A refined diagnosis method for the ventilation difficulty level of underground roadways

Abstract

The present invention provides a refined diagnosis method for the ventilation difficulty level of underground roadways, which relates to the technical field of mine ventilation. The present invention includes the following steps: Step 1, obtain the roadway characteristic parameters and the air flow characteristic parameters in the roadway; Step 2, calculate the frictional air resistance of the rough wall of the roadway; Step 3, calculate the air resistance of the roadway facilities and structures; Step 4, calculate the total air resistance of the roadway; Step 5, calculate the equivalent orifice of the roadway and the ratio of various types of air resistance in the roadway. The refined diagnosis method for the ventilation difficulty level of underground roadways of the present invention, by obtaining the roadway characteristic parameters and the air flow characteristic parameters in the roadway, accurately calculates the air resistance values of various types in the roadway, accurately calculates the equivalent orifice of the roadway to judge the ventilation difficulty level of the roadway, and accurately calculates the ratio of various types of air resistance in the roadway, providing a data basis for targeted implementation of ventilation air resistance reduction measures for the roadway.

Description

Technical Field

[0001] The present invention relates to the technical field of mine ventilation, and more particularly to a refined diagnosis method for the ventilation difficulty degree of underground roadways. Background Art

[0002] As an important index for evaluating the ventilation difficulty degree of mines, the equivalent orifice has been widely used in the underground mine exploitation in various countries. In the traditional evaluation process, the ventilation difficulty degree of mines is divided into three levels according to the size of the equivalent orifice: when the equivalent orifice A≥2m 2 the mine ventilation is easy; when 2m 2 >equivalent orifice A>1m 2 the mine ventilation is medium; when the equivalent orifice A≤1m 2 the mine ventilation is difficult. However, with the development and extension of modern large-scale mines and the increase of mining depth, the ventilation routes are complex and growing rapidly. The expansion of the mining scale requires a larger ventilation air volume, resulting in ventilation difficulties, increased energy consumption, and potential hazards such as gas accumulation. The traditional equivalent orifice grading method can no longer meet the needs of accurate assessment of ventilation capacity in modern mines. There are many mines where the equivalent orifice of the mine is much larger than 2m 2 but the ventilation capacity is difficult and the air volume is insufficient.

[0003] Based on this, domestic scholars have comprehensively considered the influence of different factors on the ventilation system and the "Coal Industry Mine Design Code", and proposed different equivalent orifice grading standards and correction methods, making the standard for evaluating the ventilation difficulty degree of mines by the equivalent orifice more clear. However, the previous research still cannot solve the problem that as a single index, it cannot effectively reflect the details of the ventilation difficulty degree, and it is an evaluation of the ventilation difficulty degree of the whole mine, which cannot achieve the refined evaluation of the branch roadways and their internal facilities, nor can it be used to guide mine ventilation engineers on how to adopt appropriate resistance reduction measures. Summary of the Invention

[0004] The present invention provides a refined diagnosis method for the ventilation difficulty degree of underground roadways to accurately calculate the equivalent orifice of the roadway and the ratio of various types of wind resistance in the roadway.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A refined diagnosis method for the ventilation difficulty degree of underground roadways, the method comprising the following steps:

[0007] Step 1, obtain the roadway characteristic parameters and the air flow characteristic parameters in the roadway;

[0008] Step 2, calculate the frictional wind resistance of the rough wall surface of the roadway;

[0009] Step 3, calculate the wind resistance of the roadway facilities and structures;

[0010] Step 4: Calculate the total air resistance of the roadway;

[0011] Step 5: Calculate the equivalent orifice of the roadway and the air resistance ratios of various types in the roadway.

[0012] Further, in Step 1, the roadway characteristic parameters include the roadway perimeter, roadway cross-sectional area, and roadway length;

[0013] Among them, the roadway perimeter U h and the roadway cross-sectional area A h are calculated by the following formulas:

[0014]

[0015] In the formula,

[0016] U s is the cross-sectional perimeter at the starting end of the roadway, in m; U m is the cross-sectional perimeter at the ending end of the roadway, in m; A s is the cross-sectional area at the starting end of the roadway, in m 2 ; A m is the cross-sectional area at the ending end of the roadway, in m 2 .

