Experimental device for testing non-uniform distribution of hydrogen-doped natural gas and use method

Abstract

The invention discloses an experimental device for testing non-uniform distribution of hydrogen-doped natural gas and a use method, and relates to the technical field of hydrogen-doped natural gas layering. According to the experimental device for testing uneven distribution of hydrogen-doped natural gas, hydrogen-doped natural gas of different proportions can be configured, different gas flow rates and gas storage tank pressures can be set, the natural gas and hydrogen mixing and standing process in long-distance hydrogen-doped natural gas pipelines in cities and towns can be simulated, physical property parameter monitoring in the mixing and standing process is achieved, and the experimental device is suitable for large-scale popularization and application. According to the invention, reasons influencing non-uniform distribution of hydrogen-doped natural gas are analyzed, a plurality of gas outlets are formed in the gas storage tank, so that the concentration distribution conditions of hydrogen and natural gas at different positions of the gas storage tank under specific conditions can be obtained, gas in a pipeline and the gas storage tank is replaced before an experiment is started, the influence of other gas on a test result is reduced, and the test efficiency is improved. And the precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen-doped natural gas stratification, and in particular to an experimental device for testing uneven distribution of hydrogen-doped natural gas and a use method thereof. Background Art

[0002] In the context of responding to global climate change and accelerating green and low-carbon development, hydrogen energy as a new energy carrier and potential fuel is gaining increasing attention. Using existing natural gas pipelines to transport hydrogen is the best way to achieve large-scale hydrogen transportation.

[0003] Due to the different densities of natural gas and methane, with the addition of hydrogen, the hydrogen-blended natural gas will have an uneven volume fraction distribution under the action of gravity during storage, pipeline shutdown and pipeline operation, which can easily form local high-concentration aggregation areas of hydrogen components, causing hydrogen embrittlement damage and destruction. In addition, hydrogen has low ignition energy and low auto-ignition temperature, and is extremely easy to spontaneously ignite, posing potential safety hazards to pipelines and stations.

[0004] Current research on hydrogen embrittlement considers the hydrogen concentration field inside pipelines or gas tanks to be uniformly distributed, which cannot restore the actual distribution of the hydrogen concentration field in pipelines or gas tanks, resulting in certain deviations in the analysis of pipeline hydrogen embrittlement hazards.

[0005] Therefore, conducting experimental research on the uneven distribution of hydrogen-blended natural gas plays a very important role in the safety evaluation of future hydrogen-blended natural gas pipelines or gas storage tanks. Summary of the invention

[0006] The purpose of the present invention is to provide an experimental device and a method for using it for testing the uneven distribution of hydrogen-blended natural gas, which can realize the concentration field distribution monitoring of natural gas and hydrogen blending and static process in urban and long-distance hydrogen-blended natural gas pipelines, as well as the physical property parameter monitoring of the blending and static process. It can also simulate experiments on the uneven distribution of other different mixed gases to solve the technical problems raised in the background technology.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: an experimental device for testing the uneven distribution of hydrogen-blended natural gas, comprising a gas cylinder assembly, a pressure reducing valve (4), a pneumatic ball valve (5), a gas flow meter (6), a gas storage tank assembly and a main pipeline (23);

[0008] The outer side of the main pipeline (23) is connected in sequence with a pressure reducing valve (4), a pneumatic ball valve (5), a gas flow meter (6) and a gas storage tank assembly;

[0009] The bottom end of the pressure reducing valve (4) is fixedly connected to a gas cylinder assembly.

[0010] Furthermore, the gas cylinder assembly comprises a nitrogen cylinder (1), a natural gas cylinder (2) and a hydrogen cylinder (3), and the nitrogen cylinder (1), the natural gas cylinder (2) and the hydrogen cylinder (3) are all connected to a pressure reducing valve (4).

[0011] Furthermore, the gas storage tank assembly comprises a gas storage tank (7), a safety valve (8), an air inlet (11), a pressure gauge (10), a first air outlet (12), a second air outlet (13), a third air outlet (14), a fourth air outlet (15) and a sewage outlet (16); the top of the gas storage tank (7) is provided with a safety valve (8) and an air inlet (11); the safety valve (8) is located on one side of the air inlet (11); the end of the air inlet (11) away from the gas storage tank (7) is connected to A first stop valve (9), the air inlet (11) is connected to the main pipeline (23) through the first stop valve (9), the first stop valve (9) is used to cut off the flow of the experimental gas, one side of the gas storage tank (7) is provided with a first gas outlet (12), a second gas outlet (13), a third gas outlet (14) and a fourth gas outlet (15) from top to bottom, the bottom end of the gas storage tank (7) is provided with a sewage outlet (16), and the outer surface of the gas storage tank (7) is provided with a pressure gauge (10).

