Detachable multiphase medium explosion flame flow field testing device and method

Abstract

The invention discloses a detachable multiphase medium explosion flame flow field testing device and method. The detachable multiphase medium explosion flame flow field testing device comprises a driving section, an observation section, a driven section and / or a bent pipe section, supporting and moving modules are arranged at the bottoms of the driving section, the observation section, the driven section and the bent pipe section and are used for supporting, moving and combining all the sections; the starting end of the combined testing device is provided with an ignition flange, and the tail end is provided with a flange blind plate; explosion-proof membranes are arranged among the sections. An ignition electrode is arranged on the ignition flange and is used for igniting the combustible medium at the starting end; the driving section is used for being filled with combustible gas, and the driven section and the bent pipe section are used for being filled with combustible solid / liquid. The driving section, the driven section and the bent pipe section are provided with a plurality of test holes and observation windows which are respectively used as pressure monitoring positions and image monitoring to obtain flame front propagation time so as to obtain flame front speed; and the observation section is used for monitoring and obtaining flame flow field changes. The flame flow field propagation condition can be clearly and visually recorded.

Description

Technical Field

[0001] This invention relates to the field of explosion and shock dynamics testing, and more particularly to a detachable multiphase medium explosion flame flow field testing device and method. Background Technology

[0002] Regarding the explosion characteristics of multiphase mixtures, different proportions of combustible media produce varying explosion pressures, and differences in ignition environment and combustible media content also lead to variations in explosion characteristics. Furthermore, proper control of the confined space and overall environmental structure can regulate the flame front propagation rate during multiphase explosions, thereby effectively reducing the generation and development of explosion pressure. Therefore, it is necessary to systematically study multiphase combustible media explosions under different confined space abrupt changes and flame propagation structure abrupt changes, to explore their pressure change characteristics, and to observe flame propagation patterns.

[0003] Existing research has largely focused on simplified conditions, and there is still a lack of systematic exploration of the combustion and explosion behavior of multiphase media under complex working conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a detachable multiphase medium explosion flame flow field testing device and method to clearly and intuitively record the flame flow field propagation, flame front velocity changes, and internal pressure changes of the explosion system. This device can be used to measure the influence of different medium combinations and confined space changes on the combustion and explosion characteristics of the mixture, thus solving the problems mentioned in the background art.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A detachable multiphase medium explosion flame flow field testing device includes a driving section, an observation section, a driven section, and / or a bend section.

[0007] The bottom of the driving section, observation section, driven section, and bend section is equipped with a support and movement module, which is used to support and move each section in combination to achieve different test objectives.

[0008] The combined test device is equipped with an ignition flange at the starting end and a flange blind plate at the end to create a closed environment for multiphase media; explosion-proof diaphragms are provided between each section to complete the isolation of each section space and the isolation of different flammable media;

[0009] The ignition flange is equipped with an ignition electrode for igniting the combustible medium at the starting end.

[0010] The driving section is used to fill combustible gas, while the driven section and the bend section are used to fill combustible solids / liquids.

[0011] Multiple test holes and observation windows are provided on the driving section, driven section, and bend section, which serve as pressure monitoring positions and image monitoring points to obtain the flame front propagation time and thus the flame front velocity.

[0012] The observation section is used to monitor and acquire changes in the flame flow field.

[0013] The significant advantages of this invention compared to existing technologies are:

[0014] This invention utilizes interconnected and detachable test sections of different types to explore the influence of structural changes on the evolution of the flame flow field during multiphase media explosions by altering the confined space. It can be used to conduct combustion and explosion experiments on different flammable media. The multifunctional, detachable device facilitates cleaning of the pipe environment and is convenient for testing personnel. The ignition electrode is installed at the center of the front end of the drive section to complete the ignition operation of the flammable medium. Through devices such as explosion-proof diaphragms and flange blind plates, the flammable medium is isolated from flammable solids / liquids. Various experiments, including flammable medium explosions, multiphase media explosions, and explosion suppression, are conducted to explore the impact of shock wave generation during secondary explosions on multiphase media mixtures. Simultaneously, it can be used to investigate the specific effects of confined space irregularities such as bends and straight pipes on changes in the flame flow field. By recording the flame propagation path, flame front velocity changes, and multiphase media combustion and explosion characteristics, the dynamic evolution process and coupling mechanism during multiphase media combustion and explosion can be explored. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the hollow flange of the present invention;

[0018] Figure 3 This is a schematic diagram of the ignition flange and flange blind plate of the present invention;

[0019] Figure 4 This is a cross-sectional view of the pressure sensor base of the present invention;

[0020] Figure 5 This is a pressure-time curve of a 25% hydrogen explosion-induced dust explosion in an experimental example of the present invention.

