Construction method of coal and gas outburst amount comprehensive calculation model

Abstract

The invention discloses a method for constructing a coal and gas outburst amount comprehensive calculation model, which is characterized in that the coal and gas outburst amount comprehensive calculation model is established by starting from the desorption thermodynamics of structural coal and combining the mass of gushing coal, the burial depth, the unit equivalent desorption enthalpy and the physical and mechanical properties of the structural coal, and the coal and gas outburst amount can be accurately calculated. The method plays an important role in prediction and prevention of coal and gas outburst in mining areas.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety production technology, specifically to a method for constructing a comprehensive calculation model for coal and gas outburst volume. Background Technology

[0002] Coal and gas outbursts are a type of mine dynamic disaster characterized by the gradual accumulation and sudden release of energy within the coal seam-surrounding rock system during mining activities. Coal and gas outbursts are a major factor restricting safe production in coal mines, threatening the personal safety of underground workers, affecting mining progress, and ultimately impacting the long-term development of coal mining enterprises. Due to the complexity of the causes of coal and gas outbursts, coupled with the subjective and limited selection of indicators, imperfections in prediction methods, and various influencing factors such as the impact of inaccurate prediction (or verification) borehole depths at the coal face and uneven borehole distribution in thick coal areas, as well as the existence of indicators with difficult-to-determine uniform critical values ​​and those not included as predictors of outburst risk, coal and gas outbursts have occurred even with "low indicators" and with low prediction accuracy. These unfavorable factors all pose a potentially serious threat to safe mine production.

[0003] Therefore, it is necessary to provide a new method for predicting and preventing coal and gas outbursts to solve the above-mentioned technical problems. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for constructing a comprehensive calculation model for coal and gas outburst. Starting from the desorption thermodynamics of structural coal, and combining the mass of the outburst coal body, burial depth, unit equal desorption enthalpy, and physical and mechanical properties of structural coal, a comprehensive calculation model for coal and gas outburst is established. This model can accurately calculate the amount of coal and gas outburst and plays an important role in the prediction and prevention of coal and gas outburst in mining areas.

[0005] The technical solution of the present invention is as follows:

[0006] A method for constructing a comprehensive calculation model for coal and gas outburst amounts includes the following steps:

[0007] Step S1: Collect parameters from coal and gas outburst events that have occurred in the mining area, including the mass Q of the outburst coal body, the burial depth H, the firmness coefficient f, the gas pressure P, and the initial gas release velocity ΔP.

[0008] Step S2: Construct the temperature-pressure-adsorption function relationship of the structured coal;

[0009] Step S3: Based on the geothermal gradient and geopressure gradient of the coal mine, and the temperature-pressure-adsorption function relationship of the structural coal, calculate the adsorption capacity V and the unit equal desorption enthalpy ΔH of the structural coal at the corresponding burial depth. GZM And the coal and gas outburst threshold θ, which combines desorption thermodynamics and mechanics; among which,

[0010]

[0011] θ=△H GZM ×f 2 ;

[0012] Step S4, with the coal and gas outburst amount Q as the dependent variable, and the following parameters as variables: firmness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, adsorption capacity V of structural coal at the temperature and pressure generated at that burial depth, and unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the mass regression equation for coal and gas outbursts in the mining area:

[0013] Q=7781f+79P-9△P+D+9K-185V+1002△H GZM -14234θ

[0014] in,

[0015]

[0016]

[0017] D-Comprehensive Index 1;

[0018] K-Comprehensive Index 2;

[0019] Step S5, with the coal and gas outburst volume V1 as the dependent variable, and the following parameters as variables: firmness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, adsorption capacity V of the structural coal at the temperature and pressure generated at that burial depth, and unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the volumetric regression equation for coal and gas outbursts in the mining area:

[0020] V1=145010f+3770P+2230△P+60D+110K-6720V+43650△H GZM -238320θ

[0021] in,

[0022]

[0023]

[0024] D-Comprehensive Index 1;

[0025] K-Comprehensive Index 2.

