Gob-side entry retaining goaf positive and negative pressure synergistic fire extinguishing device based on fuzzy PID algorithm

Abstract

The utility model belongs to the technical field of mine safety and the technical field of automatic control, and particularly relates to a gob-side entry retaining gob positive and negative pressure synergistic fire extinguishing device based on a fuzzy PID algorithm. Comprising the steps that a plurality of drill holes are formed; a grouting pipeline, an exhaust pipeline and a nitrogen injection pipeline are arranged in each drill hole, a grouting nozzle is arranged on the grouting pipeline, an exhaust nozzle is arranged on the exhaust pipeline, a nitrogen injection nozzle is arranged on the nitrogen injection pipeline, the exhaust pipeline is communicated with an exhaust main pipe, and the nitrogen injection pipeline is communicated with a nitrogen injection main pipe; the grouting pump truck is connected with the grouting main pipe, and the grouting main pipe is connected with the grouting pipeline; the sensor group is arranged in the goaf and used for collecting goaf environment parameters; and the control system is in signal connection with the sensor group and is in signal connection with the valves on the exhaust pipeline and the nitrogen injection pipeline, and the control system dynamically adjusts the nitrogen injection flow and the exhaust negative pressure based on the real-time environmental parameters of the goaf.

Description

Technical Field

[0001] This utility model belongs to the fields of mine safety technology and automation control technology, specifically a positive and negative pressure coordinated fire extinguishing device for goaf areas along the goaf based on fuzzy PID algorithm. Background Technology

[0002] Goaf areas along the goaf are prone to spontaneous combustion due to air leakage. In the initial stage, the fire can be extinguished by rapidly injecting inert gas. However, due to the limitations of construction conditions and outdated fire-fighting equipment, this method often fails to achieve the desired rapid fire extinguishing effect. In the later stage, it may lead to the excessive levels of toxic and harmful gases, and in severe cases, it may cause a gas explosion. Therefore, it is crucial to achieve rapid fire extinguishing in goaf areas along the goaf.

[0003] The existing fire extinguishing technology for goaf areas along the goaf has shortcomings such as limited construction and equipment, poor fire extinguishing effect, and high safety risks. These are mainly due to the single technical means, outdated equipment, and lack of precise control.

[0004] 1. Limited construction conditions and firefighting equipment lead to poor fire suppression effectiveness: Current technologies for fire suppression in goaf areas along roadways often employ inert gas injection. However, due to limitations in construction conditions, drilling depth and angle are difficult to control precisely. Under complex geological conditions, boreholes are prone to deviation, affecting gas injection effectiveness. Outdated firefighting equipment makes it difficult to precisely adjust nitrogen injection flow rate and pressure, resulting in uneven nitrogen distribution and inability to fully cover the fire area in the goaf, thus hindering rapid fire suppression.

[0005] 2. Later-stage toxic and harmful gas exceedances: Due to ineffective initial firefighting, the fire continues to develop, leading to the ongoing oxidation and decomposition of coal in the goaf, producing large amounts of toxic and harmful gases, such as carbon monoxide. These gases accumulate in the goaf, and when their concentration exceeds safety standards, they pose a serious threat to the lives of mine workers. Improper gas injection and ventilation management during firefighting may also cause toxic and harmful gases to spread to other areas.

[0006] 3. In severe cases, it may trigger a gas explosion: Combustible gases such as methane are already present in the goaf. When a fire continues to develop and firefighting measures are inadequate, the high temperature can cause a large amount of methane to be released. If the oxygen content and methane concentration in the goaf reach the explosion limit at this time, a gas explosion is highly likely to occur upon contact with an ignition source. The lack of effective monitoring and precise control of key parameters such as methane concentration during firefighting makes it impossible to detect and eliminate potential explosion hazards in a timely manner. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a fire extinguishing device for positive and negative pressure coordination in goaf areas along the goaf, based on a fuzzy PID algorithm.

