Coal mine accident risk monitoring method based on visual information analysis

Abstract

The invention relates to the field of coal mine risk monitoring, in particular to a coal mine accident risk monitoring method based on visual information analysis, which specifically comprises the following steps: S1, acquiring methane concentration information of a target area in a mine tunnel by adopting a visual monitoring unit, and calculating a first methane concentration of the target area; s2, acquiring mine tunnel air quality information of a target area in the mine tunnel, and correcting the first methane concentration according to the mine tunnel air quality information to generate a second methane concentration; s3, the mine tunnel temperature of the target area in the mine tunnel is obtained, the second methane concentration is corrected according to the mine tunnel temperature, and a third methane concentration is generated; according to the method, when the methane concentration of each target area of the mine tunnel is calculated, the influence of dust and water vapor in the air on laser scattering is considered, the methane concentration of the interval area is calculated according to the air flowing condition in the mine tunnel, and compared with a common methane concentration calculation method, the calculation precision is higher.

Description

Technical Field

[0001] The present invention relates to the field of coal mine risk monitoring, and in particular to a coal mine accident risk monitoring method based on visual information analysis. Background Art

[0002] In the process of coal mining, a large amount of methane is produced, and the excessive methane concentration in the mine tunnel will pose a threat to the life safety of employees. In order to ensure the life safety of employees, the laser scatterometer and the camera can be used to calculate the methane concentration at the corresponding position, and then the risk value in the mine tunnel is calculated based on the methane concentration. The laser scatterometer is generally set at intervals, and the methane concentration in the interval area between two laser scatterometers is often unable to be directly measured. Generally, the average of the methane concentrations at the corresponding positions of adjacent laser scatterometers is taken. When the air flow speed in the mine tunnel is faster, the methane concentration in the interval area is affected by the air flow speed and flow direction. The methane concentration in the interval area calculated only by the above method is quite different from the actual methane concentration, which leads to the risk value calculated based on it not being in line with the actual situation, affecting the management personnel's work in the mine and the employee scheduling measures. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a coal mine accident risk monitoring method based on visual information analysis, which solves the technical problem in the prior art that the risk value calculated when the air flow speed is fast is significantly different from the actual situation.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for coal mine accident risk monitoring based on visual information analysis specifically comprises the following steps:

[0006] S1. Use the visual monitoring unit to obtain the methane concentration information of the target area in the mine tunnel and calculate the first methane concentration of the target area

[0007] S2. Obtain the air quality information of the target area in the mine tunnel, and calculate the first methane concentration according to the air quality information of the mine tunnel. Correction is performed to generate a second methane concentration

[0008] S3, obtaining the mine tunnel temperature T of the target area in the mine tunnel, and calculating the second methane concentration according to the mine tunnel temperature T. Correction is performed to generate the third methane concentration

[0009] S4. According to the third methane concentration in the target area Calculate the fourth methane concentration in the interval area The interval area represents the position between two adjacent target areas;

[0010] S5. Based on the third methane concentration of each target area and the fourth methane concentration in each interval area Calculate the risk value for each position.

[0011] Furthermore, the visual monitoring unit includes a laser scatterometer and a monitoring device.

[0012] Furthermore, in step S1, the following steps are specifically included:

[0013] S11, obtaining the mass density ρ of the gas in the target area;

[0014] S12. Calculate the number of gas molecules N according to the mass density ρ. The calculation formula is:

[0015]

[0016] Where N A represents Avogadro's constant; V represents the volume of gas in the mine tunnel; M represents the molar mass of methane;

[0017] S13. Calculate the molecular scattering cross section constant C, the calculation formula is:

[0018]

[0019] Where n represents the refractive index of methane;

[0020] S14. Calculate the scattered light intensity I of the laser scattering instrument s , and its calculation formula is:

[0021]

[0022] In the formula, I0 represents the incident light intensity; C represents the molecular scattering cross-section constant; λ represents the laser wavelength; r represents the distance from the observation point to the scattering center;

[0023] S15. Calculate the first methane concentration in the target area The calculation formula is:

[0024]

[0025] Wherein, e represents the base of the natural logarithm; α represents the methane absorption coefficient; and L represents the path length of the laser.

