Hydrogen-doped natural gas pipeline stratification experimental device and stratification experimental method

Abstract

The application discloses a kind of hydrogen-doped natural gas pipeline layered experimental device and layered experimental method belonging to hydrogen-doped natural gas equipment range.The hydrogen-doped natural gas pipeline layered experimental device includes hydrogen mixing section, standing experimental section, corner experimental section, flow experimental section, reserved experimental section and mixed gas conveying pipe section composition;Among them, hydrogen mixing section includes the natural gas pipeline and hydrogen pipeline that structure is exactly the same and static mixer;Adjusting valve, pressure gauge and flowmeter are installed on each experimental section pipeline, can be easily adjusted the flow of hydrogen and natural gas pipeline, realize under different hydrogen-doped ratio hydrogen and natural gas are mixed, meet the different hydrogen-doped ratio demand required by experiment.The application can carry out standing and flow state hydrogen-doped natural gas layered experiment, it is convenient to change pipeline pressure, hydrogen-doped ratio, stop time and other parameters, it is favorable to reveal complex pipeline undulation and complex pipeline parameter working condition hydrogen-doped natural gas layered mechanism.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of hydrogen-doped natural gas equipment, and particularly relates to a hydrogen-doped natural gas pipeline stratification experimental device and a stratification experimental method. BACKGROUND

[0002] Hydrogen energy transportation is an important part of the hydrogen energy industry chain. Hydrogen is added to natural gas to form hydrogen-doped natural gas, which is then transported through a natural gas pipeline. This is considered a safe, economical and efficient way to transport hydrogen. Due to the large difference in density between hydrogen and natural gas, when the pipeline inevitably stops or the gas flow rate in the pipeline is low, the hydrogen and natural gas in the pipeline will stratify due to the large density difference between hydrogen and natural gas, with high-concentration hydrogen at the top of the pipeline and natural gas accumulating at the bottom of the pipeline. Stratification of hydrogen-doped natural gas pipelines can cause local hydrogen concentration to be too high, seriously affecting the combustion stability of hydrogen-doped natural gas and the gas safety of end users.

[0003] Therefore, it is of great significance to reveal the internal mechanism of stratification of hydrogen-doped natural gas pipelines under low-speed flow and shutdown conditions. Currently, there is little experimental research on the stratification phenomenon of hydrogen-doped natural gas pipelines. There are only simple experiments on the stratification of hydrogen-doped natural gas in vertical pipes. In engineering practice, the components and piping of hydrogen-doped natural gas pipelines are complex and variable, including horizontal pipes, inclined pipes, vertical pipes, and connecting pieces such as bends and valves at different angles, and the pipeline pressure, hydrogen-doping ratio, shutdown time and other parameters are also complex and variable, which will have a significant impact on the stratification of hydrogen-doped natural gas pipelines. However, there is currently no experimental device that can simultaneously study the stratification mechanism of complex hydrogen-doped natural gas pipelines under static and flow conditions.

[0004] Therefore, based on years of experience and practice in the natural gas and hydrogen pipeline transportation industry, the inventors propose a hydrogen-doped natural gas pipeline stratification experimental device to overcome the shortcomings of the prior art. SUMMARY

[0005] The application aims to provide a hydrogen-doped natural gas pipeline layered experiment device and a layered experiment method, which are characterized by comprising a hydrogen-doping section A, a static experiment section B, a corner experiment section C, a flow experiment section D, a reserved experiment section E and a mixed gas conveying pipe section F; wherein the hydrogen-doping section A comprises a natural gas pipeline 1, a hydrogen pipeline 2 and a static mixer 3; the natural gas pipeline 1 and the hydrogen pipeline 2 are completely identical in structure, and any one of the pipelines is composed of a double ball valve 5, a 1# ball valve 20, a pressure regulating valve 21, a 1# ball valve with a pressure gauge 25, a 2# ball valve 26 and the static mixer 3 in series; wherein a differential pressure meter 27 is installed on the static mixer 3; a 1# nitrogen purging port 12, a 1# pressure gauge 15 and a flow meter 18 are sequentially installed between the double ball valve 5 and the 1# ball valve 20 of the natural gas pipeline 1; the output of the static mixer 3 is connected with a 3# ball valve 4 and a 4# ball valve 6 of the reserved experiment section E in series; and the output of the static mixer 3 is connected with a 5# ball valve 7, a 2# ball valve with a pressure gauge 9 and a 6# ball valve 10 in series; the 6# ball valve 10 is connected with a 7# ball valve 11, an 8# ball valve 13 in a horizontal pipe section G, a 9# ball valve 14, a 10# ball valve 16 in a 45° upward inclined pipe section H and an 11# ball valve 17, a 12# ball valve 19 in a vertical pipe section K in parallel, thereby forming the static experiment section B; the static experiment section B, the corner experiment section C, the flow experiment section D and the mixed gas conveying pipe section F are connected in series; a 13# ball valve 24 of the mixed gas conveying pipe section F is connected with the 4# ball valve 6 of the reserved experiment section E; and a vent valve 23 and a 2# pressure gauge 22 are installed on the pipeline of the mixed gas conveying pipe section F, thereby forming the whole hydrogen-doped natural gas pipeline layered experiment device.