[0021] Figure 6 This is a diagram showing the evolution of the flame flow field in a dust explosion induced by a 25% hydrogen explosion in an experimental example of this invention.

[0022] Figure 7This is a diagram showing the evolution of the flame flow field when the structure of a dust explosion induced by a 25% hydrogen explosion occurs in an experimental example of this invention.

[0023] In the diagram: 1-Ignition electrode, 2-High-pressure ball valve, 3-High-precision pressure gauge, 4-Test hole, 5-Small observation window, 6-Drive section, 7-Explosion-proof diaphragm, 8-Large observation section, 9-Flange, 10-Driven section, 11-Bend section, 12-Portable mobile platform, 13-Universal casters. Detailed Implementation

[0024] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0025] like Figure 1 As shown, the present invention proposes a detachable multiphase medium explosion flame flow field testing device, including an ignition electrode 1, a high-pressure resistant ball valve 2, a high-precision pressure gauge 3, a test hole 4, a small observation window 5, a drive section 6, an explosion-proof diaphragm 7, a large observation section 8, a flange 9, a driven section 10, a bend section 11, a portable mobile platform 12, and omnidirectional casters 13.

[0026] The driving section 6, driven section 10, and bend section 11 each have multiple identical structures, which can be connected by flanges 9 and bolts. The ends of the driving section 6, driven section 10, and bend section 11 can all be connected to the ignition flange 14 and the flange blind plate 15. These three types of mechanisms can complete different experimental requirements through different assembly sequences. Flange blind plates 15 can also be installed on both sides of the driving section 6, driven section 10, and bend section 11 to ensure that a closed environment is created for the multiphase medium during testing. That is, the flange blind plate 15 is set at the end of the combined testing device. Figure 1 The example only shows one combination where the ignition flange 14 is located at the end of the drive section 6 and the flange blind plate 15 is located at the end of the bend section 11.

[0027] Each section is equipped with multiple test holes 4 as needed. The test holes 4 are threaded connections, which can be connected to the sensor base 16 or other experimental equipment to monitor pressure changes at different locations.

[0028] Figure 1 In the example, the ignition electrode 1 is fixed at the center of the first end of the drive section 6 and connected to the power supply. It can ignite the combustible medium in the drive section 6 and provide energy for the combustible medium in the drive section 6.

[0029] Figure 1In the example, the high-pressure ball valve 2 and the high-precision pressure gauge 3 are fixed to the outer wall of the front end of the drive section 6. The high-pressure ball valve 2 is connected to experimental instruments such as vacuum pumps and air compressors. The high-precision pressure gauge 3 accurately controls the proportion of combustible medium at the drive section 6.

[0030] The test hole 4 is connected to the sensor base 16 by a thread. Multiple test holes 4 are arranged at intervals along the axial direction of the drive section 6, the driven section 10, and the bend section 11. The axial direction of the test hole 4 is perpendicular to the axial direction of the drive section 6 and the driven section 10. The sensor base 16 is equipped with a pressure sensor, and the pressure curve changes at different positions of the drive section 6 and the driven section 10 are collected by a data acquisition system.

[0031] Furthermore, multiple small observation windows 5 are symmetrically arranged along both sides of the driving section 6 and the driven section 10, which can capture the evolution of the flame flow field at the driving section 6 and the driven section 10 during the test using a high-speed camera and an infrared thermal imager, and can calculate the change in flame front velocity through the position of adjacent small observation windows 5.

[0032] Furthermore, the large observation section is equipped with square glass windows at 8 locations. The glass is made of high-temperature resistant material and can record the complete flame flow field changes at the 8 locations of the large observation section using a high-speed camera and an infrared thermal imager.

[0033] Furthermore, explosion-proof diaphragms 7 are provided between the connecting flanges 9 of each section. The explosion-proof diaphragms 7 can isolate the space between the driving section 6 and the driven section 10 and the bend section 11. There are sealing gaskets between the flange connections of the driving section 6, the driven section 10 and the bend section 11, which can complete the isolation treatment of multiphase media.

[0034] The driving section 6, the driven section 10, and the bend section 11 can be freely combined and installed to achieve different testing purposes.

[0035] Furthermore, each section is connected to a portable mobile platform 12. The bottom of the portable mobile platform 12 is equipped with multiple omnidirectional casters 13 to support the testing equipment and facilitate subsequent assembly and disassembly, while avoiding interference from the near-ground effect during external testing experiments.