[0026] Furthermore, in step S2, the following steps are specifically included:

[0027] S21, obtain the dust concentration C in each mine tunnel Dand water vapor concentration C W The mine air quality information is used to calculate the comprehensive absorption factor α based on the mine air quality information. W (C W , C D );

[0028] S22. Calculate dust impact factor F D , and its calculation formula is:

[0029] F D =1+k D ×C D

[0030] In the formula, k D Indicates the dust influence coefficient;

[0031] S23. Calculate the water vapor influence factor F W , and its calculation formula is:

[0032]

[0033] In the formula, α W represents the water vapor absorption coefficient; L represents the path length of the laser; e represents the base of the natural logarithm;

[0034] S24, according to the dust impact factor F D and water vapor influence factor F W Calculate the comprehensive impact factor F DW , and its calculation formula is:

[0035] F DW =F D ×F W

[0036] S25, according to the comprehensive impact factor F DW Calculate the second methane concentration The calculation formula is:

[0037]

[0038] In the formula, Indicates the first methane concentration.

[0039] Further, in step S21, the comprehensive absorption factor α W (C W , C D ) is:

[0040]

[0041] In the formula, α1, α2 and α3 represent the basic absorption coefficient, the first, second and third absorption coefficients, respectively.

[0042] Furthermore, in step S3, the following steps are specifically included:

[0043] S31, setting an extreme temperature range, and determining whether the mine tunnel temperature information is within the extreme temperature range;

[0044] If yes, proceed to step S32;

[0045] If not, then the second methane concentration As the third methane concentration And proceed to step S4;

[0046] S32. Calculate the temperature correction factor F T , and its calculation formula is:

[0047]

[0048] In the formula, T0 represents the reference temperature; β represents the temperature influence index;

[0049] S33, based on the temperature correction factor F T Calculate the third methane concentration The calculation formula is:

[0050]

[0051] In the formula, Indicates the second methane concentration in the target area.

[0052] Furthermore, in step S4, the following steps are specifically included:

[0053] S41, obtaining air flow information and employee movement information of each target area;

[0054] S42. Calculate the ventilation coefficient for each target area The calculation formula is:

[0055]

[0056] In the formula, represents the ventilation coefficient of the i-th target area; C downwidn Indicates the third methane concentration of the adjacent target area in the downwind direction; C upwind The third methane concentration of the adjacent target area in the upwind direction; V represents the average wind speed of the i-th target area;

[0057] S43, calculating the air flow increment ΔC of each target area airflow (t) i, and its calculation formula is:

[0058]

[0059] Where, ΔC airflow (t) i represents the air flow increment of the i-th target area; V(t) represents the wind speed of the i-th target area at time point t; represents the third methane concentration of the i-th target area;

[0060] S44. Define the nearby position influence coefficient w i , and its calculation formula is:

[0061]

[0062] In the formula, w i represents the influence coefficient of the nearby position of the i-th target area; d ij represents the distance from the i-th target area to the j-th interval area; Represents the distance attenuation coefficient; ω v represents the wind direction influence coefficient; θ represents the angle between the mine tunnel corresponding to the i-th target area and the j-th interval area;

[0063] S45. Calculate the fourth methane concentration in the interval area

[0064] Further, in step S45, the fourth methane concentration The calculation formula is:

[0065]

[0066] In the formula, represents the fourth methane concentration of the jth interval area.

[0067] Furthermore, in step S5, the following steps are specifically included:

[0068] S51, constructing a mine road route map according to the location and length of the mine road, and marking each target area and interval area as a marked position;

[0069] S52, calculate the distance influence coefficient k from each marked position in the mine tunnel to the safe position d , and its calculation formula is:

[0070]

[0071] Where V wind Indicates the average wind speed in the mine tunnel; D irepresents the length of the shortest path from the i-th marked position to the safe position in the mine tunnel; a and b are the first and second empirical constants respectively;

[0072] S53, calculate the distance risk value f (D i ), and its calculation formula is:

[0073]

[0074] S54. Obtaining the employee density ρ in the mine avg , and calculate the employee density influence coefficient k ρ , and its calculation formula is:

[0075]

[0076] Where c and d represent the third and fourth empirical constants respectively; e represents the base of the natural logarithm;

[0077] S55. Calculate the employee density influence coefficient g(ρ i ), and its calculation formula is:

[0078]

[0079] In the formula, ρ i represents the employee density at the i-th position in the mine;

[0080] S56. Calculate the risk value R of each marked position i .

