A smart control simulation system and smart control method for mine gas extraction

Abstract

A smart control and simulation system for mine gas drainage includes a system control server, and a gas cylinder, a drainage simulation unit, and a variable negative pressure drainage pump connected in sequence to form a gas guiding passage. The variable negative pressure drainage pump provides drainage negative pressure to extract the gas medium in the gas cylinder through the drainage simulation unit. The drainage simulation unit includes a coal seam permeability simulation device, a drainage borehole simulation device, a gas flow stop valve, a flow meter, a concentration meter, and a solenoid valve. The coal seam permeability simulation device and the drainage borehole simulation device are connected by an intermediate pipeline. The coal seam permeability simulation device extends a transparent glass cover through an input pipeline and connects to the gas cylinder. The drainage borehole simulation device extends a transparent glass cover through an output pipeline and connects to the variable negative pressure drainage pump. The flow meter and concentration meter are located on the output pipeline. This invention ensures the high efficiency and safety of the system operation during gas drainage, reduces human control, lowers drainage costs, and improves gas drainage efficiency.

Description

Technical Field

[0001] This invention relates to the field of coal mine gas extraction technology, specifically to an intelligent control simulation system and intelligent control method for mine gas extraction. Background Technology

[0002] As shallow coal mining gradually depletes, my country's mines are increasingly entering the deep mining stage. This is accompanied by increasing ground stress and a growing number of low-permeability, high-gas coal seams, making gas control more difficult. Gas drainage is the most economical and effective technical measure for preventing coal and gas outbursts, achieving gas drainage standards, preventing gas accumulation and exceeding limits, and utilizing coalbed methane. Existing drainage systems have certain drawbacks in actual operation. They typically require manual underground monitoring and control, a complex, labor-intensive, and time-consuming process with relatively large measurement errors, resulting in insignificant control effects—a significant gap between the drainage effect and the expected result. The poor real-time and intelligent nature of manual control in underground gas drainage leads to poor drainage efficiency. Furthermore, since a fully established intelligent control mechanism for gas drainage is not yet in place, gas drainage control relies heavily on human experience. Changes in the operating conditions of each part of the drainage system affect the control results, and the real-time data after control deviates from the ideal data, making dynamic intelligent control of operating parameters within the drainage system impossible. Therefore, further research is needed on intelligent control models for gas extraction to explore the potential relationships between operating parameters in the extraction system, in order to construct a physical control model and improve the safety and efficiency of gas extraction. Summary of the Invention

[0003] Based on this, the present invention provides an intelligent control simulation system and intelligent control method for mine gas drainage to find the optimal control variables. Furthermore, this system solves the problems of inaccurate, poor feedback, and slow control caused by manual control in mine gas drainage, ensuring the high efficiency and safety of the system operation during gas drainage. This guides mine gas drainage, optimizes the drainage system, reduces manual control, lowers drainage costs, and improves gas drainage efficiency, further realizing the intelligent and unmanned operation of the mine gas drainage process.

[0004] To achieve the above objectives, the present invention provides an intelligent control simulation system for mine gas extraction, comprising a system control server, and a gas cylinder, an extraction simulation unit, and a variable negative pressure extraction pump connected in sequence to form a gas guiding passage. The variable negative pressure extraction pump is used to provide extraction negative pressure so that the gas medium in the gas cylinder is extracted through the extraction simulation unit, wherein:

[0005] The extraction simulation unit includes a coal seam permeability simulation device, an extraction borehole simulation device, an airflow stop valve, a flow meter, a concentration meter, and a solenoid valve. Both the coal seam permeability simulation device and the extraction borehole simulation device are housed within a sealed transparent glass enclosure. They are connected via an intermediate pipeline. The coal seam permeability simulation device extends from the transparent glass enclosure through an input pipeline and connects to the gas cylinder. The extraction borehole simulation device extends from the transparent glass enclosure through an output pipeline and connects to the variable negative pressure extraction pump. The airflow stop valve and the flow meter are located on the input pipeline, and the flow meter and the concentration meter are located on the output pipeline. The coal seam permeability simulation device is used to simulate the permeability of the coal seam, and the extraction borehole simulation device is used to simulate a gas extraction borehole in the coal seam.

