Multi-stage management and control method for gas extraction

Abstract

The invention discloses a gas extraction multi-stage management and control method which is specifically implemented according to the following steps: step 1, building a gas extraction measurement and control platform; 2, the actual gas concentration value N in the extraction pipeline is monitored in real time; 3, setting a gas concentration reference value M of each extraction pipeline, and judging whether the actual concentration of the extraction pipeline needs to be regulated or not according to monitoring conditions; 4, the gas concentration in the drill hole, the pipe network and the pumping station extraction pipeline is regulated and controlled in sequence; 5, adjusting the concentration reference value M, and repeating the step 4; if the monitoring condition cannot be met after the step 4 is repeated, executing the step 6; and 6, after instrument faults are eliminated, the current state is maintained for extraction. Through judgment and calculation of the gas extraction measurement and control platform, multi-stage comprehensive management and adjustment control of mine gas extraction are achieved, the mine gas extraction efficiency and the extraction level are improved, and reasonable distribution of the extraction capacity of the whole gas extraction system and remarkable improvement of the energy efficiency are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine gas drainage, and relates to a multi-level control method for gas drainage. Background Art

[0002] Gas is the number one killer in coal mines. The main component of gas is methane, which is a flammable and explosive gas. When the gas concentration in the air reaches the explosion limit and encounters a fire source (such as electric spark, open fire, frictional spark, etc.), a violent explosion will occur. The high-temperature and high-pressure air wave generated by the gas explosion will not only directly cause casualties, but also destroy roadways, equipment and other facilities, seriously damaging the production system of the coal mine. Although gas itself is non-toxic, it is lighter than air and is likely to accumulate in high places such as the top of coal mine roadways. When the gas concentration in the coal mine is relatively high, it will correspondingly reduce the oxygen content in the air, endangering the lives of the workers in the coal mine.

[0003] At the same time, gas is also a clean energy source that can be developed and utilized, with certain economic value. Therefore, the gas in the coal mine can be drained to ensure production safety while obtaining economic income. At present, whether it is gas disaster prevention and control or gas development and utilization, gas drainage is the most basic and main means. Common drainage methods include in-seam drainage (drilling holes are arranged in the coal seam being mined for drainage), adjacent seam drainage (draining the upper and lower adjacent coal seams of the coal seam being mined to reduce the gas outburst from the adjacent seams to the mining seam), gob drainage (draining the gas accumulated in the gob), etc.

[0004] However, at present, the management and control of gas drainage-related facilities and working conditions mostly rely on manual experience, lacking effective control means, and it is impossible to efficiently achieve multi-level control from gas drainage boreholes, gas drainage pipe networks to gas drainage systems to effectively prevent gas disasters and efficiently develop gas resources. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-level control method for gas drainage, which solves the problems of low gas drainage efficiency and time-consuming and cumbersome control steps in the prior art.

[0006] The technical solution adopted by the present invention is a multi-level control method for gas drainage, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform on the mine drainage network for performing the following specific steps; Step 2: Real-time monitor the actual gas concentration value N in the drainage pipeline; Step 3: Set the gas concentration reference value M for each drainage pipeline, and judge whether the actual concentration of the drainage pipeline needs to be adjusted according to the monitoring conditions; If the monitoring conditions are met, continue to monitor the current situation; if the monitoring conditions are not met, execute Step 4; Step 4: Regulate the gas concentration in the boreholes, pipeline network, and pumping station extraction pipelines in sequence; after the regulation is completed, if the monitoring conditions are met, the regulation ends and continuous monitoring is carried out. If the monitoring conditions are not met, repeat Step 4; after reaching the repetition limit, execute Step 5; Step 5: Adjust the concentration reference value M and repeat Step 4; if the monitoring conditions still cannot be met after repeating Step 4, execute Step 6; Step 6: After excluding instrument failures, maintain the current state for gas extraction.