[0081] Furthermore, in step S56, the risk value R i The calculation formula is:

[0082] R i =C CH4，k ×f(D i )×g(ρ i )

[0083] In the formula, R i represents the risk value of the i-th marked position in the mine tunnel; C CH4，k Represents the methane concentration at the i-th marked position in the mine tunnel.

[0084] Compared with the prior art, the present invention provides a coal mine accident risk monitoring method based on visual information analysis, which has the following beneficial effects:

[0085] 1. When calculating the methane concentration of each target area in the mine tunnel, the present invention takes into account the influence of dust and water vapor in the air on laser scattering, and calculates the methane concentration of the interval area according to the air flow in the mine tunnel. Compared with the common methane concentration calculation method, the calculation accuracy is higher.

[0086] 2. The present invention quantifies the effects of water vapor concentration, dust concentration and the interaction between the two on methane concentration, and optimizes the first methane concentration accordingly, thereby effectively improving the accuracy of calculating the methane concentration, so as to facilitate a more accurate calculation of the risk value in the mine tunnel.

[0087] 3. The present invention takes into account the influence of extreme temperature in the pipeline on laser scattering, so the methane concentration is corrected according to the temperature at extreme temperature. Compared with the common methane concentration calculation method, its calculation accuracy can be effectively improved.

[0088] 4. When calculating the methane concentration in the interval area, the present invention takes into account the influence of the air flow in the mine tunnel and the air flow of different speeds and directions in the adjacent mine tunnels on the methane concentration in the interval area. Compared with other calculation methods, the calculation accuracy is higher, so as to calculate the risk value more accurately in the later stage.

[0089] 5. Compared with the common calculation method, the present invention takes into account the influence of the distance from each position in the mine to the safe position and the employee density on the risk value, so the calculation of the risk value of each position in the mine is more accurate, which is convenient for management personnel to make timely and effective response measures to reduce the possibility of casualties. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0091] Figure 1 It is a flow chart of a method for monitoring coal mine accident risk based on visual information analysis of the present invention;

[0092] Figure 2 It is a schematic diagram of the air flow in the mine tunnel of the present invention. DETAILED DESCRIPTION

[0093] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0094] Coal is a fossil fuel that is formed from the remains of plants in ancient times under high temperature, high pressure and anaerobic conditions over a long geological period. In this process, organic matter is decomposed and part of the hydrocarbons are converted into gaseous state, mainly including methane (CH4). Most of the generated methane will be adsorbed in the microporous structure of coal or stored in the rock cracks around the coal seam. Since coal has a large specific surface area and porosity, it can effectively adsorb a large number of methane molecules. When there are dense rock layers covering the coal seams, these rock layers can prevent methane from escaping upward. Dispersed into the atmosphere, methane can be sealed in the coal seam and its surrounding rocks for a long time. Therefore, during the coal mining process, as the coal seam is exposed and the pressure is reduced, the methane originally adsorbed in the coal body will gradually be released. In addition, changes in ground stress caused by activities such as tunneling may also cause methane to gush out quickly. This means that when workers are mining coal, there may be a large amount of methane in the mine tunnel. This methane is flammable and explosive and may cause suffocation to workers, posing a serious safety threat to workers. Therefore, it is necessary to monitor the methane concentration in the mine tunnel in real time. For this purpose, Figure 1 As shown, the present invention proposes a coal mine accident risk monitoring method based on visual information analysis, which specifically includes the following steps:

[0095] S1. Use the visual monitoring unit to obtain the methane concentration information of the target area in the mine tunnel and calculate the first methane concentration of the target area Specifically, since a common methane concentration test method is to install a number of methane sensors in the mine tunnel or install a portable methane detector on the worker to monitor the methane concentration at various locations in the mine tunnel in real time, and the monitoring accuracy of the portable methane detector and the methane sensor is relatively low, and they are easily affected by the ambient temperature and humidity, and the performance and stability of the instrument are poor, resulting in false alarms or missed alarms, the visual monitoring unit includes a laser scatterometer and a monitoring device, and calculates the first methane concentration through the scattering of the laser. In step S1, the following steps are specifically included:

