Leakage and explosion experiment system for high-pressure buried gas pipeline in tunnel

Abstract

The invention relates to a leakage and explosion experiment system for a high-pressure buried gas pipeline in a tunnel. The system is composed of a tunnel model test field, a natural gas pipeline, a leakage device, a gas distribution unit, a concentration sensor, a free field pressure sensor, a visual window, a high-reflection camera, an ignition unit, a synchronous controller and a data acquisition unit. Through the system provided by the invention, the tunnel space diffusion law of the leaked natural gas of the buried pipeline in the tunnel, the flame propagation characteristics generated by ignition of the leaked natural gas in the tunnel, the flame frontal surface form and the tunnel exit free field pressure can be deeply researched; and serious consequences caused by leakage diffusion and burning explosion of the buried high-pressure gas pipeline in the tunnel are relieved.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas leakage and explosion, and in particular to a leakage and explosion experimental system for a high-pressure buried gas pipeline in a tunnel. Background Art

[0002] In recent years, the technology of natural gas pipeline crossing tunnels has been widely used in long-distance pipelines. Natural gas pipelines may leak due to material defects, construction reasons, etc., and may explode when encountering an ignition source. The leakage, diffusion and explosion of buried high-pressure gas pipelines in tunnels can cause serious consequences. Therefore, a system for studying the leakage, diffusion and explosion of buried high-pressure gas pipelines in tunnels is urgently needed in the prior art. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a leakage and explosion test system for a high-pressure buried gas pipeline in a tunnel, aiming to solve at least one of the above-mentioned technical problems.

[0004] In the first aspect, the technical solution of the present invention to solve the above technical problems is as follows: a high-pressure buried gas pipeline leakage and explosion experimental system in a tunnel, comprising a tunnel model test field, a natural gas pipeline, a leakage device, a gas distribution unit, a concentration sensor, a free-field pressure sensor, a visual window, an overhead camera, an ignition unit, a synchronous controller and a data acquisition unit, wherein the leakage device, the gas distribution unit, the concentration sensor, the free-field pressure sensor, the overhead camera, the ignition unit and the data acquisition unit are respectively connected to the synchronous controller;

[0005] The tunnel model test site is composed of a deep open channel and a semicircular dome, the semicircular dome is sealed by a tape, and the semicircular dome is fixedly connected to the ground by bolts. The tunnel model test site is used to build a tunnel for experiments;

[0006] The leakage device is fixedly connected to the natural gas pipeline, the gas distribution unit is fixedly connected to the natural gas pipeline, a visual window is provided on the semicircular arch, and the visual window is fixed by being buried in soil; the overhead camera is placed at a position facing the visual window to shoot the flame propagation process;

[0007] The synchronous controller is used to control the opening of the valve on the natural gas pipeline through the gas distribution unit, so as to control the gas leakage in the natural gas pipeline through the leakage device, synchronously control the ignition unit to ignite the leaked natural gas in the tunnel, and control the opening of the overhead camera;

[0008] The concentration sensor is connected through the top of the semicircular dome of the tunnel model test site and is used to monitor the concentration change of natural gas in the tunnel;

[0009] The free-field pressure sensor is fixedly connected to the fixed rod and faces the arched exit of the tunnel, and is used to test the pressure of the field explosion wave generated by the natural gas in the tunnel when it explodes;

[0010] The data acquisition unit is used to acquire the data respectively acquired by the concentration sensor, the free-field pressure sensor and the overhead camera.

[0011] The beneficial effects of the present invention are as follows: based on the system provided by the scheme, the leakage and explosion of the buried high-pressure natural gas pipeline in the tunnel are simulated. Based on the data collected in this situation, the spatial diffusion law of the natural gas leakage in the tunnel, and the flame propagation characteristics, flame front morphology, and free field pressure of the tunnel outlet caused by the ignition of the leaked natural gas in the tunnel can be studied in depth, thereby reducing the serious consequences of the leakage, diffusion and explosion of the buried high-pressure gas pipeline in the tunnel.

