Visual annular combustion pipeline group, experimental device and method

Abstract

The invention relates to the technical field of combustion experiment devices, and discloses a visual annular combustion pipeline group, an experiment device and a method. The pipeline set comprises a plurality of pipe sections which are sequentially spliced inside to form a closed-loop type channel. Any pipe section can be used as an ignition section for mounting an ignition system, and the ignition system is used for igniting combustible premixed gas in the channel to generate flames which are propagated in two directions and are finally converged and collided; the two opposite sides, parallel to the plane where the channel is located, of all the pipe sections are observation sides, the observation sides are provided with observation windows used for observing the flame propagation and collision process, and each pipe section can further be provided with a pressure collecting system used for collecting the pressure in the channel in the process. The device can be used for researching the flame form, pressure and speed evolution law in the flame opposite propagation collision process in the combustion process of combustible gas in the annular pipeline.

Description

Technical Field

[0001] The invention relates to the technical field of combustion experimental devices, in particular to a visualized annular combustion pipeline group, and a flame propagation collision experimental device and method using the pipeline group. Background Art

[0002] The study of flame acceleration originated from coal mine gas explosions. Later generations used closed long straight pipes to ignite the combustible premixed gas at one end, and the flame maintained a self-acceleration process until the other end, with a unique flame propagation direction. In industrial explosion accidents, since the leakage of combustible gas is restricted by local conditions, the gas diffused after the leakage is extremely uneven, and the local ignition source can cause the flame propagation direction to be non-unique, and there is a situation where the flames propagate in opposite directions and collide, inducing flame acceleration or even explosion.

[0003] The flame propagation process can be divided into several parts, including the collision of shock waves generated in front of the flame, the collision of shock waves and flames, and the collision of flames. The collision of shock waves will strongly compress the local area, which may form hot spots to induce explosions; the collision of shock waves and flames will have a significant impact on the shape of the flame surface, increase the heat release rate, and accelerate the spread of flames; the collision of flames and flames will cause the flow field of unburned gas flowing in the opposite direction in front of the flame front to cause flow blockage, and the local heat concentration will promote flame acceleration and even explosion.

[0004] In order to simulate and simplify the flame collision in disaster accidents, conduct in-depth research on the flame propagation collision and other collision phenomena, and enrich the research on the flame propagation process, it is necessary to design a visual experimental scheme to study the flame propagation collision. Summary of the invention

[0005] In order to overcome the defects in the above-mentioned prior art, the present invention provides a visualized annular combustion pipe group, an experimental device and a method for studying the morphology, pressure and velocity evolution laws of the flame propagation collision process during the combustion of combustible gas in an annular pipe.

[0006] To achieve the above object, the present invention provides the following technical solutions: The present invention discloses a visualized annular combustion pipeline group, comprising a plurality of pipe sections, which are sequentially spliced ​​together to form a closed-loop channel inside; any pipe section can be used as an ignition section for installing an ignition system, which is used to ignite combustible premixed gas inside the channel to generate a flame that propagates in both directions and eventually converges and collides; all pipe sections are observation sides on two opposite sides parallel to the plane where the channel is located, and the observation sides are provided with observation windows for observing the flame propagation and collision process, and each pipe section can also be installed with a pressure collection system for collecting the internal pressure of the channel during the process.

[0007] As a further improvement of the above scheme, all pipe sections are divided into annular pipe sections and straight pipe sections; wherein the annular pipe section is semicircular and has two sections, and the ends of the two annular pipe sections are arranged facing each other; the straight pipe section has at least two sections, and all the straight pipe sections are divided into two rows and respectively arranged between the two annular pipe sections to form a closed runway-shaped channel.

[0008] As a further improvement of the above scheme, the ignition system includes an igniter and a semiconductor nozzle; all pipe sections are located on the inner side of the closed loop and are provided with at least one first hole, and each first hole is used to install the semiconductor nozzle or nozzle plug; wherein, when a semiconductor nozzle is installed in one of the first holes of any pipe section, nozzle plugs are installed in the remaining first holes of all pipe sections; the igniter and the semiconductor nozzle are electrically connected and are used to trigger the semiconductor nozzle to generate electric sparks; The pressure acquisition system includes a plurality of pressure sensors, and all pipe sections located outside the closed loop are provided with at least one second hole, and each of the second hole is used to install a pressure sensor.

