An experimental device for inhibiting gas desorption by synergistic action of surfactant and magnetization

Abstract

The invention discloses an experimental device for inhibiting gas desorption by synergistic action of a surfactant and magnetization. The experimental device mainly consists of five parts, including a vacuum degassing system, a high-pressure gas charging system, a magnetized water injection system, a coal body gas desorption measurement system and a computer control system. The experimental device can quantitatively inject magnetized water into coal bodies that have adsorbed gas, simulate water injection on-site in a coal mine in a laboratory to inhibit gas desorption, and monitor parameters such as gas pressure in real time during the experiment. The experimental results can be used to study the influence of magnetized water on coal body gas desorption, so as to provide a scientific basis and theoretical foundation for preventing gas disasters.

Description

Technical Field

[0001] The invention relates to an experimental device for inhibiting gas desorption by synergistic action of a surfactant and magnetization, and relates to the technical field of coal mining. Background Art

[0002] Gas over-limit is one of the main causes of gas accidents. Analysis of the source of gas outburst in the working face shows that coal falling is the main reason for the gas concentration over-limit in the general working face. Therefore, how to reduce this part of gas outburst has become the focus of preventing gas over-limit in the working face. The research results show that after water injection into the coal seam, the gas content and gas pressure gradient of the coal seam decrease, and water enters the cracks and microcracks of the coal seam through seepage diffusion and blocks them, and the gas desorption amount and desorption rate are reduced.

[0003] In order to reduce or eliminate the gas hazards in the coal mining process, before coal seam mining, coal seam water injection, hydraulic punching, hydraulic flushing, hydraulic cutting, hydraulic fracturing and hydraulic extrusion are generally used to treat the mined coal seams. However, the surface free energy of most coal seams in my country is low and the water permeability is poor. This feature makes it difficult for water to evenly wet the coal body, and the inhibitory effect of water injection on gas desorption is not obvious. In order to improve the wetting properties of the coal body, many scholars have adopted the method of adding surfactants or magnetizing water during the water injection process. At present, the research on the influencing factors of gas desorption by relevant scholars at home and abroad mainly focuses on single influencing factors such as water. There are few reports on the comprehensive effects of reagents on coal gas desorption amount, desorption rate, etc. under different temperature, pressure and other conditions from the perspective of inhibiting or promoting gas desorption. The synergistic effect of reagents and magnetization is rarely involved, and the corresponding supporting technologies and systems need to be further developed.

[0004] In order to overcome the above-mentioned defects, the applicant has independently developed a test bench to study the influence of the synergistic effect of surfactants and magnetization on the amount of coal gas desorption, gas desorption rate and gas diffusion, analyze the influence of different liquids on the coal gas desorption performance, and reveal the control mechanism of reagents on the inhibition or promotion of coal gas, prevent the problem of excessive gas concentration in the working face and reduce the risk of coal seam outbursts, providing a certain basis for safe production in coal mines. Summary of the invention

[0005] The general devices for adding liquid in the laboratory usually add liquid first and then degas, or add liquid at low pressure first and then fill with high-pressure gas. These will cause water to be lost during the degassing process, affecting the accuracy of the experimental results. The amount of added liquid cannot be accurately controlled, and the required experimental requirements cannot be met. The laboratory environment consistent with the underground conditions cannot be truly achieved. In addition, the problem of uneven liquid addition in the coal sample tank has not been effectively solved. In the process of magnetized water research, most laboratory research uses static magnetization to prepare it, and this magnetization method is not effective in improving the performance of the solution. More importantly, static magnetization is more suitable for related testing and research in the laboratory, and its magnetized water preparation efficiency is low. Due to the large demand for active magnetized water in industrial applications, static magnetization cannot meet it well.

[0006] The purpose of the present invention is to provide a device for real-time monitoring of comprehensive parameters of coal gas desorption during liquid injection, analyze the influence of the synergistic effect of liquid injection and magnetization on coal gas desorption and diffusion, and provide a theoretical basis for preventing gas disasters.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The invention discloses an experimental device for inhibiting gas desorption by synergistic action of surfactant and magnetization.