[0012] Based on the above technical solution, the present invention can also be improved as follows.

[0013] Furthermore, the leakage device includes a solenoid valve and a pagoda head, the solenoid valve is fixedly connected to the natural gas pipeline by means of threads, and the pagoda head is fixedly connected to the solenoid valve by means of threads.

[0014] Furthermore, the gas distribution unit includes a gas cylinder, a pressure reducing valve, a gas pipeline and a pressure gauge, the gas cylinder is fixedly connected to the pressure reducing valve by a thread, the pressure reducing valve is fixedly connected to the gas pipeline by a thread, the gas pipeline is fixedly connected to the natural gas pipeline by a thread, and the pressure gauge is fixedly connected to the natural gas pipeline by a thread.

[0015] Furthermore, the ignition unit includes a detonator, a wire and an ignition head. The detonator is bundled and connected with the wire, the wire is bundled and connected with the ignition head, and the ignition head is inserted into a reserved hole on the semicircular arch and fixedly connected by tape.

[0016] Further, the data acquisition unit includes a charge amplifier, a data acquisition instrument and a terminal device, the data acquisition unit and the free field sensor are respectively connected to the charge amplifier through a connecting line, the charge amplifier is connected to the data acquisition instrument through a connecting line, and the data acquisition instrument is connected to the terminal device through a connecting line;

[0017] The terminal device is used to receive and display the data sent by the data acquisition unit through the charge amplifier and the data acquisition instrument.

[0018] Furthermore, the terminal device is also used to determine the diffusion law of natural gas in the tunnel based on the received data.

[0019] Furthermore, the deep open channel is cast with cement, and the semicircular dome is made of prefabricated steel structure plates.

[0020] Furthermore, the natural gas pipeline is composed of DN273 steel pipes, and the natural gas pipeline includes multiple pipe sections, each of which is connected by flanges and compacted with sealing rings.

[0021] Furthermore, the concentration sensor includes a methane concentration sensor and a carbon dioxide concentration sensor.

[0022] Furthermore, the viewing window is made of acrylic plate.

[0023] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments of the present invention are briefly introduced below.

[0025] Figure 1 A schematic diagram of a leakage and explosion test system for a high-pressure buried gas pipeline in a tunnel provided by an embodiment of the present invention;

[0026] Figure 2 A schematic structural diagram of another high-pressure buried gas pipeline leakage and explosion experimental system in a tunnel provided by an embodiment of the present invention.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1. Tunnel model test site; 2. Natural gas pipeline; 3. Leakage device; 4. Gas distribution unit; 5. Concentration sensor; 6. Free field pressure sensor; 7. Visual window; 8. Overhead camera; 9. Ignition unit; 10. Synchronous controller; 11. Data acquisition unit. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0031] See also Figure 1 and 2As shown, the embodiment of the present application provides a leakage and explosion test system of a high-pressure buried gas pipeline in a tunnel, including a tunnel model test site 1, a natural gas pipeline 2, a leakage device 3, a gas distribution unit 4, a concentration sensor 5, a free-field pressure sensor 6, a visual window 7, and an overhead camera 8 ( Figure 2 ), an ignition unit 9, a synchronous controller 10 and a data acquisition unit 11, wherein the leakage device 3, the gas distribution unit 4, the concentration sensor 5, the free field pressure sensor 6, the overhead camera 8, the ignition unit 9 and the data acquisition unit 11 are respectively connected to the synchronous controller 10 ( Figure 2 Sync trigger as shown in );

[0032] The tunnel model test site 1 is composed of a deep open channel and a semicircular dome, the semicircular dome is sealed by a tape, and the semicircular dome is fixedly connected to the ground by bolts. The tunnel model test site 1 is used to build a tunnel for experiments;