[0009] As a further improvement of the above scheme, at least one pipe section is also provided with a third hole position, and each of the third hole positions is used to install an inflation port or an inflation end plug; when the third hole position is used for inflation, an inflation port is installed, and the inflation port is used to connect to the gas distribution system to fill the interior of the channel with combustible premixed gas; when the third hole position is not used for inflation, an inflation end plug is installed; at least two pipe sections are also provided with a fourth hole position, and each of the fourth hole positions is used to install a static pressure sensor, and the static pressure sensor is used to measure the gas pressure when the interior of the channel is filled with combustible premixed gas, and at least two of the static pressure sensors are symmetrically distributed on the channel.

[0010] As a further improvement of the above scheme, the observation window includes quartz glass and a cover plate; a first opening communicating with the interior of the channel is provided on the observation side of the tube segment, and a projection range of the first opening on a plane where the observation side is located is larger than a projection range of the channel on the plane, thereby forming an assembly space adapted to the quartz glass on the tube segment, and the quartz glass is clamped and fixed in the assembly space by the cover plate to seal the first opening; a second opening is also provided on the cover plate to avoid the quartz glass, and a height of the second opening is the same as a height of the channel.

[0011] As a further improvement of the above solution, a silicone pad is provided between the cover plate and the quartz glass, and sealing silicone grease is applied.

[0012] As a further improvement of the above solution, adjacent pipe sections are connected via flanges.

[0013] The present invention also discloses a flame propagation collision experiment device, comprising a pipeline group, a gas distribution system, an ignition system, a schlieren system and a pressure collection system; wherein the pipeline group adopts the visualized annular combustion pipeline group as described above; the gas distribution system is used to provide a certain pressure of combustible premixed gas to the inside of the channel; the ignition system is used to ignite the combustible premixed gas inside the channel to generate a flame that propagates in both directions and eventually converges and collides; the schlieren system is used to collect schlieren images of the flame propagation process and the collision process inside the channel through an observation window; the pressure collection system is used to collect the internal pressure of the channel during the flame propagation process and the collision process.

[0014] As a further improvement of the above scheme, the schlieren system includes two sets of adjustable optical path systems and high-speed cameras, which are respectively placed in the observation windows of the pipe sections where the flame acceleration process and the flame collision process are located; wherein each set of optical path systems includes a light source, a first focusing lens, an aperture slit, a collimating lens, a second focusing lens and a knife edge in sequence along the light transmission direction; the light emitted by the light source passes through the first focusing lens and converges at the aperture slit, the light is amplified and converted into parallel light through the collimating lens, the parallel light passes through the observation window of the corresponding pipe section and reaches the second focusing lens, the light is focused again and passes through the knife edge, and enters the high-speed camera after light cutting.

[0015] The present invention also discloses a flame counter-propagation collision experimental method, which is applied to the flame counter-propagation collision experimental device. The experimental method comprises the following steps, namely S1 to S3.

[0016] S1. Assemble a visual annular combustion pipeline group with a specific channel shape according to the experimental needs, confirm the position of the ignition section and install the ignition system on the ignition section, install the gas distribution system and pressure collection system on the pipeline group, and check the air tightness of the pipeline group and the stability of the gas distribution system, ignition system, and pressure collection system.

[0017] S2. A Schlieren system is set up in the pipe sections where the flame acceleration process and the flame collision process of the pipeline group are located. One set of optical path systems and high-speed cameras are used to shoot the flame acceleration process, and the other set of optical path systems and high-speed cameras are used to shoot the flame collision process.

[0018] S3. Combustible premixed gas is configured through the gas distribution system, and a certain pressure of combustible premixed gas is filled into the vacuum channel. After standing for a set time, the ignition system is triggered. At the same time, the Schlieren system and the pressure acquisition system record and store data.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The visualized annular combustion pipeline group disclosed in the present invention can be used to study the evolution of the morphology, pressure, and velocity of the flame propagation collision process in the combustion process of the combustible gas in the annular pipeline. The pipeline group is spliced ​​by multiple pipe sections, and local ignition can cause the flame to propagate in both directions. By changing the ignition position, two experimental effects can be achieved: flame collision in the annular pipe section and flame collision in the straight pipe section.

