Automatic measuring device and measuring method for natural desorption amount of multi-path coal bed gas

Abstract

The automatic measuring device comprises coal sample desorption tanks arranged in corresponding temperature regulators, and a gas pipeline corresponding to each coal sample desorption tank is provided with an electromagnetic valve, an electromagnetic valve II, a pressure reducing valve, a speed regulating valve, a speed regulating valve, an electronic flowmeter I and an electronic flowmeter II. The control acquisition board is used for controlling the work of the corresponding temperature regulators, the automatic valves, the electromagnetic valves, the pressure reducing valves, the speed regulating valves and the electronic flow meters, so that the multi-path measurement of the natural desorption amount of the coal bed gas can be realized, and the multi-path measurement of the natural desorption amount of the coal bed gas can be realized on the premise that each path does not influence each other; control of all valves of a gas path and collection of flow data are synchronously achieved, the measuring efficiency of the natural desorption amount of the coal bed gas can be greatly improved, the whole process is automatic, and errors caused by traditional manual reading are reduced.

Description

Technical Field

[0001] The present invention relates to a device and process for measuring the natural desorption amount of coalbed methane, specifically an automatic measuring device for the natural desorption amount of multi-channel coalbed methane and its measuring method, belonging to the technical field of test equipment for measuring coalbed methane content. Background Technique

[0002] The content of coalbed methane is one of the key parameters characterizing the characteristics of coal reservoirs. Whether it is the calculation of coalbed methane resources, the prediction of the productivity of coalbed methane wells, the evaluation of resource development potential, the optimization of development target areas and the layout of well patterns in the exploration and development of coalbed methane resources, or the evaluation of the danger degree of coal seam gas, the prediction of mine gas emission, ventilation design and management, etc., the data of coalbed methane content must be used.

[0003] The natural desorption amount of coalbed methane is an important part of the coalbed methane content. At present, the drainage method is mostly used to read the desorption amount of coalbed methane, but the traditional drainage measuring cylinder has low precision and requires manual data reading, and the measuring process is cumbersome. When actually measuring the coalbed methane content, the direct desorption amount measurement time of a single coal sample exceeds 8 hours, and often multiple coal samples need to be measured simultaneously, which further increases the time and labor costs and is extremely prone to data reading errors. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic measuring device for the natural desorption amount of multi-channel coalbed methane and its measuring method. The device has a simple structure and high measuring precision, can measure the natural desorption amount of multi-channel coalbed methane on the premise that each channel does not affect each other, synchronously realize the control of each valve in the gas path and the acquisition of flow data, can greatly improve the measuring efficiency of the natural desorption amount of coalbed methane, and is fully automated in the whole process, reducing the error of traditional manual reading.

[0005] In order to achieve the above purpose, the present invention provides an automatic measuring device for the natural desorption amount of multi-channel coalbed methane, including coal sample desorption tank I, coal sample desorption tank II, and coal sample desorption tank III. The coal sample desorption tank I, coal sample desorption tank II, and coal sample desorption tank III are respectively placed in temperature regulator I, temperature regulator II, and temperature regulator II;

[0006] The coal sample desorption tank I is connected to one end of the automatic valve I through a gas pipeline. The other end of the automatic valve I is connected to one end of the solenoid valve I and the solenoid valve II respectively through a gas pipeline. The other end of the solenoid valve I is connected to a pressure reducing valve through a gas pipeline and then connected to one end of the speed regulating valve I. The other end of the solenoid valve II is connected to one end of the speed regulating valve II through a gas pipeline. The other ends of the speed regulating valve I and the speed regulating valve II are both connected to one end of the control and acquisition board. The other end of the control and acquisition board is connected to the exhaust port. The electronic flowmeter I and the electronic flowmeter II are placed in the control and acquisition board;

[0007] The coal sample desorption tank II is connected to one end of the automatic valve II through a gas pipeline. The coal sample desorption tank III is connected to one end of the automatic valve III through a gas pipeline. The other end of the automatic valve II is connected to one end of the solenoid valve III and the solenoid valve IV respectively through a gas pipeline. The other end of the automatic valve III is connected to one end of the solenoid valve V and the solenoid valve VI respectively through a gas pipeline. The other end of the solenoid valve III and the other end of the solenoid valve V are both connected to the inlet pipeline of the pressure reducing valve. The other end of the solenoid valve IV and the other end of the solenoid valve VI are both connected to the inlet pipeline of the speed regulating valve II;

[0008] The temperature regulators I, II, and III, the automatic valves I, II, and III, the solenoid valves I, II, III, IV, V, and VI, the pressure reducing valve, the speed regulating valves I and II, the electronic flow meters I and II are all connected to the control and acquisition board through electronic circuits.