[0006] The system control server is connected to the variable negative pressure extraction pump, flow meter, concentration meter, solenoid valve, and leakage detection meter installed on the extraction borehole simulation device.

[0007] As a further preferred technical solution of the present invention, there are multiple extraction simulation units, and the multiple extraction simulation units are connected in parallel between the gas cylinder and the variable negative pressure extraction pump.

[0008] As a further preferred technical solution of the present invention, the coal seam permeability simulation device includes a sealed first transparent plastic tube, the first transparent plastic tube is filled with first coal particles with adjustable density, one end of the first transparent plastic tube is connected to the output pipeline, and the other end of the first transparent plastic tube is connected to the intermediate pipeline.

[0009] As a further preferred embodiment of the present invention, the first transparent plastic tube is provided with two filter screens with adjustable spacing, the first coal particle is sandwiched between the two filter screens, one of the filter screens is connected to an adjusting screw, the adjusting screw is used to adjust the spacing between the two filter screens, thereby adjusting the density of the first coal particle to change the permeability of the coal seam permeability simulation device.

[0010] As a further preferred technical solution of the present invention, the extraction borehole simulation device includes a sealed second transparent plastic tube for simulating a coal seam gas leakage ring, an extraction tube is inserted into the second transparent plastic tube, a second coal particle is filled between the extraction tube and the second transparent plastic tube, the extraction tube extends from one end of the second transparent plastic tube and is connected to the output pipeline, the other end of the second transparent plastic tube is connected to the intermediate pipeline, and a leakage interface for installing the gas leakage detection meter is provided on the second transparent plastic tube.

[0011] As a further preferred embodiment of the present invention, the borehole leakage rate of the extraction borehole simulation device satisfies the following calculation formula:

[0012]

[0013] Q L The air leakage rate per unit volume of the second coal particle per unit time, in m. 3 / (m 3 *d); P a Atmospheric pressure, 0.101 MPa; P n The absolute pressure for extraction is measured in MPa; R L For air leakage resistance, MPa 11 / 7 *d.

[0014] As a further preferred embodiment of the present invention, the particle size of the first coal particle and the second coal particle are both 6-10 mm.

[0015] As a further preferred technical solution of the present invention, the gas medium in the gas cylinder is carbon dioxide at 8-10 MPa, and a pressure reducing valve is provided at the opening of the gas cylinder; the adjustable range of the extraction negative pressure provided by the variable negative pressure extraction pump is 0-45 kPa.

[0016] As another aspect of the present invention, the present invention also provides an intelligent control method for the above-mentioned intelligent control simulation system for mine gas extraction, characterized by comprising the following steps:

[0017] S1. Open the gas cylinder to release the gas medium at the preset pressure, adjust the permeability of the coal seam permeability simulation device, and wait for the values ​​of each extraction parameter to stabilize. The extraction parameters include medium concentration, medium flow rate, borehole leakage, extraction negative pressure, and solenoid valve opening. The medium concentration, medium flow rate, and borehole leakage are measured by a concentration meter, a flow meter, and a leakage detection meter, respectively. The extraction negative pressure and solenoid valve opening are obtained by feedback from the variable negative pressure extraction pump and the solenoid valve.

[0018] S2. Gradient-adjustable variable negative pressure extraction pump, the extraction negative pressure varies from 20-45 kPa, and is adjusted by 5 kPa each time. Record the changes of each extraction parameter under different extraction negative pressures, and analyze the functional relationship between the extraction negative pressure and the extraction parameters.

[0019] S3. Based on the changes in the medium concentration, the MPC control algorithm is used to obtain the optimized target feedback control of the variable negative pressure extraction pump and solenoid valve until the medium concentration flowing out of the corresponding extraction simulation unit dynamically approaches the optimal target.