[0008] This utility model adopts the following technical solution: a positive and negative pressure coordinated fire extinguishing device for goaf retention along the goaf based on fuzzy PID algorithm, comprising:

[0009] Drilling, wherein the drilling is carried out on the side of the goaf along the goaf, and multiple drilling holes are set up;

[0010] Each borehole is equipped with a grouting pipeline, an air extraction pipeline, and a nitrogen injection pipeline. The grouting pipeline is equipped with a grouting nozzle, the air extraction pipeline is equipped with an air extraction nozzle, and the nitrogen injection pipeline is equipped with a nitrogen injection nozzle. The air extraction pipeline is connected to the main air extraction pipeline, and the nitrogen injection pipeline is connected to the main nitrogen injection pipeline.

[0011] Grouting pump truck, the grouting pump truck is connected to the grouting main pipe, and the grouting main pipe is connected to the grouting pipeline;

[0012] A sensor array, which is installed in the goaf area to collect environmental parameters of the goaf area;

[0013] The control system is connected to the sensor group and to the valves on the extraction pipeline and the nitrogen injection pipeline. The control system dynamically adjusts the nitrogen injection flow rate and extraction negative pressure based on the real-time environmental parameters of the empty area.

[0014] In some embodiments, the sensor group includes an oxygen sensor, a gas sensor, a carbon monoxide concentration sensor, a temperature sensor, and a pressure sensor.

[0015] In some embodiments, the boreholes include horizontal boreholes and upwardly inclined boreholes, which are arranged intersectingly with each other.

[0016] In some embodiments, the elevation angle of the upward inclined borehole is 15°-45°, the distance between the horizontal borehole and the inclined borehole is 2-5 meters, and the depth of the inclined borehole is 1-3 meters deeper than that of the horizontal borehole.

[0017] In some embodiments, the grouting nozzle, nitrogen injection nozzle, and air extraction nozzle are distributed in three sections within the borehole, wherein the grouting nozzle is located at the bottom section of the borehole, the air extraction nozzle is located in the middle section, and the nitrogen injection nozzle is located at the borehole opening section, with a spacing of 0.5-1.2 meters between each nozzle.

[0018] In some embodiments, a protective steel pipe is provided inside the borehole.

[0019] In some embodiments, the control system includes:

[0020] The data acquisition module is connected to the sensor group and receives oxygen concentration, gas concentration, carbon monoxide concentration, temperature and pressure parameters collected by each sensor.

[0021] The target setting module is used to set the safety target values ​​and allowable fluctuation ranges for various environmental parameters;

[0022] The fuzzy inference module is configured with an error calculation unit, a fuzzification processing unit, a fuzzy rule base, and a defuzzification unit, wherein:

[0023] The error calculation unit is used to calculate the error e and the error change rate ec based on the deviation between the actual measured value and the target value of each sensor in the sensor group.

[0024] The fuzzification processing unit converts e and ec into fuzzy quantities and forms a fuzzy subset;

[0025] The fuzzy rule base stores control rules. Based on the input fuzzy subset and the fuzzy rule base, the fuzzy set is calculated.

[0026] The defuzzification unit converts the fuzzy inference result into a precise value;

[0027] The PID parameter self-tuning module adjusts the control parameters in real time based on the precise values ​​obtained after defuzzification.

[0028] The execution control module is connected to the negative pressure regulating valve of the air extraction pipeline and the flow regulating valve of the nitrogen injection pipeline. The execution control module calculates and outputs control parameters based on the PID parameter self-tuning module and drives the actuator.

[0029] In some embodiments, , , where r is the target value and y is the actual value.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. Solving the problem of rapid fire extinguishing: Existing methods of rapidly injecting inert gas for fire extinguishing are limited by construction conditions and outdated fire extinguishing equipment, making it difficult to achieve rapid fire extinguishing. This utility model, through an innovative drilling arrangement and multi-pipeline coordinated operation, first uses cement grout to seal air leaks, and then combines nitrogen injection and air extraction to create positive and negative pressure synergy, striving to improve the fire extinguishing speed and achieve the goal of efficient fire extinguishing.