[0009] The coal sample desorption tanks I, II, and III are all cylindrical, with a height of not less than 30 cm and a volume of not less than 1000 cm 3 , and can maintain airtightness under a pressure of 0.5 MPa.

[0010] The range of the electronic flow meter I is 0 - 1000 sccm, and the working pressure is 0 - 0.5 MPa. The range of the electronic flow meter II is 0 - 100 sccm, and the working pressure is 0 - 0.5 MPa.

[0011] The temperature adjustment ranges of the temperature regulators I, II, and III are 0 - 100 °C.

[0012] The range of the pressure reducing valve is 0 - 1.2 MPa.

[0013] A measurement method for an automated multi-channel coalbed methane natural desorption volume measurement device includes the following steps:

[0014] ① Drill a sampling borehole on the ground, place the obtained coal samples in each coal sample desorption tank, and ensure the airtightness inside the coal sample desorption tank;

[0015] ② Turn on the power of the measurement device, operate the control and acquisition board, and adjust the temperatures of the temperature regulators I, II, and III to the reservoir temperature of the coal samples;

[0016] ③ The control acquisition board controls to open the automatic valve I, and the coal sample desorption tank I starts to desorb. The control acquisition board controls to open the solenoid valve I, adjusts the pressure reducing valve to limit the pressure in the gas pipeline within the working pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed regulating valve I to limit the gas flow in the pipeline within the maximum range of the electronic flowmeter I, which is 1000 sccm. The control acquisition board collects and processes the data of the electronic flowmeter I. After the control acquisition board monitors that the gas flow in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve I to close and the solenoid valve II to open, adjusts the speed regulating valve II to limit the gas flow in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I. When the gas flow in the pipeline drops to 100 sccm, it collects and processes the data of the electronic flowmeter II. After the control acquisition board monitors that the gas flow in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve II to close and closes the automatic valve I, ending the measurement of the desorption volume of the coal sample desorption tank I and waiting for subsequent tests;

[0017] ④ The control acquisition board controls to open the automatic valve II, and the coal sample desorption tank II starts to desorb. The control acquisition board controls to open the solenoid valve III, adjusts the pressure reducing valve to limit the pressure in the gas pipeline within the working pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed regulating valve I to limit the gas flow in the pipeline within the maximum range of the electronic flowmeter I, which is 1000 sccm. The control acquisition board collects and processes the data of the electronic flowmeter I. After the control acquisition board monitors that the gas flow in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve III to close and the solenoid valve IV to open, adjusts the speed regulating valve II to limit the gas flow in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I. When the gas flow in the pipeline drops to 100 sccm, it collects and processes the data of the electronic flowmeter II. After the control acquisition board monitors that the gas flow in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve IV to close and closes the automatic valve II, ending the measurement of the desorption volume of the coal sample desorption tank II and waiting for subsequent tests;

[0018] ⑤ The control acquisition board controls the opening of the automatic valve III, and the coal sample desorption tank III starts desorption. The control acquisition board controls the opening of the solenoid valve V, adjusts the pressure reducing valve to limit the pressure in the gas pipeline within the working pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed control valve I to limit the gas flow in the pipeline within the maximum range of the electronic flowmeter I, which is 1000 sccm. The control acquisition board collects and processes the data of the electronic flowmeter I. After the control acquisition board monitors that the gas flow in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve V to close and the solenoid valve VI to open, adjusts the speed control valve II to limit the gas flow in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I. When the gas flow in the pipeline drops to 100 sccm, it collects and processes the data of the electronic flowmeter II. After the control acquisition board monitors that the gas flow in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve VI to close and closes the automatic valve III, ending the determination of the desorption volume of the coal sample desorption tank III and waiting for subsequent tests;

[0019] ⑥ Measure the desorption volume of the coal sample in the coal sample desorption tank I again according to step ③, measure the desorption volume of the coal sample in the coal sample desorption tank II again according to step ④, and measure the desorption volume of the coal sample in the coal sample desorption tank III again according to step ⑤. Through the control acquisition board, control the alternating tests of the coal sample desorption tank I, the coal sample desorption tank II, and the coal sample desorption tank III to achieve multiple channels. The control acquisition board controls the measurement time interval to ensure that each coal sample desorption tank is measured once within 5 minutes after the first filling, then measured 6 times within 1 hour at 10 - minute intervals, then measured 4 times within 1 hour at 15 - minute intervals, measured 2 times within 1 hour at 30 - minute intervals, then measured once at 60 - minute intervals, and finally measured 2 times at 120 - minute intervals, with a cumulative measurement of 8 hours. After continuous measurement for 8 hours, determine the desorption time interval according to the specific desorption flow rate, with a maximum not exceeding 24 hours;

[0020] ⑦ After the control acquisition board identifies that the average desorption volume of the natural desorption of each coal sample desorption tank for 7 consecutive days is not greater than 10 cm 3 , end the measurement and automatically analyze and export the measurement data.