[0033] The leakage device 3 is fixedly connected to the natural gas pipeline 2, the gas distribution unit 4 is fixedly connected to the natural gas pipeline 2, a visual window 7 is arranged on the semicircular dome (optionally, there may be multiple visual windows 7), and the visual window 7 is fixed by being buried in the soil; the overhead camera 8 is placed at a position facing the visual window 7 ( Figure 2 The position of the visual window in the middle is used to shoot the flame propagation process, that is, the flame propagation process after the natural gas is ignited;

[0034] The synchronous controller 10 is used to control the opening of the valve on the natural gas pipeline 2 through the gas distribution unit 4, so as to control the gas leakage in the natural gas pipeline 2 through the leakage device 3, synchronously control the ignition unit 9 to ignite the natural gas leaking in the tunnel, and control the opening of the overhead camera 8; that is, the overhead camera 8 is turned on for collection while the natural gas is ignited. In the present application scheme, multiple overhead cameras 8 can be set to simultaneously shoot the flame propagation process from different angles and different positions;

[0035] The concentration sensor 5 is connected to the top of the semicircular dome of the tunnel model test site 1 (for example, Figure 2 A concentration measuring point preset on the top of the semicircular dome shown in the figure) is used to monitor the concentration change of natural gas in the tunnel;

[0036] The free field pressure sensor 6 is fixedly connected to the fixed rod and faces the arched exit of the tunnel, and is used to test the pressure of the field explosion wave generated by the natural gas in the tunnel when it explodes;

[0037] The data acquisition unit 11 is used to collect data collected by the concentration sensor 5, the free field pressure sensor 6 and the overhead camera 8. The concentration sensor 5 is used to collect the concentration of the gas after the natural gas is burned, the free field pressure sensor 6 is used to collect the free field pressure at the tunnel exit and the pressure of the field explosion wave generated by the natural gas during combustion and explosion, and the overhead camera 8 is used to collect the combustion process and explosion process of the natural gas.

[0038] In order to ensure the safety of the ignition unit 9, the synchronization controller 10 and the data acquisition unit 11, they can be placed in a safe location away from the tunnel, as shown in the following example. Figure 2 shown.

[0039] Optionally, the gas distribution unit 4 includes a gas cylinder (which may be Figure 2 The methane bottle shown in the figure), a pressure reducing valve, a gas pipeline and a pressure gauge, the gas bottle is fixedly connected to the pressure reducing valve by a thread, the pressure reducing valve is fixedly connected to the gas pipeline by a thread, the gas pipeline is fixedly connected to the natural gas pipeline 2 by a thread, and the pressure gauge is fixedly connected to the natural gas pipeline 2 by a thread.

[0040] During the experiment, the gas distribution unit 4 is connected to the synchronous controller 10, and the synchronous controller 10 is specifically used for:

[0041] The valve of the control gas cylinder is opened, and natural gas of a specified pressure is injected into the natural gas pipeline 2 through the gas transmission pipeline. The injection pressure of the natural gas is recorded in real time by a pressure gauge. When the injection pressure is too high, the pressure can be reduced based on the pressure reducing valve. After a certain amount of natural gas is injected, the switch valve of the gas cylinder is closed.

[0042] Optionally, the leakage device 3 includes a solenoid valve and a pagoda head, the solenoid valve is fixedly connected to the natural gas pipeline 2 by threads, and the pagoda head is fixedly connected to the solenoid valve by threads.

[0043] During the experiment, the leakage device 3 is connected to the synchronous controller 10, and the synchronous controller 10 is specifically used for:

[0044] After closing the switch valve of the gas cylinder, the solenoid valve of the leakage device 3 is opened through the pagoda head control, so that natural gas begins to leak from the natural gas pipeline 2 into the tunnel. After the concentration of natural gas in the tunnel model test field 1 reaches the preset explosion concentration, the solenoid valve is closed.

[0045] Optionally, the ignition unit 9 includes an initiator ( Figure 2 The delayed ignition trigger shown in the figure), the wire and the ignition head, the detonator is bundled and connected with the wire, the wire is bundled and connected with the ignition head, the ignition head is inserted into the reserved hole on the semicircular arch and fixedly connected by tape.