[0032] 2. Achieving uniform nitrogen distribution: In previous fire extinguishing processes, uneven nitrogen injection affected the extinguishing effect. This invention uses a fuzzy PID algorithm to control the nitrogen injection flow rate and the negative pressure of the extraction, dynamically adjusting the control parameters based on real-time environmental parameters of the goaf, resulting in a more uniform nitrogen distribution within the goaf, enhancing the inerting effect, and effectively suppressing spontaneous combustion of coal.

[0033] 3. Avoiding the risk of excessive levels of toxic and harmful gases and gas explosions: Existing technologies, due to untimely or incomplete fire extinguishing, can easily lead to excessive levels of toxic and harmful gases in the later stages, and in severe cases, may even cause gas explosions. This solution reduces the duration of fires and the generation of toxic and harmful gases through rapid fire extinguishing and precise gas control. At the same time, it monitors and regulates the gas composition in the goaf in real time to prevent gas accumulation from reaching the explosion limit, thus ensuring safe production in the mine. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of this utility model;

[0035] Figure 2 A schematic diagram showing the included angle between a horizontal borehole and an upwardly inclined borehole used for borehole mining.

[0036] Figure 3 This is a schematic diagram of the control principle of this utility model;

[0037] In the diagram, 1-grouting nozzle; 2-nitrogen injection nozzle; 3-extraction nozzle; 4-grouting pipeline; 5-extraction pipeline; 6-nitrogen injection pipeline; 7-hole protection steel pipe; 8-goaf retention roadway; 9-grouting pump truck; 10-grouting main pipe; 11-grouting valve; 12-extraction main pipe; 13-nitrogen injection main pipe. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0039] like Figure 1 As shown, a fire extinguishing device for positive and negative pressure coordination in goaf areas along the goaf, based on a fuzzy PID algorithm, includes:

[0040] The drilling is a drilling operation carried out on the side of the goaf along the goaf 8 roadway, and multiple drilling operations are set up.

[0041] Each borehole is equipped with a grouting pipe 4, an air extraction pipe 5, and a nitrogen injection pipe 6. A grouting nozzle 1 is installed on the grouting pipe 4, an air extraction nozzle 3 is installed on the air extraction pipe 5, and a nitrogen injection nozzle 2 is installed on the nitrogen injection pipe 6. The air extraction pipe 5 is connected to the main air extraction pipe 12, and the nitrogen injection pipe 6 is connected to the main nitrogen injection pipe 13.

[0042] Grouting pump truck 9, which is connected to grouting main pipe 10, and grouting main pipe 10 is connected to grouting pipeline 4;

[0043] A sensor array, which is installed in the goaf area to collect environmental parameters of the goaf area;

[0044] The control system is connected to the sensor group and to the valves on the extraction pipeline 5 and the nitrogen injection pipeline 6. The control system dynamically adjusts the nitrogen injection flow rate and extraction negative pressure based on the real-time environmental parameters of the empty area.

[0045] Specifically, the sensor group includes an oxygen sensor, a gas sensor, a carbon monoxide concentration sensor, a temperature sensor, and a pressure sensor.

[0046] Specifically, the boreholes include horizontal boreholes and upwardly inclined boreholes, which are arranged alternately. The elevation angle of the upwardly inclined boreholes is 15°-45°, the distance between the horizontal boreholes and the inclined boreholes is 2-5 meters, and the depth of the inclined boreholes is 1-3 meters deeper than that of the horizontal boreholes.

[0047] Specifically, the grouting nozzle 1, the nitrogen injection nozzle 2, and the air extraction nozzle 3 are distributed in three sections within the borehole. The grouting nozzle 1 is located at the bottom of the borehole, the air extraction nozzle 3 is located in the middle section, and the nitrogen injection nozzle 2 is located at the borehole opening. The distance between each nozzle is 0.5-1.2 meters.