[0021] The single - measurement time for each channel does not exceed 2 minutes; the opening and closing switching time of the automatic valves I, II, III, solenoid valves I, II, III, IV, V, and VI is less than 2 s; the acquisition frequency of the electronic flowmeters I and II is 1 hz, and the acquisition accuracy is 0.01 ml.

[0022] Compared with the prior art, in the present invention, three coal sample desorption tanks are respectively placed in temperature regulators, and the temperatures of the coal samples are set through the corresponding temperature regulators. Solenoid valves, solenoid valve II, pressure reducing valves, speed regulating valves, speed regulating valves, electronic flowmeter I, and electronic flowmeter II are respectively arranged on the gas pipelines corresponding to each coal sample desorption tank. The control acquisition board is used to control the operation of the corresponding temperature regulators, automatic valves, solenoid valves, pressure reducing valves, speed regulating valves, and electronic flowmeters, so as to realize the multi-channel measurement of the natural desorption amount of coalbed methane. The present invention can measure the natural desorption amount of multi-channel coalbed methane on the premise that each channel does not affect each other, synchronously realize the control of each valve in the gas path and the acquisition of flow data, can greatly improve the measurement efficiency of the natural desorption amount of coalbed methane, and is fully automated, reducing the error of traditional manual reading. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the working principle of the present invention.

[0024] In the figure: 1, Temperature regulator I; 2, Temperature regulator II; 3, Temperature regulator III; 4, Coal sample desorption tank I; 5, Coal sample desorption tank II; 6, Coal sample desorption tank III; 7, Automatic valve I; 8, Automatic valve II; 9, Automatic valve III; 10, Solenoid valve I; 11, Solenoid valve II; 12, Solenoid valve III; 13, Solenoid valve IV; 14, Solenoid valve V; 15, Solenoid valve VI; 16, Pressure reducing valve; 17, Speed regulating valve I; 18, Speed regulating valve II; 19, Control acquisition board; 20, Electronic flowmeter I; 21, Electronic flowmeter II; 22, Exhaust port. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] As Figure 1 shown, an automatic measuring device for the natural desorption amount of multi-channel coalbed methane includes a coal sample desorption tank I 4, a coal sample desorption tank II 5, and a coal sample desorption tank III 6. The coal sample desorption tank I 4, the coal sample desorption tank II 5, and the coal sample desorption tank III 6 are respectively placed in the temperature regulator I 1, the temperature regulator II 2, and the temperature regulator II 3;

[0027] One end of the coal sample desorption tank I 4 is connected to one end of the automatic valve I 7 through a gas pipeline. The other end of the automatic valve I 7 is respectively connected to one ends of the solenoid valve I 10 and the solenoid valve II 11 through a gas pipeline. The other end of the solenoid valve I 10 is connected to the pressure reducing valve 16 through a gas pipeline and then connected to one end of the speed regulating valve I 17. The other end of the solenoid valve II 11 is connected to one end of the speed regulating valve II 18 through a gas pipeline. The other ends of the speed regulating valve I 17 and the speed regulating valve II 18 are both connected to one end of the control acquisition board 19. The other end of the control acquisition board 19 is connected to the exhaust port 22. The electronic flowmeter I 20 and the electronic flowmeter II 21 are placed in the control acquisition board 19;

[0028] The coal sample desorption tank II 5 is connected to one end of the automatic valve II 8 through a gas pipeline. The coal sample desorption tank III 6 is connected to one end of the automatic valve III 9 through a gas pipeline. The other end of the automatic valve II 8 is connected to one ends of the solenoid valve III 12 and the solenoid valve IV 13 respectively through a gas pipeline. The other end of the automatic valve III 9 is connected to one ends of the solenoid valve V 14 and the solenoid valve VI 15 respectively through a gas pipeline. The other ends of the solenoid valve III 12 and the solenoid valve V 14 are both connected to the intake pipeline of the pressure reducing valve 16. The other ends of the solenoid valve IV 13 and the solenoid valve VI 15 are both connected to the intake pipeline of the speed regulating valve II 18;

[0029] The temperature regulator I 1, the temperature regulator II 2, the temperature regulator III 3, the automatic valve I 7, the automatic valve II 8, the automatic valve III 9, the solenoid valve I 10, the solenoid valve II 11, the solenoid valve III 12, the solenoid valve IV 13, the solenoid valve V 14, the solenoid valve VI 15, the pressure reducing valve 16, the speed regulating valve I 17, the speed regulating valve II 18, the electronic flowmeter I 20, and the electronic flowmeter II 21 are all connected to the control and acquisition board 19 through electronic circuits.