[0096] S11, obtaining the mass density ρ of the gas in the target area; specifically, directly monitoring the mass density ρ in the mine tunnel through a density sensor;

[0097] S12. Calculate the number of gas molecules N according to the mass density ρ. The calculation formula is:

[0098]

[0099] Where N A represents Avogadro's constant; V represents the gas volume in the mine tunnel; M represents the molar mass of methane; in the present invention, N A is 6.022×10 23 mol -1; M is 16 g / mol; V is calculated by the actual volume of the mine tunnel at the corresponding position;

[0100] S13. Calculate the molecular scattering cross section constant C, the calculation formula is:

[0101]

[0102] Wherein, n represents the refractive index of methane; in the present invention, the value of n is 1;

[0103] S14. Calculate the scattered light intensity I of the laser scattering instrument s , and its calculation formula is:

[0104]

[0105] Wherein, I0 represents the incident light intensity; C represents the molecular scattering cross-section constant; λ represents the laser wavelength; r represents the distance from the observation point to the scattering center; in the present invention, I0 and λ can be directly obtained according to the setting parameters of the laser scattering instrument;

[0106] S15. Calculate the first methane concentration in the target area The calculation formula is:

[0107]

[0108] Wherein, e represents the base of the natural logarithm; α represents the methane absorption coefficient; L represents the path length of the laser; in the present invention, the value of α is 0.3 m -1 *atm -1 ; L is determined by the set path length when setting up the laser scattering instrument.

[0109] In step S1 of the present invention, in order to improve the accuracy of monitoring the methane concentration, a laser scattering instrument is used to replace the portable methane detector and the methane sensor.

[0110] S2. Obtain the air quality information of the target area in the mine tunnel, and calculate the first methane concentration according to the air quality information of the mine tunnel. Correction is performed to generate a second methane concentration Specifically, when calculating the first methane concentration C CH4 When the water vapor and coal dust in the mine tunnel affect the intensity and scattering of the laser, it will cause the first methane concentration C CH4 The calculation result is not accurate enough, so when obtaining the first methane concentration C CH4 Afterwards, it needs to be corrected, and for this purpose, in step S2, the following steps are specifically included:

[0111] S21, obtain the dust concentration C in each mine tunnel D and water vapor concentration CW The mine air quality information is used to define the comprehensive absorption factor α based on the mine air quality information. W (C W , C D ); Specifically, the dust concentration C can be directly obtained through the dust concentration detector and the water vapor concentration detector D and water vapor concentration C W ; Since water vapor and coal dust coexist in the mine tunnel, the two may mix or form aerosols, so their influence on laser scattering is relatively complex, which in turn affects the accuracy of calculating the methane concentration. Therefore, in step S21, the comprehensive absorption factor α W (C W , C D ) is:

[0112]

[0113] In the formula, α1, α2 and α3 represent the basic absorption coefficient, the first, second and third absorption coefficients respectively; in the present invention, Indicates the basic absorption coefficient of water vapor to laser in the absence of coal dust; α1 indicates the water vapor concentration C W Comprehensive absorption factor α W (C W , C D );α2 represents the dust concentration C D Comprehensive absorption factor α W (C W , C D ); α3 represents the water vapor concentration C W and dust concentration C D The interaction between the two factors affects the overall absorption factor α W (C W , C D ) α1, α2 and α3 are 0.3, 0.015, 0.03 and 0.0003 m respectively -1 *atm -1 ;

[0114] S22. Calculate dust impact factor F D , and its calculation formula is:

[0115] F D =1+k D ×C D

[0116] In the formula, k D represents the dust influence coefficient; specifically, since the dust in the mine tunnel is mostly coal dust, k DThe value is 0.02m 2 / g; dust impact factor F D Used to indicate the influence of coal dust on the calculated methane concentration;

[0117] S23. Calculate the water vapor influence factor F W , and its calculation formula is:

[0118]

[0119] In the formula, α W represents the water vapor absorption coefficient; L represents the path length of the laser; e represents the base of the natural logarithm; in the present invention, α W The value is 1.5m -1 *atm -1 ;

[0120] S24, according to the dust impact factor F D and water vapor influence factor F W Calculate the comprehensive impact factor F DW , and its calculation formula is:

[0121] F DW =F D ×F W

[0122] S25, according to the comprehensive impact factor F DW Calculate the second methane concentration The calculation formula is:

[0123]

[0124] In the formula, Indicates the first methane concentration.