[0006] The natural gas and the hydrogen gas are uniformly mixed in the hydrogen-doping section A according to a given ratio to form hydrogen-doped natural gas, the hydrogen-doped natural gas enters the static experiment section B through the 5# ball valve 7, the 2# ball valve with a pressure gauge 9 and the 6# ball valve 10, and the static experiment is carried out in the static experiment section B through the horizontal pipe section G, the 45° upward inclined pipe section H and the vertical pipe section K; then the hydrogen-doped natural gas enters the corner experiment section C and the flow experiment section D to carry out experiments, thereby completing the hydrogen-doped natural gas pipeline layered experiment; further, the mixed gas after the experiment enters the mixed gas conveying pipe section F, is vented through the vent valve 23 or enters the downstream processing and utilization through the 13# ball valve 24, thereby completing the hydrogen-doped natural gas pipeline layered experiment under the stop transmission and flow working conditions.

[0007] The reserved experiment section E is used to meet the experimental improvement requirements possibly involved in the later experiment.

[0008] The pressure regulating valves and the ball valves with pressure gauges are installed on the natural gas pipeline 1 and the hydrogen pipeline 2, so that the pressure of the natural gas pipeline and the hydrogen pipeline can be conveniently adjusted, the hydrogen gas and the natural gas can be mixed under different pressures, and the different pipeline pressure requirements of the experiment can be met.

[0009] The flow meters are installed on the natural gas pipeline and the hydrogen pipeline, which can conveniently adjust the flow of the hydrogen pipeline and the natural gas pipeline, and realize the mixing of hydrogen and natural gas at different hydrogen mixing ratios, so as to meet the requirement of different hydrogen mixing ratios in experiments.

[0010] The standing experimental section B comprises a horizontal pipe section G, a 45° upward pipe section H, a vertical pipe section K and ball valves connected at both ends of the three pipe sections with different angles, which are used for simulating different pipe undulations; the standing experimental time of each pipe section with different angles can be conveniently controlled, and the standing experiments of the pipe sections with different angles are not affected.

[0011] The corner experimental section C comprises a 90° elbow pipe section, which is used for simulating the pipe conditions at the elbow and corner of the pipe; the gas sampling ports m 15 -m 22 After reaching the specified experimental time, the hydrogen analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 15 -m 22

[0012] The flow experimental section D is a horizontal straight pipe section, which is used for simulating the stratification phenomenon of the pipe under normal flow conditions; the gas sampling ports m 23 -m 26 After reaching the specified experimental time, the hydrogen analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 23 -m 26

[0013] The reserved experimental section E is used to meet the experimental requirements of more research conditions and provide a reserved interface for future experimental modification.

[0014] The mixed gas conveying pipe section F comprises a vent valve 23, which can vent the gas in the entire experimental device after the experiment is completed or in an emergency, so as to ensure the safety of the experimental device; and the vent valve 23 can also vent the gas in the entire experimental device when the experimental device is purged with nitrogen and the gas is replaced.

[0015] The steel material of the pipe in the hydrogen-mixed natural gas pipeline stratification experimental device is preferably hydrogen embrittlement resistant steel material; the sealing connection of the valve and the instrument is preferably made of materials and processed by processes that can prevent hydrogen leakage.

[0016] A stratification experimental method of a hydrogen-mixed natural gas pipeline stratification experimental device, characterized in that the stratification experimental method of the hydrogen-mixed natural gas pipeline stratification experimental device comprises the following steps:

[0017] Step S1, checking the equipment,

[0018] ​​Check whether the hydrogen-doped natural gas pipeline stratification experimental device is in normal working condition, including: whether the hydrogen-doping section is working normally, whether the valves and instruments of the static experiment section, the corner experiment section, the flow experiment section and the reserved experiment section are opened and closed as required, whether the instrument readings of the pressure gauges and flowmeters are normal, and whether the hydrogen analyzer is working normally;

[0019] Step S2, nitrogen purging and replacement:

