Method for predicting gas emission quantity of stope face based on pressure relief extraction condition

Abstract

The invention discloses a method for predicting the gas emission quantity of a stope face based on pressure relief extraction conditions, which belongs to the field of coal mine safety and comprises the following steps: finely dividing gas emission sources into four parts, namely a coal wall, mined-down coal, residual coal in a goaf and an adjacent layer, respectively establishing emission quantity calculation models of the sources, and calculating the emission quantity of the coal wall, the mined-down coal, the residual coal and the adjacent layer; and a pressure relief extraction correction coefficient is introduced in adjacent layer calculation, and a comprehensive prediction mathematical model is constructed. According to the method, the prediction precision is remarkably improved, working face gas control and safe recovery are effectively guided, the defects that in the prior art, conservative estimation is too high, and the control cost is high are overcome, and reliable technical support is provided for efficient and safe production of a mine.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of coal mine safety, and particularly relates to a gas emission amount prediction method for a mining face under pressure relief and extraction conditions. BACKGROUND

[0002] At present, the prediction of the gas emission amount of a mining face in China usually adopts a source prediction method. The method simplifies the gas emission amount of the working face into two parts, i.e., the gas emission of the coal seam and the gas emission of the adjacent layer, for estimation. Although the method has applicability under certain conditions, the division of the gas emission sources is relatively general, and the release characteristics and the space-time variation law of the gas from different sources such as the coal wall, the fallen coal and the residual coal in the goaf under the fully mechanized mining condition are not fully considered. Especially when the coal group is mined and the pressure relief and extraction are implemented, the existing method cannot effectively represent the substantial influence of the pressure relief and extraction on the gas emission behavior of the adjacent layer, resulting in a large deviation between the prediction model and the actual situation.

[0003] Due to the insufficient analysis of the gas emission source composition in the existing prediction method and the lack of specific correction of the gas emission law under the pressure relief and extraction condition, the prediction result is often significantly larger and the conservativeness is too high in the engineering application. This not only causes the over-investment of the gas control measures during the mining period and increases the unnecessary cost, but also affects the scientific decision of the efficient and safe production of the mine. Therefore, there is an urgent need for a prediction method which can more accurately reflect the pressure relief and extraction condition and independently quantitatively analyze each gas emission source, so as to improve the reliability of the prediction result and provide effective guidance for the comprehensive gas control of the working face. SUMMARY

[0004] To solve the above technical problems, the application provides a gas emission amount prediction method for a mining face under pressure relief and extraction conditions, which comprises the following steps. determining the gas emission source composition of the mining face, wherein the sources include the coal wall gas emission, the fallen coal gas emission, the residual coal gas emission in the goaf and the adjacent layer gas emission; calculating the coal wall gas emission amount, the fallen coal gas emission amount, the residual coal gas emission amount in the goaf and the adjacent layer gas emission amount based on the gas emission source composition; predicting the total gas emission amount of the mining face according to the calculated gas emission amounts of each gas emission source, and establishing a mathematical model for predicting the gas emission amount of the mining face under the pressure relief and extraction condition.

[0005] Optionally, the determination of the gas emission source composition of the mining face comprises the following steps: according to the gas flow theory and the characteristics of the fully mechanized mining, the gas emission sources of the mining face are divided into four parts, i.e., the coal wall gas emission, the fallen coal gas emission, the residual coal gas emission in the goaf and the adjacent layer gas emission.

[0006] Optionally, the calculating the coal wall gas emission quantity comprises: calculating the coal wall gas relative emission quantity based on the unit area gas emission intensity at the time of the coal wall exposure, the working face length, the gas drainage zone width, the coal density, the working face recovery rate, the working face average advancing degree, and the coal wall gas emission decay coefficient. wherein the calculating is obtained by dividing the cumulative gas emission quantity in the coal wall exposure time by the coal mining quantity of one coal mining cycle.

[0007] Optionally, the calculating the coal wall gas emission quantity comprises: calculating the coal wall gas relative emission quantity based on the unit area gas emission intensity at the time of the coal wall exposure, the working face length, the gas drainage zone width, the coal density, the working face recovery rate, the working face average advancing degree, and the coal wall gas emission decay coefficient. wherein the calculating is obtained by dividing the cumulative gas emission quantity in the coal wall exposure time by the coal mining quantity of one coal mining cycle.

