Movable underground coal mine gas extraction method

Abstract

The invention relates to the technical field of gas extraction, in particular to a movable underground coal mine gas extraction method. The method comprises the following steps: acquiring gas concentration data of each key position of an underground coal mine at each moment; acquiring an initial gas extraction position according to the gas concentration data of the key position in the initial specified time period; according to the gas concentration data difference between the reference position and the initial gas extraction position in each target time period and the increasing condition of the gas concentration data of the reference position, the extraction degree of each reference position at the ending moment of each target time period is obtained, and then a second gas extraction position is obtained; and in the same way, the gas extraction position is obtained in real time, and gas extraction of the underground coal mine is stopped until the gas concentration data of the key positions are all smaller than the preset gas concentration safety threshold value. According to the method, the gas extraction position is obtained in real time, so that the gas extraction efficiency is improved, and the situation that the gas concentration in the coal mine is too high is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of gas drainage, and particularly to a movable gas drainage method for coal mines underground. Background Art

[0002] The gas in coal mines underground is a combustible gas mainly composed of methane, which is released from coal seams during the coal mining process. The gas is generated by the chemical changes and pyrolysis reactions of organic substances in coal seams under long-term geological conditions. The gas is toxic and flammable, posing a great threat to the safety of coal mining and affecting the efficiency of coal mining. In order to improve the efficiency and safety of coal mining, gas drainage in coal mines underground has become an important measure.

[0003] In the existing methods, gas in coal mines underground is drained by setting fixed positions. However, in actual situations, due to the fixed wind direction formed by the ventilation system in coal mines underground, it will interfere with the conventional diffusion mode of gas, and the position of gas leakage is random. Therefore, draining gas in coal mines underground through fixed positions will result in untimely gas drainage in coal mines underground, causing too high gas concentration in coal mine shafts, increasing the explosion risk, and seriously affecting the safety and efficiency of coal mining. Summary of the Invention

[0004] In order to solve the technical problem that draining gas in coal mines underground through fixed positions will lead to untimely gas drainage in coal mines underground and cause too high gas concentration in coal mine shafts, the purpose of the present invention is to provide a movable gas drainage method for coal mines underground, and the specific technical solution adopted is as follows: In a first aspect, an embodiment of the present invention provides a movable gas drainage method for coal mines underground, and the method includes the following steps: Obtain the gas concentration data at each key position in the coal mine underground at each moment in real time; According to the gas concentration data of each key position and its preset comparison key position within the initial specified time period, and the difference in the change of gas concentration data between each key position and other key positions, obtain the diffusion degree of each key position at the end moment of the initial specified time period; obtain the initial gas drainage position based on the diffusion degree; The time period formed by the start time of gas drainage at the initial gas drainage position and each subsequent time is used as the target time period; all key positions at non-initial gas drainage positions are used as reference positions; according to the gas concentration data differences between each reference position and the initial gas drainage position within each target time period, the growth of the gas concentration data at each reference position, and the diffusion degree of each reference position at the end of each target time period, the drainage degree of each reference position at the end of each target time period is obtained; based on the drainage degree, the second gas drainage position is obtained. And so on, each gas drainage position is obtained in real time until the gas concentration data of all key positions are less than the preset gas concentration safety threshold, and the gas drainage in the coal mine underground is stopped.

[0005] Further, the method for obtaining the diffusion degree is as follows: According to the gas concentration data of each key position within the initial specified time period and the differences in the changes of the gas concentration data between each key position and other key positions, the gas enrichment degree of each key position at the end of the initial specified time period is obtained. According to the gas concentration data of each key position and its preset comparison key position within the initial specified time period, the correlation degree of each key position at the end of the initial specified time period is obtained. The result of normalizing the product of the gas enrichment degree and the correlation degree of each key position at the end of the initial specified time period is used as the diffusion degree of each key position at the end of the initial specified time period.

[0006] Further, the method for obtaining the gas enrichment degree is as follows: For any key position, the gas concentration data of this key position within the initial specified time period is fitted into a gas concentration curve according to the time sequence. The mean value of all gas concentration data on the gas concentration curve is used as the gas concentration performance degree of this key position within the initial specified time period. The mean value of the tangent slopes corresponding to all gas concentration data on the gas concentration curve is obtained as the gas concentration change value of this key position within the initial specified time period. The differences between the gas concentration change value of this key position within the initial specified time period and the gas concentration change values of each other key position within the initial specified time period are all used as the first characteristic values. The sum of the gas concentration change value of this key position within the initial specified time period and the mean value of the first characteristic values is used as the steepness of the gas concentration change of this key position within the initial specified time period. Take the sum of the gas concentration manifestation degree and the steepness of the gas concentration change as the gas enrichment degree at the key position at the end of the initial specified time period.

[0007] Furthermore, the method for obtaining the correlation degree is as follows: Take the direction from the air inlet to the air outlet in the coal mine underground as the wind direction; For any key position, arrange the key position and each of its preset comparison key positions in sequence according to the wind direction to obtain the reference position sequence corresponding to the key position; Select any key position in the reference position sequence as the analysis position, and take the difference between the maximum gas concentration data of the analysis position and its adjacent next key position in the initial specified time period as the first value; Take the distance between the analysis position and its adjacent next key position as the first distance; Take the ratio of the first value to the first distance as the gas concentration decreasing value of the analysis position; Take the result of negative correlation and normalization of the variances of the gas concentration decreasing values of all key positions in the reference position sequence as the correlation degree at the key position at the end of the initial specified time period.

