Gas monitoring system and monitoring process thereof, beam tube working state judgment method and fire prediction method

Abstract

The invention relates to the technical field of coal mine underground gas monitoring, in particular to a gas monitoring system, a monitoring process of the gas monitoring system, a beam tube working state judgment method and a fire prediction method.The gas monitoring system comprises an electronic differential pressure gauge, a third electromagnetic valve, a gas suction pump, a positive pressure water filter, a flow meter and a sensor assembly, the sensor assembly is arranged on the outer side of a goaf, the third electromagnetic valve is a three-way valve, the gas inlet end G of the third electromagnetic valve is communicated into a closed wall of the goaf and used for collecting gas in the goaf, the end H and the end I of the third electromagnetic valve are communicated with the electronic differential pressure gauge and the gas suction pump respectively, and the working state of the beam tube is judged according to the real-time flow of the gas in a pipeline. And based on the detected gas data, performing fire prediction in a non-priori condition mode. The gas detection accuracy can be improved, the gas detection efficiency is improved, the working state of the beam tube is judged in time, and fire prediction is carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of underground coal mine gas monitoring, in particular to a gas monitoring system and a monitoring process thereof, a bundle tube working state judgment method and a fire prediction method. Background Art

[0002] At present, domestic coal mines use pre-buried gas samplers, bundle tubes and gas monitoring rods in places where monitoring personnel cannot enter, such as the goaf of the coal mining face, the corner of the return air, the high-risk area of ​​the tunnel, the unused coal chute, and the closed area of ​​the goaf and reserved lanes. The common monitoring method is to use a hand-held balloon or gas sampler for sampling, and then send the gas sample to the bladder and then to the ground monitoring room for gas analysis. The gas sampling process and the process of sending the bladder to the ground require a certain amount of operation time. At the same time, the gas is prone to change if it stays in the bladder for too long, which reduces the accuracy of gas monitoring.

[0003] At the same time, since the confined areas are mostly located in remote locations underground and are closed spaces, it is difficult for personnel to reach them. If the monitoring pipeline is damaged or blocked by falling rocks, it is impossible to judge from the monitoring data, and it is difficult to find fire hazards or accidents, which may cause hidden dangers. Moreover, there is currently no convenient and simple fire prediction method for gas monitoring results. At present, the prediction of spontaneous combustion in coal mines is based on a single gas indicator (such as CO content) or a multi-indicator coefficient (such as the alkane-olefin ratio C2H6 / C2H4). However, there are many types of coal, and the ignition characteristics of each type of coal are different. Using a unified indicator to estimate based on experience and a single parameter value has low accuracy. Summary of the invention

[0004] The present invention aims to solve the above problems and provides a gas monitoring system and its monitoring process, a method for determining the working state of a bundle tube and a method for predicting fire. The technical solutions adopted are as follows: A gas monitoring system comprises an electronic differential pressure gauge, a third solenoid valve, an air suction pump, a positive pressure water filter, a flow meter and a sensor assembly which are connected in sequence, wherein the sensor assembly is arranged outside a goaf, the third solenoid valve is a three-way valve, the air inlet end G of the third solenoid valve is connected to the closed wall of the goaf for collecting gas in the goaf, the H end and the I end of the third solenoid valve are respectively connected to the electronic differential pressure gauge and the air suction pump, when the GH gas path of the third solenoid valve is connected, the electronic differential pressure gauge measures the air pressure difference between the goaf and the outside, when the GI gas path of the third solenoid valve is connected, the air suction pump draws air from the goaf and passes it into the sensor assembly for gas monitoring, and the H end and the I end of the third solenoid valve are not connected.

[0005] Based on the above scheme, the sensor assembly includes a sensor chamber and a sensor. There are multiple sensors, which are detachably installed in the sensor chamber. The multiple sensors are connected in sequence, and the target detection gas of each sensor is different. The sensor chamber is provided with an air inlet and an air outlet connected to its internal space, and the air inlet and the air outlet are connected to the sensor.

[0006] Preferably, there are multiple goafs to be monitored, and monitoring points are set in each goaf, and gas circuit valves for controlling the on-off of the gas circuit are set between different monitoring points; at the same time, at most only one monitoring point is connected to the air inlet end of the third solenoid valve.