[0026] Furthermore, in step S2, the temperature-pressure-adsorption capacity function relationship of the structured coal is as follows:

[0027]

[0028] Where V is the adsorption capacity of the structured coal, and M 3 / t;

[0029] M is the molecular weight of methane;

[0030] T is the absolute temperature;

[0031] A is a fixed micropore geometry constant of the porous medium;

[0032] B is the adsorption flow coefficient;

[0033] P represents the gas pressure;

[0034] β is a parameter that measures the relative influence of adsorption pressure;

[0035] △ represents the parameter that measures the relative influence of adsorption temperature.

[0036] Compared with existing technologies, the method for constructing a comprehensive calculation model for coal and gas outbursts provided by this invention has the following advantages:

[0037] The method for constructing a comprehensive calculation model for coal and gas outburst provided by this invention starts from the desorption thermodynamics of structural coal and combines the mass of the outburst coal body, burial depth, unit equal desorption enthalpy, and physical and mechanical properties of structural coal to establish a comprehensive calculation model for coal and gas outburst. It can accurately calculate the amount of coal and gas outburst and plays an important role in the prediction and prevention of coal and gas outburst in mining areas. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described below.

[0039] This invention takes Pingdingshan Coal Mine in Henan Province as an example to provide a detailed explanation of the calculation model construction method of this invention.

[0040] Parameters were collected from coal and gas outburst incidents that have occurred in Pingdingshan coal mine, Henan Province, including the mass of the outburst coal body Q, burial depth H, firmness coefficient f, gas pressure P, and initial gas emission velocity ΔP. These parameters are listed in Table 1, arranged from smallest to largest by the mass of the outburst medium.

[0041] Table 1: Parameter Collection Table for Pingdingshan Coal Mine

[0042]

[0043] Where Q is in t; H is in m; P is in MPa; and ΔP is in m / s.

[0044] Based on the isothermal adsorption data of structural coal series from Pingdingshan Coal Mine No. 5 (Reference: Jian Kuo, Fu Xuehai, Zhang Yugui. Analysis of coalbed methane desorption stage and calculation of maximum instantaneous desorption amount in structural coal [J]. Coal Science and Technology, 2015, 43(4):57-62.), the temperature-pressure-adsorption amount function relationship of structural coal from Pingdingshan Coal Mine No. 5 is constructed as follows:

[0045]

[0046] Where V is the adsorption capacity of the structured coal, and M 3 / t;

[0047] M is the molecular weight of methane;

[0048] T is the absolute temperature;

[0049] A is a fixed micropore geometry constant of the porous medium;

[0050] B is the adsorption flow coefficient;

[0051] p represents the gas pressure;

[0052] β is a parameter that measures the relative influence of adsorption pressure;

[0053] △ represents the parameter that measures the relative influence of adsorption temperature.

[0054] Based on the geothermal and geopressure gradients of the coal mine, and the temperature-pressure-adsorption function relationship of the structural coal, the adsorption capacity V and the unit isobaric desorption enthalpy ΔH of the structural coal are calculated at the corresponding burial depth. GZM The coal and gas outburst threshold θ is determined by a combination of desorption thermodynamics and mechanics; among which,

[0055] Unit equal volume desorption enthalpy ΔH GZM The calculation formula is as follows:

[0056]

[0057] △H GZM The unit is kJ / mol. -1 m -3 t;

[0058] V, unit is M 3 / t;

[0059] The formula for calculating the coal and gas outburst threshold θ, which combines desorption thermodynamics and mechanics, is as follows:

[0060] θ=△H GZM ×f2 ;

[0061] Based on the geothermal gradient of 3℃ / 100m and the geopressure gradient of 1MPa / 100m in the Pingdingshan coal mine, the adsorption capacity V and the unit isobaric desorption enthalpy ΔH of the structured coal are calculated. GZM The calculated values ​​of parameters such as the coal and gas outburst threshold θ, which combine the thermodynamics and mechanics of desorption, are shown in Table 2:

[0062] Table 2: Calculation Results of Desorption Thermodynamic Parameters Corresponding to the Outburst Mass of Structural Coal

[0063]

[0064]

[0065] in,

[0066]

[0067] D-Comprehensive Index 1;

[0068] K-Comprehensive Index 2.