[0020] 2. The multi-section pipe segments of the pipeline group can be divided into arc and straight shapes, so that they can be spliced ​​to form various forms of closed-loop channels according to experimental requirements, providing a hardware foundation for the study of flame acceleration mechanisms in straight and curved pipelines. In addition, it is also possible to choose to replace pipe segments of different sizes, curvatures, and lengths to further enrich the types of experiments.

[0021] 3. The experimental device and method disclosed in the present invention provide two sets of adjustable optical paths and high-speed cameras. The high-speed schlieren system relies on a visualization window to respectively shoot the flame acceleration process and the flame collision process through two sets of high-speed cameras. The flame images are captured at two positions at the same time, which can be used to observe the morphological changes of the flames from propagating towards each other to the entire collision process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a plan view of the visualized annular combustion pipeline group in Example 1 of the present invention when the channel is in the shape of a playground runway.

[0023] Figure 2 It is a plan view schematic diagram of a circular channel of a visualized annular combustion pipe group in an embodiment of the present invention.

[0024] Figure 3 It is a plan view schematic diagram when the channel of the visualized annular combustion pipeline group in the embodiment of the present invention is a rounded rectangle.

[0025] Figure 4 This is a schematic diagram of the three-dimensional structure of the playground track-shaped visualized annular combustion pipeline group (only the right annular quartz glass is shown) in Example 1 of the present invention.

[0026] Figure 5 for Figure 4 Visualization of the annular combustion duct group with the semiconductor nozzle installed in the front view of the left annular pipe section.

[0027] Figure 6 for Figure 4 Visualization of the front view of the semiconductor nozzle of the annular combustion pipe group when it is installed in the lower straight pipe section.

[0028] Figure 7 Schematic diagram of an explosion of the annular pipe segment in Example 1 of the present invention (only some components are shown).

[0029] Figure 8Schematic diagram of an exploded view of a straight pipe section in an embodiment of the present invention (only some components are shown).

[0030] Fig. 9 Schematic diagram of the flame propagation collision experimental device in Example 2 of the present invention.

[0031] In the figure: T0, pipe section; T01, first port; T02, second port; T1, channel; 1, annular pipe section; 2, straight pipe section; 3, semiconductor nozzle; 4, charging port; 5, static pressure sensor; 6, nozzle plug; 7, charging end plug; 8, pressure sensor; 11, annular pipe section body; 12, flange; 13, annular quartz glass; 14, annular cover plate; 21, straight pipe section body; 22, rectangular quartz glass ; 23. Rectangular cover plate; 24. Lining plate; 25. Screw hole on the lower wall; 91. Gas distribution system; 92. Ignition system; 921. Ignitor; 93. Schlieren system; 931. Optical path system; 9310. Light source; 9311. First focusing lens; 9312. Aperture slit; 9313. Collimating lens; 9314. Second focusing lens; 9315. Knife edge; 932. High-speed camera; 94. Pressure acquisition system. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1 This embodiment provides a visualized annular combustion pipeline group, including multiple pipe sections T0, which are spliced ​​in sequence through flanges 12 to form a closed-loop channel T1 inside the pipe sections.

[0034] See also Figures 1 to 3 The pipe segment T0 can be in a straight line, a half arc (semicircle), or a quarter arc. Different numbers and shapes of pipe segments T0 can be selected and combined according to experimental requirements to form annular channels T1 of different shapes (colored areas in the figure). In some embodiments, the following can be formed: Figure 1 The playground runway-shaped (waist-shaped) channel T1 shown, or formed as Figure 2 The circular annular channel T1 shown can also be formed as follows Figure 3The rounded rectangular channel T1 shown. Of course, it can also be other shapes, as long as it can form a closed loop for the flames to be triggered from the same ignition segment and finally collide with each other. In addition, the arc and other dimensions of the arc-shaped pipe segment T0 can also be selected by yourself to adjust the incident angle before the flames collide with each other; the number and unit length of the straight-line pipe segments T0 installed on the same straight line can also be selected by yourself to adjust the stroke of flame acceleration.