[0030] The coal sample desorption tanks I 4, II 5, and III 6 are all cylindrical, with a height of not less than 30 cm and a volume of not less than 1000 cm 3 , and can maintain airtightness under a pressure of 0.5 MPa.

[0031] The measuring range of the electronic flowmeter I 20 is 0 - 1000 sccm, and the working pressure is 0 - 0.5 MPa. The measuring range of the electronic flowmeter II 21 is 0 - 100 sccm, and the working pressure is 0 - 0.5 MPa.

[0032] The temperature adjustment ranges of the temperature regulator I 1, the temperature regulator II 2, and the temperature regulator III 3 are 0 - 100 °C.

[0033] The measuring range of the pressure reducing valve 16 is 0 - 1.2 MPa.

[0034] A measuring method for an automatic measuring device for the natural desorption amount of multi-channel coalbed methane includes the following steps:

[0035] ① Drill a sampling borehole on the ground, place the obtained coal samples in each coal sample desorption tank, and ensure the airtightness inside the coal sample desorption tank;

[0036] ② Turn on the power of the measuring device, operate the control and acquisition board 19, and adjust the temperatures of the temperature regulator I 1, the temperature regulator II 2, and the temperature regulator III 3 to the reservoir temperature of the coal samples;

[0037] ③The control acquisition board 19 controls the opening of the automatic valve I 7, and the coal sample desorption tank I 4 starts desorption. The control acquisition board 19 controls the opening of the solenoid valve I 10, adjusts the pressure reducing valve 16 to limit the pressure in the gas pipeline within the operating pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed control valve I 17 to limit the gas flow rate in the pipeline within the maximum range of the electronic flowmeter I 20, which is 1000 sccm. The control acquisition board 19 collects and processes the data of the electronic flowmeter I 20. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve I 10 to close and the solenoid valve II 11 to open, adjusts the speed control valve II 18 to limit the gas flow rate in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I 20. When the gas flow rate in the pipeline decreases to 100 sccm, it collects and processes the data of the electronic flowmeter II 21. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve II 11 to close and closes the automatic valve I 7, ending the measurement of the desorption amount of the coal sample desorption tank I 4 and waiting for subsequent tests;

[0038] ④The control acquisition board 19 controls the opening of the automatic valve II 8, and the coal sample desorption tank II 5 starts desorption. The control acquisition board 19 controls the opening of the solenoid valve III 12, adjusts the pressure reducing valve 16 to limit the pressure in the gas pipeline within the operating pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed control valve I 17 to limit the gas flow rate in the pipeline within the maximum range of the electronic flowmeter I 20, which is 1000 sccm. The control acquisition board 19 collects and processes the data of the electronic flowmeter I 20. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve III 12 to close and the solenoid valve IV 13 to open, adjusts the speed control valve II 18 to limit the gas flow rate in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I 20. When the gas flow rate in the pipeline decreases to 100 sccm, it collects and processes the data of the electronic flowmeter II 21. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve IV 13 to close and closes the automatic valve II 8, ending the measurement of the desorption amount of the coal sample desorption tank II 5 and waiting for subsequent tests;

[0039] ⑤ The control acquisition board 19 controls the opening of the automatic valve III 9, and the coal sample desorption tank III 6 starts desorption. The control acquisition board 19 controls the opening of the solenoid valve V 14, adjusts the pressure reducing valve 16 to limit the pressure in the gas pipeline within the operating pressure of the electronic flowmeter, which is 0 - 0.5 MPa, and adjusts the speed control valve I 17 to limit the gas flow rate in the pipeline within the maximum range of the electronic flowmeter I 20, which is 1000 sccm. The control acquisition board 19 collects and processes the data of the electronic flowmeter I 20. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 150 sccm for more than 2 s, it controls the solenoid valve V 14 to close and the solenoid valve VI 15 to open, adjusts the speed control valve II 18 to limit the gas flow rate in the pipeline within 1000 sccm, collects and processes the data of the electronic flowmeter I 20. When the gas flow rate in the pipeline drops to 100 sccm, it collects and processes the data of the electronic flowmeter II 21. After the control acquisition board 19 monitors that the gas flow rate in the pipeline is lower than 5 sccm for more than 2 s, it controls the solenoid valve VI 15 to close and closes the automatic valve III 9, ending the determination of the desorption volume of the coal sample desorption tank III 6 and waiting for subsequent tests;