[0008] Optionally, the calculating the coal wall gas emission quantity comprises: calculating the coal wall gas relative emission quantity based on the unit area gas emission intensity at the time of the coal wall exposure, the working face length, the gas drainage zone width, the coal density, the working face recovery rate, the working face average advancing degree, and the coal wall gas emission decay coefficient. wherein the calculating is obtained by dividing the cumulative gas emission quantity in the coal wall exposure time by the coal mining quantity of one coal mining cycle.

[0009] Optionally, the calculating the coal wall gas emission quantity comprises: calculating the coal wall gas relative emission quantity based on the unit area gas emission intensity at the time of the coal wall exposure, the working face length, the gas drainage zone width, the coal density, the working face recovery rate, the working face average advancing degree, and the coal wall gas emission decay coefficient. wherein the calculating is obtained by dividing the cumulative gas emission quantity in the coal wall exposure time by the coal mining quantity of one coal mining cycle.

[0010] Optionally, the calculating the coal wall gas emission quantity comprises: calculating the coal wall gas relative emission quantity based on the unit area gas emission intensity at the time of the coal wall exposure, the working face length, the gas drainage zone width, the coal density, the working face recovery rate, the working face average advancing degree, and the coal wall gas emission decay coefficient.

[0011] Optionally, the correction coefficient is determined by a ratio of the gas emission amount under the actual pressure relief and extraction condition of the adjacent layer to the relative gas emission amount of the adjacent layer, and is used to adjust the calculation of the gas emission amount of the adjacent layer to reflect the influence of the pressure relief and extraction condition.

[0012] In another aspect, the present application also provides an electronic device, comprising a memory, a processor, and a computing program stored in the memory and executable on the processor, and the processor implements the method when executing the computing program.

[0013] In another aspect, the present application also provides a computer readable storage medium, which stores a computer program, and the computer program implements the method when executed by a processor.

[0014] Compared with the prior art, the present application has the following advantages and technical effects: The present application significantly improves the accuracy of the gas emission amount prediction of the mining working face under the pressure relief and extraction condition by finely dividing the gas emission sources of the mining working face and respectively establishing the emission amount calculation model of each source, and introducing the correction coefficient of the pressure relief and extraction on the gas emission amount of the adjacent layer. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of this application and of the drawings illustrate to explain the application, and do not limit the application. In the drawings: Figure 1 The method flowchart of the embodiments of the present application is shown in the figure; DETAILED DESCRIPTION

[0016] It should be noted that the embodiments and the features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0017] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0018] Embodiment one As shown in the figure, the present embodiment provides a gas emission amount prediction method of a mining working face under pressure relief and extraction condition, comprising: Figure 1 ​a. determining the gas emission source composition of the mining face, the gas emission source of the mining face including coal wall gas emission, fallen coal gas emission, goaf residual coal gas emission or / and adjacent layer gas emission; b. calculating the emission amount of each gas emission source respectively, wherein, the calculation formula of the coal wall gas emission amount is: (1) in the formula, Q1 is the relative emission amount of the coal wall gas, unit: m 3 / t, V0 is the gas emission intensity of the coal wall when it is just exposed, unit: m 3 / (m 2 ·min), u is the average advancing degree of the working face, unit: m / min, L is the length of the working face, unit: m, L H is the width of the gas discharge zone, unit: m, β is the attenuation coefficient of the coal wall gas emission, unit: min -1 , C is the recovery rate of the working face, and δ is the density of the coal, unit: t / m 3 ; the calculation formula of the fallen coal gas emission amount is: (2) in the formula, Q2 is the relative emission amount of the fallen coal gas, unit: m 3 / t; V1 is the initial gas emission intensity of the fallen coal, unit: m 3 / (t·min); n is the attenuation coefficient of the fallen coal gas emission, unit: min -1 ; L is the length of the working face, unit: m; L H is the width of the gas discharge zone, unit: m; V2 is the average traction speed of the coal mining machine, unit: m / min; the calculation formula of the goaf residual coal gas emission amount is: (3) in the formula, Q3 is the relative emission amount of the goaf residual coal gas, unit: m 3 / t; V1 is the initial gas emission intensity of the goaf residual coal, unit: m 3 / (t·min); C is the recovery rate of the working face; L is the length of the working face, unit: m; L H is the width of the gas discharge zone, unit: m; n is the attenuation coefficient of the goaf residual coal gas emission, unit: min -1 ; l1 is the distance from the coal wall of the working face to the rear hydraulic support, unit: m; l2 is the width of the unstable zone of the gas concentration in the goaf along the advancing direction of the working face, unit: m; When calculating the gas emission amount of the adjacent layer, a correction coefficient of the influence of pressure relief gas drainage on the gas emission amount of the adjacent layer is introduced, and the calculation formula is: (4) In the formula, Q 4 is the relative gas emission amount of the adjacent layer, m 3 / t; m i is the coal seam thickness of the first i adjacent layer, unit: m; M is the working face mining height, unit: m; η i is the gas emission rate of the first i adjacent layer, unit: %; W 0i is the original gas content of the first i adjacent layer, unit: m 3 / t; W ci is the residual gas content of the first i adjacent layer, unit: m 3 / t; K v The influence coefficient under the condition of pressure relief gas drainage is the correction coefficient of the influence of pressure relief gas drainage on the gas emission amount of the adjacent layer; c. According to the emission amount of each gas emission source calculated in step b, the gas emission amount of the recovery working face is predicted, and a mathematical model for predicting the gas emission amount of the recovery working face under the condition of pressure relief gas drainage is established.