[0020] Close ball valves 3, 4, 4, 5, 6, 6, 10, 13, 24, open 7, 8, 9, 10, 11, 12, 19, open vent valve 23, open 2 nitrogen purge port 8, then use nitrogen to purge the hydrogen-doped natural gas pipeline stratification experimental device, and replace the gas in the device with nitrogen to prevent residual gas in the device from forming explosive gas with hydrogen-doped natural gas and ensure the safety of the device. The gas after purging and replacement is discharged by the vent valve 23;

[0021] Step S3, device pre-running

[0022] After purging and replacement, close 2 nitrogen purge port 8, keep vent valve 23 open, hydrogen-doped natural gas with given pressure and hydrogen-doping ratio is provided from the hydrogen-doping section to the downstream experimental part, the hydrogen-doped natural gas passes through the static experiment section B, the corner experiment section C and the flow experiment section D and is discharged by the vent valve 23, keep the device pre-running for 2-3 minutes, open 13 ball valve 24, close vent valve 23;

[0023] Step S4, static experiment

[0024] At the beginning of the experiment, close 6 ball valve 10, open 7, 8, 9, 10, 11, 12, 19, make the hydrogen-doped natural gas enter the pipe section, open 6 ball valve 10 after the end of charging, close 7, 8, 9, 10, 11, 12, 19, start the static stratification experiment; the horizontal pipe section G is provided with gas sampling ports m1-m4 at equal intervals in the axial and radial directions, the 45° upward inclined pipe section H is provided with gas sampling ports m5-m9 at equal intervals in the axial and radial directions, and the vertical pipe K is provided with gas sampling ports m 10 -m 14 After reaching the specified static time, measure the hydrogen component concentration at the gas sampling ports m1-m 14

[0025] Step S5, flow experiment

[0026] ​After the static test, the flow test can be carried out when the device is running normally. The hydrogen-doped natural gas first enters the 90° bend pipe section of the corner test section C. Gas sampling ports m are arranged at equal intervals in the flow direction and radial direction in this pipe section. 15 -m 22 After the specified experimental time has elapsed, a hydrogen analyzer is used to sample the gas at the gas sampling port m. 15 -m 22 Measuring the concentration of hydrogen components;

[0027] Hydrogen-blended natural gas simultaneously enters the horizontal straight pipe section of the flow test section D, with gas sampling ports m arranged at equal intervals in both the flow direction and radial direction of the pipe section. 23 -m 26 After the specified experimental time has elapsed, a hydrogen analyzer is used to sample the gas at the gas sampling port m. 23 -m 26 Measure the concentration of hydrogen components;

[0028] When ball valves 7#11, 8#13, 9#14, 10#16, 11#17, and 12#19 in the static test section B are simultaneously opened, stratification experiments under flow conditions can also be conducted in the horizontal pipe section G, the 45° upward-sloping pipe section H, and the vertical pipe section K. After the specified experimental time is reached, a hydrogen analyzer is used to sample gas at the gas sampling ports m1-m. 14 Measuring the concentration of hydrogen components;

[0029] Step S6: Post-experiment processing

[0030] After the experiment is completed, repeat step S2 to purge and replace the stratification experimental device with nitrogen, and check whether the valves and instruments on the stratification experimental device are opened and closed as required.

[0031] The static stratification experiment process is as follows: At the beginning of the experiment, ball valve #6 (10) is closed, and ball valves #7 (11), #8 (13), #9 (14), #10 (16), #11 (17), and #12 (19) are opened to allow hydrogen-blended natural gas to enter each pipe section. After the gas filling is completed, ball valve #6 (10) is opened, and ball valves #7 (11), #8 (13), #9 (14), #10 (16), #11 (17), and #12 (19) are closed to begin the static stratification experiment. Gas sampling ports are arranged at equal intervals on pipe sections at different angles. In the horizontal pipe section G, gas sampling ports m1-m4 are arranged at equal intervals in both the axial and radial directions. In the 45° upward-sloping pipe section H, gas sampling ports m5-m9 are arranged at equal intervals in both the axial and radial directions. In the vertical pipe section K, gas sampling ports m1-m4 are arranged at equal intervals in the axial direction. 10 -m 14 After the specified settling time is reached, a hydrogen analyzer is used to sample gas from port m1 to m2. 14 Measure the concentration of hydrogen components.

[0032] When the 6# ball valve 10, the 7# ball valve 11, the 8# ball valve 13, the 9# ball valve 14, the 10# ball valve 16, the 11# ball valve 17 and the 12# ball valve 19 in the static experiment section B are opened at the same time, the static experiment section B can also carry out the stratification experiment under the flow condition in the horizontal pipe section G, the 45° upward inclined pipe section H and the vertical pipe section K.