[0007] The features of the present invention also lie in: The gas extraction measurement and control platform is specifically built according to the following steps: Step 1-1: According to the layout of the existing gas extraction system and pipeline network in the mine, construct a pumping station extraction regulation group, a pipeline network extraction regulation group, and a borehole extraction regulation group; Step 1-2: Install a gas extraction measurement and control server on the ground, and input the gas extraction multi-level control system into the gas extraction measurement and control server; Step 1-3: Connect the pumping station extraction regulation group, the pipeline network extraction regulation group, the borehole extraction regulation group, and the gas extraction measurement and control server through wired or wireless means to form an information transmission network above and below the mine, and transmit the information and instructions between each part.

[0008] The pumping station extraction regulation group includes a gas extraction pumping station, a pumping station measurement and control sub-station, and one or more groups of measurement and control devices installed on the pumping station extraction pipeline, which are connected by wired or wireless; the pipeline network extraction regulation group includes a pipeline network measurement and control sub-station and one or more groups of measurement and control devices installed on each pipeline network extraction pipeline, which are connected by wired or wireless; the borehole extraction regulation group includes a borehole measurement and control sub-station and one or more groups of measurement and control devices installed on each borehole extraction pipeline, which are connected by wired or wireless; the pumping station measurement and control sub-station, the pipeline network measurement and control sub-station, and the borehole measurement and control sub-station are all PLC measurement and control sub-stations; the gas extraction multi-level control system receives the parameter information collected by each PLC measurement and control sub-station, judges whether regulation is required, makes a regulation decision, and sends a regulation instruction to the corresponding PLC measurement and control sub-station.

[0009] One group of measurement and control devices includes 1 gas multi-parameter monitor and 1 electric control valve; the gas multi-parameter monitor collects gas extraction parameters, including gas concentration and extraction negative pressure; the electric control valve collects working condition parameters, including valve opening and closing state and valve opening degree.

[0010] The monitoring condition is that the actual gas concentration value N in the extraction pipeline is not less than the gas concentration reference value M.

[0011] The specific steps of Step 4 are: Step 4-1: Input the gas drainage multi-level regulation model into the gas drainage multi-level control system, set the gas concentration c in the model as the concentration reference value M, input the cumulative drainage days d, and obtain the corresponding target negative pressure value P0; Step 4-2: The gas drainage multi-level control system sends a regulation instruction to the PLC measurement and control sub-station belonging to the drainage pipeline to be regulated, changes the opening of the electric regulation valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the regulation ends; After the regulation ends, if the actual concentration value N in the drainage pipeline meets the monitoring conditions, maintain the valve opening at this time and continue to monitor the gas concentration in the drainage pipeline; If the actual concentration value N in the drainage pipeline does not meet the monitoring conditions, repeat Step 4; after reaching the upper limit of the repetition times, execute Step 5.

[0012] The gas drainage multi-level regulation model is: (1), In the formula: is the gas compression coefficient, = 1; is the gas temperature, with the unit of K; is the drainage negative pressure, with the unit of Pa; is the density of the mixed gas, with the unit of kg / m 3 ; is the gas concentration, with the unit of %; is the specific heat capacity of the mixed gas, = 0.287 kJ / (kg·k); is the specific heat capacity of the gas, = 0.5182 kJ / (kg·k).

[0013] The upper limit of the repetition times in Step 4 is three times.

[0014] The beneficial effects of the present invention are: The disclosed gas drainage multi-level control method of the present invention can monitor the drainage parameters and working conditions of the drainage boreholes, drainage pipe networks, and drainage pump stations in real time. Through the evaluation and calculation of the gas drainage measurement and control platform, it realizes the multi-level comprehensive management and adjustment control of the mine gas drainage boreholes, pipe networks, supporting drainage facilities, and drainage working conditions of the entire drainage system, improves the mine gas drainage efficiency and drainage level, realizes the reasonable distribution of the drainage capacity of the entire gas drainage system and the significant improvement of energy efficiency, and provides technical support for gas disaster prevention and gas resource development. Description of the Drawings

[0015] Figure 1 is the schematic flow chart of the gas drainage multi-level control method of the present invention; Figure 2This is a schematic diagram of the gas drainage measurement and control platform architecture in the present invention.