[0069] Since coal and gas outbursts are related to multiple factors, including the adsorption-desorption thermodynamics of structural coal and its physical and mechanical properties, predicting or estimating the dependent variable using the optimal combination of multiple independent variables is more effective and realistic than using only a single independent variable. Due to the complexity of the internal laws governing objective phenomena and the limitations of human understanding, it is difficult to establish a mathematical model that conforms to the underlying causal relationships of actual objects. Typically, a method of collecting large amounts of data and building models based on statistical analysis is adopted, with statistical regression models being the most widely used.

[0070] In this invention, the coal and gas outburst amount Q is taken as the dependent variable, and the following parameters are used: the firmness coefficient f, the gas pressure P, the initial gas release velocity ΔP, the comprehensive index D, the comprehensive index K, the adsorption amount V of the structural coal at the temperature and pressure generated at the burial depth, and the unit isobaric desorption enthalpy ΔH at the adsorption amount. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the mass regression equation for coal and gas outbursts in the mining area:

[0071] Q=7781f+79P-9△P+D+9K-185V+1002△H GZM -14234θ.

[0072] In coal and gas outbursts, gas outbursts occur alongside the coal solids. In this invention, the volume V1 of the coal and gas outburst that has already occurred in the Pingdingshan mining area is taken as the dependent variable. Factors used include the robustness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, the adsorption capacity V of the structural coal at the temperature and pressure at that burial depth, and the unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM The coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, is used as the independent variable. Data are shown in Table 3.

[0073] Table 3: Calculation Results of Desorption Thermodynamic Parameters Corresponding to Gas Outburst Volume

[0074]

[0075]

[0076] Where V1 is in meters 3 With the coal and gas outburst volume V1 as the dependent variable, and the following parameters as variables: firmness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, adsorption capacity V of the structural coal at the temperature and pressure generated at that burial depth, and unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the volumetric regression equation for coal and gas outbursts in the mining area:

[0077] V1=145010f+3770P+2230△P+60D+110K-6720V+43650△H GZM -238320θ.

[0078] The following detailed description of the integrated calculation model for coal and gas outburst volume of the present invention is provided through specific embodiments.

[0079] Example 1

[0080] A coal and gas outburst occurred at a depth of 872 meters in the Fifth Mining Area of ​​Pingdingshan Coal Mine. The outburst coal mass was 65.5 tons. At the time, the measured soundness coefficient was 0.31, the gas pressure was 1.15 MPa, and the initial gas release velocity was 12.5 m / s. The calculated comprehensive index D was 7.56, and the comprehensive index K was 40.98. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 872 meters was 13.32 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6177 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0575. Substituting these values ​​into the regression equation for calculating the coal and gas outburst mass in the Pingdingshan mining area, the outburst coal mass is determined to be 64.8 tons.

[0081] Example 2

[0082] A coal and gas outburst occurred at a depth of 495 meters in the No. 8 mining area of ​​Pingdingshan Coal Mine. The mass of the outburst coal was 144 tons. At the time of the outburst, the measured soundness coefficient was 0.5, the gas pressure was 1.84 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 4.87, and the comprehensive index K was 16.0. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 495 meters was 11.14. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.7386 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.1847. Substituting these values ​​into the regression equation for calculating the coal and gas outburst mass in the Pingdingshan mining area, the outburst coal mass is determined to be 163.5 tons.