[0033] The beneficial effects of the present application are (1) the stratification experiment of hydrogen-doped natural gas in horizontal pipes, inclined pipes, vertical pipes and bends under static and flow conditions can be carried out; (2) the parameters such as pipe pressure, hydrogen-doping ratio and shutdown time can be conveniently changed, which is conducive to revealing the stratification mechanism of hydrogen-doped natural gas under complex pipe undulation and complex pipe parameter conditions. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Fig. 1 is a structural schematic diagram of a hydrogen-doped natural gas pipeline stratification experiment device;

[0035] Figure 2 Fig. 1 is a structural schematic diagram of a hydrogen-doped natural gas pipeline stratification experiment device; DETAILED DESCRIPTION

[0036] The present application provides a hydrogen-doped natural gas pipeline stratification experiment device and method, which will be further described below in combination with the drawings and examples.

[0037] As Figure 1 , Figure 2The hydrogen-doped natural gas pipeline layered experimental device shown comprises a hydrogen-doping section A, a static experimental section B, a corner experimental section C, a flow experimental section D, a reserved experimental section E and a mixed gas conveying pipe section F; wherein the hydrogen-doping section A comprises a natural gas pipeline 1, a hydrogen pipeline 2 and a static mixer 3; the natural gas pipeline 1 and the hydrogen pipeline 2 are completely identical in structure, and any one pipeline is composed of a double ball valve 5, a 1# ball valve 20, a pressure regulating valve 21, a 1# ball valve with a pressure gauge 25, a 2# ball valve 26 and the static mixer 3 in series; wherein a differential pressure gauge is installed on the static mixer 3, and a 1# nitrogen purging port 12, a 1# pressure gauge 15 and a flow meter 18 are sequentially installed between the double ball valve 5 and the 1# ball valve 20 of the natural gas pipeline 1; the output of the static mixer 3 is connected in series with a 3# ball valve 4 and a 4# ball valve 6 of the reserved experimental section E; and the output of the static mixer 3 is connected in series with a 5# ball valve 7, a 2# ball valve with a pressure gauge 9 and a 6# ball valve 10; the 6# ball valve 10 is connected in parallel with a 7# ball valve 11 and an 8# ball valve 13 in a horizontal pipe section G, a 9# ball valve 14 and a 10# ball valve 16 in a 45° upward inclined pipe section H and an 11# ball valve 17 and a 12# ball valve 19 in a vertical pipe section K, thereby forming the static experimental section B; the static experimental section B, the corner experimental section C, the flow experimental section D and the mixed gas conveying pipe section F are connected in series; a 13# ball valve 24 of the mixed gas conveying pipe section F is connected with the 4# ball valve 6 of the reserved experimental section E; a vent valve 23 and a 2# pressure gauge 22 are installed on the pipeline of the mixed gas conveying pipe section F, thereby forming the overall hydrogen-doped natural gas pipeline layered experimental device.

[0038] Natural gas and hydrogen are uniformly mixed in the hydrogen-doping section A according to a given ratio to form hydrogen-doped natural gas, the hydrogen-doped natural gas enters the static experimental section B through the 5# ball valve 7, the 2# ball valve with a pressure gauge 9 and the 6# ball valve 10, and the static experimental section B is subjected to static experiments through the horizontal pipe section G, the 45° upward inclined pipe section H and the vertical pipe section K; then the hydrogen-doped natural gas enters the corner experimental section C and the flow experimental section D for experiments, thereby completing the hydrogen-doped natural gas pipeline layered experiments; further, the mixed gas after the experiments enters the mixed gas conveying pipe section F, is vented through the vent valve 23 or enters the downstream for processing and utilization through the 13# ball valve 24, thereby completing the hydrogen-doped natural gas pipeline layered experiments under the conditions of stoppage and flow.

[0039] The reserved experimental section E is used to meet the experimental improvement requirements possibly involved in the later experimental stage.

[0040] The natural gas pipeline 1 and the hydrogen pipeline 2 are provided with pressure regulating valves and ball valves with pressure gauges, so that the pressure of the natural gas pipeline and the hydrogen pipeline can be conveniently adjusted, hydrogen and natural gas can be mixed under different pressures, and different pipeline pressure requirements for experiments can be met.

[0041] The natural gas pipeline and hydrogen pipeline are equipped with flow meters, which can easily adjust the flow rate of hydrogen and natural gas, and realize the blending of hydrogen and natural gas at different hydrogen blending ratios to meet the different hydrogen blending ratio requirements of the experiment.

[0042] The static test section B includes a horizontal pipe section G, a 45° upward-sloping pipe section H, a vertical pipe section K, and ball valves connected to both ends of the three different angle pipe sections, used to simulate different pipeline undulations; it can conveniently control the static test time of each pipe section at different angles and ensure that the static tests of each pipe section at different angles do not affect each other.