[0020] S4. Repeat steps S2 and S3 to find the control mechanism of the extraction negative pressure and the solenoid valve opening in relation to the extraction parameters, and obtain the optimal control scheme.

[0021] The intelligent control simulation system and intelligent control method for mine gas extraction of the present invention, by adopting the above technical solution, can achieve the following beneficial effects:

[0022] 1) The intelligent control simulation system for mine gas extraction of the present invention consists of a gas cylinder, an extraction simulation unit and a variable negative pressure extraction pump connected in sequence to form a gas guiding passage. The system is intelligently controlled by the system control server, which can realistically simulate the actual process of underground gas extraction. Moreover, it has a simple structure, is visually controllable, and is easy to operate in experiments.

[0023] 2) The intelligent control simulation system for mine gas extraction of the present invention simulates the actual process of underground gas extraction through physical similarity. The experimental laws and control mechanisms obtained can provide a theoretical basis for the intelligent management of underground gas extraction in the future. It greatly optimizes the gas extraction system, reduces the workers' control over the extraction process, reduces extraction costs, improves gas extraction efficiency, and transforms the uncontrollable gas extraction into controllable gas extraction, so as to further realize the intelligent and unmanned management of the gas extraction process.

[0024] 3) The intelligent control method of the intelligent control simulation system for mine gas drainage of the present invention studies the relationship between the changes of drainage parameters, including drainage negative pressure, drainage concentration, and drainage flow rate, to construct a control model. By intelligently adjusting the opening of the variable negative pressure drainage pump and the solenoid valve, the drainage negative pressure of the borehole is adjusted, thereby dynamically changing the drainage concentration, flow rate, etc. The time series form of each parameter variable is explored, the pairwise coupling relationship between each parameter is verified, and the control model is continuously corrected and optimized based on the feedback of the collected data, providing a basis for intelligent control of actual mine gas drainage. Attached Figure Description

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 A schematic diagram of a structure of an embodiment of the intelligent control simulation system for mine gas extraction provided by the present invention;

[0027] Figure 2 Schematic diagrams of coal seam permeability simulation device and extraction borehole simulation device;

[0028] Figure 3 This is a flowchart of an MPC-based intelligent control and optimization method.

[0029] In the diagram: 1. Gas cylinder; 2. Gas flow stop valve; 3. Flow meter; 4. Transparent glass cover; 5. Coal seam permeability simulation device; 51. First transparent plastic tube; 52. Filter screen; 53. First coal particle; 54. Adjusting screw; 6. Extraction borehole simulation device; 61. Second transparent plastic tube; 62. Leakage detection gauge; 63. Second coal particle; 64. Extraction pipe; 7. Concentration meter; 8. Solenoid valve; 9. Variable negative pressure extraction pump; 10. System control server; 11. Input pipeline; 12. Intermediate pipeline; 13. Output pipeline.

[0030] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Terms such as "upper," "lower," "left," "right," "middle," and "one" used in the preferred embodiments are merely for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0032] like Figure 1 and 2 As shown, the present invention provides a mine gas extraction intelligent control simulation system, including a system control server 10, and a gas cylinder 1, an extraction simulation unit, and a variable negative pressure extraction pump 9 connected in sequence to form a gas guiding passage. The variable negative pressure extraction pump 9 is used to provide extraction negative pressure so that the gas medium in the gas cylinder 1 is extracted through the extraction simulation unit.

[0033] Specifically, the gas medium in gas cylinder 1 is carbon dioxide at 8-10 MPa. A pressure-reducing valve is installed at the opening of gas cylinder 1. Adjusting the valve allows the gas medium in gas cylinder 1 to be output at a preset pressure. Gas cylinder 1 also has a pressure gauge to display the current pressure value, ensuring normal gas flow during the experiment. This gas medium is used to simulate methane gas released in coal mines. Of course, methane gas or nitrogen can also be selected according to experimental requirements. Carbon dioxide is readily available and safe, making it a preferred choice. The adjustable negative pressure provided by the variable negative pressure extraction pump 9 has an adjustment range of 0-45 kPa.