[0083] Example 3

[0084] A coal and gas outburst occurred at a depth of 807 meters in the No. 8 mining area of ​​Pingdingshan Coal Mine. The mass of the outburst coal was 450 tons. At the time, the measured soundness coefficient was 0.11, the gas pressure was 2.12 MPa, and the initial gas emission velocity was 17.0 m / s. The calculated comprehensive index D was 71.8, and the comprehensive index K was 154.55. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 807 meters was 13.01 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6325 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0077. Substituting these values ​​into the regression equation for calculating the coal and gas outburst mass in the Pingdingshan mining area, the outburst coal mass is determined to be 451 tons.

[0085] Example 4

[0086] A coal and gas outburst occurred at a depth of 514 meters in the No. 10 mining area of ​​Pingdingshan Coal Mine. The outburst coal mass was 170 tons. At the time, the measured soundness coefficient was 0.50, the gas pressure was 1.77 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 4.85, and the comprehensive index K was 16.0. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 514 meters was 11.28 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.7295 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.1824. Substituting these values ​​into the regression equation for calculating the coal and gas outburst mass in the Pingdingshan mining area, the outburst coal mass is determined to be 155.5 tons.

[0087] Example 5

[0088] A coal and gas outburst occurred at a depth of 620 meters in the No. 12 mining area of ​​Pingdingshan Coal Mine. The outburst coal mass was 25.0 tons. At the time, the measured soundness coefficient was 0.11, the gas pressure was 2.25 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 59.3, and the comprehensive index K was 72.73. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 620 meters was 11.99 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6863 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0083. Substituting these values ​​into the regression equation for calculating the coal and gas outburst mass in the Pingdingshan mining area, the outburst coal mass is determined to be 26.8 tons.

[0089] Example 6

[0090] A coal and gas outburst occurred at a depth of 872 meters in the Fifth Mining Area of ​​Pingdingshan Coal Mine. The volume of the outburst gas was 5036 cubic meters. At the time of the outburst, the measured soundness coefficient was 0.31, the gas pressure was 1.15 MPa, and the initial gas release velocity was 12.5 m / s. The calculated comprehensive index D was 7.56, and the comprehensive index K was 40.98. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 872 meters was 13.32 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6177 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0575. Substituting these values ​​into the regression equation for calculating the coal and gas outburst volume in the Pingdingshan mining area, the outburst gas volume is determined to be 5159 cubic meters.

[0091] Example 7

[0092] A coal and gas outburst occurred at a depth of 495 meters in the No. 8 mining area of ​​Pingdingshan Coal Mine. The volume of the outburst gas was 13,400 cubic meters. At the time of the outburst, the measured soundness coefficient was 0.5, the gas pressure was 1.84 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 4.87, and the comprehensive index K was 16.0. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 495 meters was 11.14. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.7386 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.1847. Substituting these values ​​into the regression equation for calculating the coal and gas outburst volume in the Pingdingshan mining area, the outburst gas volume is determined to be 12707 cubic meters.

[0093] Example 8

[0094] A coal and gas outburst occurred at a depth of 807 meters in the No. 8 mining area of ​​Pingdingshan Coal Mine. The volume of the outburst gas was 22,000 cubic meters. At the time of the outburst, the measured soundness coefficient was 0.11, the gas pressure was 2.12 MPa, and the initial gas release velocity was 17.0 m / s. The calculated comprehensive index D was 71.8, and the comprehensive index K was 154.55. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 807 meters was 13.01 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6325 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0077. Substituting these values ​​into the regression equation for calculating the coal and gas outburst volume in the Pingdingshan mining area, the outburst gas volume is determined to be 21,517 cubic meters.