[0008] Furthermore, the method for obtaining the initial gas drainage position is as follows: Take the key position corresponding to the maximum diffusion degree at the end of the initial specified time period as the initial gas drainage position.

[0009] Furthermore, the method for obtaining the drainage degree is as follows: For any target time period and any reference position, obtain the gas leakage degree at the reference position at the end of the target time period according to the difference in gas concentration data between the reference position and the initial gas drainage position within the target time period, as well as the growth situation of the gas concentration data at the reference position; Take the result of normalizing the product of the gas leakage degree and the diffusion degree at the reference position at the end of the target time period as the drainage degree at the reference position at the end of the target time period.

[0010] Furthermore, the method for obtaining the gas leakage degree is as follows: For any moment within the target time period, obtain the difference between the gas concentration data of the reference position at this moment and the gas concentration data of the initial gas drainage position at this moment as the second characteristic value of the reference position at this moment; Take the result of accumulating the second characteristic values of the reference position at each moment within the target time period as the first gas leakage reference degree at the reference position at the end of the target time period. The difference between the gas concentration data at the reference position at this moment and the gas concentration data at the previous adjacent moment is used as the third eigenvalue at the reference position at this moment; The difference between the third eigenvalue at the end moment of the target time period at the reference position and the average value of the third eigenvalues at all moments in the target time period at the reference position is used as the second gas leakage reference degree at the reference position at the end moment of the target time period; The added result of the first gas leakage reference degree and the second gas leakage reference degree is used as the gas leakage degree at the reference position at the end moment of the target time period.

[0011] Further, the method for obtaining the second gas extraction position based on the extraction degree is as follows: When the extraction degree is greater than the preset extraction degree threshold, the corresponding reference position is used as the second gas extraction position.

[0012] Further, the method for obtaining the preset comparison key position is as follows: For any key position, a preset number of key positions located after the key position along the wind direction are used as the preset comparison key positions of the key position.

[0013] Further, the key positions are the air inlet, air outlet, main air duct in the coal mine and the coal seam positions prone to gas leakage.

[0014] The present invention has the following beneficial effects: Based on the gas concentration data of each key location and its preset comparison key location within the initial specified time period, as well as the difference in the change of gas concentration data between each key location and other key locations, the diffusion degree of each key location at the end of the initial specified time period is obtained, which accurately reflects the gas leakage situation existing at each key location at the end of the initial specified time period. Furthermore, based on the diffusion degree, the initial gas drainage location is accurately obtained, improving the gas drainage rate in the coal mine; in order to accurately and efficiently drain the gas in the coal mine subsequently, the time period formed by the start time of gas drainage at the initial gas drainage location and each subsequent moment is used as the target time period. According to the difference in gas concentration data between each reference location and the initial gas drainage location within each target time period, the growth situation of the gas concentration data of each reference location, and the diffusion degree of each reference location at the end of each target time period, the drainage degree of each reference location at the end of each target time period is obtained, indirectly reflecting the possibility that each reference location can be used as a new gas drainage location at each moment. Furthermore, based on the drainage degree, the second gas drainage location is accurately obtained, and so on, obtaining each gas drainage location in real time, effectively improving the efficiency of gas drainage in the coal mine and avoiding the situation of too high gas concentration in the coal mine; until the gas concentration data of all key locations are less than the preset gas concentration safety threshold, the gas drainage in the coal mine is stopped, effectively ensuring the safety in the coal mine and improving the efficiency and safety of coal mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 Schematic flowchart of a movable gas drainage method in a coal mine provided by an embodiment of the present invention; Figure 2 Flowchart of a method for obtaining the diffusion degree provided by an embodiment of the present invention; Figure 3 Flowchart of a method for obtaining the drainage degree provided by an embodiment of the present invention; Figure 4 Structural diagram of a movable gas drainage system in a coal mine provided by an embodiment of the present invention; Figure 5 Schematic diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following specifically describes, in conjunction with the accompanying drawings and preferred embodiments, a movable gas drainage method in coal mines, including its specific implementation manners, structures, features and effects. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs.

[0019] The following specifically describes the specific solution of a movable gas drainage method in coal mines provided by the present invention in conjunction with the accompanying drawings.

[0020] Embodiment 1: The specific scenario of this embodiment is as follows: During the process of draining gas in coal mines, considering the fixed wind direction of the ventilation system in coal mines and the randomness of gas leakage points, the gas diffusion pattern is irregular, increasing the difficulty of determining the priority gas drainage position, and thus affecting the efficiency and safety of gas drainage in coal mines. In order to improve the accuracy of determining the gas drainage position, the gas concentration and diffusion situation at the positions where gas leakage is likely to occur are dynamically monitored and analyzed, and the gas drainage position is analyzed in real time, effectively improving the efficiency and safety of gas drainage in coal mines. It should be noted that the gas drainage equipment in this embodiment corresponds to only one gas drainage position.