[0007] On the basis of the above scheme, the gas circuit valve is a first solenoid valve and a second solenoid valve, the first solenoid valve and the second solenoid valve are both three-way valves, the B end of the first solenoid valve is connected to the first monitoring point in the first goaf, the A end is connected to the G end of the third solenoid valve, the C end is connected to the D end of the second solenoid valve, and the E end and the F end of the second solenoid valve are respectively connected to the second monitoring point in the second goaf and the third monitoring point in the third goaf; the B end and the C end of the first solenoid valve are not connected, and the E end and the F end of the second solenoid valve are not connected; When the AB gas circuit of the first solenoid valve is connected and the AC gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the first monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is connected, and the DF gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the second monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is disconnected, and the DF gas circuit is connected, the air intake end G of the third solenoid valve is connected to the third monitoring point.

[0008] Preferably, the positive pressure water filter is provided with an exhaust port, which is connected to the outside to discharge excess gas and filtered water.

[0009] A monitoring process of a gas monitoring system, using the above-mentioned gas monitoring system, includes the following steps: S1. The third solenoid valve is started, and the GH gas path is connected, and the electronic differential pressure gauge measures the pressure difference between the goaf and the outside world; S2. Judge the measured air pressure difference: if the air pressure in the goaf is lower than the air pressure outside the closed wall, it means that the closed wall in the goaf is leaking; if the air pressure in the goaf is higher than the air pressure outside the closed wall, it means that there is no safety hazard and the next step of monitoring is carried out; S3. A flow meter is set upstream of the suction pump, and the suction pump is started. The flow meter monitors and determines the gas flow in the pipeline in real time. If the flow is normal, the next step of monitoring is carried out; S4. The gas discharged from the self-priming pump enters the sensor assembly after being filtered by the positive pressure water filter, and the content and concentration of various gases are detected in real time.

[0010] A method for judging the working state of a bundle pipe, in the monitoring process of a gas monitoring system, step S3 judges the state of a gas pipeline based on the monitoring result of the gas flow, comprising the following steps: A1. Calculate the theoretical real-time flow rate of the pipeline; A2. Calculate the theoretical real-time flow rate by proportional assignment to obtain the flow threshold range; A3. If the real-time gas flow rate in the pipeline is greater than the upper limit of the flow rate threshold, the pipeline is judged to be broken and in a disconnected state; if the real-time gas flow rate in the pipeline is less than the lower limit of the flow rate threshold, the pipeline is judged to be blocked and in a blocked state; A4. If the pipeline is in a disconnected state, the gas pipeline outside the goaf shall be inspected, repaired and replaced; if the pipeline is in a blocked state, the pipeline inside the goaf shall be maintained; A5. During and after pipeline maintenance, monitor the gas flow in real time until the gas flow is within the flow threshold range.

[0011] Based on the above solution, the loss flow of the pipeline for (1) Where D is the pipe diameter, is the dynamic viscosity of the gas, L is the length of the pipeline, is the pressure loss, pressure loss for (2) (3) (4) In the formula is the friction loss, For local losses, is the friction factor, is the gas density, is the gas density, is the local resistance coefficient, which is determined by the structure and number of valves and elbows in the pipeline. Real-time traffic for - (5) In the formula is the rated flow rate of the pipeline; The range of the assigned pipeline viscosity coefficient is 0.8~1.1, and the assigned pipeline length coefficient is 0.9~1.2. Define the lower limit of the traffic threshold as , define the upper limit of the flow threshold as , then the flow threshold is [ , ].

[0012] A fire prediction method, in the monitoring process of the gas monitoring system, step S4 analyzes the detection results of the gas content and concentration, including the following steps: B1. Preprocess the collected gas monitoring result data, including first removing outliers and missing values ​​in the data, and then standardizing the data; B2. Construct feature vectors using data from different time points at each monitoring point , with different gas concentrations and temperatures at the same time as the components of the characteristic vector, that is, , where O2, CO, CO2, CH4, C2H4, C2H2 and T represent the O2 concentration, CO concentration, CO2 concentration, CH4 concentration, C2H4 concentration, C2H2 concentration and temperature of the monitoring point at that time, respectively; B3. For different feature vectors, calculate the Euclidean distance between the vectors and use the Euclidean distance as the metric of similarity; B4. Under non-a priori conditions, use clustering algorithms to perform cluster analysis on the 100 sets of data collected and calculate the cluster centers; B5. Set the Euclidean distance threshold to determine whether the feature vector formed by the newly received data is close enough to the cluster center; B6. If the Euclidean distance between the feature vector formed by the newly received data and all cluster centers exceeds the Euclidean distance threshold, it indicates that the data point is abnormal and has a fire hazard; B7. When it is determined that there is a fire hazard, a fire warning will be issued to the host computer to prompt the staff to take safety measures or start the fire extinguishing procedure.