[0036] Furthermore, the aforementioned method for testing the explosion flow field of a detachable multiphase medium explosion flame specifically includes the following steps:

[0037] S1. A flammable solid / liquid medium is pre-placed at the driven section 10, and an explosion-proof diaphragm 7 is placed at the flange 9 between the driven section 6 and the driven section 10 to isolate the flammable solid / liquid medium from the flammable medium in the driven section 6. When a flammable solid / liquid medium is also placed in the bend section 11, an explosion-proof diaphragm 7 is also installed between the driven section 10 and the bend section 11.

[0038] S2. Connect the portable power supply to the ignition electrode 1 and fix it to the ignition flange 14, ensuring that the ignition electrode is located at the center of the front end of the drive section 6. Connect the drive section 6, observation section 8, driven section 10, and bend section 11 in sequence. Fix the ignition flange to the front end of the drive section 6 and fix the flange blind plate to the right end of the bend section 11.

[0039] S3. Using the pipelines connected to the vacuum pump, air compressor, gas cylinder, etc. via the high-pressure ball valve 2, the combustible medium required for the test is filled into the drive section 6, and the ratio of combustible medium in the drive section 6 is precisely controlled according to the high-precision pressure gauge 3.

[0040] S4. Confirm the connection status between the data acquisition system and the pressure sensor at sensor base 16, and complete the ignition at drive section 6 through ignition electrode 1.

[0041] S5. The combustible medium in the drive section 6 explodes, and the explosion-proof diaphragm 7 is ruptured at the same time. A shock wave signal is generated in the test system to characterize the typical sonic boom characteristics, and an incident shock wave is generated. When the incident shock wave propagates to the driven section 10, the combustible solid / liquid medium is hoisted to complete a secondary explosion. The changes in the flame flow field are photographed through the small observation window 5 and the large observation section 8.

[0042] S6. The pressure changes at different locations inside the pipe are monitored by pressure sensors at 16 locations on the sensor base, and the flame front velocity is calculated by observing the flame propagation through the small observation window 5.

[0043] The method for calculating the speed of the flame vanguard is as follows:

[0044] ;

[0045] in, Flame Vanguard Speed, t represents the distance between two adjacent small observation windows, and t is the time difference between the propagation of the flame front to the two adjacent small observation windows, which may be obtained by a camera.

[0046] S7. After the experiment is completed, the data from the high-speed camera and data acquisition unit are processed to obtain the evolution of the flame flow field and the pressure changes of the driving section 6, the driven section 10, and the bend section 11. The high-pressure ball valve 2 is opened to release pressure and the inside of the pipe is cleaned to complete the test operation.

[0047] When conducting tests under other confined space conditions, such as Scheme 1: connecting the driving section 6, observation section 8, and driven section 10 can complete the process of flame flow field change and pressure-time curve of multiphase medium explosion in a sealed container; Scheme 2: connecting the driving section 6, bend section 11 (with added combustible solid / liquid), and observation section 8 can complete the influence of confined space changes on flame flow field during multiphase medium explosion, and analyze the influence of confined space bending on flame flow field by comparing and analyzing the flame propagation at observation section 8.

[0048] In this example, using hydrogen as the combustible medium in the driving section and aluminum powder as the combustible medium in the driven section, two experimental apparatuses were assembled: a straight-pipe closed test device and a straight-pipe-bend open test device. The pressure changes in the test devices during the multiphase media explosion were analyzed, and the flow field evolution during the explosion was captured by a high-speed camera to explore the coupling mechanism of different confined spaces on the explosion flame flow field.

[0049] Figure 5 The pressure-time curve of dust explosion induced by 25% hydrogen explosion at test point 10 of the driven section;

[0050] In the driven section 10, the main reaction is between residual hydrogen and aluminum powder with oxygen in the driven section. The aluminum powder particles in the high temperature and high pressure environment are rapidly activated and undergo a violent oxidation reaction, releasing energy higher than that of hydrogen explosion, causing the pressure to rise again. This results in a significant second peak on the time-pressure curve. The time interval between the two peaks reflects the difference in chemical activation energy between hydrogen and aluminum powder. Aluminum powder needs to undergo a more complex surface oxidation process, which leads to a reaction activation energy of aluminum powder that is greater than that of hydrogen, resulting in a slower reaction rate. Therefore, the time-pressure curve shows a significant double-peak phenomenon.

[0051] Figure 6 The evolution of the flame flow field in a dust explosion induced by a 25% hydrogen explosion.

[0052] At t=0.8 ms, the flame front propagates into the high-speed frame; at t=4.8 ms, the flame front reaches the farthest point of the pipe, after which the flame begins to reflect; at t=9.7 ms, the flame front disappears from the high-speed frame; at t=17.1 ms, the flame reappears, and disappears again at t=22 ms. The above images demonstrate that flame reflection occurs during a multiphase explosion within the testing device.