[0021] The present invention proposes a movable gas drainage method in coal mines. Please refer to Figure 1 , which shows a schematic flow chart of a movable gas drainage method in coal mines provided by an embodiment of the present invention. The method includes the following steps: Step S1: Real-time obtain the gas concentration data at each key position in the coal mine at each moment.

[0022] In coal mines, gas usually accumulates in coal seams and is likely to spill out from coal seam fissures and coal walls. To safely and efficiently extract gas in coal mines, in this embodiment, gas concentration sensors are installed at positions in coal mines where gas leakage is likely to occur, such as the air inlet, air outlet, main air ducts, and coal seam positions. For better illustration, in this embodiment, the position where each gas concentration sensor is located is regarded as a key position. To analyze in real time the positions for gas extraction in coal mines, in this embodiment, the gas concentration data at each key position in the coal mine at each moment is obtained in real time through gas concentration sensors; among them, the key positions are the air inlet, air outlet, main air ducts, and coal seam positions in the coal mine where gas leakage is likely to occur. Among them, the gas concentration sensors collect data synchronously, that is, the gas concentration sensors collect data at the same moment. In this embodiment, the time interval between the collection of two adjacent gas concentration data by the gas concentration sensor is set to 1 second. The implementer can set the time interval between the collection of two adjacent gas concentration data by the gas concentration sensor according to the actual situation, and no limitation is made here.

[0023] It should be noted that this embodiment analyzes a complete gas extraction process as an example.

[0024] Step S2: According to the gas concentration data at each key position and its preset comparison key position within the initial specified time period, as well as the difference in the change of gas concentration data between each key position and other key positions, obtain the diffusion degree of each key position at the end moment of the initial specified time period; based on the diffusion degree, obtain the initial gas extraction position.

[0025] It is known that in this embodiment, the gas drainage equipment only targets one gas drainage location. To ensure the efficiency and safety of gas drainage in coal mines, during the process of gas drainage in coal mines, it is necessary to determine the optimal gas drainage location in real time. Among them, the optimal gas drainage location must belong to a certain key location because the location where gas leakage occurs must be a certain key location. In actual situations, the key location with a denser gas concentration is more likely to have gas leakage. Therefore, to improve the efficiency of gas drainage, the key location with a denser gas concentration is more likely to be the gas abstraction location. At the same time, considering that when gas leaks, the gas will spread in all directions. Therefore, the gas concentration data of the key location closer to the gas leakage point shows an upward trend. To quickly drain the gas, the key location with a more obvious upward trend in gas concentration data is more likely to be the gas leakage location, and thus more likely to be the gas drainage location. To determine the first key location for gas drainage during the gas drainage process of the gas drainage equipment, this embodiment first sets the initial specified time period to 10 minutes. The implementer can set the size of the initial specified time period according to the actual situation, which is not limited here. Among them, the start time of the initial specified time period is the time when the gas concentration sensor starts to collect data at each key location.

[0026] When the gas concentration data of a certain key location in the initial specified time period is larger and the upward trend is more obvious than that of other key locations in the initial specified time period, it indirectly reflects that this key location is more likely to be the gas leakage location, and this key location is more likely to be the initial gas drainage location, that is, the first key location for gas drainage during the gas drainage process. Further considering that the fixed wind direction formed by the ventilation system in the coal mine will affect the distribution of gas at the leakage point, the gas concentration data of the key location farther away from the gas leakage point along the wind direction is smaller, and the decrease in gas concentration is uniform because the wind speed of the ventilation system in the coal mine is fixed. To more accurately determine the initial gas drainage location, this embodiment thus obtains the preset comparison key location for each key location according to the wind direction, and then further analyzes the possibility of each key location being the gas drainage location based on the gas concentration data of each key location and its preset comparison key location within the initial specified time period.

[0027] Therefore, this embodiment obtains the diffusion degree of each key location at the end of the initial specified time period according to the gas concentration data of each key location and its preset comparison key location within the initial specified time period, as well as the difference in the change of gas concentration data between each key location and other key locations. Among them, the greater the diffusion degree, the more likely the corresponding key location is to be the initial gas drainage location. Therefore, this embodiment obtains the initial gas drainage location based on the diffusion degree.

[0028] Preferably, in a feasible implementation manner of this embodiment, for the method of obtaining the diffusion degree, please refer to Figure 2 , which shows a flowchart of a method for obtaining the diffusion degree provided in this embodiment. The method includes the following steps: Step S201: According to the gas concentration data at each key position within the initial specified time period and the difference in the change of gas concentration data between each key position and other key positions, obtain the gas enrichment degree at each key position at the end moment of the initial specified time period.

[0029] Within the initial specified time period, when the maximum gas concentration data of a certain key position is larger and the upward trend of the gas concentration data at this key position is more obvious than that of other key positions, it indicates that the gas concentration at this key position is higher, and this key position may be a gas leakage point. Furthermore, this key position is more likely to be the initial gas extraction position. Therefore, in this embodiment, according to the gas concentration data at each key position within the initial specified time period and the difference in the change of gas concentration data between each key position and other key positions, the gas enrichment degree at each key position at the end moment of the initial specified time period is obtained. Among them, the greater the gas enrichment degree, the more likely the corresponding key position is to be the initial gas extraction position.