[0034] The extraction simulation unit includes a coal seam permeability simulation device 5, an extraction borehole simulation device 6, an airflow stop valve 2, a flow meter 3, a concentration meter 7, and a solenoid valve 8. Both the coal seam permeability simulation device 5 and the extraction borehole simulation device 6 are housed within a sealed transparent glass cover 4. They are connected via an intermediate pipeline 12. The coal seam permeability simulation device 5 extends from the transparent glass cover 4 through an input pipeline 11 and connects to the gas cylinder 1. The extraction borehole simulation device 6 extends from the transparent glass cover 4 through an output pipeline 13 and connects to the variable negative pressure extraction pump 9. The airflow stop valve 2 and the flow meter 3 are located on the input pipeline 11, and the flow meter 3 and the concentration meter 7 are located on the output pipeline 13. The coal seam permeability simulation device 5 is used to simulate the permeability of the coal seam, and the extraction borehole simulation device 6 is used to simulate a gas extraction borehole in the coal seam.

[0035] The coal seam permeability simulation device 5 and the extraction borehole simulation device 6 are enclosed by a transparent glass cover 4 to avoid interference from other external factors, such as temperature, humidity, indoor air pressure, and air flow, which may have some unnecessary impact on the experimental results, and to ensure that the experiment is carried out under controllable conditions.

[0036] The system control server 10 is connected to the variable negative pressure extraction pump 9, flow meter 3, concentration meter 7, solenoid valve 8, and leakage detection meter 62 installed on the extraction borehole simulation device 6. The system control server 10 can obtain the corresponding extraction parameters through the flow meter 3, concentration meter 7, and leakage detection meter 62, and then adjust the opening degree of the solenoid valve 8 and the extraction negative pressure of the variable negative pressure extraction pump 9 according to the extraction parameters.

[0037] The system control server 10 is connected to the solenoid valve 8 located at the end of the output pipeline 13. During the experiment, the opening of the solenoid valve 8 is adjusted according to the predicted parameters predicted by the system control server 10. For example, when the concentration is higher than the set value, the opening of the solenoid valve 8 is increased in time; when the concentration value is lower than the expected minimum experimental value, the opening of the solenoid valve 8 is decreased in time, thereby increasing the extraction efficiency and improving the extraction effect to the optimal value.

[0038] The variable negative pressure extraction pump 9 is connected to the system control server 10. During the experiment, the variable negative pressure extraction pump 9 is adjusted first, for example, by gradually increasing the power of the pump. The variation law between extraction negative pressure and medium flow rate, medium concentration and extraction leakage is explored. Based on the variation law, the optimal feedback value between concentration and solenoid valve 8 is sought to construct a correction feedback model.

[0039] The permeability coefficient of an actual coal seam can be calculated experimentally. This system controls its permeability to approach an ideal state to better simulate the extraction environment of different coal seams. The coal seam permeability simulation device 5 includes a sealed cylindrical first transparent plastic tube 51. The first transparent plastic tube 51 is filled with first coal particles 53 wrapped in gauze with adjustable density (coal particle spacing). One end of the first transparent plastic tube 51 is connected to the output pipeline 13, and the other end is connected to the intermediate pipeline 12. The particle size of the first coal particles 53 is 6-10mm. The first transparent plastic tube 51 is provided with two filter screens 52 with adjustable spacing. The first coal particles 53 are sandwiched between the two filter screens 52. One filter screen 52 is fixedly set, and the other filter screen 52 is movably set and connected to an adjusting screw 54. The adjusting screw 54 is used to adjust the spacing between the two filter screens 52, thereby adjusting the spacing of the first coal particles 53 to change the permeability of the coal seam permeability simulation device 5.