[0013] On the basis of the above scheme, after the cluster center is formed, the cluster center is continuously calculated and updated through the newly received data.

[0014] The beneficial effects of the present invention are: 1. Gas is collected and tested directly outside the underground goaf, which shortens the time for sampling and testing, improves the accuracy and efficiency of gas detection, and greatly reduces the workload of underground workers; 2. One set of monitoring system can meet the gas detection needs of multiple goafs, saving costs, reducing equipment failure rate and improving monitoring reliability; 3. By monitoring the real-time gas flow in the system, the status of the bundled pipe can be judged in time, so that corresponding measures can be taken to ensure the normal operation of the system, effectively avoid the phenomenon of missed fire hazards, and improve the safety of underground work; 4. Based on the above-mentioned gas monitoring system, a fire prediction algorithm without prior conditions is proposed. Combined with the pressure difference analysis results, it can comprehensively judge the presence and specific degree of fire hazards based on the gas in the goaf. The calculation is simple and fast, and it can be updated according to the increase of real-time data, thereby improving the accuracy of fire hazards and identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 : Flowchart of the working process of the gas monitoring system, the method for judging the working state of the bundle tube and the method for predicting fire of the present invention; Figure 2 : Schematic diagram of the principle of the gas monitoring system of the present invention; Figure 3 : Schematic diagram of the sensor assembly structure of the present invention; Figure 4 : A cross-sectional view of the sensor assembly of the present invention; Figure 5 : Partial data capture of the gas content and concentration detection results of the present invention; Figure 6 : Schematic diagram of cluster analysis coordinate scatter points of the present invention; Figure 7 : Schematic diagram of the setting range of the Euclidean distance threshold of the present invention; Figure 8 : Schematic diagram of fire hazard data point coordinates of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0017] In the description of the present invention, it should be understood that the terms "center", "length", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0018] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0019] like Figures 1 to 4 As shown, a gas monitoring system includes an electronic differential pressure gauge, a third solenoid valve, an air suction pump, a positive pressure water filter, a flow meter and a sensor assembly which are connected in sequence, wherein the sensor assembly is arranged outside the goaf, the third solenoid valve is a three-way valve, the air inlet end G of the third solenoid valve is connected to the closed wall of the goaf for collecting gas in the goaf, the H end and the I end of the third solenoid valve are connected to the electronic differential pressure gauge and the air suction pump respectively, when the GH gas path of the third solenoid valve is connected, the electronic differential pressure gauge measures the air pressure difference between the goaf and the outside world, when the GI gas path of the third solenoid valve is connected, the air suction pump draws air from the goaf and passes it into the sensor assembly for gas monitoring, the H end and the I end of the third solenoid valve are not connected, so as to avoid excessive negative pressure generated by the air suction pump and damage to the differential pressure gauge.

[0020] There are multiple goafs to be monitored, and monitoring points are set in each goaf, and gas valves for controlling the on-off of the gas path are set between different monitoring points; at most only one of the monitoring points is connected to the gas inlet end of the third solenoid valve at the same time. Thus, gas monitoring in multiple goafs can be completed through one set of monitoring equipment.

[0021] Preferably, taking the number of goafs as three as an example, the gas circuit valves are a first solenoid valve and a second solenoid valve, both the first solenoid valve and the second solenoid valve are three-way valves, the B end of the first solenoid valve is connected to the first monitoring point in the first goaf, the A end is connected to the G end of the third solenoid valve, the C end is connected to the D end of the second solenoid valve, the E end and the F end of the second solenoid valve are respectively connected to the second monitoring point in the second goaf and the third monitoring point in the third goaf; the B end and the C end of the first solenoid valve are not connected, and the E end and the F end of the second solenoid valve are not connected; When the AB gas circuit of the first solenoid valve is connected and the AC gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the first monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is connected, and the DF gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the second monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is disconnected, and the DF gas circuit is connected, the air intake end G of the third solenoid valve is connected to the third monitoring point.

