrogen explosion containment and suppression is characterized by using pressure sensors and photodiodes to obtain explosion pressure data and flame signals at the ends of the flame arrestor section during the synergistic effect of hydrogen explosion containment and suppression. This allows for the analysis of the influence of factors such as pipe length-to-diameter ratio, gas equivalence ratio, porous material parameters (thickness, porosity, location, type), and explosion suppressant parameters (spray particle size, spray angle, type) on the explosion characteristics of combustible gases. The method explores the attenuation effect of porous materials on explosion overpressure and the suppression mechanism of flame propagation speed, as well as the control effect of targeted intervention of explosion suppressants on the development of the explosion flame. It reveals the targeted suppression mechanism of hydrogen explosions, the adsorption mechanism of active free radicals by the vessel wall material, and the competitive mechanism of the microporous structure of porous materials on conduction, radiation, and convective heat transfer, providing ideas and methods for experimental research on the synergistic effect of hydrogen explosion containment and suppression.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0048] (1) This invention provides an experimental device and method for studying the synergistic effect of hydrogen explosion blocking and suppression, which can obtain the explosion pressure, pipeline flame velocity and the influence of blocking and targeted suppression on the flame during the process of combustible gas explosion blocking and targeted suppression.

[0049] (2) This invention uses a pressure sensor to obtain the pressure change characteristics during the process of blocking and targeted suppression of combustible gas explosion, and uses a photodiode to obtain the average flame propagation speed in a closed circular pipe, so as to analyze the relationship between the overpressure of the explosion flame and the average flame propagation speed of the synergistic effect of blocking and suppressing hydrogen explosion, analyze the evolution law of pressure wave, and develop a model and design method for the synergistic effect of blocking and suppressing hydrogen explosion.

[0050] This invention presents an experimental apparatus for the synergistic effect of hydrogen explosion containment and suppression, a method for calculating the average flame velocity in a closed circular pipe, a porous media containment system, and an explosion suppression system. Based on the operational steps, it allows for the analysis of the influence of factors such as pipe length-to-diameter ratio, gas equivalence ratio, porous material parameters (thickness, porosity, location, type), and explosion suppressant parameters (spray particle size, spray angle, type) on the explosion characteristics of combustible gases. It explores the attenuation effect of porous materials on explosion overpressure and the suppression mechanism of flame propagation velocity, as well as the control effect of targeted intervention of explosion suppressants on the development of the explosion flame. It reveals the targeted suppression mechanism of hydrogen explosions, the adsorption mechanism of active free radicals by the container wall material, and the competitive mechanism of the microporous structure of porous materials on conduction, radiation, and convective heat transfer, providing ideas and methods for experimental research on the synergistic effect of hydrogen explosion containment and suppression. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall experimental apparatus of the present invention.

[0052] Figure 2 This is a schematic diagram of the installation of a circular pipe pressure sensor and photodiode components.

[0053] Figure 3 This is a schematic diagram showing the connection between the circular pipe and the fire-resistant section, as well as the installation of the porous material and fixing sleeve of the fire-resistant section.

[0054] Figure 4 This is a schematic diagram of an explosion suppression tank and a premixing tank.

[0055] Figure 5 This is a schematic diagram showing the connection between the second section of the pipeline and the flame arrestor and explosion suppression tank.

[0056] Figure 6 This is a schematic diagram of the PLC and control logic for the explosion suppression tank spraying system.

[0057] Figure 7 This is a schematic diagram illustrating the attenuation effect of metal wire mesh with porosities of 0.25 and 0.36 and thicknesses of 50 mm, 100 mm, and 150 mm on the pressure of a pipeline explosion flame.

[0058] In the diagram: 1. Circular pipe; 2. Pressure sensor; 3. Explosion suppressor; 4. Pressure sensor mounting bolt; 5. Photodiode; 6. Gas distribution pipe inlet; 7. Photodiode mounting bolt; 8. Quartz glass; 9. Left flange of the pipe; 10. Ignition electrode; 11. Flame arrestor; 12. Porous material; 13. Fixing sleeve; 14. Bolt; 15. Right flange of the pipe; 16. Solenoid valve; 17. Nozzle; 18. Explosion suppressor inlet; 19. Explosion suppressor water inlet; 20. Gas cylinder; 21. Air cylinder; 22. Premixed tank; 23. Pressure reducing valve; 24. Pipeline needle valve; 25. Pressure gauge; 26. Vacuum pump; 27. PU tubing; 28. Sensor power supply box; 29. ​​Data acquisition instrument; 30. High-voltage ignition coil; 31. Timing controller; 32. Sealing gasket; 33. Sealing ring; 34. Explosion suppressor retaining ring; 35. Premixed tank inlet. Detailed Implementation