[0040] ⑥ Measure the desorption volume of the coal sample in the coal sample desorption tank I 4 again according to step ③, measure the desorption volume of the coal sample in the coal sample desorption tank II 5 again according to step ④, and measure the desorption volume of the coal sample in the coal sample desorption tank III 6 again according to step ⑤. By controlling the control acquisition board 19 to control the coal sample desorption tanks I 4, II 5, and III 6 to perform alternating tests, multiplexing is achieved; the control acquisition board 19 controls the measurement time interval to ensure that each coal sample desorption tank is measured once within 5 min after the first loading, and then measured 6 times at 10 - min intervals for 1 h, then measured 4 times at 15 - min intervals for 1 h, measured 2 times at 30 - min intervals for 1 h, then measured once at 60 - min intervals, and finally measured 2 times at 120 - min intervals, with a cumulative measurement of 8 h. After continuously measuring for 8 h, determine the desorption time interval according to the specific desorption flow rate, with a maximum not exceeding 24 h;

[0041] ⑦ After the control acquisition board 19 identifies that the average desorption volume of the natural desorption of each coal sample desorption tank for 7 consecutive days is not greater than 10 cm 3 the measurement ends, and the measurement data is automatically analyzed and exported.

[0042] The single - measurement time for each path does not exceed 2 min; the opening and closing switching time of the automatic valve I 7, automatic valve II 8, automatic valve III 9, solenoid valve I 10, solenoid valve II 11, solenoid valve III 12, solenoid valve IV 13, solenoid valve V 14, and solenoid valve VI 15 is less than 2 s; the acquisition frequency of the electronic flowmeter I 20 and electronic flowmeter II 21 is 1 hz, and the acquisition accuracy is 0.01 ml.

[0043] Embodiment

[0044] ① Drill sampling holes during ground construction. Place the three groups of coal samples obtained into each coal sample desorption tank, ensuring the airtightness of the tank.

[0045] ② Turn on the power of the measuring device. Operate and control the acquisition board 19, and adjust the temperature of each temperature regulator to the reservoir temperature of the coal sample, which is 35°C.

[0046] ③ Control the acquisition board 19 to control the opening of the automatic valve I 7. The coal sample desorption tank I 4 starts to desorb. Control the acquisition board 19 to control the opening of the solenoid valve I 10. The pressure reducing valve 16 and the speed regulating valve I 17 automatically adjust the pressure and gas flow in the pipeline. Control the acquisition board 19 to collect and process the data of the electronic flowmeter I 20. After reaching the switching threshold, control the acquisition board 19 to control the closing of the solenoid valve I 10 and the opening of the solenoid valve II 11. The speed regulating valve II 11 adjusts the gas flow in the pipeline. According to the flow value, control the acquisition board 19 to collect and process the data of the electronic flowmeter I 20 and the electronic flowmeter II 21. When the gas flow in the pipeline is lower than 5 sccm for more than 2 s, control the acquisition board 19 to control the closing of the solenoid valve II 11 within 2 s and close the automatic valve I 7, ending the measurement of the desorption volume of the coal sample desorption tank I 4. Control the acquisition board 19 to calculate the total desorption volume of this test, which is 91.91 ml.

[0047] ④ Control the acquisition board 19 to control the opening of the automatic valve II 8. The coal sample desorption tank II 5 starts to desorb. Control the acquisition board 19 to control the opening of the solenoid valve III 12. The pressure reducing valve 16 and the speed regulating valve I 17 automatically adjust the pressure and gas flow in the pipeline. Control the acquisition board 19 to collect and process the data of the electronic flowmeter I 20. After reaching the switching threshold, control the acquisition board 19 to control the closing of the solenoid valve III 12 and the opening of the solenoid valve IV 13. The speed regulating valve II 18 adjusts the gas flow in the pipeline. According to the flow value, control the acquisition board 19 to collect and process the data of the electronic flowmeter I 20 and the electronic flowmeter II 21. When the gas flow in the pipeline is lower than 5 sccm for more than 2 s, control the acquisition board 19 to control the closing of the solenoid valve IV 13 within 2 s and close the automatic valve II 8, ending the measurement of the desorption volume of the coal sample desorption tank II 5. Control the acquisition board 19 to calculate the total desorption volume of this test, which is 95.21 ml.

