Prejudgment method for influence degree of natural wind pressure on stability of mine ventilation system

Abstract

The invention discloses a method for pre-judging the influence degree of natural wind pressure on the stability of a mine ventilation system, and the method comprises the steps: obtaining the ventilation resistance of a roadway branch through measuring the natural wind pressure of a mine closed loop, and the air density, the elevation difference, the wind resistance and the air volume of the roadway branch in the closed loop; the influence index Fi of the closed return natural wind pressure on the roadway branch is obtained, and the influence degree of the natural wind pressure on the mine ventilation system can be pre-judged according to the Fi, so that preventive measures are taken in advance, the breeze or wind flow reversal phenomenon of an individual roadway is treated in advance, the stability of the mine ventilation system is ensured, and the safety of the mine ventilation system is improved. The coal mine safety production is ensured.

Description

Technical Field

[0001] The invention relates to the field of coal mine safety, and in particular to a method for predicting the influence of natural wind pressure on the stability of a mine ventilation system. Background Art

[0002] The natural wind pressure in mines is an important factor that cannot be ignored in mine ventilation. It is an important factor that affects the stability of the mine ventilation system, safe production of mines, and high production and efficiency. Natural wind pressure can change the direction and speed of mine ventilation, increase the resistance of the mine ventilation system, and affect the mine environment. In the design and management of mine ventilation, the influence of natural wind pressure must be fully considered, and corresponding measures must be taken to utilize and control natural wind pressure to ensure safe production in mines. Under the influence of natural wind pressure, if there is a breeze or wind flow reversal in individual tunnels, the breeze in the tunnel can easily lead to insufficient oxygen supply in the tunnel, affecting normal operations and personnel health. The reversal of wind flow in the tunnel can easily cause toxic and harmful gases to spread to a larger area, thereby expanding the scope of the disaster.

[0003] In the relevant technologies, currently in the process of mine ventilation system design and on-site ventilation system management, due to the influence of natural wind pressure, there is no method to pre-determine the degree of influence of natural wind pressure on the mine ventilation system, and preventive measures cannot be taken in advance. Breezes or windflow reversals may occur in individual tunnels, which will have an adverse impact on coal mine safety production. Summary of the invention

[0004] In order to predict the impact of natural wind pressure on the mine ventilation system, to deal with the breeze or wind reversal phenomenon in individual tunnels in advance, to ensure the stability of the mine ventilation system and to ensure the safety of coal mines, the present application provides a method for predicting the impact of natural wind pressure on the stability of the mine ventilation system.

[0005] The present application provides a method for predicting the influence of natural wind pressure on the stability of a mine ventilation system, which adopts the following technical solution:

[0006] A method for predicting the influence of natural wind pressure on the stability of a mine ventilation system, comprising:

[0007] The natural wind pressure of a closed circuit in a mine is set as h N , the lane branch in the closed loop is set to i, and the air density of the lane branch is set to ρ i , the elevation difference of lane branch i is set to H i , the wind resistance of lane branch i is set to R i , the air volume of lane branch i is set to Q i , g is the acceleration of gravity, and the ventilation resistance of the tunnel branch is set to h fi ,but

[0008] The natural wind pressure h of the closed loop N =ρ i HkDJ i , then the influence index of the natural wind pressure of the closed loop on the lane branch i is set to F i ,but

[0009] If F i ≥0, the natural wind pressure of the closed loop promotes the ventilation of the lane branch i in the closed loop, and it can be determined that the wind flow of the lane branch i is stable;

[0010] If -1 <F i <0, the natural wind pressure of the closed loop will cause the wind flow of the lane branch i to reverse, and it can be determined that the wind flow of the lane branch is unstable;

[0011] If F i = -1, the natural wind pressure of the closed loop will result in no wind in the lane branch i;

[0012] If F i <-1, and the wind speed of the lane branch i is less than the minimum allowable wind speed required for this type of lane, then the natural wind pressure of the closed loop has a greater impact on the wind flow of the lane branch i, and it can be determined that the wind flow of the lane branch is unstable;

[0013] If F i <-1, and the wind speed of the lane branch i meets the allowable wind speed range required for this type of lane, then the natural wind pressure of the closed loop has little effect on the wind flow of the lane branch i, and it can be determined that the wind flow of the lane branch i is stable.