[0043] like Figure 2 A schematic diagram showing the arrangement of gas sampling ports on the experimental section of the layered experimental setup; wherein,

[0044] The corner test section C includes a 90° bend pipe section, used to simulate pipe bends and turns; gas sampling ports m are arranged at equal intervals in the flow direction and radial direction on the pipe section. 15 -m 22 After the specified experimental time has elapsed, a hydrogen analyzer is used to sample the gas at the gas sampling port m. 15 -m 22 Measure the concentration of hydrogen components.

[0045] The flow test section D is a horizontal straight pipe section used to simulate the stratification phenomenon in a pipeline under normal flow conditions; gas sampling ports m are arranged at equal intervals in the flow direction and radial direction on the pipe section. 23 -m 26 After the specified experimental time has elapsed, a hydrogen analyzer is used to sample the gas at the gas sampling port m. 23 -m 26 Measure the concentration of hydrogen components.

[0046] The reserved experimental section E is used to meet the experimental needs of more research conditions and to provide a reserved interface for future experimental modifications.

[0047] The mixed gas delivery pipe section F includes a vent valve 23, which can vent the gas of the entire experimental device after the experiment is completed or in an emergency to ensure the safety of the experimental device; it can also vent the gas of the entire experimental device when the experimental device is purged with nitrogen and replaced with gas.

[0048] The steel used for the pipeline in the hydrogen-blended natural gas pipeline stratification test device is preferably hydrogen-resistant steel; the sealing connections of valves and instruments are preferably made of materials and processes that prevent hydrogen leakage.

[0049] A stratification test method for a hydrogen-blended natural gas pipeline stratification test device, characterized in that the stratification test of hydrogen-blended natural gas under complex pipeline undulations and parameters in both shutdown and flow conditions includes the following steps:

[0050] Step S1, check the equipment,

[0051] Check whether the hydrogen-doped natural gas pipeline stratification experimental device is in normal working condition, including: whether the hydrogen-doping section is working normally, whether the valves and instruments of the standing experimental section, the corner experimental section, the flow experimental section, and the reserved experimental section are opened and closed as required, whether the instrument readings of the pressure gauges and flowmeters are normal, and whether the hydrogen analyzer is working normally;

[0052] Step S2, nitrogen purging and replacement:

[0053] Close ball valves 3, 4, 4, 5, 6, 7, 6, 10, 13, 24, open ball valves 7, 8, 9, 10, 11, 12, 19, open the vent valve 23, open the 2# nitrogen purging port 8, and then use nitrogen to purge the hydrogen-doped natural gas pipeline stratification experimental device. The gas in the device is replaced with nitrogen to prevent residual gas in the device from forming explosive gas with hydrogen-doped natural gas and to ensure the safety of the device. The gas after purging and replacement is discharged by the vent valve 23;

[0054] Step S3, device pre-running

[0055] After purging and replacement, close the 2# nitrogen purging port 8, keep the vent valve 23 open, and the hydrogen-doping section provides hydrogen-doped natural gas with a given pressure and hydrogen-doping ratio to the downstream experimental part. The hydrogen-doped natural gas passes through the standing experimental section B, the corner experimental section C, and the flow experimental section D and is discharged by the vent valve 23. After keeping the device pre-running for 2-3 minutes, open the 13# ball valve 24 and close the vent valve 23.

[0056] Step S4, standing experiment

[0057] At the beginning of the experiment, close the 6# ball valve 10, open the 7# ball valve 11, 8# ball valve 13, 9# ball valve 14, 10# ball valve 16, 11# ball valve 17, and 12# ball valve 19 to make the hydrogen-doped natural gas enter the pipe section. After the inflation is completed, open the 6# ball valve 10 and close the ball 7# ball valve 11, 8# ball valve 13, 9# ball valve 14, 10# ball valve 16, 11# ball valve 17, and 12# ball valve 19 to start the standing stratification experiment (such as Figure 2 The arrangement of the gas sampling ports in the stratification experimental device is shown in the figure), the horizontal pipe section G is arranged with gas sampling ports m1-m4 at equal intervals in the axial and radial directions, the 45° upward inclined pipe section H is arranged with gas sampling ports m5-m9 at equal intervals in the axial and radial directions, and the vertical pipe K is arranged with gas sampling ports m 10 -m 14 After the specified standing time is reached, use the hydrogen analyzer to sample the gas at the gas sampling ports m1-m 14Measuring the hydrogen component concentration;

[0058] Step S5, flow experiment

[0059] After the standing experiment is finished, the flow experiment can be performed when the device is normally operated. The hydrogen-doped natural gas first enters the 90° elbow pipe section of the corner experiment section C, and the gas sampling ports m are arranged at equal intervals in the flow direction and radial direction of the pipe section 15 -m 22 After the specified experiment time is reached, the hydrogen gas analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 15 -m 22 Measuring the hydrogen component concentration;