[0125] In step S2 of the present invention, in order to increase the first methane concentration To improve the accuracy, it is necessary to consider the effect of the interaction between water vapor and coal dust on laser scattering. Therefore, firstly, according to the dust concentration C D and water vapor concentration C W Calculate the comprehensive absorption factor α W (C W , C D ), and calculate the comprehensive impact factor F based on it DW , and then the first methane concentration Correction is performed to generate a second methane concentration By quantifying the effects of water vapor concentration, dust concentration and the interaction between the two on methane concentration and optimizing the first methane concentration based on them, the accuracy of calculating methane concentration can be effectively improved, so as to facilitate a more accurate calculation of the risk value in the mine tunnel.

[0126] S3, obtaining the mine tunnel temperature T of the target area in the mine tunnel, and calculating the second methane concentration according to the mine tunnel temperature T. Correction is performed to generate the third methane concentration Specifically, in a coal mine environment, due to factors such as natural heat sources deep underground, heat generated by mechanical activities, and poor ventilation, the temperature in the mine tunnel may rise significantly, especially during deep-shaft mining; while in open-pit mines in cold regions or mine tunnels working under winter conditions, the temperature may drop significantly, especially in high latitudes or high altitudes. In addition to the dust and water vapor in the mine tunnel, which will affect the first methane concentration, In addition to affecting the calculation accuracy, if the mine is in extreme temperature conditions, it will also affect the first methane concentration. The calculation accuracy is affected, therefore, in step S3, the following steps are specifically included:

[0127] S31, setting an extreme temperature range, and determining whether the mine tunnel temperature information is within the extreme temperature range;

[0128] If yes, proceed to step S32;

[0129] If not, then the second methane concentration As the third methane concentration And proceed to step S4; specifically, if the temperature in the mine tunnel exceeds 60 degrees Celsius or is lower than -20 degrees Celsius, it indicates that it is in an extreme temperature range;

[0130] S32. Calculate the temperature correction factor F T , and its calculation formula is:

[0131]

[0132] Wherein, T0 represents the reference temperature; β represents the temperature influence index; in the present invention, T0 is 20 degrees Celsius; β is 0.7;

[0133] S33, based on the temperature correction factor F T Calculate the third methane concentration The calculation formula is:

[0134]

[0135] In the formula, Indicates the second methane concentration in the target area.

[0136] In step S3 of the present invention, when the temperature in the mine tunnel is in a normal temperature range (i.e., a non-extreme temperature range), the effect of temperature on laser scattering is low and can be ignored. When the temperature in the mine tunnel is in an extreme temperature range, it means that it will affect the scattering of the laser, resulting in a low precision in the calculation of the methane concentration, so it needs to be corrected. Therefore, when the temperature in the pipeline is in an extreme temperature range, the temperature correction factor F is first calculated. T To express the influence of temperature on methane concentration, It means that the third methane concentration can be obtained by correcting the second methane concentration. The present invention takes into account the influence of extreme temperature in the pipeline on laser scattering, so the methane concentration is corrected according to the temperature at extreme temperature. Compared with the common methane concentration calculation method, its calculation accuracy can be effectively improved.