[0040] The system control server 10 includes a control server, a computer, a display screen, and a PLC module. By collecting data such as medium concentration, medium flow rate, extraction negative pressure, and borehole leakage, the control server simulates the required opening degree of the solenoid valve 8 to obtain the optimal control selection. Then, the PLC controls the solenoid valve 8, changing its opening to achieve the best extraction effect for the entire extraction system. The display screen shows a 3D visualization of the entire system, the monitoring values ​​of each sensor, and the predicted control target parameters. The computer stores the data in a database for later retrieval and data analysis. The main function of the control server is to perform real-time statistical analysis, fitting analysis, and prediction of the collected sensor data, and to provide correction feedback based on the control target. It then controls the solenoid valve 8 and the variable negative pressure pump according to the optimal value to bring the entire system to an ideal state.

[0041] The extraction borehole simulation device 6 includes a sealed, cylindrical second transparent plastic tube 61 for simulating a coal seam gas leakage ring. An extraction tube 64 (with sieve holes on its wall) is inserted into the second transparent plastic tube 61. The space between the extraction tube 64 and the second transparent plastic tube 61 is filled with second coal particles 63 wrapped in gauze. A filter screen 52 may also be provided on the outer circumference of the extraction tube 64 as needed. The extraction tube 64 extends from one end of the second transparent plastic tube 61 and is connected to the output pipeline 13. The other end of the second transparent plastic tube 61 is connected to the intermediate pipeline 12. A leakage interface for installing the gas leakage detection gauge 62 is provided on the second transparent plastic tube 61. The particle size of the second coal particles 63 is 6-10 mm. When the negative pressure of the extraction increases, the leakage rate and pressure value of the extraction borehole simulation device 6 will also increase with the negative pressure. In actual extraction borehole leakage, the leakage airflow is usually considered to be turbulent, and the pressure gradient is proportional to the 1.75th power of the airflow velocity. Therefore, the borehole leakage rate of the extraction borehole simulation device 6 satisfies the following calculation formula:

[0042]

[0043] Q L The air leakage rate per unit volume of the second coal particle 63 per unit time is expressed in m. 3 / (m 3 *d); P a Atmospheric pressure, 0.101 MPa; P n The absolute pressure for extraction is measured in MPa; R L For air leakage resistance, MPa 11 / 7 *d.

[0044] In one specific implementation, there are multiple extraction simulation units, which are connected in parallel between the gas cylinder 1 and the variable negative pressure extraction pump 9. In the experiment, at least one of the extraction simulation units can be used as the experimental group, and the rest as the control group.

[0045] This invention simulates an underground gas extraction system. Based on actual underground gas extraction pumps and drilling equipment, it performs physical similarity simulations. An adjustable solenoid valve (8) and a control server are added to the simulation system to simulate the underground gas extraction process and achieve intelligent control. Experiments using this simulated underground gas extraction system reveal the coupling relationship between extraction negative pressure, gas concentration, gas flow rate, and borehole leakage, providing theoretical guidance for intelligent gas control in real-world mines. This invention designs and innovates a physical similarity simulation device based on actual mine extraction systems. The experimental process is simple and convenient. By analyzing the data changes of extraction parameters (concentration, flow rate, negative pressure) and the coupling relationships between them, a dynamic feedback control model for negative pressure can be constructed, enabling real-time control and iterative data updates, providing theoretical guidance for intelligent underground gas extraction.

[0046] The present invention also provides an intelligent control method for the intelligent control simulation system for mine gas extraction described in the above embodiments, the method comprising the following steps:

[0047] S1. Open gas cylinder 1 to release gas medium at preset pressure, adjust the permeability of coal seam permeability simulation device 5, and wait for the values ​​of each extraction parameter to stabilize. The extraction parameters include medium concentration, medium flow rate, borehole leakage, extraction negative pressure, and solenoid valve 8 opening. The medium concentration, medium flow rate, and borehole leakage are measured by concentration meter 7, flow meter 3, and leakage detection meter 62, respectively. The extraction negative pressure and solenoid valve 8 opening are obtained by feedback from variable negative pressure extraction pump 9 and solenoid valve 8.

[0048] The permeability selection needs to be determined based on the actual permeability coefficient of the coal seam in the mine to be simulated. This is achieved by adjusting the coal seam permeability simulation device 5 to match the actual permeability of the coal seam. The pressure of the gas medium released from gas cylinder 1 is controlled by a pressure reducing valve, and the pressure is selected according to the experimental requirements.