[0060] The hydrogen-doped natural gas simultaneously enters the horizontal straight pipe section of the flow experiment section D, and the gas sampling ports m are arranged at equal intervals in the flow direction and radial direction of the pipe section 23 -m 26 After the specified experiment time is reached, the hydrogen gas analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 23 -m 26 Measuring the hydrogen component concentration;

[0061] When the 7# ball valve 11, the 8# ball valve 13, the 9# ball valve 14, the 10# ball valve 16, the 11# ball valve 17, and the 12# ball valve 19 in the standing experiment section B are simultaneously opened, the stratification experiment under the flow condition can also be performed in the horizontal pipe section G, the 45° upward inclined pipe section H, and the vertical pipe section K. After the specified experiment time is reached, the hydrogen gas analyzer is used to measure the hydrogen component concentration at the gas sampling ports m1-m 14 Measuring the hydrogen component concentration;

[0062] Step S6, processing after the experiment is finished

[0063] After the experiment is finished, the nitrogen gas is blown and replaced to the stratification experiment device according to step S2, and whether the valves and instruments on the stratification experiment device are switched according to the requirements is checked.

[0064] The standing stratification experiment process: when the experiment starts, the 6# ball valve 10 is closed, and the 7# ball valve 11, the 8# ball valve 13, the 9# ball valve 14, the 10# ball valve 16, the 11# ball valve 17, and the 12# ball valve 19 are opened, so that the hydrogen-doped natural gas enters each pipe section. After the gas charging is finished, the 6# ball valve 10 is opened, and the 7# ball valve 11, the 8# ball valve 13, the 9# ball valve 14, the 10# ball valve 16, the 11# ball valve 17, and the 12# ball valve 19 are closed, and the standing stratification experiment starts. The gas sampling ports are arranged at equal intervals on each pipe section of different angles. The gas sampling ports m1-m4 are arranged at equal intervals in the axial and radial directions of the horizontal pipe section G, the gas sampling ports m5-m9 are arranged at equal intervals in the axial and radial directions of the 45° upward inclined pipe section H, and the gas sampling ports m are arranged at equal intervals in the axial direction of the vertical pipe section K 10 -m 14After the specified standing time is reached, a hydrogen analyzer is used to sample the gas at the gas sampling port m1-m 14 The hydrogen component concentration is measured.

[0065] When the 6# ball valve 10, the 7# ball valve 11, the 8# ball valve 13, the 9# ball valve 14, the 10# ball valve 16, the 11# ball valve 17, and the 12# ball valve 19 in the standing experiment section B are opened at the same time, the standing experiment section B can also perform stratification experiments under flow conditions in the horizontal pipe section G, the 45° upward inclined pipe section H, and the vertical pipe section K.

[0066] In summary, the technical scheme provided by the application can be seen as follows: the stratification experiment device for hydrogen-doped natural gas pipelines provided by the embodiments of the application can perform stratification experiment research on hydrogen-doped natural gas in horizontal pipes, inclined pipes, vertical pipes, and elbows, can also conveniently change pipeline pressure, hydrogen-doping ratio, shutdown time, and other parameters, can also simultaneously perform stratification experiments under shutdown conditions and flow conditions, and is conducive to the experimental research on the stratification mechanism of hydrogen-doped natural gas under shutdown and flow conditions in complex pipeline undulations and complex pipeline parameters.