[0137] S4. According to the third methane concentration in the target area Calculate the fourth methane concentration in the interval area The interval area indicates the position between two adjacent target areas. Specifically, the laser scatterers in the mine tunnel are generally not densely arranged, and there is often a certain interval between two laser scatterers. Due to the fluidity of the air, Figure 2 As shown, the common methane concentration calculation method cannot accurately evaluate the methane concentration at the interval position, resulting in low calculation accuracy of the methane concentration of the entire mine tunnel. Therefore, in step S4, the following steps are specifically included:

[0138] S41, obtaining air flow information and employee movement information of each target area; specifically, the air flow information includes the air flow speed and flow direction of each target area in the mine tunnel; the employee movement information includes the time and speed of employees walking in the mine tunnel;

[0139] S42. Calculate the ventilation coefficient for each target area The calculation formula is:

[0140]

[0141] In the formula, represents the ventilation coefficient of the i-th target area; C downwidn Indicates the third methane concentration of the adjacent target area in the downwind direction; C upwind The third methane concentration of the adjacent target area in the upwind direction; V represents the average wind speed of the i-th target area;

[0142] S43, calculating the air flow increment ΔC of each target area airflow (t) i , and its calculation formula is:

[0143]

[0144] Where, ΔC airflow (t) i represents the air flow increment of the i-th target area; V(t) represents the wind speed of the i-th target area at time point t; represents the third methane concentration of the i-th target area;

[0145] S44. Define the nearby position influence coefficient w i , and its calculation formula is:

[0146]

[0147] In the formula, w i represents the influence coefficient of the nearby position of the i-th target area; d ij represents the distance from the i-th target area to the j-th interval area; Represents the distance attenuation coefficient; ω v represents the wind direction influence coefficient; θ represents the angle between the mine tunnel corresponding to the i-th target area and the j-th interval area; specifically, The value is 0.75; ω v The value is 0.6;

[0148] S45. Calculate the fourth methane concentration in the interval area Specifically, since the distribution of mine tunnels in a mine is often complex, the air flow in each mine tunnel will be affected by each other. Therefore, in step S45, the fourth methane concentration The calculation formula is:

[0149]

[0150] In the formula, represents the fourth methane concentration of the jth interval area.

[0151] In step S4 of the present invention, in order to accurately calculate the risk value in the mine tunnel, it is necessary to obtain the methane concentration at each position in the mine tunnel. Since there is often air flow in the mine tunnel, the ventilation coefficient of each target area is first calculated. Then calculate the air flow increment ΔC for each target area based on it airflow (t) i In this way, the change in air flow in each target area can be obtained. The mine tunnels in the mine are often complicated. The air flow between adjacent mine tunnels will affect the methane concentration in the interval area. Therefore, the mutual influence of air flow between adjacent mine tunnels needs to be considered. Therefore, the influence coefficient w of the nearby position is calculated. i , and then calculate the fourth methane concentration based on it When calculating the methane concentration in the interval area, the present invention takes into account the influence of the air flow in the mine tunnel and the air flow of different speeds and directions in the adjacent mine tunnels on the methane concentration in the interval area. Compared with other calculation methods, the calculation accuracy is higher, so as to calculate the risk value more accurately in the later stage.

[0152] S5. Based on the third methane concentration of each target area and the fourth methane concentration in each interval area Calculate the risk value of each position; Specifically, when calculating the risk value according to the methane concentration in the mine tunnel, the methane concentration is generally divided into concentration intervals, and then the risk value is determined according to the concentration intervals. This method does not take into account the different positions of different employees, resulting in different times spent escaping from the mine, and their risk values ​​are also different, so the calculation process is not accurate enough, resulting in deviations in the corresponding measures taken according to the risk value. Therefore, in step S5, the following steps are specifically included:

[0153] S51, constructing a mine road route map according to the location and length of the mine road, and marking each target area and interval area as a marked position;

[0154] S52, calculate the distance influence coefficient k from each marked position in the mine tunnel to the safe position d , and its calculation formula is:

[0155]

[0156] Where V wind Indicates the average wind speed in the mine tunnel; D i represents the length of the shortest path from the i-th marked position to the safe position in the mine tunnel; a and b are the first and second empirical constants respectively; specifically, a and b are 0.005 and 0.001 respectively;

[0157] S53, calculate the distance risk value f (D i ), and its calculation formula is:

[0158]

[0159] S54. Obtaining the employee density ρ in the mine avg , and calculate the employee density influence coefficient k ρ , and its calculation formula is:

[0160]

[0161] In the formula, c and d represent the third and fourth empirical constants respectively; e represents the base of the natural logarithm; specifically, c and d are 0.1 and 0.05 respectively;

[0162] S55. Calculate the employee density influence coefficient g(ρ i ), and its calculation formula is:

[0163]

[0164] In the formula, ρ i represents the employee density at the i-th position in the mine;

[0165] S56. Calculate the risk value R of each marked position i As a further embodiment of the present invention, in step S56, the risk value R i The calculation formula is:

[0166] R i =C CH4，k ×f(D i )×g(ρ i )

[0167] In the formula, R i represents the risk value of the i-th marked position in the mine tunnel; C CH4，k Represents the methane concentration at the i-th marked position in the mine tunnel.