[0019] Further, according to the gas flow theory and the characteristics of comprehensive mechanized coal mining, the gas emission sources of the recovery working face are divided into four parts: coal wall gas emission, mined coal gas emission, goaf residual coal gas emission, and gas emission under the condition of pressure relief gas drainage of the adjacent layer.

[0020] Further, the coal wall gas emission law conforms to the formula: (5) In the formula, V1 is the gas emission intensity on the unit area of the coal wall at t time, unit: m 3 / (m 2 ·min); V0 is the gas emission intensity on the unit area when the coal wall is just exposed, unit: m 3 / (m 2 ·min); β is the coal wall gas emission decay coefficient, unit: min -1 ; t is the coal wall exposure time, unit: min.

[0021] Further, the gas emission laws of the mined coal and the goaf residual coal both conform to the formula: (8) In the formula, V2 is the gas emission intensity of the fallen coal or the residual coal in the goaf after the working face stays for t hours, unit: m 3 / (t.min); V1 is the initial gas emission intensity of the fallen coal or the residual coal in the goaf, unit: m 3 / (t.min); n is the gas emission decay coefficient of the fallen coal or the residual coal in the goaf, unit: min -1 ; t is the staying time of the fallen coal or the residual coal in the goaf, unit: min.

[0022] Further, the correction coefficient K v = actual adjacent layer gas emission amount / adjacent layer gas relative emission amount.

[0023] Example Two In this embodiment, a gas emission amount prediction method based on pressure relief extraction at the working face is provided, which comprises: a. determining the gas emission source composition of the working face, which includes the coal wall gas emission, the fallen coal gas emission, the residual coal gas emission in the goaf or / and the adjacent layer gas emission.

[0024] b. calculating the emission amount of each gas emission source respectively, the gas emission amount of the working face mainly depends on the gas emission intensity of the gas source, usually, the coal wall gas emission intensity is expressed by the gas amount emitted per square meter of the coal wall per unit time, and the fallen coal gas emission intensity is expressed by the gas amount emitted per ton of coal per unit time. Among them, The calculation formula of the coal wall gas emission amount is: (1) In the formula, Q1 is the coal wall gas relative emission amount, unit: m 3 / t, V0 is the gas emission intensity per unit area when the coal wall is just exposed, unit: m 3 / (m 2 ·min), u is the average advancing degree of the working face, unit: m / min, L is the length of the working face, unit: m, L H is the width of the gas discharge zone, unit: m, β is the coal wall gas emission decay coefficient, unit: min -1 , and C is the working face recovery rate, δ is the density of the coal, unit: t / m 3 .

[0025] The calculation formula of the fallen coal gas emission amount is: (2) In the formula, Q2 is the fallen coal gas relative emission amount, unit: m3 V1 is the initial gas emission intensity of the coal being mined, unit: m 3 n is the gas emission decay coefficient of the coal being mined, unit: min -1 L is the length of the working face, unit: m; L H is the gas discharge zone width, unit: m; V2 is the average traction speed of the coal mining machine, unit: m / min.

[0026] The calculation formula of the gas emission amount of the goaf residual coal is: (3) In the formula, Q3 is the relative emission amount of the goaf residual coal gas, unit: m 3 V1 is the initial gas emission intensity of the goaf residual coal, unit: m 3 n is the gas emission decay coefficient of the goaf residual coal, unit: min H L is the length of the working face, unit: m; L -1 is the gas discharge zone width, unit: m; l1 is the distance from the coal wall of the working face to the rear hydraulic support, unit: m; l2 is the width of the unstable zone of the gas concentration in the goaf along the advancing direction of the working face, unit: m.