Claims

1. A hydrogen-doped natural gas pipeline stratification experimental device, characterized in that, The hydrogen-doped natural gas pipeline layered experimental device comprises a hydrogen-doping section (A), a static experimental section (B), a corner experimental section (C), a flow experimental section (D), a reserved experimental section (E) and a mixed gas conveying pipe section (F); wherein the hydrogen-doping section (A) comprises a natural gas pipeline (1), a hydrogen pipeline (2) and a static mixing device (3); the natural gas pipeline (1) and the hydrogen pipeline (2) have the same structure, and any one pipeline is composed of a double ball valve (5), a 1# ball valve (20), a pressure regulating valve (21), a 1# ball valve with a pressure gauge (25), a 2# ball valve (26) and the static mixing device (3) in series connection; wherein a differential pressure gauge (27) is installed on the static mixing device (3); a 1# nitrogen purging port (12), a 1# pressure gauge (15) and a flowmeter (18) are sequentially installed between the double ball valve (5) and the 1# ball valve (20) of the natural gas pipeline (1); the output of the static mixing device (3) is connected with a 3# ball valve (4) and a 4# ball valve (6) in the reserved experimental section (E) in series connection; and is connected with a 5# ball valve (7), a 2# ball valve with a pressure gauge (9) and a 6# ball valve (10) in series connection; the 6# ball valve (10) is connected with a 7# ball valve (11), an 8# ball valve (13), a 9# ball valve (14) and a 10# ball valve (16) in parallel connection, and is connected with an 11# ball valve (17) and a 12# ball valve (19) in parallel connection, thereby forming the static experimental section (B); the static experimental section (B), the corner experimental section (C), the flow experimental section (D) and the mixed gas conveying pipe section (F) are connected in series; a 13# ball valve (24) of the mixed gas conveying pipe section (F) is connected with the 4# ball valve (6) of the reserved experimental section (E); a vent valve (23) and a 2# pressure gauge (22) are installed on the pipeline of the mixed gas conveying pipe section (F), thereby forming the whole hydrogen-doped natural gas pipeline layered experimental device; The natural gas and the hydrogen are uniformly mixed in the hydrogen-doping section (A) according to a given ratio to form hydrogen-doped natural gas; the hydrogen-doped natural gas enters the static experimental section (B) through the 5# ball valve (7), the 2# ball valve with a pressure gauge (9) and the 6# ball valve (10), and is subjected to static experiments in the static experimental section (B) through the horizontal pipe section (G), the 45° upward inclined pipe section (H) and the vertical pipe section (K); then the hydrogen-doped natural gas enters the corner experimental section (C) and the flow experimental section (D) to complete the hydrogen-doped natural gas pipeline layered experiment; further, the mixed gas after the experiment enters the mixed gas conveying pipe section (F), is vented through the vent valve (23) or enters the downstream processing and utilization through the 13# ball valve (24), thereby completing the layered experiment of the hydrogen-doped natural gas pipeline under the stop-flow and flow working conditions; The flow experimental section (D) is a horizontal straight pipe section, which is used for simulating the layered phenomenon of the pipeline under the normal flow working condition; gas sampling ports m23-m26 are arranged on the pipe section at intervals in the flow direction and the radial direction; after a specified experimental time is reached, a hydrogen analyzer is used to measure the hydrogen component concentration at the gas sampling ports m23-m26, The static experiment section (B) comprises horizontal pipe sections (G), 45° upwardly inclined pipe sections (H), vertical pipe sections (K) and ball valves connected at both ends of the three different angle pipe sections for simulating different pipe undulations; the static experiment time of each different angle pipe section can be conveniently controlled, and the static experiments of the different angle pipe sections do not affect each other, The corner experiment section (C) comprises 90° elbow pipe sections for simulating pipe bends and pipe conditions at the turning points; gas sampling ports m15-m22 are arranged at intervals in the flow direction and the radial direction on the pipe sections, and after a specified experiment time is reached, a hydrogen analyzer is used to measure the hydrogen component concentration at the gas sampling ports m15-m22.

2. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, characterized in that, The reserved experiment section (E) is used to meet the experimental improvement requirements that may be involved in the later stage of the experiment.

3. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, characterized in that, The natural gas pipeline (1) and the hydrogen pipeline (2) are each provided with a pressure regulating valve and a table ball valve, which can conveniently adjust the pressure of the natural gas pipeline and the hydrogen pipeline, so that hydrogen and natural gas can be mixed at different pressures to meet the different pipeline pressure requirements of the experiment.

4. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, characterized in that, The natural gas pipeline and the hydrogen pipeline are each provided with a flowmeter, which can conveniently adjust the flow of the hydrogen pipeline and the natural gas pipeline, so that hydrogen and natural gas can be mixed at different hydrogen mixing ratios to meet the different hydrogen mixing ratio requirements of the experiment.

5. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, characterized in that, The reserved experiment section (E) is used to meet the experimental requirements of more research conditions and provides a reserved interface for future experimental modification.

6. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, wherein, The mixed gas delivery pipe section (F) includes a vent valve (23) that can vent the gas in the entire experimental device after the experiment is completed or in an emergency to ensure the safety of the experimental device; the vent valve (23) can also vent the gas in the entire experimental device when the experimental device is nitrogen purged and gas replaced.

7. The hydrogen-doped natural gas pipeline stratification experimental device according to claim 1, characterized in that, The steel material of the pipeline in the hydrogen-mixed natural gas pipeline layered experimental device is hydrogen embrittlement resistant steel material; the sealing connection of the valves and instruments is made of materials and processes that prevent hydrogen leakage and leakage.