[0048] Drilling is carried out on the side of the goaf along the roadway, and the protective steel pipe 7 is left in the borehole to protect the borehole. Three pipes are laid in the protective steel pipe 7: a grouting pipe 4, a nitrogen injection pipe 6, and an air extraction pipe 5. The grouting pipe has a grouting valve 11 at the entrance to close the grouting pipe 4.

[0049] 1. Drilling Layout: Horizontal boreholes and upwardly inclined boreholes are arranged alternately during the goaf extraction process, such as... Figure 1 As shown, the advantage of this arrangement is that it takes into account the three-dimensional space of the goaf, enabling three-dimensional fire prevention and extinguishing of the goaf. Specifically, the horizontal boreholes I101, II103, ... of the goaf can be arranged horizontally, while the upwardly inclined boreholes I102, II104, ... can be arranged upwardly inclined.

[0050] The drilling adopts a combination of horizontal drilling and upward inclined drilling. This arrangement can take into account the three-dimensional space of the goaf, laying the foundation for subsequent three-dimensional fire prevention and extinguishing work, and enabling each pipeline to penetrate into different locations in the goaf to play its role.

[0051] 2. During implementation, first start the grouting pump truck 9. The grouting pump truck will pump cement slurry through the grouting main pipe 10 into the grouting pipeline 4 in each borehole, and then spray it outward through the grouting nozzle 1. At this time, the air extraction pipeline and nitrogen injection pipeline will not be opened temporarily. Since the grouting nozzle is close to the goaf roadway 8, the accumulated cement slurry can seal the air leakage between the goaf and the goaf roadway, isolating the goaf from the outside. Because the grouting nozzle is close to the goaf roadway, the accumulated cement slurry can seal the air leakage between the goaf and the goaf roadway, isolating the goaf from the outside and preventing oxygen from entering the goaf. This reduces the conditions for spontaneous combustion of coal at the source and creates a favorable environment for subsequent fire extinguishing operations.

[0052] 3. Simultaneously open the extraction main pipe 12 and the nitrogen injection main pipe 13. Nitrogen is injected into the goaf through the nitrogen injection nozzle 2. At the same time, due to the negative pressure, the extraction nozzle 3 draws air out, forming a local negative pressure in the goaf, which plays a role in guiding the flow of nitrogen and can make the nitrogen flow in the specified direction.

[0053] Positive and negative pressure coordination: After the main extraction pipe and the main nitrogen injection pipe are turned on, nitrogen is injected into the goaf through the nitrogen injection pipe. At the same time, the extraction pipe uses negative pressure to extract the gas, forming a local negative pressure to guide the nitrogen flow, so that the nitrogen flows in the specified direction and is more evenly distributed in the goaf, thereby improving the fire extinguishing efficiency of nitrogen and enhancing the inerting effect.

[0054] The control system includes:

[0055] The data acquisition module is connected to the sensor group and receives oxygen concentration, gas concentration, carbon monoxide concentration, temperature and pressure parameters collected by each sensor.

[0056] The target setting module is used to set the safety target values ​​and allowable fluctuation ranges for various environmental parameters;

[0057] The fuzzy inference module is configured with an error calculation unit, a fuzzification processing unit, a fuzzy rule base, and a defuzzification unit, wherein:

[0058] The error calculation unit is used to calculate the error e and the error change rate ec based on the deviation between the actual measured value and the target value of each sensor in the sensor group.

[0059] The fuzzification processing unit converts e and ec into fuzzy quantities and forms a fuzzy subset;

[0060] The fuzzy rule base stores control rules. Based on the input fuzzy subset and the fuzzy rule base, the fuzzy set is calculated.