[0059] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0060] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0061] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0062] Figures 1 to 5An experimental apparatus for studying the synergistic effect of hydrogen explosion containment and suppression is disclosed. The complete experimental apparatus includes a closed circular pipeline system, a porous medium containment system, an explosion suppression system, a gas distribution system, a data acquisition system, a high-pressure ignition system, and a synchronous control system. The closed circular pipeline system, porous medium containment system, explosion suppression system, and gas distribution system in this invention are all made of 304 stainless steel, and the overall design pressure is 6 MPa. It includes three sections of circular pipeline 1, two flame arrestor sections 11, six fixed sleeves 13, three explosion suppression containers 3, and a premixing container 22.

[0063] The sealed circular pipe 1 has an inner diameter of 40.0 mm and a volume of 1.0 L. Each pipe section has eight M24 threaded holes at both ends for connecting the pipe and fixing the porous media flame arrestor section. Two pressure sensors 2 are installed at 60 mm and 740 mm from the left flange 9 end face of each circular pipe section. Two pressure sensor fixing bolts 4 (non-standard countersunk M10 bolts) with central holes and threads are provided on the upper wall of each circular pipe section 1 to fix the pressure sensors 2. Six M8 threaded holes are provided on the left flange 9 end face of the first circular pipe section for fixing the ignition electrode flange. Four photodiodes are installed at 100 mm, 300 mm, 500 mm, and 700 mm from the left flange 9 end face of each circular pipe section. Four photodiode fixing bolts 7 (non-standard countersunk M10 bolts) with central holes and threads are provided on the lower wall of each circular pipe section 1 to fix the photodiodes 5. Each section of circular pipe 1 is equipped with one NPT1 / 4 threaded hole at the bottom for connecting to an 8mm diameter PU tube 27.

[0064] The porous medium barrier system has a fire-arresting section 11 with a length of 160mm and is equipped with three fixing sleeves 13, each with a length of 50mm. After the fire-arresting section 11 is filled with porous medium, a washer is installed at the front end of the fixing sleeve 13, and the fire-arresting section 11 is inserted to fix the porous medium.

[0065] The explosion suppression system has a volume of 1L for each explosion suppression canister 3. The top and sides of each canister 3 are equipped with three NPT1 / 4 threaded holes for connecting an 8mm diameter PU tube 27. The bottom of each canister 3 is equipped with a solenoid valve 16 and a nozzle 17. The solenoid valve 16 has a response time of 100ms and a pressure resistance of 15MPa.

[0066] The gas distribution system employs a partial pressure method. First, gas is introduced uniformly and slowly through the premixing tank inlet 35 on the premixing tank 22. After distribution, the system remains stationary for 24 hours to ensure uniform premixed gas configuration within the premixing tank 22. Subsequently, gas is introduced uniformly and slowly through the premixing tank 22 into the explosion suppression tank inlets 18 of the three circular pipes 1. After distribution, the system remains stationary for 5 minutes to ensure uniform premixed gas configuration within the device. Each gas inlet is equipped with a needle valve (or ball valve) to prevent explosions from entering the gas distribution pipeline. The premixed gas ratio is calculated based on the fuel equivalence ratio, using Dalton's law of partial pressure. Based on the vacuum level inside the premixing tank 22 and the device, and the required concentration of combustible gas for the experiment, the gases are sequentially and in the correct quantities, following the order of fuel gas first, then air.

[0067] The high-voltage ignition system uses two 1.5mm diameter copper rods as ignition electrodes 10 for conduction. The copper rods are secured to the flange and fixing bolts by being encased in PTFE insulating tubing to prevent leakage or wall ignition. Each copper rod has a tungsten tip perpendicular to its end, creating an arc ignition through tip discharge. The two tips are collinear and opposite each other, with a tip gap of approximately 2mm. The length of the ignition electrodes varies within each container to ensure the ignition position is always centered inside the container. The high-voltage ignition current is output from the high-voltage ignition coil, converting the 220V, 0.25A AC input current into a 15kV, 40mA DC high-voltage current. The continuous discharge time is set to 30ms in the timing controller's internal program. A rough estimate of the total ignition energy, calculated by integrating the current, voltage, and time, is approximately 120.0mJ.