8. The method of claim 1-7, wherein, The hydrogen-mixed natural gas pipeline layered experimental device includes the following steps for layered experiments of hydrogen-mixed natural gas under stoppage and flow conditions under complex pipeline undulations and complex pipeline parameters: Step S1, checking the equipment, Check whether the hydrogen-mixed natural gas pipeline layered experimental device is in a normal working state, including: whether the hydrogen mixing section is working normally, whether the valves and instruments of the static experiment section, the corner experiment section, the flow experiment section and the reserved experiment section are opened and closed as required, whether the instrument readings of the pressure gauges and flowmeters are normal, and whether the hydrogen analyzer is working normally; Step S2, nitrogen purging and replacement: Close the ball valve 3# ball valve (4), 4# ball valve (6), 5# ball valve (7), 6# ball valve (10), 13# ball valve (24), open 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19), open the vent valve (23), open 2# nitrogen purge port (8), and then use nitrogen to purge the hydrogen-doped natural gas pipeline layered experimental device, replace the gas in the device with nitrogen to prevent residual gas in the device from forming explosive gas with hydrogen-doped natural gas and ensure the safety of the device; the gas after purging and replacing is discharged by the vent valve (23); Step S3, device pre-running After purging and replacing, close 2# nitrogen purge port (8), keep vent valve (23) open, hydrogen-doped section provides hydrogen-doped natural gas with given pressure and hydrogen-doped ratio to the downstream experimental part, hydrogen-doped natural gas passes through the static experiment section (B), corner experiment section (C), and flow experiment section (D) and is discharged by the vent valve (23), keep the device pre-running for 2-3 minutes, open 13# ball valve (24), and close the vent valve (23); Step S4, static experiment At the beginning of the experiment, close the 6# ball valve (10), open the 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19), so that hydrogen-containing natural gas enters the pipe section, after the end of the charging, open the 6# ball valve (10), close the ball 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19), start the static stratification experiment; The horizontal pipe section (G) is provided with gas sampling ports m1-m4 at equal intervals in the axial and radial directions, and the 45° upward inclined pipe section (H) is provided with gas sampling ports m5-m9 at equal intervals in the axial and radial directions, and the vertical pipe (K) is provided with gas sampling ports m 10 -m 14 , After reaching the specified static time, measure the hydrogen component concentration at the gas sampling ports m1-m 14 using a hydrogen analyzer; Step S5, flow experiment After the end of the static experiment, the flow experiment can be carried out when the device is normally running. The hydrogen-doped natural gas first enters the 90° elbow pipe section of the corner experimental section (C), and the gas sampling ports m are arranged at equal intervals in the flow direction and radial direction of the pipe section 15 -m 22 After reaching the specified experimental time, the hydrogen gas analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 15 -m 22 ​ Hydrogen-doped natural gas enters a horizontal straight pipe section of the flow test section (D) at the same time, and gas sampling ports m are arranged on the pipe section at equal intervals in the flow direction and the radial direction 23 -m 26 After a specified test time is reached, a hydrogen gas analyzer is used to measure the hydrogen component concentration at the gas sampling ports m 23 -m 26 The hydrogen component concentration is measured; When 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19) in the static experiment section (B) are opened at the same time, stratification experiments under flow conditions can also be carried out in the horizontal pipe section (G), the 45° upward inclined pipe section (H) and the vertical pipe section (K). After reaching the specified experimental time, the hydrogen analyzer is used to collect gas samples at the gas sampling ports m1-m 14 The hydrogen component concentration is measured. Step S6, treatment after experiment After the experiment, repeat step S2 to purge and replace the layered experimental device with nitrogen, and check whether the valves and instruments on the layered experimental device meet the requirements.

9. The method of claim 8, wherein the hydrogen-doped natural gas pipeline stratification experimental apparatus is characterized by, The static stratification experiment process: close the 6# ball valve (10) at the beginning of the experiment, open the 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19), so that hydrogen-containing natural gas enters each pipe section, after the end of the charging, open the 6# ball valve (10), close the 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), 12# ball valve (19), start the static stratification experiment; arrange the gas sampling ports on each different angle pipe section at equal intervals, arrange the gas sampling ports m1-m4 at equal intervals in the axial and radial directions on the horizontal pipe section (G), arrange the gas sampling ports m5-m9 at equal intervals in the axial and radial directions on the 45° upward inclined pipe section (H), arrange the gas sampling ports m 10 -m 14 , after reaching the specified static time, measure the hydrogen component concentration at the gas sampling ports m1-m 14 using the hydrogen analyzer.

10. The method of claim 8, wherein the hydrogen-doped natural gas pipeline stratification experimental apparatus is characterized by, When 6# ball valve (10), 7# ball valve (11), 8# ball valve (13), 9# ball valve (14), 10# ball valve (16), 11# ball valve (17), and 12# ball valve (19) in the static experiment section (B) are opened at the same time, the static experiment section (B) can also perform layered experiments under flow conditions in the horizontal pipe section (G), 45° upward inclined pipe section (H), and vertical pipe section (K).

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