[0035] See also Figure 4 The pipe section T0 of the present invention is located on the inner side of the closed loop and is provided with at least one first hole, so that any pipe section T0 can be used as an ignition section for installing the ignition system 92 .

[0036] The ignition system 92 includes an igniter (not shown) and a semiconductor nozzle 3. The igniter and the semiconductor nozzle 3 are electrically connected and used to trigger the semiconductor nozzle 3 to generate an electric spark. The semiconductor nozzle 3 is used to ignite the combustible premixed gas inside the channel T1 to generate a flame that propagates in both directions and eventually converges and collides.

[0037] Each first hole is used to install a semiconductor nozzle 3 or a nozzle plug 6; wherein, when a semiconductor nozzle 3 is installed in one of the first holes of any pipe section T0, nozzle plugs 6 are installed in the remaining first holes of all pipe sections T0.

[0038] In this embodiment, the visualized annular combustion pipeline group includes two annular pipe sections 1 and two straight pipe sections 2. The annular pipe section 1 is in a semicircular shape, and the two annular pipe sections 1 are arranged with their ports facing each other; the two straight pipe sections 2 are arranged side by side between the two annular pipe sections 1 to form a channel T1 in the shape of a playground runway. In this pipeline group, a first hole position is respectively arranged on the inner side of the four pipe sections T0, and each first hole position is used to install a semiconductor nozzle 3 or a nozzle plug 6. Among them, the semiconductor nozzle 3 can be installed in the first hole position on the inner side of the annular pipe section 1, and can also be installed in the first hole position on the inner side of the straight pipe section 2. When a semiconductor nozzle 3 is installed in any first hole position, nozzle plugs 6 are installed in the other three first holes.

[0039] like Figure 5 As shown, if the left annular pipe section 1 is used as the ignition section, the semiconductor nozzle 3 is installed at the middle inner position of the left annular pipe section 1. Correspondingly, the nozzle plug 6 is installed at the middle inner position of the right annular pipe section 1. The upper and lower straight pipe sections 2 are not used as ignition sections, and the nozzle plugs 6 are installed at the middle positions of the inner sides of the two straight pipe sections 2. Figure 5 When the ignition section shown is ignited, theoretically the flame will propagate in both upward and downward directions along the middle of the left annular pipe section 1, pass through two straight pipe sections 2 respectively, and finally converge and collide in the right annular pipe section 1.

[0040] like Figure 6As shown, if the lower straight pipe section 2 is used as the ignition section, the semiconductor nozzle 3 is installed at the middle inner position of the lower straight pipe section 2. Correspondingly, the nozzle plug 6 is installed at the middle inner position of the upper straight pipe section 2. The left and right annular pipe sections 1 are not used as ignition sections, and the nozzle plugs are installed at the middle positions of the inner sides of the two annular pipe sections 1. Figure 6 When the ignition section shown is ignited, theoretically the flame will propagate to the left and right directions along the middle of the lower straight pipe section 2, pass through the two annular pipe sections 1 respectively, and finally converge and collide in the upper straight pipe section 2.

[0041] Each pipe section T0 can also be installed with a pressure collection system 94 for collecting the internal pressure of the channel T1 during the process. The pressure collection system 94 includes multiple pressure sensors 8. All pipe sections T0 located outside the closed loop are provided with at least one second hole, and each second hole is used to install a pressure sensor 8.

[0042] In this embodiment, a total of 12 pressure sensors 8 are provided. Three second holes are evenly arranged on the outsides of the two annular pipe sections 1 and the two straight pipe sections 2, and the 12 pressure sensors 8 are respectively installed on the 12 second holes.

[0043] In this embodiment, the inner side of the two straight pipe sections 2 is also provided with a third hole position, one of which is provided with a gas charging port 4, and the gas charging port 4 is used to connect with the gas distribution system 91 to fill the combustible premixed gas into the channel T1. Another third hole position is provided with a gas charging end plug 7. Of course, in other embodiments, the third hole position can also be provided on other pipe sections. The gas charging port 4 can be interchanged with the gas charging end plug 7.