[0068] The synchronous control system, within the internal program of the timing controller 31, is programmed to sequentially trigger the data acquisition instrument after a 4900ms delay following the switch being pressed. The ignition procedure is executed at 6000ms, and ignition terminates at 6030ms. This 100ms time interval ensures that the explosion pressure and photoelectric data after ignition are completely acquired, avoiding timing system errors and signal transmission delays. The ignition energy is controlled by adjusting the length of the ignition delay time.

[0069] To accurately capture the pressure change trends during the rapid reaction of a gas explosion, the data acquisition system utilizes a high-precision piezoelectric pressure sensor 2. The acquisition frequency and duration are set to 100 kS / s and 200 ms / div (10 divs in total), respectively, totaling 1 million acquisition points. To prevent the pressure sensor end face from being uneven with the adjacent inner wall surface after installation, which could cause collisions and interference between the explosion pressure waves and create abnormal pressure data peaks, a specific countersunk hollow thread is designed according to the wall thickness of the device, ensuring that the pressure sensor end face is flush with the inner wall surface of the device.

[0070] Figure 6This is a schematic diagram of the PLC and control logic. The synchronous control system includes a timing controller 31, an ignition electrode 10, a photodiode 5, a solenoid valve 16, and a data acquisition instrument 29. The timing controller 31 controls the ignition. After the first photodiode 5 at the rear end of the flame arrestor section 11 receives the light signal, it converts the light signal into an electrical signal and sends it to the timing controller 31. The timing controller 31 controls the solenoid valve 16 to open, thereby spraying the explosion suppressant and extinguishing the flame.

[0071] The experiment on the synergistic effect of hydrogen explosion containment and suppression includes the following steps:

[0072] Step (1): According to the experimental plan, install porous media fire-resistant sections with specified porosities (0.25, 0.36, 0.45) and thicknesses (10mm, 50mm, 100mm, 150mm). Connect the circular pipe flanges on both sides of the fire-resistant section with bolts to fix the porous media fire-resistant section. Install porous media fire-resistant material, pressure sensor, and photodiode at the specified positions. Place sealing rubber rings / gaskets at the flange connections and wrap PTFE tape at the threaded connections to ensure good airtightness. Build an explosion suppression system. Connect the output end of the high-pressure ignition system to the specified ignition electrode pair and connect the timing controller to the high-pressure ignition pack, data acquisition instrument, and explosion suppression tank solenoid valve respectively.

[0073] Step (2): Start the vacuum pump, evacuate the premix tank to a low vacuum (<1.0 kPa), and observe the pressure gauge reading fluctuation after a short period of stillness (about 2 minutes) to check if the airtightness is good. If the pressure value rises significantly in a short time, it indicates that the airtightness is poor. It is necessary to check the location of the incompletely sealed parts and reseal them before checking the airtightness again. If the pressure value does not rise significantly, it indicates that the airtightness is good and gas mixing can proceed.

[0074] Step (3): According to Dalton's law of partial pressure, configure the required concentration of combustible gas and air in the premixed system for the specified gas equivalence ratio, and after the pressure gauge reading stabilizes, let it stand for 24 hours to ensure that the premixed gas inside the premix tank is mixed evenly.

[0075] Step (4): Start the vacuum pump and evacuate the sealed circular pipe to a low vacuum level (<1.0 kPa). After a short period of stillness (about 2 minutes), observe the fluctuation range of the pressure gauge reading to check whether the air tightness is good. If the pressure value rises significantly in a short time, it indicates that the air tightness is not good. It is necessary to check the location of the incompletely sealed parts and reseal them before checking the air tightness again. If the pressure value does not rise significantly, it indicates that the air tightness is good and gas mixing can be carried out.

[0076] Step (5): According to Dalton's law of partial pressure, the premixed gas in the premix tank is configured to the pressure required for the experimental conditions, and after the pressure gauge reading stabilizes, it is left to stand for 5 minutes to ensure that the premixed gas inside the closed circular pipe is mixed evenly.

[0077] Step (6): Check that the signal transmission and data acquisition lines of the pressure sensor, photodiode, solenoid valve, and ignition electrode are correctly connected. After adjusting the data acquisition instrument to the ready-to-trigger state, press the low-voltage electrical push-button switch and complete the triggering and ignition operations in sequence according to the preset timing controller.