[0016] In the figure, 1. Drainage measurement and control server, 2. Pump station drainage regulation group, 3. Pipeline network drainage regulation group, 4. Borehole drainage regulation group, 5. Gas drainage pump station, 6. Pump station measurement and control sub-station, 7. Pipeline network measurement and control sub-station, 8. Borehole measurement and control sub-station, 9. Gas multi-parameter monitor, 10. Electric control valve. Detailed implementation manners

[0017] The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0018] As Figure 1 shown, the present invention provides a multi-level gas drainage control method, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform on the mine drainage network; and execute the following specific steps for monitoring and regulating the existing mine drainage pipeline concentration; As Figure 2 shown, the gas drainage measurement and control platform includes a drainage measurement and control server 1, a pump station drainage regulation group 2, a pipeline network drainage regulation group 3, and a borehole drainage regulation group 4 connected through an information transmission network.

[0019] The specific construction is carried out according to the following steps: Step 1-1: According to the layout of the existing gas drainage system and pipeline network in the mine, construct a pump station drainage regulation group 2, a pipeline network drainage regulation group 3, and a borehole drainage regulation group 4; The pump station drainage regulation group 2 includes a gas drainage pump station 5, a pump station measurement and control sub-station 6, and one or more groups of measurement and control devices installed on the pump station drainage pipeline, which are connected through an information transmission network; The pipeline network drainage regulation group 3 includes a pipeline network measurement and control sub-station 7 and one or more groups of measurement and control devices installed on each pipeline network drainage pipeline, which are connected through an information transmission network; The borehole drainage regulation group 4 includes a borehole measurement and control sub-station 8 and one or more groups of measurement and control devices installed on each borehole drainage pipeline, which are connected through an information transmission network; The pump station measurement and control sub-station 6, the pipeline network measurement and control sub-station 7, and the borehole measurement and control sub-station 8 are all PLC measurement and control sub-stations; Each group of measurement and control devices includes 1 gas multi-parameter monitor 9 and 1 electric control valve 10; Step 1-2: Install the drainage measurement and control server 1 on the ground, and input the gas drainage multi-level control system into the drainage measurement and control server 1; Step 1-3: Connect the pump station drainage regulation group (2), the pipeline network drainage regulation group (3), the borehole drainage regulation group (4), and the drainage measurement and control server 1 through wired or wireless means to form an information transmission network above and below the mine, and transmit the information and instructions between each part; The multi-level control system for gas drainage receives the parameter information collected by each PLC measurement and control sub-station, determines whether regulation is needed, makes a regulation decision, and sends a regulation instruction to the corresponding PLC measurement and control sub-station. The measurement and control equipment is regulated manually or through the PLC measurement and control sub-station.

[0020] Step 2: Real-time monitor the actual gas concentration value N in the drainage pipeline and other drainage and working condition parameters. The multi-parameter gas monitor collects drainage parameters, including gas drainage concentration and negative pressure; the electric control valve collects working condition parameters, including valve opening and closing state and valve opening degree.

[0021] Step 3: Set the reference gas concentration value M for each drainage pipeline, and judge whether the actual concentration of the drainage pipeline needs to be regulated according to the monitoring conditions. If the monitoring conditions are met, continue monitoring the current situation; if the monitoring conditions are not met, go to Step 4. The monitoring condition is that the actual gas concentration value N in the drainage pipeline is not less than the set reference gas concentration value M. The reference concentration value M is set according to the actual drainage situation of the mine and is in an adjustable state. Corresponding adjustments can be made as the concentration decreases during drainage.