[0095] Example 9

[0096] A coal and gas outburst occurred at a depth of 514 meters in the No. 10 mining area of ​​Pingdingshan Coal Mine. The volume of the outburst gas was 11,100 tons. At the time, the measured soundness coefficient was 0.50, the gas pressure was 1.77 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 4.85, and the comprehensive index K was 16.0. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 514 meters was 11.28 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.7295 kJ / mol. -1 m -3 The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.1824. Substituting these values ​​into the regression equation for calculating the coal and gas outburst volume in the Pingdingshan mining area, the outburst gas volume is determined to be 11,647 cubic meters.

[0097] Example 10

[0098] A coal and gas outburst occurred at a depth of 620 meters in the No. 12 mining area of ​​Pingdingshan Coal Mine. The volume of the outburst gas was 1435 cubic meters. At the time, the measured soundness coefficient was 0.11, the gas pressure was 2.25 MPa, and the initial gas release velocity was 8.0 m / s. The calculated comprehensive index D was 59.3, and the comprehensive index K was 72.73. The calculated adsorption capacity of the structural coal at the temperature and pressure at a depth of 620 meters was 11.99 M. 3 / t, the unit isobaric desorption enthalpy at this adsorption capacity is 0.6863 kJ / mol. -1 m -3The coal and gas outburst threshold, calculated using a combination of desorption thermodynamics and mechanics, is 0.0083. Substituting these values ​​into the regression equation for calculating the coal and gas outburst volume in the Pingdingshan mining area, the outburst gas volume is determined to be 1236 cubic meters.

[0099] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A method for constructing a comprehensive calculation model for coal and gas outburst amounts, characterized in that, Includes the following steps: Step S1: Collect parameters from coal and gas outburst events that have occurred in the mining area, including the mass Q of the outburst coal body, the burial depth H, the firmness coefficient f, the gas pressure P, and the initial gas release velocity ΔP. Step S2: Construct the temperature-pressure-adsorption function relationship of the structured coal; Step S3: Based on the geothermal gradient and geopressure gradient of the coal mine, and the temperature-pressure-adsorption function relationship of the structural coal, calculate the adsorption capacity V and the unit equal desorption enthalpy ΔH of the structural coal at the corresponding burial depth. GZM And the coal and gas outburst threshold θ, which combines desorption thermodynamics and mechanics; among which, θ=△H GZM ×f 2 ; Step S4, with the coal and gas outburst amount Q as the dependent variable, and the following parameters as variables: firmness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, adsorption capacity V of structural coal at the temperature and pressure generated at that burial depth, and unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the mass regression equation for coal and gas outbursts in the mining area: Q=7781f+79P-9△P+D+9K-185V+1002△H GZM -14234θ in, D-Comprehensive Index 1; K-Comprehensive Index 2; Step S5, with the coal and gas outburst volume V1 as the dependent variable, and the following parameters as variables: firmness coefficient f, gas pressure P, initial gas release velocity ΔP, comprehensive index D, comprehensive index K, adsorption capacity V of the structural coal at the temperature and pressure generated at that burial depth, and unit isobaric desorption enthalpy ΔH at that adsorption capacity. GZM Using the coal and gas outburst threshold θ, derived from the combined desorption thermodynamics and mechanics, as the independent variable, an 8-variable linear regression was performed to obtain the volumetric regression equation for coal and gas outbursts in the mining area: V1=145010f+3770P+2230△P+60D+110K-6720V+43650△H GZM -238320θ in, D-Comprehensive Index 1; K-Comprehensive Index 2.

2. The method for constructing the comprehensive calculation model for coal and gas outburst volume according to claim 1, characterized in that, In step S2, the temperature-pressure-adsorption capacity function relationship of the structured coal is as follows: Where V is the adsorption capacity of the structured coal, and M 3 / t; M is the molecular weight of methane; T is the absolute temperature; A is a fixed micropore geometry constant of the porous medium; B is the adsorption flow coefficient; P represents the gas pressure; β is a parameter that measures the relative influence of adsorption pressure; △ represents the parameter that measures the relative influence of adsorption temperature.

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