Device and method for testing detonation pressure relief of hydrogen-doped natural gas in pipeline compressor room

Abstract

The invention provides a detonation pressure relief testing device and method for hydrogen-doped natural gas in a pipeline compressor room. The design aims to research the detonation phenomenon of the hydrogen-doped natural gas in the pipeline compressor room. The testing device comprises a detonation pipeline system, an obstacle combination system, a mixed gas distribution system, a data acquisition system, an image acquisition system, a high-energy ignition system and a detonation pressure relief system. The detonation pipeline system provides a gas explosion place, the mixed gas distribution system provides hydrogen-doped natural gas with different hydrogen doping ratios, the high-energy ignition system provides different ignition energies and ignition times, the data acquisition system records detonation parameters and flame propagation characteristics in an experiment, and the obstacle combination system serves as various devices in a compressor room. The detonation pressure relief system provides a compressor room explosion venting structure design, the invention provides a device for researching hydrogen-doped natural gas detonation accident characteristic evolution, the hydrogen-doped natural gas detonation-to-detonation conversion conditions are clear, and a hydrogen-doped natural gas detonation pressure relief mechanism in a pipeline compressor room is analyzed.

Description

Technical field:

[0001] The present invention relates to the field of combustible gas explosion safety, and in particular to a pipeline compressor hydrogen-blended natural gas detonation pressure relief test device and method. Background technology:

[0002] Hydrogen is a green, environmentally friendly, renewable, clean energy. Due to the high production and use costs of pure hydrogen, blending hydrogen into existing natural gas pipelines for transportation has become an important solution for rapidly realizing large-scale storage and transportation of hydrogen energy. However, hydrogen has a fast combustion speed, a wide range of explosion limits, and a low minimum ignition energy. A small amount of hydrogen in natural gas will greatly increase the risk and intensity of explosion.

[0003] When hydrogen-blended natural gas is stored and transported in the compressor room, once a leak occurs, the gas quickly gathers outside the pipeline, and the energy generated by the explosion cannot be effectively diffused in the closed space of the pipeline compressor room, resulting in an increase in energy density, further enhancing the destructive power of the explosion. At the same time, the explosion may cause the hydrogen-blended natural gas transported in the pipeline to explode, causing a chain explosion accident. Since the equipment in the compressor room acts as an obstacle, the explosion of hydrogen-blended natural gas may experience a phenomenon of deflagration turning into detonation under the induction of the obstacle. The flame propagation and overpressure in the detonation stage are far more serious than those in the deflagration stage in terms of the increase in size and flow field changes, which can easily cause damage to various equipment, walls and surrounding buildings in the compressor room.

[0004] The inventors found that there are few studies on the explosion mechanism of hydrogen-blended natural gas in large-scale spaces. The focus is only on the explosion mechanism during the deflagration of hydrogen-blended natural gas. There is a lack of a dedicated test device and method for studying the detonation pressure relief of hydrogen-blended natural gas in a compressor room. Summary of the invention:

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a compressor room hydrogen-blended natural gas explosion pressure relief test device and method, aiming to fill the gap in the explosion characteristics of hydrogen-blended natural gas under large-scale space conditions, and provide a theoretical basis for the explosion phenomenon and explosion relief of hydrogen-blended natural gas in an actual compressor room.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: detonation pipeline system, obstacle combination system, mixed gas distribution system, data acquisition system, image acquisition system, high-energy ignition system and detonation pressure relief system.

[0007] A compressor room hydrogen-blended natural gas explosion pressure relief test device, comprising:

[0008] Furthermore, the stainless steel detonation square tube used in the pipeline system is composed of four short tubes with visual windows (pressure resistance above 25MPa, length×width: 200mm×40mm) connected (width×height of pipeline section: 75mm×40mm), the tube thickness is 20mm, and each section is 1m long.

[0009] Furthermore, the four sections of the pipeline are connected and sealed by square flanges, screws and O-rings.

[0010] Furthermore, the high-energy ignition system is divided into a high-voltage power supply device, a resistor, a capacitor group, a switch and an igniter. Before the experiment, the capacitor group is charged by the high-voltage power supply device. The capacitor group is composed of two capacitors in parallel, and the supply voltage is adjustable.