[0022] Step 4: Regulate the gas concentration in the boreholes, pipe networks, and pumping station drainage pipelines in sequence; after the regulation is completed, if the monitoring conditions are met, end the regulation and continue monitoring; if the monitoring conditions are not met, repeat Step 4; after reaching the upper limit of the repetition times, execute Step 5. The specific steps are as follows: Step 4-1: Input the multi-level gas drainage regulation model into the multi-level control system for gas drainage, set the gas concentration c in the model as the reference concentration value M, input the cumulative drainage days d, and obtain the corresponding target negative pressure value P0. The multi-level gas drainage regulation model is: (1), In the formula: is the gas compression coefficient, = 1; is the gas temperature, in units of K; is the drainage negative pressure, in units of Pa; is the density of the mixed gas, in units of kg / m 3 ; is the gas concentration of the mixed gas, in units of %; is the specific heat capacity of the mixed gas, = 0.287 kJ / (kg·k); is the specific heat capacity of the gas, = 0.5182 kJ / (kg·k); Step 4-2: The multi-level control system for gas drainage sends a control instruction to the PLC measurement and control sub-station belonging to the drainage pipeline to be controlled, changes the opening degree of the electric control valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the control ends; After the control ends, if the actual concentration value N in the drainage pipeline meets the monitoring conditions, maintain the valve opening at this time and continue to monitor the gas concentration in the drainage pipeline; If the actual concentration value N in the drainage pipeline does not meet the monitoring conditions, repeat Step 4; after reaching the upper limit of the repetition times, execute Step 5.

[0023] Step 5: Adjust the concentration reference value M and repeat Step 4; if the monitoring conditions still cannot be met after repeating Step 4, execute Step 6.

[0024] Step 6: After eliminating the instrument failure, maintain the current state for gas drainage.

[0025] As the gas drainage work progresses, the gas content in the borehole gradually decays. If the monitoring conditions still cannot be met after adjusting the concentration reference value M, the system prompts the staff. After manually eliminating problems such as instrument failures, it is considered that the gas concentration is at a low level at this time, and adjusting the negative pressure can no longer achieve obvious effects. Maintain the current state and continue gas drainage without further control.

[0026] Through continuous evaluation and calculation of the above process, the parameters of borehole drainage, pipeline network drainage, and pumping station drainage are adjusted and controlled step by step, realizing the reasonable distribution of the drainage capacity of the entire gas drainage system and the significant improvement of energy efficiency.

[0027] Embodiment 1 This embodiment provides a multi-level control method for gas drainage, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform in the mine; According to the actual gas drainage system and drainage status of a certain mine, 3 groups of measurement and control devices are arranged on the borehole drainage pipeline; 2 groups of measurement and control devices are arranged on the pipeline network drainage pipeline; 1 group of measurement and control devices are arranged on the pumping station drainage pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the borehole, pipeline network, and pumping station. A drainage measurement and control server 1 is arranged on the ground, and an information transmission network above and below the well is formed through communication facilities such as communication cables and switches, building a mine gas drainage measurement and control platform; Step 2: The gas drainage measurement and control platform collects the concentration parameters in the gas drainage pipeline in real time; Step 3: The gas drainage measurement and control platform judges whether the drainage pipeline network where each drainage control group is located needs to be controlled by collecting the concentration parameters and setting the concentration reference value M; Step 3-1: Set the drainage concentration reference value M of the borehole drainage pipeline to 15%; Step 3-2: When the extraction has been carried out for 10 days, through monitoring, the actual concentration value N in the extraction pipeline is 10%, which is lower than the set reference value M, and it is judged that regulation is required; Step 4: Regulate the extraction pipeline concentrations of the boreholes, pipeline network, and pumping station in sequence; Regulate the 3 valves on the borehole extraction pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level regulation model for gas extraction, input the extraction days of 10 days and the target concentration value of 15% into the model, and obtain the corresponding output negative pressure value P of 13.5 kPa; Step 4-2: The multi-level control system for gas extraction sends a regulation instruction to the PLC measurement and control sub-station belonging to the extraction pipeline to be regulated, changes the opening degree of the electric regulation valve on the extraction pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the regulation ends; After the regulation ends, the actual data concentration C for the day's working condition is obtained as 15.6% and the negative pressure P is 13.3 kPa. The concentration C is greater than the reference value M, and the regulation is completed.