[0046] During the experiment, the ignition unit 9 is connected to the synchronization controller 10, which is specifically used for:

[0047] After closing the electromagnetic valve of the leakage device 3, the ignition unit 9 is controlled to perform combustion and explosion, and the experimental data is recorded.

[0048] Optionally, the data acquisition unit 11 includes a charge amplifier, a data acquisition instrument ( Figure 2 The data acquisition system shown in ) and the terminal device (which can be a PC, for example, Figure 2 The data acquisition unit 11 and the free field sensor are connected to the charge amplifier through connecting wires, the charge amplifier is connected to the data acquisition instrument through connecting wires, and the data acquisition instrument is connected to the terminal device through connecting wires;

[0049] The terminal device is used to receive and display the data sent by the data acquisition unit 11 through the charge amplifier and the data acquisition instrument.

[0050] Optionally, the terminal device is further used to determine the diffusion law of natural gas in the tunnel based on the received data.

[0051] Optionally, the deep open channel is cast in cement, and the semicircular dome is made of prefabricated steel structural plates.

[0052] Optionally, the natural gas pipeline 2 is made of a DN273 steel pipe, and the natural gas pipeline 2 includes multiple pipe sections, each of which is connected by a flange and compacted with a sealing ring.

[0053] The length of each pipe section may be 4 m, and the natural gas pipeline 2 includes a total of 5 pipe sections.

[0054] Optionally, the concentration sensor 5 includes a methane concentration sensor and a carbon dioxide concentration sensor.

[0055] Optionally, there may be multiple concentration sensors 5, and multiple collection points may be pre-set along the length direction of the natural gas pipeline 2 ( Figure 2 ), for example, the concentration measurement points are set at equal intervals, such as Figure 2 As shown, each sampling point is correspondingly provided with a concentration sensor 5. If the concentration sensor 5 includes a methane concentration sensor and a carbon dioxide concentration sensor, the concentration sensor 5 provided at each sampling point includes a methane concentration sensor and a carbon dioxide concentration sensor.

[0056] Optionally, the viewing window 7 is made of an acrylic plate.

[0057] Based on the solution of this application, the working principle is:

[0058] After checking the air tightness of the test system, ensure that the leakage device 3, gas distribution unit 4, concentration sensor 5, free field pressure sensor 6, overhead camera 8, ignition unit 9, synchronous controller 10, and data acquisition unit 11 are in normal working condition. Then open the valve of the gas cylinder to inject natural gas of specified pressure into the natural gas pipeline 2, close the switch valve of the gas cylinder, open the solenoid valve, and let the natural gas start to leak from the natural gas pipeline 2 into the tunnel. Observe the concentration change of natural gas in the tunnel model test field 1. After reaching the preset explosion concentration, close the solenoid valve and record the data. Then, perform explosion through the ignition unit 9 and record the experimental data.

[0059] The solution of this application has the following beneficial effects:

[0060] 1. The experimental system of this scheme consists of a tunnel model test site 1, a natural gas pipeline 2, a leakage device 3, a gas distribution unit 4, a concentration sensor 5, a free field pressure sensor 6, a visual window 7, an overhead camera 8, an ignition unit 9, a synchronous controller 10, and a data acquisition unit 11.

[0061] 2. Through the experimental system of this scheme, the spatial diffusion law of natural gas leaked from the buried pipeline in the tunnel, as well as the flame propagation characteristics, flame front morphology and free field pressure at the tunnel exit caused by the ignition of the leaked natural gas in the tunnel are studied.

[0062] 3. The overall structure of this scheme is reasonable, which can meet the research on the leakage and explosion characteristics of the high-pressure buried natural gas pipeline 2 in the tunnel, has low maintenance cost and is easy to use.

[0063] It should be noted that the modules involved in the embodiments of the present invention may be implemented by software or hardware, wherein the name of a module does not limit the module itself in some cases.