[0168] After obtaining the risk value R of each marked position i Later, managers can schedule employees to work or escape based on this information.

[0169] Since the common risk value calculation method does not take into account the influence of the distance from each marked position to the safe position and the employee density on the risk value, in step S5 of the present invention, the distance influence coefficient k of each marked position to the safe position in the mine tunnel is first calculated. d and employee density influence coefficient k ρ , and calculate the distance risk value f(D i ) and the employee density influence coefficient g(ρ i ), and finally calculate the risk value R of each marked position i Compared with the common calculation method, the risk value of each position in the mine is calculated more accurately by taking into account the distance from each position in the mine to the safe position and the impact of employee density on the risk value, so it is convenient for managers to make timely and effective response measures based on it to reduce the possibility of casualties.

[0170] When calculating the methane concentration in each target area of ​​the mine tunnel, the present invention takes into account the influence of dust and water vapor in the air on laser scattering, and calculates the methane concentration in the interval area according to the air flow in the mine tunnel. Compared with the common methane concentration calculation method, the calculation accuracy is higher, and when calculating the risk value, the distance from the corresponding position to the safe position and the influence of the employee density on the risk value are taken into account, thereby further improving the calculation accuracy of the risk value.

[0171] Those skilled in the art can understand that all or part of the steps in the following embodiments can be completed by instructing the relevant hardware through a program, so the present application can be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0172] The above implementation methods have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A coal mine accident risk monitoring method based on visual information analysis, characterized in that: The following steps are involved: S1. Use the visual monitoring unit to obtain the methane concentration information of the target area in the mine tunnel and calculate the first methane concentration of the target area S2. Obtain the air quality information of the target area in the mine tunnel, and calculate the first methane concentration according to the air quality information of the mine tunnel. Correction is performed to generate a second methane concentration S3, obtaining the mine tunnel temperature T of the target area in the mine tunnel, and calculating the second methane concentration according to the mine tunnel temperature T. Correction is performed to generate the third methane concentration S4. According to the third methane concentration in the target area Calculate the fourth methane concentration in the interval area The interval area represents the position between two adjacent target areas; S5. Based on the third methane concentration of each target area and the fourth methane concentration in each interval area Calculate the risk value for each position.

2. The method for monitoring coal mine accident risk according to claim 1, characterized in that: The visual monitoring unit includes a laser scatterometer and monitoring equipment.

3. The method for monitoring coal mine accident risk according to claim 1, characterized in that: In step S1, the following steps are specifically included: S11, obtaining the mass density ρ of the gas in the target area; S12. Calculate the number of gas molecules N according to the mass density ρ. The calculation formula is: Where N A represents Avogadro's constant; V represents the volume of gas in the mine tunnel; M represents the molar mass of methane; S13. Calculate the molecular scattering cross section constant C, the calculation formula is: Where n represents the refractive index of methane; S14. Calculate the scattered light intensity I of the laser scattering instrument s , and its calculation formula is: In the formula, I0 represents the incident light intensity; C represents the molecular scattering cross-section constant; λ represents the laser wavelength; r represents the distance from the observation point to the scattering center; S15. Calculate the first methane concentration in the target area The calculation formula is: Wherein, e represents the base of the natural logarithm; α represents the methane absorption coefficient; and L represents the path length of the laser.