[0028] Embodiment 2 This embodiment provides a multi-level control method for gas extraction, which is specifically implemented according to the following steps: Step 1: Build a gas extraction measurement and control platform in the mine; According to the actual gas extraction system and extraction status of a certain mine, 5 groups of measurement and control devices are arranged on the borehole extraction pipeline; 3 groups of measurement and control devices are arranged on the extraction pipeline network; 2 groups of measurement and control devices are arranged on the extraction pumping station pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the boreholes, pipeline network, and pumping station. A gas extraction measurement and control server 1 is arranged on the ground, and an information transmission network between the well and the ground is formed through communication facilities such as communication cables and switches, and a gas extraction measurement and control platform for the mine is built; Step 2: The gas extraction measurement and control platform collects the concentration parameters in the gas extraction pipeline in real time; Step 3: The gas extraction measurement and control platform judges whether the extraction pipeline network where each extraction regulation group is located needs to be regulated by collecting the concentration parameters and setting the concentration reference value M; Step 3-1: Set the concentration reference value M for the borehole extraction pipeline to 30%; Step 3-2: When the extraction has been carried out for 15 days, through monitoring, the actual concentration value N in the extraction pipeline is 25%, which is lower than the set reference value M, and it is judged that regulation is required; Step 4: Regulate the extraction pipeline concentrations of the boreholes, pipeline network, and pumping station in sequence; Regulate the 5 valves on the borehole extraction pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level control model of gas drainage, input the drainage days of 15 days and the target concentration value of 30% into the model, and obtain the corresponding output negative pressure value P of 14 kPa; Step 4-2: The multi-level control system of gas drainage sends a control instruction to the PLC measurement and control sub-station belonging to the drainage pipeline that needs to be controlled, changes the opening of the electric control valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. The control ends when the actual negative pressure value P reaches the target negative pressure value P0; After the control ends, the actual data concentration C of the day's working condition is obtained as 27% and the negative pressure P is 15 kPa. Since the concentration C is less than the reference value M, continue the control; Step 5: After 3 times of control, the target concentration value of 30% is still not reached. After judging that the gas content has decayed, adjust the reference value M to 26%, the adjusted output negative pressure value P is 15.3 kPa, and conduct drainage at a fixed negative pressure to end the control.

[0029] Embodiment 3 This embodiment provides a multi-level control method for gas drainage, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform in the mine; According to the actual gas drainage system and drainage status of a certain mine, 2 groups of measurement and control equipment are arranged on the borehole drainage pipeline; 1 group of measurement and control equipment is arranged on the drainage network pipeline; 1 group of measurement and control equipment is arranged on the drainage pump station pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the borehole, network and pump station. A drainage measurement and control server 1 is arranged on the ground, and an information transmission network above and below the well is formed through communication facilities such as communication cables and switches, and a mine gas drainage measurement and control platform is built; Step 2: The gas drainage measurement and control platform collects the concentration parameters in the gas drainage pipeline in real time; Step 3: The gas drainage measurement and control platform judges whether the drainage network where each drainage control group is located needs to be controlled by collecting the concentration parameters and setting the concentration reference value M; Step 3-1: Set the drainage concentration reference value M to 10%; Step 3-2: When the drainage reaches the 30th day, through monitoring, the actual concentration value N in the drainage pipeline is 8%, which is lower than the set reference value M, and it is judged that control is required; Step 4: Control the drainage pipeline concentrations of the borehole, network and pump station in sequence; Control the 2 valves on the borehole drainage pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level control model of gas drainage, input the drainage days of 30 days and the target concentration value of 10% into the model, and obtain the corresponding output negative pressure value P of 13.2 kPa; Step 4-2: The multi-level gas drainage control system sends a control instruction to the PLC measurement and control sub-station belonging to the drainage pipeline to be controlled, changes the opening degree of the electric control valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the control ends. After the control ends, the actual data concentration C on the day is obtained as 11% and the negative pressure P is 13 kPa. Since the actual concentration C is greater than the concentration reference value M, the control is completed.