[0049] S2, Gradient-adjustable variable negative pressure extraction pump 9, the extraction negative pressure varies from 20-45 kPa, and is adjusted by 5 kPa each time. The changes in each extraction parameter under different extraction negative pressures are recorded, and the functional relationship between the extraction negative pressure and the extraction parameters is analyzed.

[0050] Specifically, when the extraction negative pressure and extraction concentration are between 25-45 kPa, the extraction concentration first increases and then decreases; among them, the extraction concentration is relatively high when the negative pressure is between 30-40 kPa, and when the extraction negative pressure is greater than 35 kPa, the higher the extraction negative pressure, the lower the concentration. In the range of 25-35 kPa, the concentration is relatively high as the negative pressure increases; within the entire system's extraction negative pressure variation range, the coal seam gas leakage also increases as the extraction negative pressure increases.

[0051] S3. Based on the changes in the medium concentration, the MPC control algorithm is used to obtain the optimized target feedback control of the variable negative pressure extraction pump 9 and the solenoid valve 8 until the medium concentration flowing out of the corresponding extraction simulation unit dynamically approaches the optimal target.

[0052] S4. Repeat steps S2 and S3 to find the control mechanism of the extraction negative pressure and the opening degree of solenoid valve 8 with the extraction parameters, and obtain the optimal control scheme.

[0053] In practice, the concentration meter 7 collects the medium concentration of the output pipeline 13 (extraction pipeline 64) and transmits the data to the system control server 10 for analysis and prediction. Based on the prediction results, it provides real-time dynamic feedback to ensure that the extraction concentration reaches the optimal level.

[0054] The system control server 10 performs analysis and prediction based on the dynamic fitting of time series such as extraction concentration, predicts the change state of concentration at future sampling time points, and determines the corresponding expression of the future predicted state of concentration and the time curve of the RNN prediction model. With the goal of infinitely approaching the optimal concentration, the error between the actual value of concentration at each time point and the predicted value after MPC control is calculated, and correction feedback is performed to obtain the correction feedback model. The control learning algorithm is continuously updated through rolling optimization of the prediction model and feedback correction, and the extraction negative pressure control strategy is dynamically optimized online to realize the inversion of the extraction negative pressure control prediction model, and further reveal the mechanism of negative pressure feedback control of gas extraction boreholes under rolling optimization. The method of intelligent control optimization of gas extraction based on MPC is the existing technology. For details, please refer to "Ma Li, Shi Xinli, Li Shugang, et al. Research on intelligent control model of gas extraction based on MPC [J]. Coal Science and Technology, 2022, 50(8):82-90."

[0055] The flowchart of the intelligent control and optimization of gas extraction based on MPC in this invention is as follows: Figure 3 As shown, the specific process is as follows:

[0056] Step 1: At the sampling point at the initial time t=k, data are collected from the relevant characteristic parameters of the extraction system using sensors. The characteristic parameters include controlled variables (extraction concentration, extraction flow rate, extraction negative pressure and extraction pump efficiency ratio) and control variables (solenoid valve 8 opening degree, extraction pump power).

[0057] Step 2: Determine whether the values ​​of all current characteristic parameters meet the safety and efficiency constraints of the sampling system. If any constraint is not met, stop sampling and end the intelligent control process; if all constraints are met, proceed to Step 3.

[0058] Step 3: Using historical data prior to the current sampling time point, analyze the time series information of the controlled variable through an RNN recurrent neural network to obtain the ideal dynamic fitting curve, and use it as the reference curve that the MPC model needs to dynamically approach.

[0059] Step 4: Use MPC to predictively model the control quantity. The input is the current state of the controlled quantity of the sampling system. The goal is to dynamically approach the reference curve, and the output is the regulation strategy of the control quantity.

[0060] Step 5: Estimate the ideal output of the controlled variable under the current control strategy, and calculate the error between the actual value of the controlled variable and the current control variable.