[0030] Preferably, in a feasible implementation manner of this embodiment, the method for obtaining the gas enrichment degree is as follows: For any key position, fit the gas concentration data of this key position in the initial specified time period into a gas concentration curve according to the time sequence; among them, the method of fitting the curve is a well-known technology and will not be elaborated here. Take the mean value of all gas concentration data on the gas concentration curve as the gas concentration performance degree of this key position in the initial specified time period. The greater the gas concentration performance degree, the higher the gas concentration of this key position in the initial specified time period. To ensure the efficiency of gas extraction, this key position is more likely to be the initial gas extraction position; Further obtain the mean value of the tangent slopes corresponding to all gas concentration data on the gas concentration curve as the gas concentration change value at this key position during the initial specified time period; the greater the gas concentration change value, the greater the degree of increase in the gas concentration at this key position during the initial specified time period. To more accurately highlight the increase in the gas concentration at this key position during the initial specified time period, in this embodiment, the difference between the gas concentration change value at this key position during the initial specified time period and the gas concentration change value at each other key position during the initial specified time period is further obtained as the first eigenvalue; the greater the first eigenvalue, the more obvious the increase in the gas concentration at this key position during the initial specified time period. To accurately represent the increase in the gas concentration at this key position during the initial specified time period, the sum of the gas concentration change value at this key position during the initial specified time period and the mean value of the first eigenvalue is then used as the steepness of the gas concentration change at this key position during the initial specified time period; the greater the steepness of the gas concentration change, the more significant the increase in the gas concentration at this key position during the initial specified time period, indirectly indicating that the gas concentration at this key position is denser during the initial specified time period, and this key position is more likely to be the initial gas drainage position. Then, the sum of the gas concentration manifestation degree and the steepness of the gas concentration change is used as the gas enrichment degree at this key position at the end of the initial specified time period.

[0031] Among them, the calculation formula for the gas enrichment degree is: ; in the formula, is the gas enrichment degree of the i-th key position at the end of the initial specified time period; is the gas concentration manifestation degree of the i-th key position during the initial specified time period; is the gas concentration change value of the i-th key position during the initial specified time period; R is the number of key positions; is the first eigenvalue; is the steepness of the gas concentration change of the i-th key position during the initial specified time period.

[0032] So far, the gas enrichment degree of each key position at the end of the initial specified time period is obtained.

[0033] Step S202: According to the gas concentration data of each key position and its preset comparison key position during the initial specified time period, obtain the correlation degree of each key position at the end of the initial specified time period.

[0034] In this embodiment, the direction from the air inlet to the air outlet in the coal mine is taken as the wind direction. For any key position, a preset number of key positions located after this key position along the wind direction are taken as the preset comparison key positions of this key position. In this embodiment, the preset number is set to 6, and the implementer can set the size of the preset number according to the actual situation, which is not limited here. As the wind direction changes, when the gas concentrations of a certain key position and its preset comparison key positions show a uniform decrease, it indicates that this key position is more likely to be a gas leakage position. In order to improve the efficiency of gas extraction in the coal mine, this key position is more likely to be the initial gas extraction position. Therefore, in this embodiment, by analyzing the gas concentration data of each key position and its preset comparison key positions within the initial specified time period, the correlation degree of each key position at the end of the initial specified time period is obtained. The greater the correlation degree, the higher the gas concentration of the corresponding key position, and the more likely the corresponding key position is to be the initial gas extraction position.

[0035] Preferably, in an implementable manner of this embodiment, the method for obtaining the correlation degree is as follows: For any key position, arrange this key position and its each preset comparison key position in sequence according to the wind direction to obtain the reference position sequence corresponding to this key position; Select any key position in the reference position sequence as the analysis position, and take the difference between the maximum gas concentration data of the analysis position and its adjacent next key position in the initial specified time period as the first value; Take the Euclidean distance between the analysis position and its adjacent next key position as the first distance; Among them, the method for obtaining the Euclidean distance is a well-known technology and will not be elaborated here. Take the ratio of the first value to the first distance as the gas concentration decreasing value of the analysis position; Obtain the gas concentration decreasing values of each key position in the reference position sequence. It should be noted that for the last key position in the reference position sequence, there is no adjacent next key position, so the gas concentration decreasing value of the last key position in the reference position sequence is not obtained. In order to analyze whether the gas concentration decrease between this key position and its preset comparison key positions is stable, furthermore, take the result of the negative correlation and normalization of the variances of the gas concentration decreasing values of all key positions in the reference position sequence as the correlation degree of this key position at the end of the initial specified time period. The greater the correlation degree, the smaller the variance of the gas concentration decreasing values of all key positions in the reference position sequence, indicating that the gas concentration decrease from this key position to its preset comparison key positions is more stable, indirectly indicating that this key position is more likely to be a gas leakage point and this key position is more likely to be the initial gas extraction position.

[0036] Among them, the calculation formula of the correlation degree is: ; In the formula, is the correlation degree of the i-th key position at the end of the initial specified time period; is the variance of the decreasing values of the gas concentrations at all key positions in the reference position sequence corresponding to the i-th key position; exp is a specified function with the natural constant as the base.

[0037] Thus, the degree of association of each key position at the end time of the initial specified time period is obtained.

[0038] Step S203: Take the result of normalizing the product of the gas enrichment degree and the degree of association of each key position at the end time of the initial specified time period as the diffusion degree of each key position at the end time of the initial specified time period.