[0022] When the number of goafs is other than that, the solenoid valves can be arranged according to the above scheme, and the gas circuits between the solenoid valves can be designed.

[0023] The sensor assembly includes a sensor chamber and a sensor. There are multiple sensors, which are detachably installed in the sensor chamber. The multiple sensors are connected in sequence, and the target detection gas of each sensor is different. The sensor chamber is provided with an air inlet and an air outlet connected to its internal space, and the air inlet and the air outlet are connected to the sensor. Through the above structure, multiple gases can be detected by a set of sensor assemblies, and the faulty sensors can be replaced separately, saving equipment costs.

[0024] The positive pressure water filter is used to filter the moisture in the gas input into the sensor assembly. The positive pressure water filter is provided with an exhaust port, which is connected to the outside to discharge the excess gas and the filtered moisture.

[0025] The monitoring process of the above gas monitoring system includes the following steps: S1. The third solenoid valve is started, and the GH gas circuit is connected. The electronic differential pressure gauge measures the pressure difference between the goaf and the outside world. The gas circuit is opened and closed as needed, and the goaf to be monitored is selected, and it is set to switch the detection of each goaf in turn; S2. Judge the measured air pressure difference: if the air pressure in the goaf is lower than the air pressure outside the closed wall, it means that the closed wall in the goaf is leaking and there is a fire risk. Further analysis and calculation are required based on the fire prediction method to determine whether there is a fire hazard. If the air pressure in the goaf is higher than the air pressure outside the closed wall, it means there is no safety hazard and the next step of monitoring is carried out; S3. A flow meter is set upstream of the suction pump, and the suction pump is started. The flow meter monitors and judges the gas flow in the pipeline in real time. If the flow is normal, the next step of monitoring is carried out; if there is an abnormality in the gas flow, it is necessary to judge the working status of the bundle tube, and then perform corresponding equipment maintenance according to the judgment result; S4. The gas discharged from the self-priming pump enters the sensor assembly after being filtered by the positive pressure water filter, and the content and concentration of various gases are detected in real time.

[0026] A method for judging the working state of a bundle pipe, in the monitoring process of a gas monitoring system, step S3 judges the state of a gas pipeline based on the monitoring result of the gas flow, comprising the following steps: A1. Calculate the theoretical real-time flow rate of the pipeline; A2. Calculate the theoretical real-time flow rate by proportional assignment to obtain the flow threshold range; A3. If the real-time gas flow rate in the pipeline is greater than the upper limit of the flow rate threshold, the pipeline is judged to be broken and in a disconnected state; if the real-time gas flow rate in the pipeline is less than the lower limit of the flow rate threshold, the pipeline is judged to be blocked and in a blocked state; A4. If the pipeline is in a disconnected state, the gas pipeline outside the goaf should be inspected, repaired and replaced; if the pipeline is in a blocked state, the pipeline inside the goaf should be maintained, such as re-drilling holes in the closed wall of the goaf to set up new monitoring points, and inserting new gas pipes inside; A5. During and after pipeline maintenance, monitor the gas flow in real time until the gas flow is within the flow threshold range.

[0027] Specifically, the loss flow of the pipeline for (1) Where D is the pipe diameter, is the dynamic viscosity of the gas, L is the length of the pipeline, is the pressure loss, pressure loss for (2) (3) (4) In the formula is the friction loss, For local losses, is the friction factor, is the gas density, is the gas density, is the local resistance coefficient, which is determined by the structure and number of valves and elbows in the pipeline. Theoretical real-time traffic for - (5) In the formula is the rated flow rate of the pipeline; The range of the assigned pipeline viscosity coefficient is 0.8~1.1, and the assigned pipeline length coefficient is 0.9~1.2. Define the lower limit of the traffic threshold as , define the upper limit of the flow threshold as , then the flow threshold is [ , ].