[0009] The experimental device comprises a vacuum degassing system, a high-pressure gas charging system, a magnetized water injection system, a coal gas desorption system and a computer control system; the vacuum degassing system and the high-pressure gas charging system work together to form the front end of the experimental device, providing the required vacuum environment and high-pressure environment for the experiment; the magnetized water injection system is connected to the high-pressure gas charging system through a water injection pipeline, and after reaching adsorption equilibrium, liquid is added to the coal in the adsorption state; the coal gas desorption system provides a desorption space for the coal sample that has reached adsorption equilibrium; the computer control system collects data during the experiment, transmits it to the computer, and calculates the coal gas desorption amount;

[0010] The vacuum degassing system includes a vacuum pump, a pressure gauge, a degassing pipeline and a valve. The vacuum pump is responsible for pumping gas to provide a vacuum environment for the system, and the pressure gauge displays the pipeline gas pressure in real time.

[0011] The high-pressure inflation system includes a high-pressure gas bottle, a high-pressure helium bottle, a buffer tank, a coal sample tank, a reference tank, an inflation pipeline, a high-precision pressure sensor, and a valve. The gas outlets of the high-pressure gas bottle and the high-pressure helium bottle are provided with a pressure reducing valve and a pressure reducing valve. The buffer tank is provided with a pressure gauge and a valve. The high-pressure helium bottle provides the required gas for the test, the reference tank is used to calibrate the volume of the coal sample tank, the buffer tank temporarily stores gas, and the pressure sensor monitors the vacuum degree of the system in real time. The system mainly provides a high-pressure environment for the coal sample tank, so that the coal sample reaches adsorption equilibrium, calibrates the volume of the coal sample tank, and checks the air tightness of the overall device.

[0012] The magnetized water injection system comprises a permanent magnet, a Gauss meter, a mass flow meter, a booster metering pump, a water tank, and a coal sample tank. The permanent magnet is connected to the Gauss meter. The water tank forms a magnetization pipeline through a booster metering pump, a valve, a pressure gauge, a valve, a mass flow meter, a valve, and a permanent magnet. The water tank forms a water injection pipeline through a booster metering pump, a valve, a pressure gauge, a valve, a mass flow meter, and a valve. Both the magnetization pipeline and the water injection pipeline can be connected to the coal sample tank through a one-way valve. The liquid in the water tank is pressurized and injected into the coal sample tank through a booster metering pump. The permanent magnet provides a relatively stable magnetic field environment for the system. The magnetic field strength required for the test is adjusted by a Gauss meter, and the injection amount and injection rate are controlled by a mass flow meter. The system is mainly designed for adding liquid to a coal body with a certain pressure, i.e., a coal body in an adsorbed state, after reaching adsorption equilibrium. Specifically, the required liquid is injected into the coal body after adsorption equilibrium through a booster metering pump to achieve the purpose of high-pressure injection. Liquid passing through the magnetization pipeline can also be injected into the coal body in adsorption equilibrium to achieve the purpose of synergistic effect of magnetization and injection.

[0013] The coal gas desorption system comprises a water bath space, a gas collecting device, a measuring cylinder, and a valve. The water bath space comprises a temperature sensor, a heating rod, a stirrer, a reference tank, a desorption tank, a coal sample tank, and a high-precision pressure sensor. A coal powder filter is arranged at the inlet of the coal sample tank, and a coal powder filter and a high-precision pressure sensor are arranged at the outlet to be connected with a data acquisition device. The other end of the coal sample tank outlet is controlled by a valve. One end of the valve is connected to the valve, the gas collecting device and the measuring cylinder, and the other end is connected to the valve and the desorption tank. The water bath space provides a constant temperature test environment for water bath heating for the test device, and the coal powder filter is used to prevent fine coal powder from being sucked into the system to affect the air tightness of the system. The system mainly provides a desorption space for the coal sample that has reached adsorption equilibrium, and records the pressure change of the gas gas over time during the desorption process, and finally obtains the gas desorption characteristic curve of the coal body.