[0048] ⑤ The control acquisition board 19 controls the opening of the automatic valve III 9, and the coal sample desorption tank III 6 starts desorbing. The control acquisition board 19 controls the opening of the solenoid valve V 14. The pressure reducing valve 16 and the speed regulating valve I 17 automatically adjust the pressure and gas flow rate in the pipeline. The control acquisition board 19 collects and processes the data of the electronic flowmeter I 20. After reaching the switching threshold, the control acquisition board 19 controls the closing of the solenoid valve V 14 and the opening of the solenoid valve VI 15. The speed regulating valve II 18 adjusts the gas flow rate in the pipeline. According to the flow rate value, the control acquisition board 19 collects and processes the data of the electronic flowmeter I 20 and the electronic flowmeter II 21. When the gas flow rate in the pipeline is lower than 5 sccm for more than 2 s, the control acquisition board 19 controls the closing of the solenoid valve VI 15 within 2 s, closes the automatic valve III 9, and ends the measurement of the desorption amount of the coal sample desorption tank III 6. The control acquisition board 19 calculates the total desorption amount of this test to be 94.23 ml;

[0049] ⑥ After the first measurement of each coal sample desorption tank is completed, the control acquisition board 19 controls the measurement time interval to alternately test each coal sample desorption tank. The control acquisition board 19 collects and records the single desorption amount and calculates the cumulative desorption amount;

[0050] ⑦ For the coal sample desorption tank I 4, following the process of step ③, it is tested 6 times at 10 - minute intervals, obtaining a cumulative desorption amount of 510.96 ml. Then it is tested 4 times at 15 - minute intervals, obtaining a cumulative desorption amount of 783.47 ml. Then it is tested 2 times at 30 - minute intervals, obtaining a cumulative desorption amount of 1032.88 ml. Then it is tested 1 time at 60 - minute intervals, obtaining a cumulative desorption amount of 1244.44 ml. Finally, it is measured 2 times at 120 - minute intervals, obtaining a cumulative desorption amount of 1902.54 ml;

[0051] ⑧ For the coal sample desorption tank II 5, following the process of step ④, it is tested 6 times at 10 - minute intervals, obtaining a cumulative desorption amount of 490.86 ml. Then it is tested 4 times at 15 - minute intervals, obtaining a cumulative desorption amount of 766.51 ml. Then it is tested 2 times at 30 - minute intervals, obtaining a cumulative desorption amount of 997.62 ml. Then it is tested 1 time at 60 - minute intervals, obtaining a cumulative desorption amount of 1178.49 ml. Finally, it is measured 2 times at 120 - minute intervals, obtaining a cumulative desorption amount of 1734.94 ml;

[0052] ⑨ For the coal sample desorption tank III 6, following the process of step ⑤, it is tested 6 times at 10 - minute intervals, obtaining a cumulative desorption amount of 502.55 ml. Then it is tested 4 times at 15 - minute intervals, obtaining a cumulative desorption amount of 775.58 ml. Then it is tested 2 times at 30 - minute intervals, obtaining a cumulative desorption amount of 1013.32 ml. Then it is tested 1 time at 60 - minute intervals, obtaining a cumulative desorption amount of 1192.56 ml. Finally, it is measured 2 times at 120 - minute intervals, obtaining a cumulative desorption amount of 1874.78 ml;

[0053] ⑩ After each coal sample desorption tank has been measured for 8 hours, the desorption volume data is measured once every 24 hours. When the control acquisition board 19 recognizes that the average desorption volume of the natural desorption of each coal sample desorption tank for 7 consecutive days is not greater than 10 cm 3 , the measurement of the natural desorption volume ends, and the measurement data is automatically analyzed and exported. Finally, the cumulative desorption volume of the coal sample desorption tank I 4 is 3210.56 ml, the cumulative desorption volume of the coal sample desorption tank II 5 is 3024.78 ml, and the cumulative desorption volume of the coal sample desorption tank III 6 is 3182.49 ml.