[0039] It is known that the greater the gas enrichment degree and the greater the degree of association, the more likely the corresponding key position is the initial gas drainage position. Therefore, in this embodiment, the result of normalizing the product of the gas enrichment degree and the degree of association of each key position at the end time of the initial specified time period is taken as the diffusion degree of each key position at the end time of the initial specified time period.

[0040] Among them, the calculation formula for the diffusion degree is: ; in the formula, is the diffusion degree of the i-th key position at the end time of the initial specified time period; is the gas enrichment degree of the i-th key position at the end time of the initial specified time period; is the degree of association of the i-th key position at the end time of the initial specified time period; norm is a normalization function.

[0041] Thus, the diffusion degree of each key position at the end time of the initial specified time period is obtained.

[0042] It is known that the greater the diffusion degree, the more likely the corresponding key position is the initial gas drainage position. Therefore, in this embodiment, the key position corresponding to the maximum diffusion degree at the end time of the initial specified time period is taken as the initial gas drainage position.

[0043] In addition, in underground coal mines, when the drainage rate of the gas drainage equipment is too low, it may not be able to effectively reduce the gas concentration in the underground coal mine, resulting in too high gas concentration in the coal mine shaft and increasing the risk of explosion; when the drainage rate of the gas drainage equipment is too high, it may cause a sudden drop in the pressure in the coal mine shaft, thus triggering water inrush from coal seams or other safety problems in the coal mine shaft. Therefore, in this embodiment, according to the diffusion degree of the initial gas drainage position at the end time of the initial specified time period, the gas drainage rate at the start time of gas drainage at the initial gas drainage position is obtained. Among them, the end time of the initial specified time period is the start time of gas drainage at the initial gas drainage position.

[0044] Among them, the calculation formula for the gas drainage rate is: ; where V is the gas drainage rate at the start time of gas drainage at the initial gas drainage position. is the preset standard gas drainage rate; C is the degree of diffusion of the initial gas drainage position at the end time of the initial specified time period. Among them, the preset standard gas drainage rate is set by the staff according to the actual situation and is not limited here.

[0045] Step S3: Take the time period formed by the start time of gas drainage at the initial gas drainage position and each subsequent moment as the target time period; take all key positions of non-initial gas drainage positions as reference positions; according to the difference in gas concentration data between each reference position and the initial gas drainage position within each target time period, the growth of the gas concentration data of each reference position, and the degree of diffusion of each reference position at the end time of each target time period, obtain the drainage degree of each reference position at the end time of each target time period; obtain the second gas drainage position based on the drainage degree.

[0046] Specifically, during the process of gas drainage at the initial gas drainage position in the coal mine, new gas leakage points may suddenly leak. Therefore, it is very necessary to monitor the gas concentration data of all key positions in real time to promptly detect the key positions that need to be given priority for gas drainage, which can effectively avoid the situation of excessive gas concentration in the coal mine due to untimely gas drainage. To determine the new gas drainage position in real time, in this embodiment, the time period formed by the start time of gas drainage at the initial gas drainage position and each subsequent moment is taken as the target time period. For better subsequent description, all key positions of non-initial gas drainage positions are taken as reference positions. During the gas drainage process, when gas leakage occurs at a certain reference position, the gas concentration data of this reference position will increase significantly. Starting from the start time of gas drainage at the initial gas drainage position, the more the gas concentration data of this reference position exceeds the gas concentration data of the initial gas drainage position as a whole, the more the gas drainage equipment should give priority to draining gas at this reference position; at the same time, the greater the degree of diffusion of this reference position at the end time of a certain target time period, the more likely this reference position is to be the second gas drainage position at the end time of this target time period. Therefore, in this embodiment, according to the difference in gas concentration data between each reference position and the initial gas drainage position within each target time period, the growth of the gas concentration data of each reference position, and the degree of diffusion of each reference position at the end time of each target time period, the drainage degree of each reference position at the end time of each target time period is obtained. Among them, the greater the drainage degree, the more likely the corresponding reference position needs to be drained at the corresponding moment. Furthermore, in this embodiment, the second gas drainage position is obtained based on the drainage degree.

[0047] Preferably, in a method that can be implemented in this embodiment, for the method of obtaining the drainage degree, please refer to Figure 3 , which shows a flowchart of a method for obtaining the drainage degree provided in this embodiment. The method includes the following steps: Step S301: For any target time period and any reference position, based on the difference in gas concentration data between the reference position and the initial gas drainage position within the target time period, and the growth of the gas concentration data at the reference position, obtain the gas leakage degree at the reference position at the end of the target time period.

[0048] When the gas concentration data at a certain reference position within a certain target time period is much greater than the gas concentration data at the initial gas drainage position within the target time period, it indicates that the gas leakage situation at the reference position at the end of the target time period is more serious compared to the initial gas drainage position. In order to avoid untimely gas drainage in the coal mine, therefore, gas drainage should be carried out at the reference position at the end of the target time period. It is known that when the gas leakage at the reference position becomes more and more serious, the gas concentration data at the reference position in the target time period will increase more and more. Therefore, in this embodiment, based on the difference in gas concentration data between the reference position and the initial gas drainage position within the target time period, and the growth of the gas concentration data at the reference position, the gas leakage degree at the reference position at the end of the target time period is obtained. The greater the gas leakage degree, the more likely the reference position is to be determined as the second gas drainage position at the end of the target time period.