[0061] Step 6: Determine whether the current sampling time point is the control end time point set by the system. If not, update the current sampling time point and use the error for rolling optimization and correction feedback, repeating steps 1 to 5. Otherwise, end the intelligent control process.

[0062] In the experiment, a negative pressure gas extraction pump was used to simulate the negative pressure of underground gas extraction. Under the action of the negative pressure gas extraction pump, the gas, after passing through the orifice solenoid valve 8 and outputting the pressure value calculated by the model, entered the coal seam simulation device through pipelines. The gas concentration, flow rate, and negative pressure of the extracted gas were analyzed by a gas monitoring device. Using characteristic experimental data as model training samples, a recurrent neural network was used as the dynamic parameter prediction model for gas extraction. The MPC predictive control algorithm was used to predict the changing trend of dynamic parameters under different control strategies. By comparing the actual measured value of the output with the ideal prediction value of the model, the prediction error of the model was obtained, and the prediction error was used to correct the model's prediction value. Using feedback correction, dynamic optimization continuously optimized the MPC predictive control algorithm to determine the optimal adjustment strategy at different times to achieve the best gas extraction effect. The local optimal control range of the negative pressure for gas extraction regulation was sought through rolling optimization of the model predictive control algorithm, and the negative pressure was intelligently adjusted by the solenoid valve 8.

[0063] The specific applications and advantages of this invention are as follows: This invention adds an intelligent control system to the traditional gas extraction system. It mainly explores the mechanism of gas extraction parameter changes under different negative pressure extraction conditions, understands the variation law of borehole gas extraction parameters, and predicts the required opening degree of the 8 solenoid valves based on the RNN prediction algorithm. This ensures that the extraction efficiency of the 64 extraction pipes reaches the predicted curve. If the extraction efficiency of one of the 64 extraction pipes does not reach the ideal state, the 8 solenoid valves will close in time to control costs. From the perspective of the overall experimental control objectives, the intelligent gas extraction control system accurately collects real-time flow and concentration changes, and the applied control algorithm is effective and reasonable. When the gas concentration is lower than the set value, the opening degree of the 8 solenoid valves is automatically increased; when the medium concentration is higher than the set value, the opening degree of the 8 solenoid valves is automatically decreased. The sensor is stable, the displayed data is normal, and the predicted data is basically consistent. Through simulation experiments, the performance of the intelligent gas extraction control system was examined from multiple aspects. During the actual experiment, the system worked normally, collected sensor signals, predicted and controlled the opening degree of the 8 solenoid valves, and the selection of various control devices was reasonable, fully meeting the design requirements. The opening degree of the 8 solenoid valves was timely and accurate, and both full opening and full closing were possible. Under the control of the MPC-based intelligent control and optimization calculation method, the entire system was able to achieve the expected results during long-term operation.

[0064] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is defined only by the appended claims.