4. The method for monitoring coal mine accident risk according to claim 1, characterized in that: In step S2, the following steps are specifically included: S21, obtain the dust concentration C in each mine tunnel D and water vapor concentration C W The mine air quality information is used to define the comprehensive absorption factor α based on the mine air quality information. W (C W , C D ); S22, according to the dust concentration C D Calculate the dust impact factor F D , and its calculation formula is: F D =1+k D ×C D In the formula, k D Indicates the dust influence coefficient; S23, according to the definition of comprehensive absorption factor α W (C W , C D ) Calculate the water vapor influence factor F W , and its calculation formula is: In the formula, α W represents the water vapor absorption coefficient; L represents the path length of the laser; e represents the base of the natural logarithm; S24, according to the dust impact factor F D and water vapor influence factor F W Calculate the comprehensive impact factor F DW , and its calculation formula is: F DW =F D ×F W S25, according to the comprehensive impact factor F DW Calculate the second methane concentration The calculation formula is: In the formula, Indicates the first methane concentration.

5. The method for monitoring coal mine accident risk according to claim 4, characterized in that: In step S21, the comprehensive absorption factor α W (C W , C D ) is: In the formula, α1, α2 and α3 represent the basic absorption coefficient, the first, second and third absorption coefficients, respectively.

6. The method for monitoring coal mine accident risk according to claim 1, characterized in that: In step S3, the following steps are specifically included: S31, setting an extreme temperature range, and determining whether the mine tunnel temperature information is within the extreme temperature range; If yes, proceed to step S32; If not, then the second methane concentration As the third methane concentration And proceed to step S4; S32. Calculate the temperature correction factor F T , and its calculation formula is: In the formula, T0 represents the reference temperature; β represents the temperature influence index; S33, based on the temperature correction factor F T Calculate the third methane concentration The calculation formula is: In the formula, Indicates the second methane concentration in the target area.

7. The method for monitoring coal mine accident risk according to claim 1, characterized in that: In step S4, the following steps are specifically included: S41, obtaining air flow information and employee movement information of each target area; S42. Calculate the ventilation coefficient for each target area The calculation formula is: In the formula, represents the ventilation coefficient of the i-th target area; C downwidn Indicates the third methane concentration of the adjacent target area in the downwind direction; C upwind The third methane concentration of the adjacent target area in the upwind direction; V represents the average wind speed of the i-th target area; S43, calculating the air flow increment ΔC of each target area airflow (t) i , and its calculation formula is: Where, ΔC airflow (t) i represents the air flow increment of the i-th target area; V(t) represents the wind speed of the i-th target area at time point t; represents the third methane concentration of the i-th target area; S44. Define the nearby position influence coefficient w i , and its calculation formula is: In the formula, w i represents the influence coefficient of the nearby position of the i-th target area; d ij represents the distance from the i-th target area to the j-th interval area; Represents the distance attenuation coefficient; ω v represents the wind direction influence coefficient; θ represents the angle between the mine tunnel corresponding to the i-th target area and the j-th interval area; S45. Calculate the fourth methane concentration in the interval area 8. The method for monitoring coal mine accident risk according to claim 7, characterized in that: In step S45, the fourth methane concentration The calculation formula is: In the formula, represents the fourth methane concentration of the jth interval area.

9. The method for monitoring coal mine accident risk according to claim 1, characterized in that: In step S5, the following steps are specifically included: S51, constructing a mine road route map according to the location and length of the mine road, and marking each target area and interval area as a marked position; S52, calculate the distance influence coefficient k from each marked position in the mine tunnel to the safe position d , and its calculation formula is: Where V wind Indicates the average wind speed in the mine tunnel; D i represents the length of the shortest path from the i-th marked position to the safe position in the mine tunnel; a and b are the first and second empirical constants respectively; S53, calculate the distance risk value f (D i ), and its calculation formula is: S54. Obtaining the employee density ρ in the mine avg , and calculate the employee density influence coefficient k ρ , and its calculation formula is: Where c and d represent the third and fourth empirical constants respectively; e represents the base of the natural logarithm; S55. Calculate the employee density influence coefficient g(ρ i ), and its calculation formula is: In the formula, ρ i represents the employee density at the i-th position in the mine; S56. Calculate the risk value R of each marked position i .

10. The method for monitoring coal mine accident risk according to claim 9, characterized in that: In step S56, the risk value R i The calculation formula is: R i =C CH4，k ×f(D i )×g(ρ i ) In the formula, R i represents the risk value of the i-th marked position in the mine tunnel; C CH4，k Represents the methane concentration at the i-th marked position in the mine tunnel.

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