[0078] Step (7): Save the pressure data and photodiode data from the data acquisition instrument. The results are as follows: Figure 7 As shown, Figure 7 This is a schematic diagram illustrating the attenuation effect of metal wire mesh with porosities of 0.25 and 0.36 and thicknesses of 50 mm, 100 mm, and 150 mm on the pressure of a pipeline explosion flame.

[0079] The specific details, basic principles, implementation methods, and main features of the present invention have been described above. The described implementation methods are only a part of the embodiments of the present invention, not all of them. Other technical solutions and implementation methods implemented through improvements and equivalent substitutions are all within the scope of protection of the present invention.

Claims

1. An experimental apparatus for the synergistic effect of hydrogen explosion prevention and suppression, characterized in that, It includes a closed circular pipeline system, a porous media barrier system, an explosion suppression system, a gas distribution system, a data acquisition system, a high-pressure ignition system, and a synchronization control system; The sealed circular pipe system includes three sections of circular pipe (1) with the same volume. A pressure sensor (2) and an explosion suppressor (3) are installed on the upper wall of the circular pipe (1), and a photodiode (5) and an air inlet (6) of the gas distribution pipeline are installed on the lower wall. An ignition electrode (10) is installed at the flange at the left end of the sealed circular pipe system. The porous media barrier system includes two fire-resistant sections (11), porous material (12), and a fixing sleeve (13). The fire-resistant sections (11) are connected to the flange of the circular pipe (1) by bolts (14). Three sections of circular pipe (1) and two fire-resistant sections (11) are arranged alternately. The explosion suppression system includes an explosion suppression tank (3), a solenoid valve (16), and nozzles (17) with different apertures and nozzle angles. An air inlet (18) and a water inlet (19) are installed on the explosion suppression tank (3). A solenoid valve (16), an explosion suppression tank fixing ring (34), and nozzles (17) are installed at the lower end of the explosion suppression tank. The explosion suppression tank (3) is set above the circular pipe (1) through the explosion suppression tank fixing ring (34), and the nozzles (17) are inserted into the circular pipe (1). The synchronous control system includes a timing controller (31), an ignition electrode (10), a photodiode (5), a solenoid valve (16), and a data acquisition instrument (29). Ignition is controlled by the timing controller (31). After the first photodiode (5) at the rear end of the flame arrestor section (11) receives the light signal, it converts the light signal into an electrical signal and sends it to the timing controller (31). The timing controller (31) controls the solenoid valve (16) to open, thereby spraying the explosion suppressant.

2. The experimental apparatus according to claim 1, characterized in that: The gas distribution system includes a gas cylinder (20), an air cylinder (21), a premix tank (22), a pressure reducing valve (23), a pipeline needle valve (24), a pressure gauge (25), a vacuum pump (26), and a PU gas pipe (27). The data acquisition system includes a piezoelectric pressure sensor (2), a sensor power supply box (28), a photodiode (5), and a data acquisition instrument (29). The pressure sensor (2) converts the pressure signal into an electrical signal, the photodiode (5) converts the light signal into an electrical signal, and the data acquisition instrument (29) records the signal according to a certain sampling frequency and time length. The high-voltage ignition system includes an ignition electrode (10), a high-voltage ignition pack (30), and a timing controller (31). The high-voltage ignition system starts the timing controller (31) through a low-voltage electrical push-button switch, which synchronously triggers the data acquisition instrument (29) and the explosion suppression canister (3) to spray. Then, it controls the high-voltage ignition pack (30) to output a high-voltage current, which generates an electric arc at the tip of the ignition electrode (10) to ignite the combustible gas. The synchronous control system includes a timing controller (31) that controls the start time and duration of spraying of the explosion suppression tank (3), controls the triggering of the data acquisition instrument (29), and controls ignition.

3. The experimental apparatus according to claim 1, characterized in that: The pressure sensor is fixed in a hollow pressure sensor fixing bolt (4), the photodiode (5) is fixed in a hollow photodiode fixing bolt (7), and quartz glass (8) is filled at the bottom of the photodiode fixing bolt (7) to assist in bearing pressure.