[0030] When the drainage lasts for 60 days, the monitored concentration C is 9%, which is less than the reference value M. According to the above process for control, based on the multi-level gas drainage control model, when the input of the model is the drainage days of 60 days and the target concentration value of 10% on the day, the corresponding output negative pressure value P is 14.5 kPa, and the opening degree of the valve is adjusted to make the drainage negative pressure reach the target value. After repeating Step 4, the actual concentration value N still does not reach the reference value M. The reference value M is adjusted and Step 4 is repeated, but the monitoring conditions still cannot be met. After excluding problems such as instrument failures, it is considered that the gas concentration is at a low level at this time, and adjusting the negative pressure can no longer achieve obvious effects. The current state is maintained and the drainage continues without further control.

[0031] Example 4 This example provides a multi-level gas drainage control method, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform in the mine. According to the actual gas drainage system and drainage status of a certain mine, 6 sets of measurement and control equipment are arranged on the borehole drainage pipeline; 4 sets of measurement and control equipment are arranged on the drainage pipeline network; 2 sets of measurement and control equipment are arranged on the drainage pump station pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the borehole, pipeline network and pump station. A drainage measurement and control server 1 is arranged on the ground, and an information transmission network above and below the well is formed through communication facilities such as communication cables and switches, and a mine gas drainage measurement and control platform is built. Step 2: The gas drainage measurement and control platform collects the concentration parameters in the gas drainage pipeline in real time. Step 3: The gas drainage measurement and control platform judges whether the drainage pipeline network where each drainage control group is located needs to be controlled by collecting the concentration parameters and setting the concentration reference value M. Step 3-1: Set the concentration reference value M of the borehole drainage pipeline to 20%. Step 3-2: When the drainage reaches the 10th day, through monitoring, the actual concentration value N in the drainage pipeline is 15%, which is lower than the set reference value M, and it is judged that control is required. Step 4: Control the drainage pipeline concentrations of the borehole, pipeline network and pump station in sequence. Control the 6 valves on the borehole drainage pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level regulation model for gas drainage, input the number of drainage days of 10 days and the target concentration value of 20% into the model, and obtain the corresponding output negative pressure value P of 13.6 kPa. Step 4-2: The multi-level control system for gas drainage sends a regulation instruction to the PLC measurement and control sub-station belonging to the drainage pipeline to be regulated, changes the opening degree of the electric regulation valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the regulation ends. After the regulation ends, the actual data concentration C of the day's working condition is obtained as 22% and the negative pressure P is 13.8 kPa. Since the concentration C is greater than the reference value M, the regulation is completed.

[0032] Embodiment 5 This embodiment provides a multi-level control method for gas drainage, which is specifically implemented according to the following steps: Step 1: Build a measurement and control platform for gas drainage in the mine. According to the actual gas drainage system and drainage status of a certain mine, 15 groups of measurement and control equipment are arranged on the borehole drainage pipeline; 5 groups of measurement and control equipment are arranged on the drainage pipeline network; 3 groups of measurement and control equipment are arranged on the drainage pump station pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the borehole, pipeline network and pump station. A drainage measurement and control server 1 is arranged on the ground, and an information transmission network above and below the well is formed through communication facilities such as communication cables and switches, thus building a measurement and control platform for mine gas drainage. Step 2: The measurement and control platform for gas drainage collects the concentration parameters in the gas drainage pipeline in real time. Step 3: The measurement and control platform for gas drainage judges whether the drainage pipeline network where each drainage regulation group is located needs to be regulated by collecting the concentration parameters and setting the concentration reference value M. Step 3-1: Set the concentration reference value M of the borehole drainage pipeline to 35%. Step 3-2: When the drainage reaches the 25th day, through monitoring, the actual concentration value N in the drainage pipeline is 25%, which is lower than the set reference value M, and it is judged that regulation is required. Step 4: Regulate the drainage pipeline concentrations of the borehole, pipeline network and pump station in sequence. Regulate the 15 valves on the borehole drainage pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level regulation model for gas drainage, input the number of drainage days of 25 days and the target concentration value of 35% into the model, and obtain the corresponding output negative pressure value P of 15 kPa. Step 4-2: The multi-level control system for gas drainage sends a regulation instruction to the PLC measurement and control sub-station belonging to the drainage pipeline to be regulated, changes the opening degree of the electric regulation valve on the drainage pipeline, and monitors the change of the negative pressure value P in real time. When the actual negative pressure value P reaches the target negative pressure value P0, the regulation ends. After the regulation ends, the actual data concentration C of the daily working condition is obtained as 30%, and the negative pressure P is 14.6 kPa. Since the concentration C is less than the reference value M, continue the regulation; Step 5: After two regulations, the actual data concentration C of the daily working condition is obtained as 36%, and the negative pressure P is 15.2 kPa. Since the concentration C is greater than the reference value M, the regulation is completed.