[0028] A fire prediction method based on multi-parameter monitoring data, in the monitoring process of the gas monitoring system, step S4 analyzes the detection results of gas content and concentration, including the following steps: B1. Figure 5 For the interception content of the collected gas monitoring data, the collected gas monitoring result data is preprocessed, including first removing the abnormal values ​​and missing values ​​in the data, and then standardizing the data; B2. Construct feature vectors using data from different time points at each monitoring point , with different gas concentrations and temperatures at the same time as the components of the characteristic vector, that is, , where O2, CO, CO2, CH4, C2H4, C2H2 and T represent the O2 concentration, CO concentration, CO2 concentration, CH4 concentration, C2H4 concentration, C2H2 concentration and temperature of the monitoring point at that time, respectively; B3. For different feature vectors, calculate the Euclidean distance between the vectors and use the Euclidean distance as the metric of similarity; for two different feature vectors and , the Euclidean distance calculation formula between .

[0029] B4. Under non-a priori conditions, cluster analysis is performed on 100 groups of normal data collected without fire hazards using a clustering algorithm, and cluster centers are calculated; Figure 6 As shown, the number of cluster centers can be multiple and they do not overlap with each other; B5. Figure 7As shown, according to the test and verification, the Euclidean distance threshold is set to determine whether the feature vector formed by the newly received data is close enough to the cluster center; B6. Figure 8 As shown in the figure, if the Euclidean distance between the feature vector formed by the newly received data and all the cluster centers exceeds the Euclidean distance threshold, it indicates that the data point is abnormal and has a fire hazard; B7. When it is determined that there is a fire hazard, a fire warning will be issued to the upper computer to prompt the staff to take safety measures or start the fire extinguishing procedure, such as conducting further equipment inspections and arranging personnel evacuation.

[0030] Preferably, after the cluster center is formed, the cluster center is continuously calculated and updated through newly received data to adapt to changes in the environment and improve the accuracy of the early warning results.

[0031] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A gas monitoring system, characterized in that: It includes an electronic differential pressure gauge, a third solenoid valve, an air suction pump, a positive pressure water filter, a flow meter and a sensor assembly which are connected in sequence. The sensor assembly is arranged on the outside of the goaf. The third solenoid valve is a three-way valve. The air inlet end G of the third solenoid valve is connected to the closed wall of the goaf to collect gas in the goaf. The H end and I end of the third solenoid valve are connected to the electronic differential pressure gauge and the air suction pump respectively. When the GH gas path of the third solenoid valve is connected, the electronic differential pressure gauge measures the air pressure difference between the goaf and the outside world. When the GI gas path of the third solenoid valve is connected, the air suction pump draws air from the goaf and passes it into the sensor assembly for gas monitoring. The H end and I end of the third solenoid valve are not connected.

2. A gas monitoring system according to claim 1, characterized in that: The sensor assembly includes a sensor chamber and a sensor. There are multiple sensors, which are detachably installed in the sensor chamber. The multiple sensors are connected in sequence, and the target detection gas of each sensor is different. The sensor chamber is provided with an air inlet and an air outlet connected to its internal space, and the air inlet and the air outlet are connected to the sensor.

3. A gas monitoring system according to claim 1, characterized in that: There are multiple goafs to be monitored, and monitoring points are set in each goaf. Gas valves for controlling the on-off of the gas path are set between different monitoring points. At the same time, at most only one monitoring point is connected to the air inlet end of the third solenoid valve.

4. A gas monitoring system according to claim 3, characterized in that: The gas circuit valves are a first solenoid valve and a second solenoid valve, both of which are three-way valves, the B end of the first solenoid valve is connected to the first monitoring point in the first goaf, the A end is connected to the G end of the third solenoid valve, the C end is connected to the D end of the second solenoid valve, and the E end and the F end of the second solenoid valve are respectively connected to the second monitoring point in the second goaf and the third monitoring point in the third goaf; the B end and the C end of the first solenoid valve are not connected, and the E end and the F end of the second solenoid valve are not connected; When the AB gas circuit of the first solenoid valve is connected and the AC gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the first monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is connected, and the DF gas circuit is disconnected, the air intake end G of the third solenoid valve is connected to the second monitoring point; when the AB gas circuit of the first solenoid valve is disconnected and the AC gas circuit is connected, and at the same time the CD gas circuit between the first solenoid valve and the second solenoid valve is connected, the DE gas circuit of the second solenoid valve is disconnected, and the DF gas circuit is connected, the air intake end G of the third solenoid valve is connected to the third monitoring point.