[0044] In addition, a fourth hole is opened on the inner side of each of the two straight pipe sections 2. The two fourth holes are symmetrically distributed about the "central axis" of the channel 1. A static pressure sensor 5 is installed at each of the two fourth holes. The static pressure sensor 5 is used to measure the gas pressure when the combustible premixed gas is filled in the channel T1.

[0045] All the tube sections T0 have observation sides on two opposite sides parallel to the plane where the channel T1 is located. The observation sides are provided with observation windows for observing flame propagation and collision processes.

[0046] The observation window includes quartz glass and a cover plate; a first opening T01 communicating with the interior of the channel T1 is provided on the observation side of the tube segment T0, and a projection range of the first opening T01 on a plane where the observation side is located is larger than a projection range of the channel T1 on the plane, thereby forming an assembly space adapted to the quartz glass on the tube segment T0, and the quartz glass is clamped and fixed in the assembly space by the cover plate to seal the first opening T01; a second opening T02 for avoiding the quartz glass is also provided on the cover plate, and a height of the second opening T02 is the same as a height of the channel T1.

[0047] Specifically, for the annular pipe section 1 and the straight pipe section 2 in this embodiment, the cross-sectional dimensions of the channel T1 formed therein are 40×60 mm, and the channel T1 of the annular pipe section 1 is a semicircular ring, with an inner wall radius of 190 mm and an outer wall radius of 250 mm. A 35 mm straight section is provided outside the two ends of the semicircular ring for welding flange 12. The length of the straight pipe section 2 is 500 mm. The thickness of the upper and lower walls of the pipe is 50 mm, and the thickness of the front and rear walls is 25 mm. In this example, the total length of the pipeline group in the horizontal direction is 1170 mm, and the total height in the vertical direction is 600 mm. The pipe body material is uniformly made of 6061 aluminum alloy, and needs to undergo a surface treatment process.

[0048] See also Figure 7 The annular pipe segment 1 may include an annular pipe segment body 11 , an annular quartz glass 13 and an annular cover plate 14 .

[0049] Among them, three third holes are set at the center of the outer side of the annular pipe section body 11 and at a position of 45° relative to the horizontal plane, which are used to install the pressure sensor 8, and the pressure sensor 8 is a packaging structure. In order to ensure that the outer side of the annular pipe section body 11 is tightly fitted with the packaging structure of the pressure sensor 8, it is necessary to cut 2mm downward on the tangent surface during processing. The first hole opened on the inner side of the annular pipe section body 11 is a threaded hole, which cooperates with the threads on the semiconductor 3 and the nozzle plug 6. A semicircular first opening T01 is opened in the middle of the annular pipe section body 11. The inner radius of the first opening T01 is 170mm, the outer radius is 270mm, the depth is 25mm, and the four corners are rounded, with a fillet radius of 10mm. The relative width of the first opening T01 is 100mm, which is 20mm wider than the 60mm width of the channel T1, so a step-like structure (assembly space) is formed, which is used here to give the annular quartz glass 13 a support. The annular quartz glass 13 is a semicircular ring with an inner radius of 190 mm, an outer radius of 260 mm, a thickness of 26 mm, and four corners with rounded corners and a rounded corner radius of 10 mm. When the annular quartz glass 13 is fitted with the step, a 1 mm thick cork rubber belt needs to be pasted on the step to prevent the glass surface from being worn at the inner boundary of the annular pipe section body 11. A total of 30 screw holes (15 on each side) can be evenly opened on both sides of the annular pipe section body 11. The annular cover plate 14 is 15 mm thick, with an annular second opening T02 in the middle that is consistent with the annular channel T1, and also has a through hole that is consistent with the position of the screw hole on the annular pipe section body 11. When installing the sealed annular quartz glass 13, a thin silicone pad needs to be placed between the annular cover plate 14 and the annular quartz glass 13 and high vacuum sealing silicone grease needs to be applied to enhance the sealing effect. The annular pipe section body 11 and the two flanges 12 are connected to form a main body by welding, and the weld needs to be cut and smoothed.