[0033] Example 6 This example provides a multi-level control method for gas drainage, which is specifically implemented according to the following steps: Step 1: Build a gas drainage measurement and control platform in the mine; According to the actual gas drainage system and drainage status of a certain mine, 3 groups of measurement and control equipment are arranged on the borehole drainage pipeline; 1 group of measurement and control equipment is arranged on the drainage pipeline network; 1 group of measurement and control equipment is arranged on the drainage pump station pipeline, and 1 PLC measurement and control sub-station is arranged beside each of the borehole, pipeline network and pump station. A drainage measurement and control server 1 is arranged on the ground, and an information transmission network between the well and the ground is formed through communication facilities such as communication cables and switches, thus building a mine gas drainage measurement and control platform; Step 2: The gas drainage measurement and control platform continuously collects the concentration parameters in the gas drainage pipeline; Step 3: The gas drainage measurement and control platform determines whether the drainage pipeline network where each drainage regulation group is located needs to be regulated by collecting the concentration parameters and setting the concentration reference value M; Step 3-1: Set the concentration reference value M of the borehole drainage pipeline to 10%; Step 3-2: When the drainage reaches the 5th day, through monitoring, the actual concentration value N in the drainage pipeline is 5%, which is lower than the set reference value M, and it is determined that regulation is required; Step 4: Regulate the drainage pipeline concentrations of the borehole, pipeline network and pump station in sequence; Regulate the 3 valves on the borehole drainage pipeline. The specific steps are as follows: Step 4-1: Based on the multi-level gas drainage regulation model, input the 5th day of the daily drainage days and the target concentration value of 10% into the model, and the corresponding output negative pressure value P is obtained as 13.2 kPa; Step 4-2: The multi-level gas drainage control system sends a regulation instruction to the PLC measurement and control sub-station to which the drainage pipeline to be regulated belongs, changes the opening of the electric regulation valve on the drainage pipeline, and continuously monitors the change of the negative pressure value P. When the actual negative pressure value P reaches the target negative pressure value P0, the regulation ends; After the regulation ends, the actual data concentration C of the daily working condition is obtained as 8%, and the negative pressure P is 13.3 kPa. Since the concentration C is less than the reference value M, continue the regulation; Step 5: If the target concentration value of 10% is still not reached after 3 regulations, reset the reference value M and repeat Step 4. If the monitoring conditions still cannot be met, and after evaluation, it is determined that the gas content has attenuated, then conduct gas extraction at the current fixed negative pressure to end the regulation.

Claims

1. A multi-level control method for gas drainage, characterized in that The implementation is specifically carried out according to the following steps: Step 1: Build a gas drainage measurement and control platform and execute the following steps; Step 2: Real-time monitor the actual gas concentration value N in the drainage pipeline; Step 3: Set the reference gas concentration value M for each drainage pipeline, and judge whether the actual concentration of the drainage pipeline needs to be regulated according to the monitoring conditions; If the monitoring conditions are met, maintain the current situation and continue monitoring; If the monitoring conditions are not met, execute Step 4; Step 4: Regulate the gas concentration in the boreholes, pipe networks, and pumping station drainage pipelines in sequence; After the regulation is completed, if the monitoring conditions are met, the regulation ends and monitoring continues. If the monitoring conditions are not met, repeat Step 4; after reaching the upper limit of the repetition times, execute Step 5; Step 5: Adjust the reference concentration value M and repeat Step 4; if the monitoring conditions still cannot be met after repeating Step 4, execute Step 6; Step 6: After excluding instrument failures, maintain the current state for gas drainage.