[0049] Preferably, in a method that can be implemented in this embodiment, the method for obtaining the gas leakage degree is as follows: For any moment within the target time period, obtain the difference between the gas concentration data at the reference position at this moment and the gas concentration data at the initial gas drainage position at this moment, as the second characteristic value of the reference position at this moment; the greater the second characteristic value, the more likely the reference position is to be a new gas drainage position. In order to accurately analyze the possibility that the reference position is confirmed as a new gas drainage position at the end of the target time period, and then the result of accumulating the second characteristic values of the reference position at each moment within the target time period is used as the first gas leakage reference degree of the reference position at the end of the target time period; the greater the first gas leakage reference degree, the more likely the reference position is to be a new gas drainage position at the end of the target time period; Among them, the calculation formula for the first gas leakage reference degree is: ; in the formula, is the first gas leakage reference degree of the x-th reference position at the end of the a-th target time period; is the number of moments in the a-th target time period; is the gas concentration data at the x-th reference position at the t-th moment in the a-th target time period; is the gas concentration data at the initial gas extraction position at the t-th moment in the a-th target time period; is the second eigenvalue; Further obtain the difference between the gas concentration data at this reference position at this moment and the gas concentration data at the previous adjacent moment as the third eigenvalue at this reference position at this moment; in order to analyze the severity of gas leakage at this reference position in this target time period, furthermore, take the difference between the third eigenvalue at the end moment of this target time period at this reference position and the average value of the third eigenvalues at all moments in this target time period at this reference position as the second gas leakage reference degree at the end moment of this target time period at this reference position; the greater the second gas leakage reference degree, the more serious the gas leakage situation at this reference position at the end moment of this target time period, indirectly reflecting that this reference position is more likely to be a new gas extraction position at the end moment of this target time period; Among them, the calculation formula for the second gas leakage reference degree is: ; in the formula, is the second gas leakage reference degree at the x-th reference position at the end moment of the a-th target time period; is the third eigenvalue at the x-th reference position at the -th moment in the a-th target time period; is the number of moments in the a-th target time period; is the third eigenvalue at the x-th reference position at the t + 1-th moment in the a-th target time period; It should be noted that there is no adjacent previous moment for the first moment in this target time period. Therefore, the third eigenvalue for the first moment in this target time period is not obtained. In order to accurately determine the gas leakage situation at this reference position at the end moment of this target time period, furthermore, take the sum of the first gas leakage reference degree and the second gas leakage reference degree as the gas leakage degree at this reference position at the end moment of this target time period.

[0050] Among them, the calculation formula for the gas leakage degree is: In the formula, is the gas leakage degree at the x-th reference position at the end moment of the a-th target time period; is the first gas leakage reference degree at the x-th reference position at the end moment of the a-th target time period; is the second gas leakage reference degree at the x-th reference position at the end moment of the a-th target time period.

[0051] Step S302: normalize the product of the gas leakage degree and the diffusion degree of the reference position at the end time of the target time period, and use the result as the extraction degree of the reference position at the end time of the target time period.

[0052] It is known that the greater the gas leakage degree and the greater the dispersion degree, both indicate that the corresponding reference position is more likely to be a new gas extraction position at the corresponding moment; and thus, this embodiment normalizes the product of the gas leakage degree and the diffusion degree of the reference position at the end of the target time period as the extraction degree of the reference position at the end of the target time period. It should be noted that this embodiment normalizes the product of the gas leakage degree and the diffusion degree of the reference position at the end of the target time period by the norm normalization function. Among them, the greater the extraction degree, the more likely the reference position is to be a new gas extraction position at the end of the target time period.

[0053] The extraction degree of each reference position at the end time of each target time period is obtained in chronological order, that is, the extraction degree of each reference position at each time after the start time of gas extraction at the initial gas extraction position is obtained.

[0054] In order to determine the second gas extraction position according to the extraction degree, the present embodiment sets the preset extraction degree threshold value to 0.6. The implementer can set the size of the preset extraction degree threshold value according to the actual situation, which is not limited here. When the extraction degree is greater than the preset extraction degree threshold value, the corresponding reference position is used as the second gas extraction position. If the extraction degree of at least two reference positions is greater than the preset extraction degree threshold value at the same time, the reference position corresponding to the maximum extraction degree is selected as the second gas extraction position. If there are at least two reference positions corresponding to the maximum extraction degree, any one reference position is selected as the second gas extraction position.

[0055] At the same time, in order to obtain the gas extraction rate at the start time of gas extraction at the second gas extraction position, and then obtain the diffusion degree at the start time of gas extraction at the second gas extraction position, it should be noted that when obtaining the diffusion degree at the start time of gas extraction at the second gas extraction position, the time period for which the gas extraction is obtained is from the start time of gas extraction at the initial gas extraction position to the start time of gas extraction at the second gas extraction position. Thus, the gas extraction rate at the start time of gas extraction at the second gas extraction position is obtained through the method for obtaining the gas extraction rate in step S2.