[0011] Furthermore, the data acquisition system is composed of a pressure sensor and an ion probe. The pressure sensor records the temporal variation of overpressure during the detonation process, and the ion probe records the average propagation velocity of the detonation wave.

[0012] Furthermore, the smoked cell measurement system is made of a glass sheet, a polyester film or a glass plate, and records the detonation cells in the detonation stage of the hydrogen-doped natural gas and measures the cell size.

[0013] Furthermore, the mixed gas distribution system is composed of a gas mixing tank, a methane gas cylinder, an ethane gas cylinder, a hydrogen gas cylinder and a computer. The computer controls the hydrogen-blended natural gas in the required proportion for the experiment, and the configured hydrogen-blended natural gas is filled into the gas mixing tank from various gas cylinders. The hydrogen-blended natural gas is left to stand in the gas mixing tank for a long time to make it uniform, and finally is filled into the detonation experiment pipeline.

[0014] Furthermore, the obstacle combination system is composed of rigid obstacles of different geometric sizes (length: 20mm, 10mm, height: 20mm, 10mm), and is reduced in size at a certain equivalent ratio to serve as application equipment in an actual compressor room space.

[0015] Furthermore, the detonation pressure relief system is composed of pressure relief port plates of different shapes (circular, square, and triangular), and the explosion relief effect of the pressure relief port on the detonation overpressure of hydrogen-blended natural gas is observed to reveal the explosion relief mechanism of hydrogen-blended natural gas.

[0016] In a second aspect of the present invention, a method for testing the detonation pressure relief of hydrogen-blended natural gas in a pipeline compressor room is provided, comprising the following steps:

[0017] First, check the air tightness of the device. If the pipeline leaks too fast, check the sealing of each joint of the detonation pipe.

[0018] Check the availability of the pressure sensor and ion probe, and proceed to the next step when each channel is operating normally;

[0019] Place the smoked sheet into the detonation tube and seal it;

[0020] The gas in the pipeline is extracted, and the premixed natural gas with hydrogen in the gas mixing tank is introduced into the pipeline so that the gas pressure in the pipeline reaches the pre-designed pressure. The pressure in the gas mixing tank during gas distribution and the pressure in the pipeline before ignition are monitored by a pressure gauge;

[0021] After the inflation is completed, you need to wait for one minute for the mixture to become still, and then use a high-voltage igniter to ignite the combustible gas; collect and save the data, repeat the above steps, and prepare for the next experiment.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The device of the present invention simplifies the space of the compressor room and can study the evolution process of the characteristics of explosion accidents in the pipeline compressor room. Different obstacles can be added to the pipeline to simulate the explosion environment of the real pipeline corridor environment.

[0024] 2. The present invention can study the changing rules of the detonation characteristic parameters of hydrogen-added natural gas under the influence of different hydrogen blending ratios, ignition energy, initial temperature and pressure, and explore the process of hydrogen-added natural gas deflagration to detonation.

[0025] 3. The present invention is different from other hydrogen-blended natural gas explosion devices. It studies the explosion characteristic parameters of hydrogen-blended natural gas deflagration, deflagration-to-detonation and detonation processes, analyzes parameters such as explosion overpressure, maximum explosion rise rate, and detonation wave velocity, and combines high-speed camera images to obtain conclusions that can reduce the explosion risk in the application of hydrogen-blended natural gas in pipeline compressor rooms.

[0026] 4. The device of the present invention can be inserted with pressure relief plates of different shapes to further change the size and shape of the pressure relief opening to analyze the explosion relief mechanism of hydrogen-blended natural gas in the pipeline compressor room.

[0027] 5. The device of the present invention can further add inert gas to carry out hydrogen-blended natural gas explosion suppression experiments, and study the influence of inert gases such as carbon dioxide and nitrogen on the deflagration-to-detonation and detonation process of hydrogen-blended natural gas. Description of the drawings:

[0028] Attached Figure 1 Schematic diagram of a pipeline compressor hydrogen-blended natural gas detonation pressure relief test device

[0029] Attached Figure 2 Schematic diagram of the gas distribution system for hydrogen-blended natural gas premix

[0030] Among them, 1- high energy ignition device, 2- ignition electrode, 3- vacuum pump, 4- one-way valve, 5- gas mixing tank, 6- air tank, 7- driving tube, 8- pressure sensor, 9- ion probe, 10- visual tube, 11- high speed camera, 12- image acquisition instrument, 13- synchronous controller, 14- data acquisition instrument, 15- pressure relief plate, 16- obstacle, 17- test tube, 18- computer, 19- gas cylinder valve, 20- methane gas cylinder, 21- ethane gas cylinder, 22- hydrogen gas cylinder. Specific implementation method:

[0031] The technical solution of the present invention is further described in detail below through specific embodiments in combination with the accompanying drawings.