[0050] See also Figure 8The straight pipe section 2 may include a straight pipe section body 21 , a rectangular quartz glass 22 , a rectangular cover plate 23 , and a lining plate 24 .

[0051] Among them, the size of the straight pipe section body 21 is 500×90×160mm, and the size of the internal channel is 40×68mm, which is 8mm larger than the size of the internal channel of the pipeline 40×60mm. This 8mm is the part of the lower wall surface of the inner part of the straight pipe section body 21 cut downward. There are lower wall screw holes 25 on both sides for installing the lining plate 24. The lining plate 24 is 8mm thick and has three through holes. Therefore, the height of the internal channel T1 of the straight pipe section 2 is 60mm, and an obstacle group can be customized to replace the lining plate 24. The first opening T01 opened in the middle of the straight pipe section body 21 is 360×100mm in size and 25mm in depth. The four corners are rounded with a radius of 10mm. The width of the first opening T01 is 100mm, which is greater than the height of the internal channel of the pipeline 60mm, so a step-like structure appears, which is used here to provide a support for the installation of the rectangular quartz glass 22. The size of the rectangular quartz glass 22 is 358×96×26mm, and the plane size needs to be slightly smaller than the opening size of the straight pipe section body 21. The four corners are also rounded, with a radius of 10mm. When the rectangular quartz glass 22 fits the internal step of the pipe, a 1mm thick cork rubber belt needs to be attached to the pipe step to prevent the glass surface from being worn at the internal boundary of the pipe. 32 screw holes are evenly and symmetrically opened on the front and back sides of the straight pipe section body 21. The rectangular cover plate 23 is 15mm thick, with a rectangular second opening T02 of 335×60mm in the middle, and also has a through hole that is consistent with the position of the screw hole on the straight pipe section body 21. When installing the sealed rectangular quartz glass 22, a thin silicone pad needs to be placed between the rectangular cover plate 23 and the rectangular quartz glass 22 and high vacuum sealing silicone grease needs to be applied to enhance the sealing effect. The straight pipe section body 21 and the two flanges 12 are connected to form a main body by welding, and the weld needs to be cut and smoothed.

[0052] The use process of the visualized annular combustion pipeline group provided in this embodiment is as follows: After the visual annular combustion pipeline group is assembled, check the pipeline sealing, check whether the static pressure sensor 5 and the pressure sensor 8 are working properly; fill a certain amount of combustible premixed gas through the charging port 4, and when the readings of the two static pressure sensors 5 are consistent, start the ignition system 92, the semiconductor nozzle 3 discharges to ignite the combustible premixed gas, the pressure sensor 8 measures the pressure data and transmits it to the computer, and the two high-speed cameras select the shooting area, synchronously shoot and record the image. Select the semiconductor nozzle 3 at different positions to ignite, such as Figure 5 When ignition is started in the left annular pipe section 1, a high-speed camera can be used to observe the flame acceleration in the straight pipe section 2 and the flame propagation and collision behavior in the right annular pipe section 1; Figure 6Ignition is ignited in the lower straight pipe section 2, and the flame acceleration in the annular pipe section 1 and the flame propagation and collision behavior in the upper straight pipe section 1 can be observed using a high-speed camera.

[0053] Example 2 See also Fig. 9 The present embodiment provides a flame propagation collision experimental device, comprising a pipeline group, a gas distribution system 91, an ignition system 92, a schlieren system 93 and a pressure collection system 94; wherein the pipeline group adopts the visualized annular combustion pipeline group as described above; the gas distribution system 91 is used to provide a certain pressure of combustible premixed gas to the inside of the channel T1; the ignition system 92 is used to ignite the combustible premixed gas inside the channel T1 to generate a flame that propagates in both directions and finally converges and collides; the schlieren system 93 is used to collect schlieren images of the flame propagation process and the collision process inside the channel T1 through an observation window; the pressure collection system 94 is used to collect the internal pressure of the channel T1 during the flame propagation process and the collision process.