[0017] Further, in Step 1, the air flow characteristic parameters in the roadway include the absolute static pressure value of the roadway air, the roadway air temperature, and the roadway air density;

[0018] Among them, the roadway air density ρ h is calculated by the following formula:

[0019]

[0020] In the formula,

[0021] P s is the absolute static pressure value of the air at the starting end of the roadway, in Pa; P m is the absolute static pressure value of the air at the ending end of the roadway, in Pa; T s is the air temperature at the starting end of the roadway, in °C; T m is the air temperature at the ending end of the roadway, in °C;

[0022] Further, the total air resistance R of the roadway h is the sum of the rough wall friction air resistance R b and the air resistance R of roadway facilities and structures s .

[0023] Further, in Step 2, the rough wall friction air resistance R of the roadway b is calculated by the following formula:

[0024]

[0025] In the formula:

[0026] f is the friction resistance coefficient, a dimensionless parameter, which takes different values according to different roadway support types. Among them, for a roadway supported by bolts and wire meshes, f takes 0.0364; for a roadway supported by a shed, f takes 0.0718; for a roadway supported by metal columns, f takes 0.0533; for a roadway supported by masonry lining, f takes 0.0144; for a roadway supported by cement shotcrete, f takes 0.0153; L h is the roadway length, in m.

[0027] Furthermore, in step 3, the air resistance R of the roadway facilities and structures s is the sum of the air resistance R of the roadway along - the - way facilities yc and the air resistance R of the roadway local facilities. jb

[0028] Furthermore, the formula for the air resistance R of the roadway along - the - way facilities yc is:

[0029]

[0030] In the formula:

[0031] K is the number of the roadway along - the - way facilities, k = 1…K; U k is the cross - sectional perimeter of the k - th along - the - way facility, in m; A k is the cross - sectional area of the k - th along - the - way facility, in m 2 .

[0032] Furthermore, the air resistance R of the roadway local facilities jb is the sum of the air resistance R of the roadway local obstacle facilities jz , the air resistance R of the roadway local chambers jd and the air resistance R of the roadway local bends; jw

[0033] The formula for the air resistance R of the roadway local obstacle facilities jz is:

[0034]

[0035] In the formula:

[0036] I is the number of the local obstacle facilities in the roadway, i = 1…I; A i is the cross - sectional area of the i - th local obstacle facility, in m 2 ;

[0037] The formula for the air resistance R of the roadway local chambers jd is:

[0038] ​​

[0039] In the formula:

[0040] J is the number of chambers in the roadway, j = 1…J; A j is the cross-sectional area of the j-th chamber, m 2 ;

[0041] The air resistance R of the local bend in the roadway jw is calculated by the formula:

[0042]

[0043] In the formula:

[0044] N is the number of bends in the roadway, n = 1…N; θ is the included angle of the i-th bend, °.

[0045] Furthermore, in step 4, the formula for calculating the total air resistance of the roadway is:

[0046] R h = R b + R yc + R jz + R jd + R jw , kg / m 7 ;

[0047] In the formula:

[0048] R h is the total air resistance of the roadway, kg / m 7 .

[0049] Furthermore, in step 5, the formula for calculating the equivalent orifice A e of the roadway is:

[0050]

[0051] The formula for the air resistance ratio q t of each type in the roadway is:

[0052]

[0053] In the formula:

[0054] R t is any one value or the sum of several values among R b , R yc , R jz , R jd , R jw and R 7 , kg / m

[0055] The beneficial technical effects of the present invention are:

[0056] The refined diagnosis method for the ventilation difficulty level of underground roadways in the present invention determines the ventilation difficulty level of roadways by obtaining roadway characteristic parameters and air flow characteristic parameters in the roadway, accurately calculating various types of air resistances in the roadway, accurately calculating the equivalent orifice of the roadway, and accurately calculating the air resistance ratio of various types in the roadway, providing a data basis for implementing targeted ventilation resistance reduction measures in the roadway. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic flow chart of the refined diagnosis method for the ventilation difficulty level of underground roadways in an embodiment of the present invention;

[0058] Figure 2 It is a plan view of the layout of a branch roadway in a certain mine in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] To make the objectives, technical solutions, and beneficial effects of the present invention clearer and more understandable, the following further elaborates on the present invention in detail with reference to specific embodiments and the accompanying drawings. Some but not all of the embodiments of the present invention will be described more comprehensively with reference to the accompanying drawings later. In fact, various embodiments of the present invention can be implemented in many different forms and should not be construed as limited to the embodiments described herein; on the contrary, these embodiments are provided to enable the present invention to meet the applicable legal requirements.