[0032] like Figure 1 and Figure 2 As shown, the components of the detonation pressure relief test device for hydrogen-blended natural gas in a pipeline compressor room are as follows: the device comprises a detonation pipeline system, a mixed gas distribution system, a high-energy ignition system, a data acquisition system, an image acquisition system, an obstacle combination system and a detonation pressure relief system. The detonation pipeline system comprises a driving tube (7), a visual tube (10) and a test tube (17), and the entire detonation process of the hydrogen-blended natural gas is carried out in the pipeline. The mixed gas distribution system comprises a vacuum pump (3), a gas mixing tank (5), an air tank (6), a methane gas cylinder (20), an ethane gas cylinder (21), a hydrogen gas cylinder (22) and a computer (18). The computer (18) detects and controls the flow rate and flow size of each gas cylinder through a one-way valve (4) and a gas cylinder valve (19), and configures the hydrogen blending ratio of the hydrogen-blended natural gas required for the entire detonation experiment. The vacuum pump (3) is used to remove air in the pipeline. The high-energy ignition system comprises a high-energy ignition device (1) and an ignition electrode (2), and ignites the premixed hydrogen-blended natural gas in the entire pipeline. The data acquisition system is composed of an image acquisition device (12), a synchronous controller (13), and a data acquisition device (14). The image acquisition device (12) acquires images of the detonation process of hydrogen-blended natural gas transmitted by a high-speed camera (11). The data acquisition device (14) acquires detonation parameters and flame propagation speed of hydrogen-blended natural gas detected by a pressure sensor (8) and an ion probe (9), such as overpressure and speed. The synchronous controller (13) coordinates and unifies the image acquisition system (12) and the data acquisition system (14). The obstacle combination system (16) simulates various equipment in the space of an actual pipeline compressor room, and the bottom is fixed to the pipeline. The explosion pressure relief system (15) is composed of pressure relief plates of different shapes, providing channels for the detonation wave to pass through each pipeline.

[0033] Example 1

[0034] This embodiment is based on Figure 1 and Figure 2The experimental device in the present invention provides an experimental method for conducting a detonation pressure relief experiment of hydrogen-blended natural gas in a pipeline compressor room using the experimental device, including:

[0035] 1. Check the air tightness of the pipeline and the integrity of each equipment system:

[0036] The integrity of each equipment system determines whether the experiment can be carried out effectively. Therefore, before each experiment, each device must be checked and debugged to ensure the smooth progress of the experiment. Whether the pipeline is airtight is related to the safety of the experiment and whether the experimental data is accurate. Therefore, before each experiment, the airtightness of the device must be checked:

[0037] Ensure that the other air inlet valves are closed, turn on the vacuum pump, extract the air in the detonation pipe, and stop pumping the vacuum when the vacuum gauge pointer rotates close to -0.1; after standing for a long time, if the vacuum gauge number does not change significantly, it can be considered that the air tightness is good.

[0038] 2. Preparation before the experiment:

[0039] The position and focal length of the high-speed camera are adjusted to ensure that the high-speed camera can completely and clearly record the flame propagation image in the visual window; and the shooting frame number is adjusted to ensure the clarity of the recorded flame propagation image.

[0040] When inflating, first evacuate the pipeline, open the hydrogen-doped natural gas inlet valve, slowly introduce hydrogen-doped natural gas into the pipeline, and close the valve when the amount of hydrogen-doped natural gas introduced into the experiment reaches the required amount; then slowly introduce air into the pipeline, and when the vacuum gauge pointer indicates close to normal pressure, close the air inlet valve and start static premixing of the mixed gas. To ensure uniform mixing of the gas, the premixing time should be as long as possible each time.