[0012] Furthermore, the first gas outlet (12), the second gas outlet (13), the third gas outlet (14), the fourth gas outlet (15) and the sewage outlet (16) are respectively provided with a second stop valve (18), a third stop valve (19), a fourth stop valve (20), a fifth stop valve (21) and a sixth stop valve (22). The second stop valve (18), the third stop valve (19), the fourth stop valve (20), the fifth stop valve (21) and the sixth stop valve (22) are used to control the flow of the experimental gas.

[0013] Furthermore, a temperature sensor (17) and a sampling port (24) are provided at the outlets of the second stop valve (18), the third stop valve (19), the fourth stop valve (20) and the fifth stop valve (21); the temperature sensor (17) is used to monitor the temperature change in the gas storage tank (7); and the sampling port (24) is used to take out the experimental gas for analysis.

[0014] Furthermore, the pneumatic ball valve (5) is provided with a solenoid valve (26), and the solenoid valve (26) is used to control the opening and closing of the pneumatic ball valve (5) locally or remotely.

[0015] Furthermore, it also includes a data acquisition system (25), the gas flow meter (6), the pressure gauge (10) and the temperature sensor (17) are all connected to the data acquisition system (25) by telecommunication, and the data acquisition system (25) is used to record the physical property parameters of the mixing and static process in real time.

[0016] The test method of the experimental device for testing the uneven distribution of hydrogen-doped natural gas includes at least the following steps:

[0017] Step 1: connect the gas cylinder assembly, the pressure reducing valve (4), the pneumatic ball valve (5), the gas flow meter (6), the gas storage tank assembly and the main pipeline (23) in sequence, and connect the gas flow meter (6), the pressure gauge (10) and the temperature sensor (17) to the data acquisition system (25);

[0018] Step 2: Check whether each instrument and equipment is operating normally;

[0019] Step 3: Check the air tightness of the pipeline;

[0020] Step 4: Before the experiment begins, open the nitrogen bottle (1) to expel the gas in the main pipeline (23) and the gas storage tank (7) to prevent the remaining gas from affecting the experimental results;

[0021] Step 5: After the gas is expelled, close the second stop valve (18), the third stop valve (19), the fourth stop valve (20), the fifth stop valve (21) and the sixth stop valve (22), install the temperature sensor (17), open the natural gas cylinder (2) and fill it with natural gas at a certain pressure according to the pressure and hydrogen blending ratio required by the experiment, then close it, and then open the hydrogen cylinder (3) and fill it with hydrogen at a certain pressure according to the partial pressure method;

[0022] Step 6: After the gas filling is completed, close the hydrogen cylinder (3), the pneumatic ball valve (5) and the first stop valve (9), disassemble the first stop valve (9) and the main pipeline (23), let the experimental gas stand, extract hydrogen-blended natural gas from the sampling port (24) at regular intervals for analysis, and record the pressure and temperature changes in the data acquisition system (25) and the distribution of natural gas and hydrogen in real time.

[0023] Step 7: After the experiment is completed, repeat steps 4 to 6 to conduct experiments on the distribution of natural gas and hydrogen during the blending and standing processes at different pressures and hydrogen blending ratios.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The experimental device for testing the uneven distribution of hydrogen-blended natural gas of the present invention can be configured with hydrogen-blended natural gas in different proportions, and different gas flow rates and gas tank pressures can be set. It can simulate the mixing and standing process of natural gas and hydrogen in urban and long-distance hydrogen-blended natural gas pipelines, realize the monitoring of physical parameters in the mixing and standing process, and analyze the reasons affecting the uneven distribution of hydrogen-blended natural gas.

[0026] 2. The present invention sets a plurality of gas outlets in the gas storage tank, thereby obtaining the concentration distribution of hydrogen and natural gas at different positions of the gas storage tank under specific conditions, and replaces the gas in the pipeline and the gas storage tank before the experiment starts, thereby reducing the influence of other gases on the test results and improving the accuracy.