Claims

1. A multi-channel coalbed methane natural desorption amount automatic measuring device, comprising a coal sample desorption tank I (4), a coal sample desorption tank II (5), and a coal sample desorption tank III (6), wherein the coal sample desorption tank I (4), the coal sample desorption tank II (5), and the coal sample desorption tank III (6) are respectively placed in a temperature regulator I (1), a temperature regulator II (2), and a temperature regulator II (3); It is characterized in that The coal sample desorption tank I (4) is connected to one end of the automatic valve I (7) through a gas pipeline, the other end of the automatic valve I (7) is connected to one end of the electromagnetic valve I (10) and one end of the electromagnetic valve II (11) through a gas pipeline, the other end of the electromagnetic valve I (10) is connected to the pressure reducing valve (16) through a gas pipeline and then connected to one end of the speed regulating valve I (17), the other end of the electromagnetic valve II (11) is connected to one end of the speed regulating valve II (18) through a gas pipeline, the other end of the speed regulating valve I (17) and the other end of the speed regulating valve II (18) are both connected to one end of the control acquisition board (19), the other end of the control acquisition board (19) is connected to the exhaust port (22), and the electronic flow meter I (20) and the electronic flow meter II (21) are placed in the control acquisition board (19); The coal sample desorption tank II (5) is connected to one end of the automatic valve II (8) through a gas pipeline, the coal sample desorption tank III (6) is connected to one end of the automatic valve III (9) through a gas pipeline, the other end of the automatic valve II (8) is connected to one end of the electromagnetic valve III (12) and the electromagnetic valve IV (13) through a gas pipeline, the other end of the automatic valve III (9) is connected to one end of the electromagnetic valve V (14) and the electromagnetic valve VI (15) through a gas pipeline, the other end of the electromagnetic valve III (12) and the other end of the electromagnetic valve V (14) are connected to the air inlet pipeline of the pressure reducing valve (16), the other end of the electromagnetic valve IV (13) and the other end of the electromagnetic valve VI (15) are connected to the air inlet pipeline of the speed regulating valve II (18); The temperature regulator I (1), the temperature regulator II (2), the temperature regulator III (3), the automatic valve I (7), the automatic valve II (8), the automatic valve III (9), the solenoid valve I (10), the solenoid valve II (11), the solenoid valve III (12), the solenoid valve IV (13), the solenoid valve V (14), the solenoid valve VI (15), the pressure reducing valve (16), the speed regulating valve I (17), the speed regulating valve II (18), the electronic flow meter I (20), and the electronic flow meter II (21) are all connected to the control acquisition board (19) through electronic circuits.

2. A multi-channel coalbed methane natural desorption amount automatic measuring device according to claim 1, characterized in that: The coal sample desorption tank I (4), coal sample desorption tank II (5), and coal sample desorption tank III (6) are all cylindrical, with a height of not less than 30 cm and a volume of not less than 1000 cm. 3 , able to maintain airtightness under 0.5MPa pressure.

3. A multi-channel coalbed methane natural desorption amount automatic measuring device according to claim 2, characterized in that: The range of the electronic flow meter I (20) is 0-1000 sccm, and the working pressure is 0-0.5 MPa. The range of the electronic flow meter II (21) is 0-100 sccm, and the working pressure is 0-0.5 MPa.

4. The multi-channel coalbed methane natural desorption amount automatic measuring device according to claim 2 is characterized in that: The temperature adjustment range of the temperature regulator I (1), the temperature regulator II (2), and the temperature regulator III (3) is 0-100°C.

5. The multi-channel coalbed methane natural desorption amount automatic measuring device according to claim 2 is characterized in that: The range of the pressure reducing valve (16) is 0-1.2 MPa.