[0014] The computer control system is composed of a circuit, a data acquisition device, a USB data connection line, and a system computer. The data during the test is collected by the data acquisition device, transmitted to the computer, and the coal gas desorption amount is calculated.

[0015] The technical effects of the present invention are as follows:

[0016] This set of experimental equipment can quantitatively inject magnetized water into the coal body that has adsorbed gas, simulate the on-site water injection in the coal mine to inhibit gas desorption in the laboratory, and monitor the gas pressure and other parameters in real time during the experiment. The test results can be used to study the influence of magnetized water on gas desorption in the coal body. The experimental equipment can prepare magnetized liquid through the above process, and conduct real-time and continuous monitoring of the comprehensive parameters of the coal sample adsorption and desorption process during the injection process, and analyze the synergistic effect of magnetization and injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the overall diagram of the experimental device;

[0018] 1- High-pressure gas bottle 2- High-pressure helium bottle 3- Buffer tank 4- First pressure gauge 5- Vacuum pump 6- Temperature sensor 7- Heating rod 8- Agitator 9- Reference tank 10- Desorption tank 11- Coal sample tank 12- High-precision pressure sensor 13- First coal powder filter 14- Second coal powder filter 15- One-way valve 16- Data acquisition device 17- Water bath space 18- Permanent magnet 19- Gauss meter 20- Mass flow meter 21- Second pressure gauge 22- Booster metering pump 23- Water tank 24- Gas collection device 25- Measuring cylinder 26- First valve 27- Second valve 28- Third valve 29- Fourth valve 30- Fifth valve 31- Sixth valve 32- Seventh valve 33- Eighth valve 34- Ninth valve 35- Tenth valve 36- Eleventh valve 37- Twelfth valve 38- First pressure reducing valve 39- Second pressure reducing valve DETAILED DESCRIPTION

[0019] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0021] In this embodiment, the data used are preferred solutions, but are not used to limit the present invention;

[0022] like Figure 1 As shown, this embodiment provides an experimental device for suppressing gas desorption by synergistic action of surfactant and magnetization, the device comprising a vacuum degassing system, a high-pressure gas charging system, a magnetized water injection system, a coal gas desorption system and a computer control system;

[0023] The vacuum degassing system is mainly used to provide the required vacuum environment for the test and to desorb the residual gas in the raw coal;

[0024] The high-pressure gas filling system mainly provides a high-pressure environment for the coal sample tank, so that the coal sample reaches adsorption equilibrium, calibrates the volume of the coal sample tank, and checks the air tightness of the overall device;

[0025] The magnetized water injection system is mainly designed for adding liquid to a coal body with a certain pressure, i.e., a coal body in an adsorption state, after reaching adsorption equilibrium. Specifically, the required liquid is injected into the coal body after adsorption equilibrium through a booster metering pump to achieve the purpose of high-pressure injection; liquid can also be injected into the coal body in adsorption equilibrium through a magnetized pipeline to achieve the purpose of synergistic effect of magnetization and injection;

[0026] The coal gas desorption system mainly provides a desorption space for the coal sample that has reached adsorption equilibrium, and records the pressure change of the gas over time during the desorption process, and finally obtains the gas desorption characteristic curve of the coal body;

[0027] The computer control system collects data from the test process through the data acquisition device 16, transmits the data to the computer, and calculates the coal gas desorption amount.

[0028] In this embodiment, before the test, the coal sample is vacuum dried at 60°C for 12 hours to remove moisture and some impurities therein, and then put into a coal sample cup, and then the coal sample cup is put into the coal sample tank 11, and the coal sample cover is tightened;

[0029] After the sample is loaded, turn on the water bath heating device to heat the temperature to the test condition, open all valves in the system, fill the entire test system with helium with a certain pressure, close the third inflation valve 28, and observe and detect whether the value displayed by the high-precision pressure sensor 12 changes;

[0030] After the air tightness inspection of the test pipeline is qualified, the calibration gas (helium) of a certain pressure injected into the buffer tank 3 in advance is injected into the coal sample tank 11, and the volume of the free space is calculated; the whole pipeline of the test bench is degassed, and the degassing time is stopped after reaching the degassing time set in the test;