[0027] 3. The experimental device of the present invention has the advantages of simple structure, high safety and good applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] In the figure: 1. Nitrogen cylinder; 2. Natural gas cylinder; 3. Hydrogen cylinder; 4. Pressure reducing valve; 5. Pneumatic ball valve; 6. Gas flow meter; 7. Gas storage tank; 8. Safety valve; 9. First stop valve; 10. Pressure gauge; 11. Air inlet; 12. First air outlet; 13. Second air outlet; 14. Third air outlet; 15. Fourth air outlet; 16. Sewage outlet; 17. Temperature sensor; 18. Second stop valve; 19. Third stop valve; 20. Fourth stop valve; 21. Fifth stop valve; 22. Sixth stop valve; 23. Main pipeline; 24. Sampling port; 25. Data acquisition system; 26. Solenoid valve. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] Embodiment 1:

[0033] See also Figure 1 The experimental device for testing the uneven distribution of hydrogen-blended natural gas includes a nitrogen cylinder 1, a natural gas cylinder 2, a hydrogen cylinder 3, a pressure reducing valve 4, a pneumatic ball valve 5, a gas flow meter 6, a gas storage tank 7, a safety valve 8, a first stop valve 9, a pressure gauge 10, an air inlet 11, a first air outlet 12, a second air outlet 13, a third air outlet 14, a fourth air outlet 15, a sewage outlet 16, a temperature sensor 17, a second stop valve 18, a third stop valve 19, a fourth stop valve 20, a fifth stop valve 21, a sixth stop valve 22, a main pipeline 23, a sampling port 24, a data acquisition system 25 and a solenoid valve 26.

[0034] The outlets of the nitrogen cylinder 1, the natural gas cylinder 2 and the hydrogen cylinder 3 are connected to the pressure reducing valve 4, which is used to control the gas flow of the nitrogen cylinder 1, the natural gas cylinder 2 and the hydrogen cylinder 3 so that the filling pressure reaches the required requirements of the experiment.

[0035] Preferably, the outlets of the nitrogen cylinder 1, the natural gas cylinder 2 and the hydrogen cylinder 3 are connected to the pressure reducing valve 4 by threaded connection.

[0036] The pressure reducing valve 4, the pneumatic ball valve 5, the gas flow meter 6, the gas storage tank 7 and the first stop valve 9 are connected to the main pipeline 23 in sequence. The pneumatic ball valve 5 is used to control the flow rate of the experimental gas to achieve the flow required for the experiment, the gas flow meter 6 is used to monitor the flow of the experimental gas, the gas storage tank 7 is used to store the experimental gas, and the first stop valve 9 is used to cut off the flow of the experimental gas to ensure that it is in a sealed state during the experiment.

[0037] The pressure reducing valve 4, the pneumatic ball valve 5, the gas flow meter 6, the gas storage tank 7 and the first stop valve 9 are connected to the main pipeline 23 by flange or threaded connection.

[0038] The gas tank 7 is provided with a safety valve 8, an air inlet 11, a pressure gauge 10, a first air outlet 12, a second air outlet 13, a third air outlet 14, a fourth air outlet 15 and a drain port 16. The safety valve 8 is used for pressure relief to ensure the safety of the experimental process. The air inlet 11 is used for filling the experimental gas into the gas tank 7 and also for taking out the experimental gas from the top of the gas tank 7. The pressure gauge 11 is used for monitoring the experimental gas pressure of the gas tank 7. The first air outlet 12, the second air outlet 13, the third air outlet 14 and the fourth air outlet 15 are used for discharging the experimental gas at different positions of the gas tank 7. The drain port 16 is used for discharging water vapor generated during the experiment and the experiment.

[0039] The first gas outlet 12, the second gas outlet 13, the third gas outlet 14, the fourth gas outlet 15 and the sewage outlet 16 are respectively provided with a second stop valve 18, a third stop valve 19, a fourth stop valve 20, a fifth stop valve 21 and a sixth stop valve 22 to control the flow of the experimental gas.

[0040] The first air outlet 12, the second air outlet 13, the third air outlet 14, the fourth air outlet 15 and the sewage outlet 16 are connected to the second stop valve 18, the third stop valve 19, the fourth stop valve 20, the fifth stop valve 21 and the sixth stop valve 22 by flange connection.

[0041] The first gas outlet 12, the second gas outlet 13, the third gas outlet 14 and the fourth gas outlet 15 are respectively provided with a temperature sensor 17 to monitor the temperature change in the gas storage tank in real time, and a sampling port 24 is provided for taking out the experimental gas for analysis.