[0054] In this embodiment, the Schlieren system 93 includes two sets of adjustable optical path systems 931 and high-speed cameras 932, which are respectively placed in the observation windows of the pipe section T0 where the flame acceleration process and the flame collision process are located; wherein each set of optical path systems 931 includes a light source 9310, a first focusing lens 9311, an aperture slit 9312, a collimating lens 9313, a second focusing lens 9314 and a knife edge 9315 in sequence along the light transmission direction; the light emitted by the light source 9310 converges at the aperture slit 9312 through the first focusing lens 9311, and the light is amplified and converted into parallel light through the collimating lens 9313, and the parallel light passes through the observation window of the corresponding pipe section T0 and reaches the second focusing lens 9314, and the light is focused again and passes through the knife edge 9315, and enters the high-speed camera 932 after cutting the light. Of course, in other embodiments, other types of existing Schlieren systems can also be used to collect images of the pipeline group, and the principle will not be repeated here.

[0055] This embodiment also provides a flame counter-propagation collision experimental method, which is applied to the flame counter-propagation collision experimental device mentioned above. The experimental method includes the following steps, namely S1 to S3.

[0056] S1. Assemble a visual annular combustion pipe group in the shape of a specific channel T1 according to experimental needs, confirm the position of the ignition section and install the ignition system 92 on the ignition section, install the gas distribution system 91 and the pressure collection system 94 on the pipe group, and check the air tightness of the pipe group and the stability of the gas distribution system 91, the ignition system 92, and the pressure collection system 94.

[0057] S2. A Schlieren system 93 is set up in the pipe section T0 of the pipeline group where the flame acceleration process and the flame collision process are located. One set of optical path system and high-speed camera is used to shoot the flame acceleration process, and the other set of optical path system and high-speed camera is used to shoot the flame collision process.

[0058] S3. Combustible premixed gas is configured through the gas distribution system 91, and a certain pressure of combustible premixed gas is filled into the vacuum channel T1. After standing for one minute, the ignition system 92 is triggered. At the same time, the schlieren system 93 and the pressure acquisition system 94 record and store data.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A visualized annular combustion pipeline group, characterized in that: The invention comprises a plurality of pipe sections (T0), wherein the plurality of pipe sections (T0) are spliced ​​in sequence to form a closed-loop channel (T1) inside; any pipe section (T0) can be used as an ignition section for installing an ignition system (92), wherein the ignition system (92) is used to ignite the combustible premixed gas inside the channel (T1) to generate a flame that propagates in both directions and eventually converges and collides; all the pipe sections (T0) are observation sides on opposite sides parallel to the plane where the channel (T1) is located, wherein the observation sides are provided with observation windows for observing the flame propagation and collision process, and each pipe section (T0) can also be installed with a pressure collection system (94) for collecting the internal pressure of the channel (T1) during the process.

2. A visualized annular combustion pipeline group according to claim 1, characterized in that: All pipe sections (T0) are divided into annular pipe sections (1) and straight pipe sections (2); wherein the annular pipe section (1) is in a semicircular shape and has two sections, and the two annular pipe sections (1) are arranged with their ends facing each other; the straight pipe section (2) has at least two sections, and all the straight pipe sections (2) are arranged in two rows and arranged between the two annular pipe sections (1) to form a closed runway-shaped channel (T1).

3. A visualized annular combustion pipeline group according to claim 1, characterized in that: The ignition system (92) comprises an igniter (921) and a semiconductor electric nozzle (3); all pipe sections (T0) are provided with at least one first hole on the inner side of the closed loop, and each first hole is used to install the semiconductor electric nozzle (3) or the electric nozzle plug (6); wherein, when a semiconductor electric nozzle (3) is installed in one of the first holes of any pipe section (T0), the electric nozzle plug (6) is installed in the remaining first holes of all pipe sections (T0); the igniter (921) and the semiconductor electric nozzle (3) are electrically connected and are used to trigger the semiconductor electric nozzle (3) to generate electric sparks; The pressure acquisition system (94) comprises a plurality of pressure sensors (8), and all pipe sections (T0) are provided with at least one second hole outside the closed loop, and each second hole is used to install a pressure sensor (8).