[0060] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inner", "outer", "upper", "lower", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0061] Please refer to Figure 1 、 Figure 2 As shown, a refined diagnosis method for the ventilation difficulty level of underground roadways includes the following steps:

[0062] Step 1: Obtain roadway characteristic parameters and air flow characteristic parameters in the roadway. Specifically, a three-dimensional laser scanner is used to scan the roadway, and the roadway characteristic parameters are measured based on the scan data, and a mine multi-parameter measuring instrument is used to measure the air flow characteristic parameters in the roadway.

[0063] In Step 1, the roadway characteristic parameters include the roadway perimeter, the roadway cross-sectional area, and the roadway length;

[0064] Among them, the roadway perimeter U h and the roadway cross-sectional area A h The calculation formulas are:

[0065]

[0066] In the formula,

[0067] U s is the perimeter of cross-section 1 at the starting end of the roadway, in m; U m is the perimeter of cross-section 2 at the ending end of the roadway, in m; A s is the area of cross-section 1 at the starting end of the roadway, in m 2 ; A m is the area of cross-section 2 at the ending end of the roadway, in m 2 ; Measured through the laser scanning point cloud data, U s is 8.6 m, U m is 8.4 m, then the perimeter U h of the roadway is 8.5 m; A s is 4.5 m 2 , A m is 4.37 m 2 , then the cross-sectional area A h of the roadway is 4.435 m².

[0068] In step 1, the air flow characteristic parameters in the roadway include the absolute static pressure value of the roadway air, the roadway air temperature, and the roadway air density;

[0069] Among them, the calculation formula for the roadway air density ρ h is:

[0070]

[0071] In the formula,

[0072] P s is the absolute static pressure value of the air at the starting end of the roadway, in Pa; P m is the absolute static pressure value of the air at the ending end of the roadway, in Pa; T s is the air temperature at the starting end of the roadway, in °C; T m the air temperature at the ending end of the roadway, in °C; Measured by a mine multi-parameter measuring instrument, the absolute static pressure value P s of the air at the starting end of the roadway is 90610 Pa, and the air temperature T s at the starting end of the roadway is 17.81 °C. The absolute static pressure value P m at the ending end is 90663 Pa, and the air temperature T s at the ending end of the roadway is 18 °C. Then the roadway air density ρ h is 1.074 kg / m 3 .

[0073] Step 2: Calculate the frictional air resistance of the rough roadway wall.

[0074] Frictional resistance R of rough roadway wall b The calculation formula is as follows:

[0075]

[0076] Where:

[0077] f is the frictional resistance coefficient, a dimensionless parameter, which takes different values according to different support types of the roadway. Among them, for a roadway supported by bolts and wire meshes, f takes 0.0364; for a roadway supported by a shed, f takes 0.0718; for a roadway supported by metal columns, f takes 0.0533; for a roadway supported by masonry lining, f takes 0.0144; for a roadway supported by cement shotcrete, f takes 0.0153. The roadways in this mine are supported by bolts and wire meshes, so f takes 0.0364, and the length L of the roadway h is 230 m. Then the frictional resistance R of the rough roadway wall b is 0.438 kg / m 7 .

[0078] Step 3: Calculate the resistance of roadway facilities and structures.

[0079] The resistance R of roadway facilities and structures s is the sum of the resistance R yc of roadway along - the - way facilities and the resistance R jb of roadway local facilities.

[0080] Roadway along - the - way facilities include belt conveyor 3, gas drainage pipe 4, water pipe 5, and cable 6. The calculation formula for the resistance R yc of roadway along - the - way facilities is as follows:

[0081]

[0082] Where:

[0083] K is the number of roadway along - the - way facilities, k = 1…K, U k is the cross - sectional perimeter of the k - th along - the - way facility, in m; A k is the cross - sectional area of the k - th along - the - way facility, in m 2 ; There are 8 along - the - way facilities in the roadways of this mine: Among them, there is 1 belt conveyor, whose bottom surface overlaps with the roadway floor. Subtracting the cross - sectional perimeter U ssj of the overlapping area is 2.8 m, and the cross - sectional area is A ssj of 0.96 m 2 ; There are 2 gas drainage pipes, and the cross - sectional perimeter U wsg of each is 1.256 m, and the cross - sectional area A wsg is 0.1256 m 2 ; There is 1 water pipe, the cross - sectional perimeter U sg is 0.628 m, and the cross - sectional area A sg is 0.0314 m2 ; There are 4 cable cross-sections, and the perimeter U of each cross-section sg is 0.3768 m, and the cross-sectional area A sg is 0.0113 m 2 ; Then the air resistance R of the in-roadway facilities along the way yc value is 1.862 kg / m 7 .