[0053] Figure 7 This is a diagram showing the evolution of the flame flow field when the structure of a dust explosion induced by a 25% hydrogen explosion occurs in an experimental example of this invention.

[0054] When the testing device is switched to the open state, as time goes by, the propagation and shape changes of the flame at the nozzle exhibit a phenomenon of repeated alternation between light and dark.

[0055] This invention utilizes interconnected and detachable testing devices of various types to investigate the impact of structural changes on the evolution of the flame flow field during multiphase media explosions by altering confined spaces. It can be used to conduct combustion and explosion experiments on different flammable media. The multifunctional, detachable devices facilitate cleaning of the internal environment and are convenient for testing personnel. The ignition electrode is installed at the center of the front end of the drive section to ignite the flammable medium. By using explosion-proof diaphragms, flange blind plates, and other devices to isolate the flammable medium from flammable solids / liquids, various experiments such as flammable medium explosions, multiphase media explosions, explosion suppression, and explosion venting are conducted to investigate the impact of shock wave generation during secondary explosions on multiphase media mixtures. Furthermore, it can be used to investigate the specific effects of confined space irregularities such as bends and straight pipes on changes in the flame flow field. By recording the flame propagation path, flame front velocity changes, and multiphase media combustion and explosion characteristics, the dynamic evolution process and coupling mechanism during multiphase media combustion and explosion can be explored.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Equivalent changes or substitutions made by those skilled in the art to the above embodiments without departing from the concept of the present invention should all fall within the protection scope of the present invention.

Claims

1. A detachable multiphase medium explosion flame flow field testing device, characterized in that, Includes the drive section, observation section, driven section and / or bend section; The bottom of the driving section, observation section, driven section, and bend section is equipped with a support and movement module, which is used to support and move each section in combination to achieve different test objectives. The combined test device is equipped with an ignition flange at the starting end and a flange blind plate at the end to create a closed environment for multiphase media; explosion-proof diaphragms are provided between each section to complete the isolation of each section space and the isolation of different flammable media; The ignition flange is equipped with an ignition electrode for igniting the combustible medium at the starting end. The driving section is used to fill combustible gas, while the driven section and the bend section are used to fill combustible solids / liquids. Multiple test holes and observation windows are provided on the driving section, driven section, and bend section, which serve as pressure monitoring positions and image monitoring points to obtain the flame front propagation time and thus the flame front velocity. The observation section is used to monitor and acquire changes in the flame flow field.

2. The detachable multiphase medium explosion flame flow field testing device according to claim 1, characterized in that, Combination forms include: The driving section, observation section, driven section, and bend section are connected in sequence to obtain the changes in flame front velocity and internal pressure changes during the explosion; the driving section, observation section, and driven section are connected in sequence to complete the process of flame flow field changes and pressure-time curves during multiphase medium explosion in a sealed container; the driving section, bend section, and observation section are connected in sequence to obtain the influence of confined space changes on the flame flow field during multiphase medium explosion.

3. The detachable multiphase medium explosion flame flow field testing device according to claim 1, characterized in that, The test hole is equipped with a sensor base for connecting a pressure sensor.

4. The detachable multiphase medium explosion flame flow field testing device according to claim 1, characterized in that, The axial arrangement of the test hole and the corresponding section is adjusted.

5. The detachable multiphase medium explosion flame flow field testing device according to claim 1, characterized in that, A square glass window is provided at the observation section.

6. The detachable multiphase medium explosion flame flow field testing device according to claim 1, characterized in that, The drive section is equipped with a ball valve for injecting combustible gas; and a pressure gauge is provided to control the proportion of combustible gas injected.

7. A method for testing the flow field of a multiphase medium explosion flame, utilizing the detachable multiphase medium explosion flame testing device according to any one of claims 1-6, characterized in that, include: Connect each section according to the test requirements and place the explosion-proof diaphragm; The drive section is filled with combustible gas, and other sections are filled with combustible solids / liquids as needed; Ignition at the drive section is achieved through the ignition electrode. The changes in the flame flow field were captured through the observation window and observation section; The monitoring device was used to measure pressure changes at different locations within the device and the time it took for the flame front to reach different observation windows. The evolution of the flame flow field, pressure-time curves, and the influence of confined space curvature on the flame flow field are observed through photography.

8. The method for testing the flow field of a multiphase medium explosion flame according to claim 7, characterized in that, The speed calculation method for the Flame Vanguard is as follows: ； in, Flame Vanguard Speed, t is the distance between two adjacent observation windows, and t is the time difference between the propagation of the flame front to the two adjacent observation windows.

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