[0041] 3. Experimental operation:

[0042] Before the experiment, first turn on the laboratory exhaust system and place the igniter as far away from the detonation pipe as possible to ensure the safety of the experiment. Set the high-speed photography system and data acquisition system to the trigger state. Press the ignition button only after the countdown ends. Collect data recorded by the pressure sensor, ion probe, and high-speed camera, and collect and analyze data such as flame propagation images, detonation overpressure, and detonation velocity during the process of hydrogen-blended natural gas deflagration to detonation propagation.

[0043] 4. Work after the experiment:

[0044] Discharge the remaining gas in the pipeline in time to ensure the safety of the experiment and reduce risks; the data of each experiment needs to be saved and recorded in time.

Claims

1. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method, characterized in that: The detonation pipeline system, obstacle combination system, mixed gas distribution system, data acquisition system, image acquisition system, high-energy ignition system and detonation pressure relief system, the pipeline is connected by a square flange; the detonation pipeline system acts as an explosion container for hydrogen-blended natural gas, the obstacle combination system acts as various equipment in the pipeline compressor room, the mixed gas distribution system provides hydrogen-blended natural gas with the required proportion and composition for the experiment, the data acquisition system records data such as the peak overpressure of hydrogen-blended natural gas detonation, the image acquisition system records the flame propagation image of hydrogen-blended natural gas detonation, the high-energy ignition system detonates the premixed hydrogen-blended natural gas, and the detonation pressure relief system induces hydrogen-blended natural gas detonation overpressure and flame changes.

2. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: The detonation pipe system is a horizontally placed straight pipe with a square cross-section (width×height: 75mm×40mm), a pipe thickness of 20mm, and each section of the straight pipe is provided with a visual window (length×width: 200mm×30mm) made of a quartz window (pressure resistance above 25MPa). Each section is 1m long, and there are four sections in total. The observation window can be used for a high-speed camera to record the flame propagation morphology.

3. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: The detonation pipe is paved with a smoke film to record the propagation front structure of the hydrogen-doped natural gas detonation wave.

4. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: The obstacle combination system is a pipeline compressor room equipment that is simplified and reduced in size at a certain ratio. As a rigid obstacle, the arrangement is 1-2 pipeline transverse sections and 1-2 pipeline longitudinal sections. The obstacle width remains consistent, and different lengths and heights are arranged and combined (length: 20mm, 10mm, height: 20mm, 10mm).

5. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: The detonation pressure relief system is a pressure relief plate with pressure relief ports in different shapes (circular, square, triangular) to observe the explosion relief effect of the pressure relief ports on the overpressure of hydrogen-blended natural gas detonation.

6. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: It also includes a data acquisition system and an image acquisition system; the data acquisition system includes a pressure sensor and an ion probe, the pressure sensor records the explosion overpressure change, and the ion probe records the flame propagation speed; the image acquisition system includes a high-speed camera, and the high-speed camera records the characteristic morphology of flame acceleration in the detonation stage.

7. A pipeline compressor room hydrogen-blended natural gas detonation pressure relief test device and method as claimed in claim 1, characterized in that: It also includes a high-energy ignition system, which is a weak ignition method. The ignition device is a synchronous high-voltage pulse generator type. The generator charges the capacitor through daily alternating current. After the capacitor is discharged, the transformer boosts the voltage to generate instantaneous high voltage at both ends of the ignition electrode to discharge and ignite.

8. A pipeline compressor room hydrogen-blended natural gas explosion pressure relief test device and method, based on the compressor room hydrogen-blended natural gas explosion characteristics test device according to any one of claims 1 to 7, characterized in that: Including gas mixing, gas distribution, ignition and data processing steps, the specific operation process is as follows: Before each experiment, the test gas should be introduced into the mixing tank based on the Dalton partial pressure method and premixed for at least 24 hours to ensure the uniformity of the combustible mixture before each experiment; After completing the premixing of the test gas, the tightness of the detonation duct must be tested before starting the experiment; Start to check whether the test instrument is normal, use a vacuum pump to exhaust the gas in the detonation pipe, and then prepare to start the experiment. Fill the uniform combustible mixture in the premix tank into the pipe, and close the valve between the pipe and the mixing tank. Then, pass the air in the air tank into the detonation pipe, and close the valve between the pipe and the mixing tank. Use a vacuum pump to remove excess combustible mixture in the connecting pipe between the pipeline and the gas mixing tank, and close all valves; After confirming that the surrounding area is safe, ignite the combustible mixture and record the experimental data to complete the experiment.

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