2. The gas drainage multi-level control method according to claim 1, wherein The gas drainage measurement and control platform is specifically built according to the following steps: Step 1-1: According to the layout of the existing gas drainage system and pipe network in the mine, construct a pumping station drainage regulation group (2), a pipe network drainage regulation group (3), and a borehole drainage regulation group (4); Step 1-2: Install a drainage measurement and control server (1) on the ground, and input a multi-level gas drainage control system into the drainage measurement and control server (1); Step 1-3: Connect the pumping station drainage regulation group (2), the pipe network drainage regulation group (3), the borehole drainage regulation group (4), and the drainage measurement and control server (1) by wired or wireless means to form an information transmission network above and below the mine, and transmit information and instructions between various parts.

3. The gas drainage multi-level control method according to claim 2, characterized in that, The pumping station drainage regulation group (2) includes a gas drainage pumping station (5), a pumping station measurement and control sub-station (6), and one or more groups of measurement and control devices installed on the pumping station drainage pipeline, which are connected by wired or wireless; the pipe network drainage regulation group (3) includes a pipe network measurement and control sub-station (7) and one or more groups of measurement and control devices installed on each pipe network drainage pipeline, which are connected by wired or wireless; the borehole drainage regulation group (4) includes a borehole measurement and control sub-station (8) and one or more groups of measurement and control devices installed on each borehole drainage pipeline, which are connected by wired or wireless; The pumping station measurement and control sub-station (6), the pipe network measurement and control sub-station (7), and the borehole measurement and control sub-station (8) are all PLC measurement and control sub-stations; the multi-level gas drainage control system receives the parameter information collected by each PLC measurement and control sub-station, judges whether regulation is needed, makes a regulation decision, and sends a regulation instruction to the corresponding PLC measurement and control sub-station.

4. The gas drainage multi-level control method according to claim 3, characterized in that One group of measurement and control devices includes 1 gas multi-parameter monitor (9) and 1 electric control valve (10); The gas multi-parameter monitor (9) collects gas drainage parameters, including gas drainage concentration and negative pressure; the electric control valve (10) collects working condition parameters, including valve opening and closing state and valve opening.

5. The gas drainage multi-level control method according to claim 1, characterized in that The monitoring condition is that the actual gas concentration value N in the drainage pipeline is not less than the reference gas concentration value M.

6. The gas drainage multi-level control method according to claim 4, wherein, The specific steps of Step 4 are as follows: Step 4-1: Input a multi-level gas drainage regulation model into the multi-level gas drainage control system, set the gas concentration c in the model as the reference concentration value M, input the cumulative drainage days d, and obtain the corresponding target negative pressure value P0; Step 4-2: The multi-level control system for gas drainage sends a control instruction to the PLC measurement and control sub-station, changes the opening degree of the electric control valve (10) on the drainage pipeline, and monitors the change of the negative pressure value P in real time. The control ends when the actual negative pressure value P reaches the target negative pressure value P0; After the control ends, if the actual concentration value N in the drainage pipeline meets the monitoring conditions, maintain the valve opening degree at this time and continue to monitor the gas concentration in the drainage pipeline; If the actual concentration value N in the drainage pipeline does not meet the monitoring conditions, repeat Step 4; after reaching the upper limit of the number of repetitions, execute Step 5.

7. The gas drainage multi-level control method according to claim 6, characterized in that, The multi-level control model for gas drainage is as follows: （1）， In the formula: is the gas compressibility factor, = 1; is the gas temperature, with the unit of K; is the drainage negative pressure, with the unit of Pa; is the density of the mixed gas, with the unit of kg / m 3 ; is the gas concentration, with the unit of %; is the specific heat capacity of the mixed gas, = 0.287 kJ / (kg·K); is the specific heat capacity of the gas, = 0.5182 kJ / (kg·K).

8. The gas drainage multi-level control method according to claim 1, characterized in that In Step 4, the upper limit of the number of repetitions is three times.

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