[0031] Connect the coal sample tank 11 and the buffer tank 3, fill the buffer tank 3 with gas of a certain pressure, then open the valve 32 of the coal sample tank 11, fill the gas in the buffer tank 3 into the coal sample tank 11, and wait for the adsorption equilibrium in the coal sample tank 11;

[0032] When the coal sample reaches the adsorption equilibrium state, the one-way valve 15 and the booster metering pump 22 of the coal sample tank 11 are opened, and the agitator 8 on the coal sample tank 11 starts to work. When the magnetized liquid is injected, the ninth valve 34 is opened, and the liquid enters between the two poles of the permanent magnet 18 through the S-shaped pipeline, repeatedly cutting the magnetic flux lines, and the Gauss meter 19 is opened to determine the magnetic field strength of the liquid passing through the permanent magnet 18. The magnetic field strength required for the test is determined by changing the arrangement and number of the magnets, and the magnetization time is recorded by a stopwatch. After reaching the required liquid flow, the valve is closed, the liquid injection is terminated, and the coal gas is waited for adsorption equilibrium again;

[0033] When the coal sample re-absorbs gas to balance, immediately open the seventh valve 32 and the eighth valve 33, pass the free gas into the gas collecting device 24, pass the liquid into the measuring cylinder 25 by pressure, read the measuring cylinder reading, and when the pressure indication number no longer changes, close the eighth valve 33, calculate the displacement gas desorption amount, open the fifth valve 30 and the seventh valve 32, and the adsorbed gas in the coal sample tank 11 is desorbed into the desorption tank 10 until the desorption balance is reached and the pressure indication number remains unchanged. The high-precision pressure sensor 12 records the changes in the coal sample tank pressure during the whole process, and transmits the data to the data acquisition device 16 to calculate the coal sample gas desorption amount.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An experimental device for inhibiting gas desorption by synergistic action of surfactant and magnetization, characterized in that: The experimental device comprises a vacuum degassing system, a high-pressure gas charging system, a magnetized water injection system, a coal gas desorption system and a computer control system; the vacuum degassing system and the high-pressure gas charging system work together to form the front end of the experimental device, providing the required vacuum environment and high-pressure environment for the experiment; the magnetized water injection system adds liquid to the coal in the adsorption state through the water injection pipeline after the coal adsorption gas reaches equilibrium; the coal gas desorption system provides a desorption space for the coal sample that has reached adsorption equilibrium; the computer control system collects data during the experiment, transmits it to the computer, and calculates the coal gas desorption amount; The vacuum degassing system comprises a vacuum pump (5), a first pressure gauge (4), a degassing pipeline and a second valve (27); the vacuum pump (5) is connected to the second valve (27) and the first pressure gauge (4) in sequence, and is controlled by the second valve (27) to provide a vacuum environment for the system and desorb residual gas in the raw coal; The high-pressure inflation system comprises a high-pressure gas bottle (1), a high-pressure helium bottle (2), a buffer tank (3), a coal sample tank (11), a reference tank (9), an inflation pipeline, a high-precision pressure sensor (12), and a valve. The gas outlets of the high-pressure gas bottle (1) and the high-pressure helium bottle (2) are provided with a first pressure reducing valve (38) and a second pressure reducing valve (39), and the buffer tank (3) is provided with a first pressure gauge (4) and a first valve (26); The magnetized water injection system comprises a permanent magnet (18), a Gauss meter (19), a mass flow meter (20), a booster metering pump (22), a water tank (23), and a coal sample tank (11); the permanent magnet (18) is connected to the Gauss meter (19); the water tank (23) is connected to the booster metering pump (22), the twelfth valve (37), the second pressure gauge (21), the eleventh valve (36), the mass flow meter (20), the ninth valve (34), and the permanent magnet (18) to form a magnetized pipeline; the magnetized pipeline comprises an S-shaped pipeline so that liquid can enter between two levels of the permanent magnet (18); the water tank (23) is connected to the booster metering pump (22), the twelfth valve (37), the second pressure gauge (21), the eleventh valve (36), the mass flow meter (20), and the tenth valve (35) to form a water injection pipeline; the magnetized pipeline and the water injection pipeline are connected to the coal sample tank (11) via a one-way valve (15); The coal gas desorption system comprises a water bath space (17), a gas collecting device (24), a measuring cylinder (25), and a valve. The water bath space comprises a temperature sensor (6), a heating rod (7), a stirrer (8), a reference tank (9), a desorption tank (10), a coal sample tank (11), and a high-precision pressure sensor (12). The inlet of the coal sample tank (11) is provided with a second coal powder filter (14), and the outlet is provided with a first coal powder filter (13). The high-precision pressure sensor (12) is connected to a data acquisition device (16); The other end of the coal sample tank (11) outlet is controlled by a seventh valve (32), one end of the seventh valve (32) is connected to an eighth valve (33), a gas collecting device (24) and a measuring cylinder (25), and the other end is connected to a fifth valve (30) and a desorption tank (10).