4. The experimental apparatus according to claim 1, characterized in that, The device includes three sections of circular pipe (1), two flame arrestor sections (11), and three explosion suppression canisters (3); two pressure sensors (2) are installed on the upper wall of each section of circular pipe (1) at 60mm and 740mm from the left flange end face to monitor the explosion pressure before and after the wire mesh; four photodiodes (5) are symmetrically placed on the lower wall at 100mm, 300mm, 500mm, and 700mm from the left flange end face to measure the average flame velocity of the pipe; the pipe flange threads on both sides of the flame arrestor section (11) can be removed after disassembly to facilitate the replacement of porous materials (12) with different porosities and thicknesses, so as to realize the experimental study of the overpressure variation law of the explosion of combustible gas in the sealed pipe under different porosities and thicknesses and the effect of explosion isolation; sealing rings / gaskets (32) are provided at the connection between the circular pipe (1) and the flame arrestor section (11).

5. The experimental method of the experimental apparatus according to any one of claims 1-4, characterized in that, Includes the following steps: Step (1): According to the experimental plan, install the porous media flame arrestor section with specified porosity and thickness, connect the circular pipe flanges on both sides of the flame arrestor section with bolts, fix the porous media flame arrestor section, install pressure sensor and photodiode at the specified position, and place sealing rubber ring / gasket at the flange connection to build the explosion suppression system, connect the output end of the high-pressure ignition system to the specified ignition electrode, and connect the timing controller to the high-pressure ignition pack, data acquisition instrument and explosion suppression tank solenoid valve respectively; Step (2): Start the vacuum pump and evacuate the premix tank to a vacuum level of <1.0 kPa, then check the airtightness; Step (3): According to Dalton's law of partial pressure, configure the required concentration of combustible gas and air in the premixed system for the specified gas equivalence ratio, and after the pressure gauge reading stabilizes, let it stand to allow the premixed gas inside the premix tank to mix evenly. Step (4): Start the vacuum pump and evacuate the sealed circular pipe to a low vacuum level of <1.0 kPa, then check the airtightness; Step (5): According to Dalton's law of partial pressure, the premixed gas in the premix tank is configured to the pressure required for the experimental conditions, and after the pressure gauge reading stabilizes, it is left to stand so that the premixed gas inside the closed circular pipe is mixed evenly. Step (6): Press the low-voltage electrical push-button switch to complete the triggering and ignition operations and the spraying of the explosion suppressant in sequence according to the preset timing controller. Step (7): Save the pressure data and photodiode data from the data acquisition instrument.

6. The experimental method according to claim 5, characterized in that: Before pressing the low-voltage electrical push-button switch in step (6), it is necessary to check that the signal transmission and data acquisition lines of the pressure sensor, photodiode, solenoid valve, and ignition electrode are correctly connected, and adjust the data acquisition instrument to the ready-to-trigger state.

7. The experimental method according to claim 5, characterized in that, The gas distribution system first evacuates the premixed tank (22) to a low vacuum level using a vacuum pump (26). Then, according to Dalton's law of partial pressure, the system switches the pipeline needle valve (24) and monitors the change in the pressure gauge (25) to achieve the specified gas mixture concentration in the premixed tank (22). After the vacuum pump (26) evacuates the sealed circular pipe (1) to a low vacuum level, the system switches the pipeline needle valve (24) and monitors the change in the pressure gauge (25) to achieve the specified pressure gas mixture in the premixed tank into the sealed circular pipe. Experiments are conducted on the synergistic effect of hydrogen explosion blocking and suppression under different gas equivalence ratios. The bottom surface of the three-section circular pipe (1) and the top end of the premixed tank (22) are each equipped with a gas distribution pipeline inlet to ensure that the overall gas distribution concentration of the pipeline system is uniform.

8. The experimental method according to claim 5, characterized in that, The high-pressure ignition system is equipped with an ignition electrode (10) at the center of the flange (9) on the left side of the first section of the circular pipe. Changing the output current and voltage of the high-pressure ignition pack can generate different ignition energies. Experiments were conducted on the synergistic effect of different ignition positions and ignition energies on the blocking and suppression of hydrogen explosions.

9. The experimental method according to claim 5, characterized in that, The twelve photodiodes (5) distributed on the three sections of circular pipe (1) successively capture the light signal, and calculate the average speed of the flame propagation in the pipe according to the distance / time. Experiments are conducted to investigate the effects of different gas equivalence ratios, different porosities of porous media, different thicknesses of porous media, and different materials of porous media on the propagation speed of combustible gas flames before and after passing through the flame arrestor section in the sealed pipe.

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