[0084] The air resistance R of the in-roadway local facilities jb is the sum of the air resistance R of the local obstacle facilities in the roadway jz , the air resistance R of the local chambers in the roadway jd and the air resistance R of the local bends in the roadway jw .

[0085] The local obstacle facilities include mine cars 7, transformers 8, etc. The calculation formula for the air resistance R of the local obstacle facilities in the roadway jz is:

[0086]

[0087] In the formula:

[0088] I is the number of local obstacle facilities in the roadway, i = 1…I; A i is the cross-sectional area of the i-th local obstacle facility, m 2 ; There are 2 local obstacle facilities in the roadway of this mine: among them, the cross-sectional area A of the mine car kc is 1.2 m 2 ; The cross-sectional area of the transformer is 1.5 m 2 , then the air resistance R of the local obstacle facilities in the roadway jz is 0.0163 kg / m 7 .

[0089] The chambers include refuge chambers, drainage drill sites, pump rooms, substations and other chambers. The calculation formula for the air resistance R of the local chambers 9 in the roadway jd is:

[0090]

[0091] In the formula:

[0092] J is the number of chambers in the roadway, j = 1…J; A j is the cross-sectional area of the j-th chamber, m 2 ; There are 2 local chambers in the roadway of this mine: the cross-sectional area A of the local chamber 9 in the roadway jd is 2 m 2 , then the air resistance R of the local chamber in the roadway jd is 0.00791 kg / m 7 .

[0093] Local airway bend air resistance R jw The calculation formula is:

[0094]

[0095] Where:

[0096] N is the number of bends in the airway, n = 1…N; θ is the included angle of the i-th bend, °; There is 1 bend 10 in the mine airway, and the bend angle is 90°, then the local airway bend air resistance R jw is 0.0271 kg / m 7 .

[0097] Step 4. Calculate the total air resistance of the airway. The total airway air resistance R h is the sum of the rough wall friction air resistance R b and the air resistance R s of airway facilities and structures.

[0098] In Step 4, the calculation formula for the total airway air resistance R h is:

[0099] R h = R b + R yc + R jz + R jd + R jw ;

[0100] The total airway air resistance is 2.351 kg / m 7 .

[0101] Step 5. Calculate the equivalent orifice of the airway and the air resistance ratios of various types in the airway.

[0102] In Step 5, the calculation formula for the equivalent orifice A e of the airway is:

[0103]

[0104] The equivalent orifice A e of this airway is 0.776 m 2 , belonging to an airway with difficult ventilation, and measures need to be taken to reduce the airway ventilation resistance.

[0105] The calculation formula for the air resistance ratios q t of various types in the airway is:

[0106]

[0107] Where:

[0108] R t is R b , R yc , Rjz , R jd and R jw or the sum of several values thereof, kg / m 7 ; where the frictional air resistance ratio q b of the rough wall of the roadway is 18.63%, and the air resistance ratio q yc of the air resistance along the roadway facilities is 79.20%, and the air resistance ratio q jz of the local obstacle facilities in the roadway is 0.69%, and the air resistance ratio q jz of the local obstacle facilities in the roadway is 0.33%, and the air resistance ratio q jw of the local bend in the roadway is 1.15%.

[0109] By accurately calculating the air resistance ratios of various types in the roadway, the main air resistance of this roadway comes from the air resistance along the facilities, providing a data basis for implementing targeted ventilation air resistance reduction measures for the roadway.

[0110] So far, this embodiment has been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the refined diagnosis method for the ventilation difficulty level of underground roadways in the present invention. The refined diagnosis method for the ventilation difficulty level of underground roadways in the present invention obtains the characteristic parameters of the roadway and the characteristic parameters of the air flow in the roadway, accurately calculates the air resistance values of various types in the roadway, accurately calculates the equivalent orifice of the roadway to judge the ventilation difficulty level of the roadway, and accurately calculates the air resistance ratios of various types in the roadway, providing a data basis for implementing targeted ventilation air resistance reduction measures for the roadway. Specifically, from a technical level, the method of the present invention has a wide range of applications. Whether the mine is in the design stage, the initial construction stage, the operation and maintenance stage, or the end mining stage, this method can be used to conduct refined diagnosis of the ventilation difficulty level of key roadways; and the diagnosis result is accurate. By accurately calculating different types of air resistance ratios, targeted mine ventilation air resistance reduction measures can be proposed; from the perspective of saving time and economic costs, the characteristic parameters of the roadway and the characteristic parameters of the air flow in the roadway required by the method of the present invention are conventional basic parameters and are easy to obtain; this method can accurately calculate the air resistance values of various types in the roadway, enabling mine ventilation technicians to intuitively obtain different types of air resistance ratios, reducing decision-making costs, and then accurately proposing roadway air resistance reduction measures; after the implementation of this method, the mine air resistance and fan energy consumption can be effectively reduced, costs can be saved, and the rationality of mine ventilation design and the safety of mine production can be improved.