[0027] When calculating the gas emission amount of the adjacent layer, the correction coefficient of the pressure relief gas extraction affecting the gas emission amount of the adjacent layer is introduced, and the calculation formula is: (4) In the formula, Q 4 is the relative emission amount of the adjacent layer gas, m 3 / t; m i is the thickness of the first i adjacent layer, unit: m; M is the mining height of the working face, unit: m; η i is the gas discharge rate of the first i adjacent layer, unit: %; W 0i is the original gas content of the first i adjacent layer, unit: m 3 / t; W ci is the residual gas content of the first i adjacent layer, unit: m 3 / t; K vThe correction coefficient of the influence of pressure relief gas drainage on the gas emission of adjacent layers. Based on the source prediction method in the "Mine Gas Emission Prediction Method" (AQ1018-2006), the gas emission of adjacent layers under pressure relief gas drainage is corrected. Under the condition of pressure relief gas drainage, the gas emission of adjacent layers is greater than the gas emission rate. After comprehensive consideration, the influence coefficient under the condition of pressure relief gas drainage is proposed K v and the gas emission calculation formula of adjacent layers under pressure relief gas drainage is corrected to obtain formula (4).

[0028] c. According to the gas emission of each gas emission source calculated in step b, the gas emission of the mining face is predicted, and a mathematical model for predicting the gas emission of the mining face under the condition of pressure relief gas drainage is established.

[0029] In this embodiment, according to the gas flow theory and the characteristics of fully mechanized coal mining, the gas emission sources of the mining face are divided into four parts: coal wall gas emission, falling coal gas emission, goaf residual coal gas emission, and adjacent layer gas emission. The gas emission of the mining face is usually determined by many factors such as the natural conditions of the coal seam and the technical conditions of the mine. In general, the gas emission sources of the mining face are divided into coal wall gas emission, falling coal gas emission, and goaf gas emission. However, due to the existence of adjacent layers, according to the gas flow theory and the characteristics of fully mechanized coal mining, the gas emission sources of the mining face are divided into four parts: coal wall gas emission, falling coal gas emission, goaf residual coal gas emission, and gas emission under the condition of pressure relief gas drainage of adjacent layers.

[0030] In this embodiment, the coal wall gas emission law conforms to the formula: (5) In the formula, V1 is the gas emission intensity of the coal wall per unit area at time t, unit: m 3 / (m 2 ·min); V0 is the gas emission intensity of the coal wall per unit area when the coal wall is just exposed, unit: m 3 / (m 2 ·min); β is the coal wall gas emission decay coefficient, unit: min -1; t is the coal wall exposure time, unit: min. The size of the coal wall gas emission intensity depends on the gas pressure of the coal seam, the pore and fracture structure of the coal seam, the adsorption performance of the coal to the gas and other conditions, in addition, the coal wall gas emission intensity is also related to the coal wall exposure time. According to the gas flow law and the field measurement result analysis, the coal wall gas emission law accords with formula (5), if the progress of a coal mining cycle of the coal mining machine of the coal mining face is L (unit: m), the average advancing speed of the coal mining face is u (unit: m / min), the time of a coal mining cycle progress of the coal mining machine is taken as t1 = l / u (unit: min), the gas emission intensity of the unit area coal wall after t time is V1 (m 3 / ㎡·min), then the cumulative gas emission amount of the unit area coal wall is: (6) After formula (5) is substituted into formula (6) and the integral is simplified, the following formula is obtained: (7) In the formula, q1 is the cumulative gas absolute emission amount of the unit area coal wall after t1 time, unit: m 3 / m 2 .

[0031] Let the effective exposure area of the coal mining face be S = d (L-2LH), the coal mining amount of a cycle be G = d1C L, then the relative gas emission amount Q1 of the coal wall can be obtained as: (1) In the formula, Q1 is the relative gas emission amount of the coal wall, unit: m 3 / t, V0 is the gas emission intensity of the unit area on the coal wall just after exposure, unit: m 3 / (m 2 ·min), u is the average advancing speed of the coal mining face, unit: m / min, L is the length of the coal mining face, unit: m, L H is the gas drainage zone width, unit: m, β is the coal wall gas emission decay coefficient, unit: min -1 , C is the coal mining rate of the coal mining face, δ is the density of the coal, unit: t / m 3 .