[0014] In summary, the present application includes at least one of the following beneficial technical effects:

[0015] 1. By measuring the natural wind pressure of the closed loop of the mine, the air density, elevation difference, wind resistance and air volume of a certain tunnel branch in the closed loop, the ventilation resistance of the tunnel branch is obtained, and then the influence index F of the natural wind pressure of the closed loop on the tunnel branch is obtained. i , through F i The size of the natural wind pressure can be used to predict the impact of the mine ventilation system, so that preventive measures can be taken in advance, and the breeze or wind reversal phenomenon in individual tunnels can be controlled in advance to ensure the stability of the mine ventilation system and ensure safe production in coal mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the closed loop of the mine and all the tunnel branches in the embodiment of the present application.

[0017] Explanation of the accompanying drawings: 1. Lane branch one; 2. Lane branch two; 3. Lane branch three; 4. Lane branch four. DETAILED DESCRIPTION

[0018] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0019] The embodiment of the present application discloses a method for predicting the degree of influence of natural wind pressure on the stability of a mine ventilation system.

[0020] Example

[0021] A closed circuit in a mine. A closed circuit in a mine refers to a closed air circuit consisting of two or more branch air ducts (the branches do not overlap, only one node overlaps) in the mine ventilation system. In this closed circuit, the natural wind pressure is set to h N , the lane branch in the closed loop is set to i, and the air density of the lane branch is set to ρ i , the elevation difference of lane branch i is set to H i , the wind resistance of lane branch i is set to R i , the air volume of lane branch i is set to Q i , g is the acceleration of gravity, and the ventilation resistance of the tunnel branch is set to h fi ,but

[0022] The natural wind pressure h of the closed loop N =ρ i gh i , then the influence index of the natural wind pressure of the closed loop on the lane branch i is set to F i ,but

[0023] If F i ≥0, the natural wind pressure of the closed loop has an influence on the passage of lane branch i in the closed loop.

[0024] The wind plays a promoting role, and it can be determined that the wind flow in the lane branch i is stable;

[0025] If -1 <F i <0, the natural wind pressure of the closed loop will cause the wind flow of the lane branch i to reverse, and it can be determined that the wind flow of the lane branch is unstable;

[0026] If F i = -1, the natural wind pressure of the closed loop will result in no wind in the lane branch i;

[0027] If F i<-1, and if the air velocity of the roadway branch i is less than the minimum allowable air velocity required for this type of roadway, the natural mine ventilation pressure of this closed loop has a greater impact on the air flow of the roadway branch i, and it can be determined that the air flow of the roadway branch i is unstable. The data of the minimum allowable air velocity of the roadway is sourced from the records in the "Coal Mine Safety Regulations"; compare according to the type of roadway that the roadway branch i belongs to with the minimum allowable air velocity of this type of roadway. For example: the minimum air velocity of the coal mining face is 0.25 m / s, the maximum air velocity is 4 m / s; the minimum air velocity of the drivage gateway in coal and semi-coal rock roadways is 0.25 m / s, the maximum air velocity is 4 m / s; the minimum air velocity of the drivage gateway in rock roadways is 0.15 m / s, the maximum air velocity is 4 m / s, etc.

[0028] If F i <-1, and if the air velocity of the roadway branch i meets the allowable air velocity range required for this type of roadway, the natural mine ventilation pressure of this closed loop has a smaller impact on the air flow of the roadway branch i, and it can be determined that the air flow of the roadway branch i is stable. The data of the air velocity range of the roadway is sourced from the records in the "Coal Mine Safety Regulations".