[0042] The second stop valve 18 , the third stop valve 19 , the fourth stop valve 20 and the fifth stop valve 21 are connected to the temperature sensor 17 and the sampling port 24 by threaded connection.

[0043] The pneumatic ball valve 5 is provided with a solenoid valve 26 for local or remote control of the opening and closing of the pneumatic ball valve 26. The gas flow meter 6, the pressure gauge 10 and the temperature sensor 17 are connected to the data acquisition system 25 for real-time recording of the physical parameters of the mixing and standing process.

[0044] Embodiment 2

[0045] Based on the experimental device for testing the uneven distribution of hydrogen-doped natural gas provided in Example 1, this embodiment provides a testing method for testing the uneven distribution of hydrogen-doped natural gas, including the following steps:

[0046] Step 1: Connect the nitrogen cylinder 1, natural gas cylinder 2, hydrogen cylinder 3, pressure reducing valve 4, pneumatic ball valve 5, gas flow meter 6, gas storage tank 7, safety valve 8, first stop valve 9, pressure gauge 10, air inlet 11, first air outlet 12, second air outlet 13, third air outlet 14, fourth air outlet 15, sewage outlet 16, temperature sensor 17, second stop valve 18, third stop valve 19, fourth stop valve 20, fifth stop valve 21, sixth stop valve 22, main pipeline 23, sampling port 24, data acquisition system 25 and solenoid valve 26 as required;

[0047] Step 2: Perform effectiveness and circuit connection diagnostics checks on each instrument and equipment;

[0048] Step 3: Close the second stop valve 18, the third stop valve 19, the fourth stop valve 20, the fifth stop valve 21 and the sixth stop valve 22, open the nitrogen bottle 1, and after the pressure gauge 10 reaches a certain value, close the nitrogen bottle 1 and the first stop valve 9, and observe whether the value of the pressure gauge 10 decreases after standing for a period of time. If there is no decrease, it means that there is no leakage in the experimental device;

[0049] Step 4: Open the nitrogen bottle 1, the pneumatic ball valve 5, the first stop valve 9, the gas flow meter 6, the second stop valve 18, the third stop valve 19, the fourth stop valve 20, the fifth stop valve 21 and the sixth stop valve 22, and expel the experimental gas in the main pipeline 23 and the gas storage tank 7 to prevent the remaining experimental gas from affecting the experimental results;

[0050] Step 5: After the expulsion of the experimental gas is completed, close the second stop valve 18, the third stop valve 19, the fourth stop valve 20, the fifth stop valve 21 and the sixth stop valve 22, install the temperature sensor 17 and the sampling port 24 at the outlets of the second stop valve 18, the third stop valve 19, the fourth stop valve 20 and the fifth stop valve 21, open the natural gas cylinder 2 and fill it with natural gas of a certain pressure according to the pressure and hydrogen blending ratio required for the experiment, then close it, and then open the hydrogen cylinder 3 and fill it with a certain amount of hydrogen according to the partial pressure method, and record the values ​​of the pressure gauge 10 and the gas flow meter 6 in the data acquisition system 25 during this process;

[0051] Step 6: After the gas filling is completed, close the hydrogen cylinder 3, the pneumatic ball valve 5, and the first stop valve 9, disassemble the first stop valve 9 and the main pipeline 23, install the temperature sensor 17 and the sampling port 24 at the first stop valve 9, let the experimental gas stand, extract the hydrogen-blended natural gas from the sampling port 24 with a sampling bag at regular intervals for analysis, record the values ​​of the pressure gauge 10 and the temperature sensor 17 in the data acquisition system 25 in real time, and use a gas chromatograph to analyze the concentrations of natural gas and hydrogen in various parts;

[0052] Step 7: After the experiment is completed, repeat steps 4 to 6 to conduct experiments on the distribution of natural gas and hydrogen during the blending and standing processes at different pressures and hydrogen blending ratios.

[0053] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An experimental device for testing the uneven distribution of hydrogen-blended natural gas, characterized by: It comprises a gas cylinder assembly, a pressure reducing valve (4), a pneumatic ball valve (5), a gas flow meter (6), a gas storage tank assembly and a main pipeline (23); The outer side of the main pipeline (23) is connected in sequence with a pressure reducing valve (4), a pneumatic ball valve (5), a gas flow meter (6) and a gas storage tank assembly; The bottom end of the pressure reducing valve (4) is fixedly connected to a gas cylinder assembly.

2. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 1, characterized in that: The gas cylinder assembly comprises a nitrogen cylinder (1), a natural gas cylinder (2) and a hydrogen cylinder (3); the nitrogen cylinder (1), the natural gas cylinder (2) and the hydrogen cylinder (3) are all connected to a pressure reducing valve (4).

3. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 1, characterized in that: The gas storage tank assembly comprises a gas storage tank (7), a safety valve (8), an air inlet (11), a pressure gauge (10), a first air outlet (12), a second air outlet (13), a third air outlet (14), a fourth air outlet (15) and a sewage outlet (16); the top of the gas storage tank (7) is provided with a safety valve (8) and an air inlet (11); the safety valve (8) is located on one side of the air inlet (11); the end of the air inlet (11) away from the gas storage tank (7) is connected to a first section The gas inlet (11) is connected to the main pipeline (23) through a first stop valve (9), and the first stop valve (9) is used to cut off the flow of the experimental gas. One side of the gas storage tank (7) is provided with a first gas outlet (12), a second gas outlet (13), a third gas outlet (14) and a fourth gas outlet (15) from top to bottom. The bottom end of the gas storage tank (7) is provided with a sewage outlet (16), and the outer surface of the gas storage tank (7) is provided with a pressure gauge (10).

4. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 3, characterized in that: The first gas outlet (12), the second gas outlet (13), the third gas outlet (14), the fourth gas outlet (15) and the sewage outlet (16) are respectively provided with a second stop valve (18), a third stop valve (19), a fourth stop valve (20), a fifth stop valve (21) and a sixth stop valve (22), and the second stop valve (18), the third stop valve (19), the fourth stop valve (20), the fifth stop valve (21) and the sixth stop valve (22) are used to control the flow of the experimental gas.

5. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 4, characterized in that: A temperature sensor (17) and a sampling port (24) are provided at the outlets of the second stop valve (18), the third stop valve (19), the fourth stop valve (20) and the fifth stop valve (21); the temperature sensor (17) is used to monitor the temperature change in the gas storage tank (7), and the sampling port (24) is used to take out the experimental gas for analysis.

6. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 1, characterized in that: The pneumatic ball valve (5) is provided with a solenoid valve (26), and the solenoid valve (26) is used to control the opening and closing of the pneumatic ball valve (5) locally or remotely.

7. The experimental device for testing uneven distribution of hydrogen-blended natural gas according to claim 1, characterized in that: The invention also comprises a data acquisition system (25), wherein the gas flow meter (6), the pressure gauge (10) and the temperature sensor (17) are all connected to the data acquisition system (25) by telecommunication, and the data acquisition system (25) is used to record the physical property parameters of the mixing and static process in real time.

8. A method for using an experimental device for testing uneven distribution of hydrogen-doped natural gas, which is used for the experimental device for testing uneven distribution of hydrogen-doped natural gas as claimed in any one of claims 1 to 7, characterized in that: At least the following steps are included: Step 1: connect the gas cylinder assembly, the pressure reducing valve (4), the pneumatic ball valve (5), the gas flow meter (6), the gas storage tank assembly and the main pipeline (23) in sequence, and connect the gas flow meter (6), the pressure gauge (10) and the temperature sensor (17) to the data acquisition system (25); Step 2: Check whether each instrument and equipment is operating normally; Step 3: Check the air tightness of the pipeline; Step 4: Before the experiment begins, open the nitrogen bottle (1) to expel the gas in the main pipeline (23) and the gas storage tank (7) to prevent the remaining gas from affecting the experimental results; Step 5: After the gas is expelled, close the second stop valve (18), the third stop valve (19), the fourth stop valve (20), the fifth stop valve (21) and the sixth stop valve (22), install the temperature sensor (17), open the natural gas cylinder (2) and fill it with natural gas at a certain pressure according to the pressure and hydrogen blending ratio required by the experiment, then close it, and then open the hydrogen cylinder (3) and fill it with hydrogen at a certain pressure according to the partial pressure method; Step 6: After the gas filling is completed, close the hydrogen cylinder (3), the pneumatic ball valve (5) and the first stop valve (9), disassemble the first stop valve (9) and the main pipeline (23), let the experimental gas stand, extract hydrogen-blended natural gas from the sampling port (24) at regular intervals for analysis, and record the pressure and temperature changes in the data acquisition system (25) and the distribution of natural gas and hydrogen in real time. Step 7: After the experiment is completed, repeat steps 4 to 6 to conduct experiments on the distribution of natural gas and hydrogen during the blending and standing processes at different pressures and hydrogen blending ratios.

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