[0061] The defuzzification unit converts the fuzzy inference result into a precise value;

[0062] The PID parameter self-tuning module adjusts the control parameters in real time based on the precise values ​​obtained after defuzzification.

[0063] The execution control module is connected to the negative pressure regulating valve of the air extraction pipeline and the flow regulating valve of the nitrogen injection pipeline. The execution control module calculates and outputs control parameters based on the PID parameter self-tuning module and drives the actuator.

[0064] To better control the nitrogen injection flow rate and extraction negative pressure, and to make the nitrogen distribution in the goaf more uniform, a fuzzy PID algorithm is used for control, as follows:

[0065] Fuzzy PID control method principle

[0066] Fuzzy PID control combines the advantages of fuzzy control and traditional PID control. Traditional PID control calculates the control input based on system error, error integral, and error derivative, enabling precise system adjustment. However, for complex, nonlinear, and time-varying systems, fixed PID parameters struggle to guarantee good control performance. Fuzzy control, on the other hand, mimics human thinking and decision-making, performing fuzzy inference on input information based on fuzzy rules. It does not rely on precise mathematical models and is highly adaptable to complex systems. Fuzzy PID control adjusts the proportional gain of the PID controller in real time using fuzzy rules. Integral coefficient and differential coefficients This enables the PID controller to automatically adjust parameters according to the actual operating conditions of the system, thereby enhancing the system's adaptability and robustness.

[0067] Fuzzy PID control method flow

[0068] 1. Data Collection

[0069] Various sensors (such as oxygen, gas, and carbon monoxide concentration sensors, temperature and pressure sensors, etc.) are used to collect environmental parameters of the goaf area and data such as nitrogen injection flow rate and negative pressure of the negative pressure extraction pipeline, and transmit them to the control system.

[0070] 2. Set target value

[0071] Based on the actual conditions and safety requirements of the goaf area, target values ​​or target ranges are set for each monitoring parameter.

[0072] 3. Error Calculation

[0073] Calculate the error e between the actual value and the target value of each monitoring parameter, and the rate of change of error ec, using the following formula: (r is the target value, y is the actual value). .

[0074] 4. Blurring process

[0075] The precise error *e* and the rate of change of error *ec* are converted into fuzzy quantities. The ranges of error and rate of change of error are divided to form fuzzy subsets, and the membership degrees of *e* and *ec* to each fuzzy subset are determined using membership functions.

[0076] 5. Fuzzy rule reasoning

[0077] Construct a fuzzy rule base, with rules in the form of "if e is..." And EC is ,So yes , yes , yes Based on the fuzzification result of the input and the rule base, fuzzy inference methods are used to calculate... , and A fuzzy set.

[0078] 6. Deblurring

[0079] Methods such as the centroid method and the maximum membership method are used to transform fuzzy set forms , and Convert to an exact value.

[0080] 7. PID parameter adjustment

[0081] Based on the adjustment amount obtained from defuzzification, the parameters of the PID controller are adjusted in real time, using the following formula: , , .

[0082] 8. PID Control Calculation

[0083] Using the adjusted PID parameters, according to the PID control formula Calculate the controller output u(t).

[0084] 9. Execution Control

[0085] The control output u(t) is transmitted to the actuator (such as the flow regulating valve of the nitrogen injection equipment, the frequency converter of the negative pressure extraction equipment, etc.) to adjust the nitrogen injection flow and the negative pressure of the negative pressure extraction pipeline.

[0086] 10. Loop Feedback

[0087] The above process is repeated continuously to form a closed-loop feedback control system, ensuring that the environmental parameters of the goaf remain stable within the target range.

[0088] Fuzzy PID control method formula

[0089] 1. Traditional PID control formula

[0090]

[0091] Where u(t) is the controller output and e(t) is the error. This is the proportionality coefficient. The integral coefficient is... is the differential coefficient.

[0092] 2. PID parameter adjustment formula

[0093]

[0094]

[0095]

[0096] , , The adjustment amount is calculated by the fuzzy controller based on the error e and the error change rate ec.