[0064] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the disclosure scope involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) by each other.

Claims

1. A high-pressure buried gas pipeline leakage and explosion test system in a tunnel, characterized in that: It includes a tunnel model test field, a natural gas pipeline, a leakage device, a gas distribution unit, a concentration sensor, a free-field pressure sensor, a visual window, an overhead camera, an ignition unit, a synchronous controller and a data acquisition unit, wherein the leakage device, the gas distribution unit, the concentration sensor, the free-field pressure sensor, the overhead camera, the ignition unit and the data acquisition unit are respectively connected to the synchronous controller; The tunnel model test site is composed of a deep open channel and a semicircular dome, the semicircular dome is sealed by a tape, and the semicircular dome is fixedly connected to the ground by bolts. The tunnel model test site is used to build a tunnel for experiments; The leakage device is fixedly connected to the natural gas pipeline, the gas distribution unit is fixedly connected to the natural gas pipeline, a visual window is provided on the semicircular arch, and the visual window is fixed by being buried in soil; the overhead camera is placed at a position facing the visual window to shoot the flame propagation process; The synchronous controller is used to control the opening of the valve on the natural gas pipeline through the gas distribution unit, so as to control the gas leakage in the natural gas pipeline through the leakage device, synchronously control the ignition unit to ignite the leaked natural gas in the tunnel, and control the opening of the overhead camera; The concentration sensor is connected through the top of the semicircular dome of the tunnel model test site and is used to monitor the concentration change of natural gas in the tunnel; The free-field pressure sensor is fixedly connected to the fixed rod and faces the arched exit of the tunnel, and is used to test the pressure of the field explosion wave generated by the natural gas in the tunnel when it explodes; The data acquisition unit is used to acquire the data respectively acquired by the concentration sensor, the free-field pressure sensor and the overhead camera.

2. The system according to claim 1, characterized in that The leakage device comprises a solenoid valve and a pagoda head. The solenoid valve is fixedly connected to the natural gas pipeline via threads, and the pagoda head is fixedly connected to the solenoid valve via threads.

3. The system according to claim 1, characterized in that The gas distribution unit includes a gas cylinder, a pressure reducing valve, a gas pipeline and a pressure gauge. The gas cylinder is fixedly connected to the pressure reducing valve by a thread, the pressure reducing valve is fixedly connected to the gas pipeline by a thread, the gas pipeline is fixedly connected to the natural gas pipeline by a thread, and the pressure gauge is fixedly connected to the natural gas pipeline by a thread.

4. The system according to claim 1, characterized in that The ignition unit comprises a detonator, a wire and an ignition head. The detonator is bundled and connected with the wire, the wire is bundled and connected with the ignition head, and the ignition head is inserted into a reserved hole on the semicircular arch and fixedly connected by an adhesive tape.

5. The system according to claim 1, characterized in that The data acquisition unit includes a charge amplifier, a data acquisition instrument and a terminal device, wherein the data acquisition unit and the free field sensor are respectively connected to the charge amplifier via a connecting line, the charge amplifier is connected to the data acquisition instrument via a connecting line, and the data acquisition instrument is connected to the terminal device via a connecting line; The terminal device is used to receive and display the data sent by the data acquisition unit through the charge amplifier and the data acquisition instrument.

6. The system according to claim 5, characterized in that The terminal device is also used to determine the diffusion law of natural gas in the tunnel based on the received data.

7. The system according to claim 1, characterized in that The deep open channel is cast in cement, and the semicircular dome is made of prefabricated steel structure plates.

8. The system according to claim 1, characterized in that The natural gas pipeline is made of DN273 steel pipe and includes multiple pipe sections. Each of the pipe sections is connected by flanges and compacted with sealing rings.

9. The system according to claim 1, characterized in that The concentration sensors include a methane concentration sensor and a carbon dioxide concentration sensor.

10. The system according to claim 1, characterized in that The viewing window is made of acrylic plate.

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