[0029] As Figure 1 shown in the mine closed loop, A, B, C, and D are the four nodes of the mine ventilation closed loop respectively. Between node A and node B is roadway branch one 1, between node B and node C is roadway branch two 2, between node C and node D is roadway branch three 3, between node A and node D is roadway branch four 4, and node A and node B are at the same horizontal level. Then the natural mine ventilation pressure h N = ρ2gH2 - ρ4gH4 - ρ3gH3;

[0030] Taking roadway branch two 2 as an example, the ventilation resistance of roadway branch two 2 Then If F2 ≥ 0, the natural mine ventilation pressure of this loop promotes the ventilation of roadway branch two 2, and it can be determined that the air flow of roadway branch two 2 is stable; if -1 < F2 < 0, the natural mine ventilation pressure of this loop will cause the air flow of roadway branch two 2 to reverse, and it can be determined that the air flow of roadway branch two 2 is unstable; if F2 = -1, the natural mine ventilation pressure of this loop will cause no air flow in roadway branch two 2; if F2 < -1, and the air velocity of roadway branch two 2 is less than the minimum allowable air velocity of this type of roadway in the "Coal Mine Safety Regulations", the natural mine ventilation pressure of this loop has a greater impact on the air flow of roadway branch two 2, and it can be determined that the air flow of roadway branch two 2 is unstable; if F2 < -1, and the air velocity of the roadway branch i meets the allowable air velocity range of this type of roadway in the "Coal Mine Safety Regulations", the natural mine ventilation pressure of this loop has a smaller impact on the air flow of roadway branch two 2, and it can be determined that the air flow of roadway branch two 2 is stable. The theoretical support of this method is the node air volume balance law, the loop mine ventilation pressure balance law, and the ventilation resistance law.

[0031] Through the prediction method of this application, through F i The size of the natural wind pressure can accurately predict the impact of the mine ventilation system, so as to take preventive measures in advance, and then deal with the breeze or wind reversal phenomenon in individual tunnels in advance, to ensure the stability of the mine ventilation system and ensure safe production in coal mines.

[0032] The implementation principle of the embodiment of the present application is: by measuring the natural wind pressure of the closed loop of the mine, the air density, elevation difference, wind resistance, and air volume of a certain lane branch in the closed loop, the ventilation resistance of the lane branch is obtained, and then the influence index F of the natural wind pressure of the closed loop on the lane branch is obtained. i , through F i The size of the natural wind pressure can be used to predict the impact of the mine ventilation system, so that preventive measures can be taken in advance, and the breeze or wind reversal phenomenon in individual tunnels can be controlled in advance to ensure the stability of the mine ventilation system and ensure safe production in coal mines.

[0033] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for predicting the influence of natural wind pressure on the stability of mine ventilation system, characterized in that: The following steps are involved: The natural wind pressure of a closed circuit in a mine is set as h N , the lane branch in the closed loop is set to i, and the air density of the lane branch is set to ρ i , the elevation difference of lane branch i is set to H i , the wind resistance of lane branch i is set to R i , the air volume of lane branch i is set to Q i , g is the acceleration of gravity, and the ventilation resistance of the tunnel branch is set to h fi ,but The natural wind pressure h of the closed loop N =ρ i HkDJ i , then the influence index of the natural wind pressure of the closed loop on the lane branch i is set to F i ,but If F i ≥0, the natural wind pressure of the closed loop promotes the ventilation of the lane branch i in the closed loop, and the wind flow of the lane branch i is determined to be stable; If -1 <F i <0, the natural wind pressure of the closed loop will cause the wind flow of the lane branch i to reverse, and the wind flow of the lane branch is determined to be unstable; If F i = -1, the natural wind pressure of the closed loop will result in no wind in the lane branch i; If F i <-1, and the wind speed of the lane branch i is less than the minimum allowable wind speed required for this type of lane, then the natural wind pressure of the closed loop has a greater impact on the wind flow of the lane branch i, and the wind flow of the lane branch is determined to be unstable; If F i <-1, and the wind speed of the lane branch i meets the allowable wind speed range required for this type of lane, then the natural wind pressure of the closed loop has little effect on the wind flow of the lane branch i, and the wind flow of the lane branch i is determined to be stable.

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