[0032] In the embodiment, the gas emission laws of the fallen coal and the residual coal in the goaf both accord with formula: (8) In the formula, V2 is the gas emission intensity of the fallen coal or the residual coal in the goaf after the coal mining face stays for t time, unit: m 3 / (t.min); V1 is the initial gas emission intensity of the fallen coal or the residual coal in the goaf, unit: m 3(t.min); n is the decay coefficient of the gas emission from the coal or the residual coal in the goaf, in min -1 ; t is the residence time of the coal or the residual coal in the goaf in the working face, in min.

[0033] The gas is continuously diffused and emitted into the working face during the transportation of the coal in the scraper conveyor, and the gas emission intensity decreases with the increase of time. According to equation (8), the absolute emission amount of the gas per unit weight of the coal is: (9) After equation (8) is substituted into equation (9) and the integral is simplified, the following equation is obtained: (10) In the equation, q2 is the cumulative gas emission amount per unit weight of the coal after the coal passes through t2, in m 3 / t; V1 is the initial gas emission intensity of the coal, in m 3 / (t.min); t2 is the residence time of the coal in the fully-mechanized working face, in min.

[0034] The gas emission amount of the coal is: (11) After equation (10) is substituted into equation (11), the following equation is obtained: (12) In the equation, Q2 is the relative gas emission amount of the coal, in m 3 / t; t2 is the residence time of the coal in the fully-mechanized working face, in min, t2=(L-L H - x ) / v2; v2 is the average traction speed of the coal mining machine, in m / min; dA is the weight of the residual coal in the infinitesimal length dx in the direction of the traction machine, in t; dA=Cdldx.

[0035] Equation (12) can be written as follows: (13) After equation (13) is simplified and integrated, the relative gas emission amount of the coal is: (2) In the equation, Q2 is the relative gas emission amount of the coal, in m 3 / t; V1 is the initial gas emission intensity of the coal, in m 3 / (t.min); n is the decay coefficient of the gas emission from the coal, in min -1 ; L is the length of the working face, in m; LH V2 is the average traction speed of the coal mining machine, in units of m / min.

[0036] The residual coal in the goaf will continue to release gas and flow into the working face during the process of gradually entering the goaf, and thus its gas emission law also conforms to formula (8). Assuming that the residual coal in the goaf is uniformly distributed from the coal wall of the working face to the goaf, then in the opposite direction of the working face advance, the absolute emission amount of the residual coal gas in the goaf is: (14) In the formula, Q3' is the cumulative gas emission amount of the residual coal in the goaf, in units of m 3 / (t·min); V3 is the gas emission intensity of the residual coal in the goaf after the working face stays for t hours, in units of m 3 / (t·min); l1 is the distance from the coal wall of the working face to the rear hydraulic support, in units of m; l2 is the width of the non-stable zone of gas concentration in the goaf along the working face advance direction (generally taken as 30 m), in units of m; dA is the weight of the residual coal in the goaf in the micro-unit length dx in the opposite direction of the working face advance, dA=(1-C)δd(L-2L H )dx, then: (15) In the formula, t3 is the effective residence time of the residual coal in the goaf, t3=x / u.

[0037] The relative emission amount of the residual coal gas in the goaf is obtained by integrating formula (15): (3) In the formula, Q3 is the relative emission amount of the residual coal gas in the goaf, in units of m 3 / t; V1 is the initial gas emission intensity of the residual coal in the goaf, in units of m 3 / (t·min); C is the working face recovery rate; L is the working face length, in units of m; L H is the gas emission zone width, in units of m; n is the gas emission decay coefficient of the residual coal in the goaf, in units of min -1 ; l1 is the distance from the coal wall of the working face to the rear hydraulic support, in units of m; l2 is the width of the non-stable zone of gas concentration in the goaf along the working face advance direction, in units of m.

[0038] In this embodiment, the correction coefficient K v =actual gas emission amount under the pressure relief extraction condition of the adjacent layer / relative emission amount of the gas of the adjacent layer. The influence coefficient under the pressure relief extraction condition K vThe relationship between the amount of pressure relief gas extracted from the adjacent layer and the amount of gas emission from the mining face and the production of the mining face during the mining process of the mining face can be determined by field statistics. According to the field measurement results, the influence coefficient under the pressure relief extraction condition can be inversely calculated as: Correction coefficient K v = actual amount of gas emission from the adjacent layer under the pressure relief extraction condition / relative amount of gas emission from the adjacent layer.