5. A gas monitoring system according to claim 1, characterized in that: The positive pressure water filter is provided with an exhaust port, which is communicated with the outside to discharge excess gas and filtered water.

6. A monitoring process of a gas monitoring system, characterized in that: Using the gas monitoring system according to any one of claims 1 to 5 comprises the following steps: S1. The third solenoid valve is started, and the GH gas path is connected, and the electronic differential pressure gauge measures the pressure difference between the goaf and the outside world; S2. Judge the measured air pressure difference: if the air pressure in the goaf is lower than the air pressure outside the closed wall, it means that the closed wall in the goaf is leaking; if the air pressure in the goaf is higher than the air pressure outside the closed wall, it means that there is no safety hazard and the next step of monitoring is carried out; S3. A flow meter is set upstream of the suction pump, and the suction pump is started. The flow meter monitors and determines the gas flow in the pipeline in real time. If the flow is normal, the next step of monitoring is carried out; S4. The gas discharged from the self-priming pump enters the sensor assembly after being filtered by the positive pressure water filter, and the content and concentration of various gases are detected in real time.

7. A method for determining the working state of a bundle tube, characterized in that: In the monitoring process of the gas monitoring system, step S3 determines the gas pipeline status based on the monitoring result of the gas flow, including the following steps: A1. Calculate the theoretical real-time flow rate of the pipeline; A2. Calculate the theoretical real-time flow rate by proportional assignment to obtain the flow threshold range; A3. If the real-time gas flow rate in the pipeline is greater than the upper limit of the flow rate threshold, the pipeline is judged to be broken and in a disconnected state; if the real-time gas flow rate in the pipeline is less than the lower limit of the flow rate threshold, the pipeline is judged to be blocked and in a blocked state; A4. If the pipeline is in a disconnected state, the gas pipeline outside the goaf shall be inspected, repaired and replaced; if the pipeline is in a blocked state, the pipeline inside the goaf shall be maintained; A5. During and after pipeline maintenance, monitor the gas flow in real time until the gas flow is within the flow threshold range.

8. A method for determining the working state of a beam tube according to claim 7, characterized in that: The loss flow of the pipeline for （1） Where D is the pipe diameter, is the dynamic viscosity of the gas, L is the length of the pipeline, is the pressure loss, pressure loss for （2） （3） （4） In the formula is the friction loss, For local losses, is the friction factor, is the gas density, is the gas density, is the local resistance coefficient, which is determined by the structure and number of valves and elbows in the pipeline. Theoretical real-time traffic for - （5） In the formula is the rated flow rate of the pipeline; The range of the assigned pipeline viscosity coefficient is 0.8~1.1, and the assigned pipeline length coefficient is 0.9~1.

2. Define the lower limit of the traffic threshold as , define the upper limit of the flow threshold as , then the flow threshold is [ , ].

9. A fire prediction method, characterized in that: In the monitoring process of the gas monitoring system, step S4 analyzes the detection results of the gas content and concentration, including the following steps: B1. Preprocess the collected gas monitoring result data, including first removing outliers and missing values ​​in the data, and then standardizing the data; B2. Construct feature vectors using data from different time points at each monitoring point , with different gas concentrations and temperatures at the same time as the components of the characteristic vector, that is, , where O2, CO, CO2, CH4, C2H4, C2H2 and T represent the O2 concentration, CO concentration, CO2 concentration, CH4 concentration, C2H4 concentration, C2H2 concentration and temperature of the monitoring point at that time, respectively; B3. For different feature vectors, calculate the Euclidean distance between the vectors and use the Euclidean distance as the metric of similarity; B4. Under non-a priori conditions, use clustering algorithms to perform cluster analysis on the 100 sets of data collected and calculate the cluster centers; B5. Set the Euclidean distance threshold to determine whether the feature vector formed by the newly received data is close enough to the cluster center; B6. If the Euclidean distance between the feature vector formed by the newly received data and all cluster centers exceeds the Euclidean distance threshold, it indicates that the data point is abnormal and has a fire hazard; B7. When it is determined that there is a fire hazard, a fire warning will be issued to the host computer to prompt the staff to take safety measures or start the fire extinguishing procedure.

10. A fire prediction method according to claim 9, characterized in that: After the cluster centers are formed, they are continuously calculated and updated through newly received data.

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