[0056] It should be noted that during the process of gas drainage at the initial gas drainage position, the gas drainage rate at each moment is different, and it is adaptively obtained according to the diffusion degree at each moment during the gas drainage process. Among them, the initial moment of the time period corresponding to the diffusion degree at each moment during the process of gas drainage at the initial gas drainage position is the start moment of gas drainage at the initial gas drainage position.

[0057] Step S4: By analogy, obtain each gas drainage position in real time until the gas concentration data at all key positions are less than the preset gas concentration safety threshold, and stop the gas drainage in the coal mine underground.

[0058] Specifically, the preset gas concentration safety threshold in this embodiment is set by the staff and is not limited here. It should be noted that the key positions used as gas drainage positions are not excluded in subsequent analyses.

[0059] So far, each gas drainage position in the coal mine underground has been obtained in real time and accurately, improving the efficiency and safety of gas drainage in the coal mine underground and being beneficial to coal mine exploitation.

[0060] In summary, this embodiment obtains the gas concentration data at each key position in the coal mine underground at each moment; obtains the initial gas drainage position according to the gas concentration data at the key positions within the initial specified time period; obtains the drainage degree at each reference position at the end of each target time period according to the difference in gas concentration data between the reference position and the initial gas drainage position and the growth situation of the gas concentration data at the reference position, and then obtains the second gas drainage position; by analogy, obtains the gas drainage position in real time until the gas concentration data at the key positions are all less than the preset gas concentration safety threshold, and stops the gas drainage in the coal mine underground. The present invention improves the efficiency of gas drainage by obtaining the gas drainage position in real time and effectively avoids the situation of too high gas concentration in the coal mine shaft.

[0061] Embodiment 2: The present invention also proposes a movable gas drainage system in the coal mine underground. Please refer to Figure 4 , which shows the structure diagram of a movable gas drainage system in the coal mine underground provided by an embodiment of the present invention. The system includes: an acquisition module 10, an initial gas drainage position acquisition module 20, a second gas drainage position acquisition module 30, and a stop module 40.

[0062] The acquisition module 10 is used to obtain the gas concentration data at each key position in the coal mine underground at each moment in real time.

[0063] The initial gas drainage position acquisition module 20 is used to obtain the diffusion degree of each key position at the end of the initial specified time period according to the gas concentration data of each key position and its preset comparison key position within the initial specified time period, and the difference in the change of gas concentration data between each key position and other key positions; and obtain the initial gas drainage position based on the diffusion degree.

[0064] The second gas drainage position acquisition module 30 is used to take each time period formed by the start time of gas drainage at the initial gas drainage position and each subsequent moment as the target time period; take the key positions other than the initial gas drainage position as the reference positions; obtain the drainage degree of each reference position at the end of each target time period according to the difference in gas concentration data between each reference position and the initial gas drainage position within each target time period, the growth of the gas concentration data of each reference position, and the diffusion degree of each reference position at the end of each target time period; and obtain the second gas drainage position based on the drainage degree.

[0065] The stop module 40 is used to continuously obtain each gas drainage position in turn until the gas concentration data of all key positions are less than the preset gas concentration safety threshold, and stop the gas drainage in the coal mine underground.

[0066] It should be noted that: for the system provided in the above embodiment, only the division of the above functional modules is used for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above. In addition, a movable coal mine underground gas drainage system provided in the above embodiment and an embodiment of a movable coal mine underground gas drainage method belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0067] Embodiment 3: The present invention also proposes a movable coal mine underground gas drainage device, which includes a memory and a processor. Among them, an executable program code is stored in the memory, and the processor is used to call and execute the executable program code to execute a movable coal mine underground gas drainage method provided in an embodiment of the present application. The device may specifically be a chip, a component or a module. The chip may include a connected processor and a memory; among them, the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a movable coal mine underground gas drainage method provided in the above embodiment.

[0068] In addition, an embodiment of the present application also protects a computer device. Please refer to Figure 5, the computer device includes a memory 401, a processor 402, and a computer program 403 stored in the memory 401 and running on the processor 402. When the processor 402 executes the computer program 403, the computer device can execute any one of the aforementioned movable coal mine underground gas drainage methods.

[0069] Embodiment 4: The present invention also provides a computer-readable storage medium. Computer program code is stored in the computer-readable storage medium. When the computer program code runs on a computer, the computer is caused to execute the above-related method steps to implement a movable coal mine underground gas drainage method provided in the above embodiment.

[0070] Embodiment 5: The present invention also provides a computer program product. When the computer program product runs on a computer, the computer is caused to execute the above-related steps to implement a movable coal mine underground gas drainage method provided in the above embodiment.

[0071] Among them, the device, computer-readable storage medium, computer program product, or chip provided in this embodiment are all used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be elaborated here.

[0072] It should be noted that: the above sequence of the embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0073] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

Claims

1. A mobile coal mine underground gas extraction method, characterized in that: The method comprises the following steps: Obtain real-time gas concentration data at each key location in the coal mine at every moment; According to the gas concentration data of each key position and its preset comparison key position within the initial specified time period, and the difference between the gas concentration data of each key position and other key positions, the diffusion degree of each key position at the end of the initial specified time period is obtained; the initial gas extraction position is obtained based on the diffusion degree; The time period formed by the start time of gas extraction at the initial gas extraction position and each time thereafter is taken as the target time period; the key positions of non-initial gas extraction positions are taken as reference positions; according to the difference in gas concentration data between each reference position and the initial gas extraction position in each target time period, the growth of gas concentration data at each reference position, and the diffusion degree of each reference position at the end time of each target time period, the extraction degree of each reference position at the end time of each target time period is obtained; the second gas extraction position is obtained based on the extraction degree; By analogy, each gas extraction location is acquired in real time until the gas concentration data at all key locations are less than the preset gas concentration safety threshold, and gas extraction in the coal mine is stopped.