2. The experimental device for suppressing gas desorption by synergistic action of surfactant and magnetization according to claim 1, characterized in that: The computer control system comprises a circuit, a data acquisition device (16), a USB data connection line, and a system computer. The computer control system collects data during the test through the data acquisition device (16), transmits the data to the computer, and calculates the coal gas desorption amount.

3. A method for using the experimental device for inhibiting gas desorption by synergistic action of surfactant and magnetization according to any one of claims 1-2, characterized in that: The test process includes the following steps: Step 1: Before the test, the coal sample is vacuum dried at 60°C for 12 hours to remove moisture and some impurities, and then placed in a coal sample cup. The coal sample cup is then placed in a coal sample tank (11) and the coal sample cover is tightened. Step 2: After the sample is loaded, turn on the water bath heating device to heat the temperature to the test condition, open all valves in the system, fill the entire test system with helium at a certain pressure, close the third inflation valve (28), and observe and detect whether the value displayed by the high-precision pressure sensor (12) changes; Step 3: After the air tightness inspection of the test pipeline is passed, the calibration gas-helium at a certain pressure injected into the buffer tank (3) in advance is injected into the coal sample tank (11), and the volume of the free space is calculated; the entire pipeline of the test bench is degassed, and the degassing operation is stopped after the degassing time set in the test is reached; Step 4: connect the coal sample tank (11) and the buffer tank (3), fill the buffer tank (3) with gas of a certain pressure, then open the seventh valve (32) of the coal sample tank (11), fill the gas in the buffer tank (3) into the coal sample tank (11), and wait for the adsorption equilibrium in the coal sample tank (11); Step 5: When the coal sample reaches the adsorption equilibrium state, the one-way valve (15) and the booster metering pump (22) of the coal sample tank (11) are opened, and the agitator (8) on the coal sample tank (11) starts to work. When the magnetized liquid is injected, the ninth valve (34) is opened, and the liquid enters between the two poles of the permanent magnet (18) through the S-shaped pipeline, repeatedly cutting the magnetic flux lines, and the Gauss meter (19) is opened to determine the magnetic field strength of the liquid passing through the permanent magnet (18). The magnetic field strength required for the test is determined by changing the arrangement and number of the magnets, and the magnetization time is recorded by a stopwatch. After the required liquid flow rate is reached, the ninth valve (34) is closed, the liquid injection is terminated, and the coal gas is waited for to reach adsorption equilibrium again; Step 6: When the coal sample re-absorbs gas to balance, immediately open the seventh valve (32) and the eighth valve (33), pass the free gas into the gas collection device (24), pass the liquid into the measuring cylinder (25) by pressure, read the measuring cylinder reading, and when the pressure indication number no longer changes, close the valve, calculate the amount of displaced gas desorption, open the fifth valve (30) and the seventh valve (32), and the adsorbed gas in the coal sample tank (11) is desorbed into the desorption tank (10) until the desorption balance is reached and the pressure indication number remains unchanged. The high-precision pressure sensor (12) records the changes in the coal sample tank pressure during the whole process, transmits the data to the data acquisition device (16), and calculates the amount of coal sample gas desorption.

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