[0097] 3. Formulas for calculating error and rate of change of error

[0098]

[0099]

[0100] r is the target value, and y is the actual value.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A gob-side entry retaining goaf positive and negative pressure cooperative fire extinguishing device based on a fuzzy PID algorithm, characterized in that, The application relates to a goaf environment control system. The goaf environment control system comprises: a plurality of drill holes for constructing a gob-side entry driving (8) in a lateral goaf, each drill hole is provided with a grouting pipeline (4), an air extraction pipeline (5) and a nitrogen injection pipeline (6), the grouting pipeline (4) is provided with a grouting nozzle (1), the air extraction pipeline (5) is provided with an air extraction nozzle (3), the nitrogen injection pipeline (6) is provided with a nitrogen injection nozzle (2), the air extraction pipeline (5) is communicated with an air extraction main pipe (12), and the nitrogen injection pipeline (6) is communicated with a nitrogen injection main pipe (13); a grouting pump truck (9) is connected with a grouting main pipe (10), the grouting main pipe (10) is connected with the grouting pipeline (4); a sensor group is arranged in the goaf and used for collecting goaf environment parameters; a control system is connected with the sensor group and connected with valves on the air extraction pipeline (5) and the nitrogen injection pipeline (6), and the control system dynamically adjusts nitrogen injection flow and air extraction negative pressure based on real-time goaf environment parameters.

2. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 1, characterized in that, The sensor group comprises oxygen sensors, gas sensors, carbon monoxide concentration sensors, temperature sensors and pressure sensors.

3. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 1, characterized in that, The drill holes comprise horizontal drill holes and upward inclined drill holes, and the drill holes are arranged in a cross mode.

4. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 3, characterized in that, The upward inclined drill holes have an elevation angle of 15-45 DEG, the horizontal drill holes and the inclined drill holes are spaced by 2-5 m, and the inclined drill holes are deeper than the horizontal drill holes by 1-3 m.

5. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 1, characterized in that, The grouting nozzle (1), the nitrogen injection nozzle (2) and the air extraction nozzle (3) are distributed in a three-section mode in the drill holes, the grouting nozzle (1) is arranged at the bottom section of the drill hole, the air extraction nozzle (3) is arranged at the middle section, the nitrogen injection nozzle (2) is arranged at the hole mouth section, and the spacing between the nozzles is 0.5-1.2 m.

6. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 1 or 3, characterized in that, A hole protection steel pipe (7) is arranged in the drill hole.

7. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 2, characterized in that, The control system comprises: a data acquisition module connected with the sensor group and receiving oxygen concentration, gas concentration, carbon monoxide concentration, temperature and pressure parameters collected by the sensors; a target setting module used for setting safe target values and allowable fluctuation ranges of the environment parameters; a fuzzy inference module provided with an error calculation unit, a fuzzy processing unit, a fuzzy rule base and a defuzzification unit, wherein: the error calculation unit is used for calculating error e and error change rate ec according to the deviation of actual measurement values of each sensor of the sensor group from target values; the fuzzy processing unit converts e and ec into fuzzy quantities and forms fuzzy subsets; the fuzzy rule base stores control rules, calculates fuzzy sets according to the input fuzzy subsets and the fuzzy rule base; the defuzzification unit converts the fuzzy inference result into an accurate value; a PID parameter self-adjusting module adjusts control parameters in real time according to the accurate value obtained through defuzzification; an execution control module is connected with a negative pressure regulating valve of the air extraction pipeline (5) and a flow regulating valve of the nitrogen injection pipeline (6), and the execution control module drives an execution mechanism according to the output control parameters calculated by the PID parameter self-adjusting module.

8. The positive and negative pressure cooperative fire extinguishing device for gob-side entry retaining based on the fuzzy PID algorithm according to claim 7, characterized in that, , where r is the target value and y is the actual value.

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