4. The visualized annular combustion pipeline group according to claim 1, characterized in that: At least one pipe section (T0) is further provided with a third hole position, each of which is used to install a charging port (4) or a charging end plug (7); when the third hole position is used for charging, a charging port (4) is installed, and the charging port (4) is used to connect to a gas distribution system (91) to fill the channel (T1) with combustible premixed gas; when the third hole position is not used for charging, a charging end plug (7) is installed; at least two pipe sections (T0) are further provided with a fourth hole position, each of which is used to install a static pressure sensor (5), and the static pressure sensor (5) is used to measure the gas pressure when the channel (T1) is filled with combustible premixed gas, and at least two of the static pressure sensors (5) are symmetrically distributed on the channel (T1).

5. The visualized annular combustion pipeline group according to claim 1, characterized in that: The observation window comprises quartz glass and a cover plate; a first opening (T01) communicating with the interior of the channel (T1) is provided on the observation side of the tube section (T0); the projection range of the first opening (T01) on the plane where the observation side is located is larger than the projection range of the channel (T1) on the plane, thereby forming an assembly space adapted to the quartz glass on the tube section (T0); the quartz glass is clamped and fixed in the assembly space by the cover plate to seal the first opening (T01); a second opening (T02) for avoiding the quartz glass is also provided on the cover plate; the height of the second opening (T02) is the same as the height of the channel (T1).

6. A visualized annular combustion pipeline group according to claim 5, characterized in that: A silicone pad is arranged between the cover plate and the quartz glass, and is coated with sealing silicone grease.

7. The visualized annular combustion pipeline group according to claim 1, characterized in that: Adjacent pipe sections (T0) are connected via flanges (12).

8. A flame propagation collision experimental device, characterized in that: The invention comprises a pipeline group, an air distribution system (91), an ignition system (92), a schlieren system (93) and a pressure collection system (94); wherein the pipeline group adopts a visualized annular combustion pipeline group as described in any one of claims 1 to 7; the air distribution system (91) is used to provide a combustible premixed gas of a certain pressure to the inside of a channel (T1); the ignition system (92) is used to ignite the combustible premixed gas inside the channel (T1) to generate a flame that propagates in both directions and eventually converges and collides; the schlieren system (93) is used to collect schlieren images of the flame propagation process and the collision process inside the channel (T1) through an observation window; and the pressure collection system (94) is used to collect the internal pressure of the channel (T1) during the flame propagation process and the collision process.

9. The flame counter-propagation collision experimental device according to claim 8, characterized in that: The schlieren system (93) comprises two sets of adjustable optical path systems (931) and a high-speed camera (932), which are respectively placed at the observation windows of the pipe section (T0) where the flame acceleration process and the flame collision process are located; wherein each set of optical path systems (931) comprises, in sequence along the light transmission direction, a light source (9310), a first focusing lens (9311), an aperture slit (9312), a collimating lens (9313), a second focusing lens (9314) and a knife edge (9315); light emitted by the light source (9310) passes through the first focusing lens (9311) and converges at the aperture slit (9312); the light is amplified and converted into parallel light through the collimating lens (9313); the parallel light passes through the observation window of the corresponding pipe section (T0) and reaches the second focusing lens (9314); the light is focused again and passes through the knife edge (9315), and enters the high-speed camera (932) after light cutting.

10. A flame propagation collision experiment method, characterized in that: Applied to a flame propagation collision experimental device as claimed in claim 9, the experimental method comprises the following steps: S1. Assemble a visualized annular combustion pipeline group in the shape of a specific channel (T1) according to experimental requirements, confirm the position of the ignition section and install the ignition system (92) on the ignition section, install the gas distribution system (91) and the pressure collection system (94) on the pipeline group, and check the air tightness of the pipeline group and the stability of the gas distribution system (91), the ignition system (92), and the pressure collection system (94); S2, setting up a Schlieren system (93) in the pipe section (T0) where the flame acceleration process and the flame collision process of the pipe group are located, wherein one set of the optical path system and the high-speed camera are used to photograph the flame acceleration process, and another set of the optical path system and the high-speed camera are used to photograph the flame collision process; S3. Combustible premixed gas is configured through the gas distribution system (91), and the combustible premixed gas at a certain pressure is filled into the channel (T1) in a vacuum state. After being left to stand for a set time, the ignition system (92) is triggered, and at the same time, the schlieren system (93) and the pressure acquisition system (94) record and store data.

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