6. A method for measuring the amount of natural desorption of coalbed methane using a multi-channel automatic measuring device, characterized in that: The following steps are involved: ① Drill sampling holes on the ground and place the coal samples in each coal sample desorption tank to ensure the air tightness of the coal sample desorption tank; ② Turn on the power of the measuring device, operate the control acquisition board (19), and adjust the temperature of the temperature regulator I (1), the temperature regulator II (2), and the temperature regulator III (3) to the reservoir temperature of the coal sample; ③ The control acquisition board (19) controls the opening of the automatic valve I (7), and the coal sample desorption tank I (4) starts to desorb. The control acquisition board (19) controls the electromagnetic valve I (10) to open, and adjusts the pressure reducing valve (16) to limit the pressure in the gas pipeline to the working pressure of the electronic flow meter 0-0.5MPa, and adjusts the speed regulating valve I (17) to limit the gas flow in the pipeline to the maximum range of 1000sccm of the electronic flow meter I (20). The control acquisition board (19) collects and processes the data of the electronic flow meter I (20); the control acquisition board (19) detects that the gas flow in the pipeline is less than 150sccm m exceeds 2s, the electromagnetic valve I (10) is controlled to close and the electromagnetic valve II (11) is opened, and the speed regulating valve II (18) is adjusted to limit the gas flow in the pipeline to 1000sccm, and the data of the electronic flow meter I (20) is collected and processed. When the gas flow in the pipeline is reduced to 100sccm, the data of the electronic flow meter II (21) is collected and processed; after the control acquisition board (19) monitors that the gas flow in the pipeline is less than 5sccm for more than 2s, the electromagnetic valve II (11) is controlled to close, and the automatic valve I (7) is closed, and the desorption amount measurement of the coal sample desorption tank I (4) is terminated, and the subsequent test is waited for; ④ The control acquisition board (19) controls the opening of the automatic valve II (8), and the coal sample desorption tank II (5) starts to desorb. The control acquisition board (19) controls the electromagnetic valve III (12) to open, and adjusts the pressure reducing valve (16) to limit the pressure in the gas pipeline to the working pressure of the electronic flow meter 0-0.5MPa, and adjusts the speed regulating valve I (17) to limit the gas flow in the pipeline to the maximum range of 1000sccm of the electronic flow meter I (20). The control acquisition board (19) collects and processes the data of the electronic flow meter I (20); the control acquisition board (19) detects that the gas flow in the pipeline is less than 150sccm m exceeds 2s, the electromagnetic valve III (12) is controlled to close and the electromagnetic valve IV (13) is opened, and the speed regulating valve II (18) is adjusted to limit the gas flow in the pipeline to 1000sccm, and the data of the electronic flow meter I (20) is collected and processed. When the gas flow in the pipeline is reduced to 100sccm, the data of the electronic flow meter II (21) is collected and processed; after the control acquisition board (19) monitors that the gas flow in the pipeline is less than 5sccm for more than 2s, the electromagnetic valve IV (13) is controlled to close, and the automatic valve II (8) is closed, and the desorption amount measurement of the coal sample desorption tank II (5) is terminated, and the subsequent test is waited for; ⑤ The control acquisition board (19) controls the opening of the automatic valve III (9), and the coal sample desorption tank III (6) starts to desorb. The control acquisition board (19) controls the electromagnetic valve V (14) to open, and adjusts the pressure reducing valve (16) to limit the pressure in the gas pipeline to the working pressure of the electronic flow meter 0-0.5MPa, and adjusts the speed regulating valve I (17) to limit the gas flow in the pipeline to the maximum range of 1000sccm of the electronic flow meter I (20). The control acquisition board (19) collects and processes the data of the electronic flow meter I (20); the control acquisition board (19) detects that the gas flow in the pipeline is less than 150sccm m exceeds 2s, the electromagnetic valve V (14) is controlled to close and the electromagnetic valve VI (15) is opened, and the speed regulating valve II (18) is adjusted to limit the gas flow in the pipeline to 1000sccm, and the data of the electronic flow meter I (20) is collected and processed. When the gas flow in the pipeline is reduced to 100sccm, the data of the electronic flow meter II (21) is collected and processed; after the control acquisition board (19) detects that the gas flow in the pipeline is less than 5sccm for more than 2s, the electromagnetic valve VI (15) is controlled to close, and the automatic valve III (9) is closed, and the desorption amount measurement of the coal sample desorption tank III (6) is terminated, and the subsequent test is waited for; ⑥ According to step ③, the desorption amount of the coal sample in the coal sample desorption tank Ⅰ (4) is measured again, according to step ④, the desorption amount of the coal sample in the coal sample desorption tank Ⅱ (5) is measured again, according to step ⑤, the desorption amount of the coal sample in the coal sample desorption tank Ⅲ (6) is measured again, and the control acquisition board (19) controls the coal sample desorption tank Ⅰ (4), the coal sample desorption tank Ⅱ (5), and the coal sample desorption tank Ⅲ (6) to be tested alternately to achieve multi-channel; the control acquisition board (19) controls the measurement time interval to ensure that each coal sample desorption tank is measured once within 5 minutes of the first tank filling, and then measured 6 times at a 10-minute interval for a full hour, and then measured 4 times at a 15-minute interval for a full hour, and then measured 2 times at a 30-minute interval for a full hour, and then measured once at a 60-minute interval, and finally measured twice at a 120-minute interval, for a total of 8 hours. After continuous measurement for 8 hours, the desorption time interval is determined according to the specific desorption flow rate, and the longest time shall not exceed 24 hours; ⑦ The control acquisition board (19) identifies the natural desorption volume of each coal sample desorption tank. The average desorption volume for 7 consecutive days is not more than 10cm 3 After that, the measurement is finished and the measurement data is automatically analyzed and exported.

7. The method for measuring the amount of natural desorption of coalbed methane by a multi-channel automatic measuring device according to claim 6, characterized in that: The single measurement time of each channel does not exceed 2 minutes; the opening and closing switching time of automatic valve Ⅰ(7), automatic valve Ⅱ(8), automatic valve Ⅲ(9), solenoid valve Ⅰ(10), solenoid valve Ⅱ(11), solenoid valve Ⅲ(12), solenoid valve Ⅳ(13), solenoid valve Ⅴ(14) and solenoid valve Ⅵ(15) is less than 2 seconds; the collection frequency of electronic flow meter Ⅰ(20) and electronic flow meter Ⅱ(21) is 1 Hz, and the collection accuracy is 0.01 ml.

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