[0111] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A refined diagnosis method for the difficulty of ventilation in underground tunnels, wherein the tunnel is a branch tunnel set in a mine, characterized in that: The method comprises the following steps: Step 1, obtaining lane characteristic parameters and lane airflow characteristic parameters; In step 1, the lane characteristic parameters include lane perimeter, lane cross-sectional area and lane length; Among them, the roadway perimeter U h and tunnel cross-sectional area A h The calculation formula is: In the formula, U s is the cross-sectional perimeter of the tunnel starting end, in m; U m is the cross-sectional perimeter at the end of the tunnel, in m; A s is the cross-sectional area at the starting end of the tunnel, in m 2 ; A m is the cross-sectional area at the end of the tunnel, in m 2 ; In step 1, the characteristic parameters of the air flow in the tunnel include the absolute static pressure value of the tunnel air, the tunnel air temperature and the tunnel air density; Among them, the air density in the tunnel is h The calculation formula is: In the formula, P s is the absolute static pressure of air at the starting end of the tunnel, in Pa; P m is the absolute static pressure of air at the end of the tunnel, in Pa; T s is the air temperature at the beginning of the tunnel, in °C; T m The air temperature at the end of the tunnel, in °C; Step 2, calculate the frictional wind resistance of the rough wall of the tunnel; In step 2, the friction resistance of the rough wall of the tunnel is R b The calculation formula is: Where: f is the friction coefficient, a dimensionless parameter, and its value varies according to the different support types of the roadway. For roadways supported by bolts and anchor nets, f is 0.0364; for roadways supported by sheds, f is 0.0718; for roadways supported by metal columns, f is 0.0533; for roadways supported by masonry, f is 0.0144; and for roadways supported by cement shotcrete, f is 0.0153. L h is the length of the lane, in m; Step 3: Calculate the wind resistance of tunnel facilities and structures; In step 3, the wind resistance of the roadway facilities and structures R s R is the wind resistance of the facilities along the roadway yc Similar wind resistance R to local facilities in the roadway jb sum; Wind resistance R of facilities along the roadway yc The calculation formula is: Where: K is the number of facilities along the roadway, k = 1…K; U k A is the cross-sectional perimeter of the kth facility along the route, in meters; k is the cross-sectional area of ​​the kth facility along the route, in m 2 ; Wind resistance of local facilities in the lane R jb is the wind resistance of local obstacles in the roadway R jz 、Wind resistance of local chamber in tunnel R jd and the local curve wind resistance R jw sum; Among them, the wind resistance of local obstacles in the roadway is R jz The calculation formula is: Where: I is the number of local obstacle facilities in the tunnel, i = 1…I; A i is the cross-sectional area of ​​the ith local obstacle facility, in m 2 ; Wind resistance of local chamber in tunnel R jd The calculation formula is: J is the number of chambers in the tunnel, j = 1…J; A j is the cross-sectional area of ​​the jth chamber, in m 2 ; Wind resistance of local bend in lane R jw The calculation formula is: Where: N is the number of bends in the lane, n=1…N; θ is the angle of the ith bend, in degrees; Step 4, calculate the total wind resistance of the tunnel; Total wind resistance of the roadway R h is the friction resistance of the rough wall of the tunnel R b and the wind resistance of tunnel facilities and structures R s sum; Step 5: Calculate the ratio of the equal volume holes in the tunnel and the wind resistance of each type in the tunnel.

2. A refined diagnosis method for the difficulty of underground tunnel ventilation according to claim 1, characterized in that: In step 4, the total wind resistance of the roadway is calculated as: R h =R b +R yc +R jz +R jd +R jw , unit is kg / m 7 ; Where: R h is the total wind resistance of the tunnel, in kg / m 7 .

3. A refined diagnosis method for the difficulty of underground tunnel ventilation according to claim 2, characterized in that: In step 5, the tunnel equal volume hole A e The calculation formula is: Ratio of various types of wind resistance in the tunnel q t The calculation formula is: Where: R t For R b , R yc , R jz , R jd and R jw Any value or the sum of several values ​​in kg / m 7 .

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