2. A movable coal mine underground gas extraction method as claimed in claim 1, characterized in that: The method for obtaining the diffusion degree is: According to the gas concentration data of each key position in the initial specified time period and the difference between the gas concentration data of each key position and other key positions, the gas enrichment degree of each key position at the end time of the initial specified time period is obtained; According to the gas concentration data of each key position and its preset comparison key position in the initial specified time period, the correlation degree of each key position at the end time of the initial specified time period is obtained; The result of normalizing the product of the gas enrichment degree and the correlation degree at each key location at the end of the initial specified time period is used as the diffusion degree of each key location at the end of the initial specified time period.

3. A movable coal mine underground gas extraction method as claimed in claim 2, characterized in that: The method for obtaining the gas enrichment degree is: For any key position, the gas concentration data of the key position in the initially specified time period is fitted into a gas concentration curve according to the time sequence; The average value of all gas concentration data on the gas concentration curve is used as the gas concentration performance level of the key position in the initial specified time period; Obtaining the average value of the tangent slopes corresponding to all gas concentration data on the gas concentration curve as the gas concentration change value of the key position in the initial specified time period; Obtain the difference between the gas concentration change value of the key position in the initial specified time period and the gas concentration change value of each other key position in the initial specified time period, and use them as the first characteristic value; The sum of the gas concentration change value of the key position in the initial specified time period and the mean value of the first characteristic value is used as the steepness of the gas concentration change of the key position in the initial specified time period; The sum of the gas concentration performance degree and the gas concentration change steepness is used as the gas enrichment degree of the key position at the end of the initial specified time period.

4. A movable coal mine underground gas extraction method as claimed in claim 2, characterized in that: The method for obtaining the degree of association is: The direction from the air inlet to the air outlet in the coal mine is taken as the wind direction; For any key position, the key position and each of its preset comparison key positions are arranged in sequence according to the wind direction to obtain a reference position sequence corresponding to the key position; Select any key position in the reference position sequence as the analysis position, and take the difference between the maximum gas concentration data of the analysis position and the next adjacent key position in the initial specified time period as the first value; The distance between the analysis position and the next adjacent key position is taken as the first distance; The ratio of the first value to the first distance is used as the decreasing value of the gas concentration at the analysis position; The variance of the gas concentration decrease values ​​of all key positions in the reference position sequence is negatively correlated and normalized, and is used as the correlation degree of the key position at the end of the initial specified time period.

5. A movable coal mine underground gas extraction method as claimed in claim 1, characterized in that: The method for obtaining the initial gas extraction position is: The key position corresponding to the maximum diffusion degree at the end of the initial specified time period is used as the initial gas extraction position.

6. A movable coal mine underground gas extraction method as claimed in claim 1, characterized in that: The method for obtaining the extraction degree is: For any target time period and any reference position, according to the difference in gas concentration data between the reference position and the initial gas extraction position within the target time period, and the growth of the gas concentration data at the reference position, the gas leakage degree of the reference position at the end time of the target time period is obtained; The product of the gas leakage degree and the diffusion degree at the reference position at the end time of the target time period is normalized as the extraction degree of the reference position at the end time of the target time period.

7. A movable coal mine underground gas extraction method as claimed in claim 6, characterized in that: The method for obtaining the gas leakage degree is: For any moment in the target time period, the difference between the gas concentration data of the reference position at the moment and the gas concentration data of the initial gas extraction position at the moment is obtained as the second characteristic value of the reference position at the moment; Accumulating the second characteristic value of the reference position at each moment within the target time period as the first gas leakage reference degree of the reference position at the end moment of the target time period; The difference between the gas concentration data of the reference position at the moment and the gas concentration data at the previous adjacent moment is used as the third characteristic value of the reference position at the moment; The difference between the third characteristic value of the reference position at the end time of the target time period and the average value of the third characteristic value of the reference position at all times in the target time period is used as the second gas leakage reference degree of the reference position at the end time of the target time period; The sum of the first gas leakage reference level and the second gas leakage reference level is used as the gas leakage level of the reference position at the end time of the target time period.

8. A movable coal mine underground gas extraction method as claimed in claim 1, characterized in that: The method for obtaining the second gas extraction position based on the extraction degree is: When the extraction degree is greater than the preset extraction degree threshold, the corresponding reference position will be used as the second gas extraction position.

9. A movable coal mine underground gas extraction method as claimed in claim 4, characterized in that: The method for obtaining the preset comparison key position is: For any key position, a preset number of key positions located behind the key position along the wind direction are used as preset comparison key positions for the key position.

10. A movable coal mine underground gas extraction method according to claim 1, characterized in that: The key positions are the air inlets, air outlets, main air ducts and coal seams in coal mines where gas leakage is prone to occur.

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