Claims

1. A mine gas extraction intelligent regulation and control simulation system, characterized in that, The system comprises a system control server, a gas cylinder, an extraction simulation unit and a variable negative pressure extraction pump connected in sequence to form a gas guiding path, wherein the variable negative pressure extraction pump is used to provide an extraction negative pressure to extract the gas medium in the gas cylinder through the extraction simulation unit. The extraction simulation unit comprises a coal seam permeability simulation device, an extraction borehole simulation device, a gas flow stop valve, a flow meter, a concentration meter and a solenoid valve, the coal seam permeability simulation device and the extraction borehole simulation device are arranged in a sealed transparent glass cover, the coal seam permeability simulation device and the extraction borehole simulation device are connected in communication through an intermediate pipeline, the coal seam permeability simulation device extends out of the transparent glass cover through an input pipeline and is connected to the gas cylinder, the extraction borehole simulation device extends out of the transparent glass cover through an output pipeline and is connected to the variable negative pressure extraction pump, the gas flow stop valve and the flow meter are arranged on the input pipeline, the flow meter and the concentration meter are arranged on the output pipeline, the coal seam permeability simulation device is used to simulate the permeability of the coal seam, and the extraction borehole simulation device is used to simulate the gas extraction borehole in the coal seam. The system control server is in signal connection with the variable negative pressure extraction pump, the flow meter, the concentration meter, the solenoid valve and a gas leakage detection meter arranged on the extraction borehole simulation device. The coal seam permeability simulation device comprises a sealed first transparent plastic pipe, the first transparent plastic pipe is filled with first coal particles with adjustable density, one end of the first transparent plastic pipe is in communication with the output pipeline, and the other end of the first transparent plastic pipe is in communication with the intermediate pipeline. The first transparent plastic pipe is provided with two filter screens with adjustable spacing, the first coal particles are clamped between the two filter screens, one of the filter screens is connected with an adjusting screw, and the adjusting screw is used to adjust the spacing of the two filter screens, so as to adjust the density of the first coal particles to change the permeability of the coal seam permeability simulation device. The extraction borehole simulation device comprises a sealed second transparent plastic pipe used to simulate a gas leakage ring of the coal seam, an extraction pipe is inserted into the second transparent plastic pipe, the second transparent plastic pipe is filled with second coal particles between the extraction pipe and the second transparent plastic pipe, the extraction pipe extends out of one end of the second transparent plastic pipe and is in communication with the output pipeline, the other end of the second transparent plastic pipe is in communication with the intermediate pipeline, and a gas leakage interface for mounting the gas leakage detection meter is formed in the second transparent plastic pipe.

2. The intelligent control and regulation simulation system for mine gas extraction according to claim 1, characterized in that, The extraction simulation unit is in parallel connection between the gas cylinder and the variable negative pressure extraction pump.

3. The intelligent control and regulation simulation system for mine gas extraction according to claim 1, characterized in that, The borehole air leakage of the extraction borehole simulation device meets the following calculation formula: wherein Q L is the air leakage amount of unit volume of second coal particles in unit time, ; P a is the atmospheric pressure, 0.101 MPa; P n is the extraction absolute pressure, MPa; R L is the air leakage resistance, .

4. The intelligent control and regulation simulation system for mine gas extraction according to any one of claims 1-3, characterized in that, The particle size of the first coal particles and the second coal particles is 6-10 mm.

5. The intelligent regulation and control simulation system for mine gas extraction according to claim 1, characterized in that, The gas medium in the gas cylinder is carbon dioxide with a pressure of 8-10 MPa, and a pressure reducing valve is arranged at the opening of the gas cylinder; and the extraction negative pressure provided by the variable negative pressure extraction pump is adjustable in the range of 0-45 KPa.

6. An intelligent control method using the intelligent control and regulation simulation system of any one of claims 1-5, characterized in that, The method comprises the following steps: S1, open the gas cylinder to release the gas medium at a preset pressure, adjust the gas permeability of the coal seam gas permeability simulation device, and wait for the stability of various extraction parameter values, wherein the extraction parameters include medium concentration, medium flow, borehole air leakage, extraction negative pressure, and electromagnetic valve opening degree, the medium concentration, medium flow, and borehole air leakage are measured by a concentration table, a flow table, and an air leakage detection table respectively, and the extraction negative pressure and the electromagnetic valve opening degree are obtained by feedback of a variable negative pressure extraction pump and an electromagnetic valve; S2, adjust the gradient of the variable negative pressure extraction pump, the extraction negative pressure changes in the range of 20-45KPa, adjust 5KPa each time, record the change values of various extraction parameters under different extraction negative pressures, and analyze and explore the functional relationship between the extraction negative pressure and the extraction parameters; S3, according to the change of the medium concentration value, the optimal target feedback control variable negative pressure extraction pump and electromagnetic valve are obtained by combining the MPC control algorithm until the medium concentration flowing out of the corresponding extraction simulation unit approaches the optimal target of rolling optimization dynamically; S4, repeat steps S1, S2 and S3 to find the control mechanism of the extraction negative pressure and the electromagnetic valve opening degree and the extraction parameters, and obtain the optimal control scheme.

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