[0039] On the other hand, the embodiment also provides an electronic device, comprising a memory, a processor, and a computing program stored in the memory and executable on the processor, and the processor implements the method when executing the computing program.

[0040] On the other hand, the embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the method.

[0041] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for predicting the gas emission amount at a coal face under pressure relief drainage conditions, characterized by, include: The sources of gas emission from the longwall face are determined, including gas emission from the coal face, gas emission from the mined coal, gas emission from the residual coal in the goaf, and gas emission from adjacent layers. Based on the composition of the gas emission sources, the gas emission from the coal face, the gas emission from the mined coal, the gas emission from the residual coal in the goaf, and the gas emission from adjacent layers are calculated respectively. Based on the calculated gas emission from each gas emission source, the total gas emission from the longwall face is predicted, and a mathematical model for predicting the gas emission from the longwall face under pressure relief and extraction conditions is established.

2. The method of claim 1, wherein, The determination of the sources of gas emission from the longwall mining face includes: based on the gas flow theory and the characteristics of fully mechanized coal mining, the sources of gas emission from the longwall mining face are divided into four parts: gas emission from the coal wall, gas emission from the mined coal, gas emission from the residual coal in the goaf, and gas emission from adjacent layers.

3. The method of claim 1, wherein, The calculation of coal wall gas emission includes: The relative gas emission rate of the coal face is calculated based on the gas emission intensity per unit area when the coal face is first exposed, the length of the working face, the width of the gas emission zone, the density of the coal, the recovery rate of the working face, the average advance of the working face, and the gas emission attenuation coefficient of the coal face. The calculation is obtained by dividing the cumulative gas emission during the coal face exposure time by the coal mining volume of one mining cycle.

4. The method of claim 1, wherein, The calculation of coal mining gas emission includes: The relative gas emission rate of the mined coal is calculated based on the initial gas emission intensity of the mined coal, the gas emission attenuation coefficient of the mined coal, the working face length, the width of the gas emission zone, and the average traction speed of the coal mining machine. The calculation is obtained by integrating the gas emission intensity as a function of the coal's residence time at the working face, and dividing by the length of the working face.

5. The method of claim 4, wherein, The calculation of the gas emission from the residual coal seam in the goaf includes: Based on the initial gas emission intensity of the goaf coal, the working face recovery rate, the working face length, the width of the gas emission zone, the gas emission attenuation coefficient of the goaf coal, the distance from the working face coal wall to the hydraulic support behind, and the width of the unstable gas concentration zone in the goaf, the relative gas emission of the goaf coal is calculated. The calculation is obtained by integrating the gas emission intensity of residual coal in the goaf as a function of time decay, taking into account the distribution of residual coal and effective residence time.

6. The method of claim 1, wherein, The calculation of gas emission from adjacent layers includes: Based on the coal seam thickness of multiple adjacent layers, working face mining height, adjacent layer gas emission rate, adjacent layer original gas content, adjacent layer residual gas content, and the correction coefficient of the influence of pressure relief and drainage gas on adjacent layer gas emission, the relative gas emission of adjacent layers is calculated. The calculation involves summing the gas outburst contributions from each adjacent layer and adjusting for the gas outburst using a correction factor.

7. The method of claim 5, wherein, The calculation of gas emission from mined coal and gas emission from residual coal in goaf is further based on the gas emission patterns of mined coal and residual coal in goaf. Specifically, the gas emission intensity decreases exponentially with increasing residence time. The gas emission intensity of mined coal or residual coal in goaf after residence time t at the working face is equal to the exponential function of the product of its initial gas emission intensity, the negative decay coefficient of the natural logarithm, and the residence time.

8. The method of claim 6, wherein, The correction coefficient is determined by the ratio of the gas emission rate under actual adjacent layer depressurization and extraction conditions to the relative gas emission rate of adjacent layers. It is used to adjust the calculation of adjacent layer gas emission rate to reflect the influence of depressurization and extraction conditions.

9. An electronic device comprising a memory, a processor, and a computing program stored in the memory and executable on the processor, characterized in that, When the processor executes the computing program, it implements the method of any one of claims 1-8.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 9. When the computer program is executed by a processor, it implements the method of any one of claims 1-8.

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