CN103993907A - Determining method of net hanging position at working face retracement stage under mine high-intensity exploiting - Google Patents

Abstract

The invention provides a method for determining the position of the hanging net in the retraction stage of the working face under the high-intensity mining of the mine. By analyzing the basic parameters such as the period of the working face to press the step and the position of the press and the length of the flexible net, three kinds of nets are established. Different calculation expressions, according to the comparison results of the average period to press the step distance, the press continuous length, the length of the flexible net and the minimum hanging net position, the average period to press the step distance and the next period to press up The distance from the starting position to the main retracement channel is substituted into the corresponding calculation expression to calculate a reasonable hanging net length. The invention realizes the scientific and reasonable determination of the hanging net position, ensures that there is no heavy pressure during the net hanging period of the fully mechanized mining face, ensures the safety and smoothness of the net hanging operation, and provides a guarantee for safe production in the withdrawal stage; at the same time, the method is beneficial to the enterprise Determining the length of flexible mesh required is a good guideline.

Description

A method for determining the position of the hanging net in the retraction stage of the working face under high-intensity mining in mine

technical field

The invention belongs to the technical field of mine mining, and in particular relates to a method for determining the position of a hanging net during the retraction stage of a working face under high-intensity mining in a mine.

Background technique

my country's coal output ranks first in the world, and the coal output in 2012 reached about 3.6 billion tons. Although the growth rate of coal production has declined due to the slowdown of my country's economic growth in recent years, coal still accounts for about 70% of China's primary energy. In the next few decades, my country's coal-based energy structure will not change. Coal consumption The total amount is generally increasing, so ensuring coal production is of great significance to the development of the national economy. The Shendong mining area is a national super-large coal production base. Due to the good coal seam conditions, it is suitable for the construction of high-yield and high-efficiency mines. The total height of the fully-mechanized mining face has reached 7.0m, the working face width is 300-450m, and the advancing length is 4500-4500m. 6000m, the daily advancing speed is 10-20m/d. The comprehensive mechanized coal mining face under high-intensity mining generally applies multi-channel rapid retraction technology. The hanging net is a necessary process in the withdrawal stage, and the quality of the hanging net directly determines whether it can be withdrawn quickly and safely.

At present, there is no scientific method at home and abroad to determine the position of the grid in the withdrawal stage of the fully mechanized mining face, and the position of the grid is mostly determined according to the work experience of the field personnel. There are many defects in the method determined according to experience. In the actual operation process, there will often be a situation where the net is hung on the pressing part of the working face, which will cause leakage at the end face of the working face or even a crushing accident, which seriously affects the safety of production.

Under high-intensity mining, each working face has its unique geological conditions, so the pressure on the working face is also different, and the method determined according to experience has a large error and cannot be generalized. Simply copying the net-hanging schemes of other working faces often hangs nets at the pressing places on the working face, leading to accidents of roof-falling and pressing frames, thereby endangering the safety of production personnel and causing huge economic losses.

Contents of the invention

The purpose of the present invention is to provide a method for determining the position of the hanging net in the retraction stage of the working face under the high-intensity mining of the mine, aiming at solving the problems of large error and low safety factor of the hanging net scheme in the mine.

The present invention is achieved in this way, a method for determining the position of the hanging net in the retraction stage of the working face under high-intensity mining in a mine, comprising the following steps:

S1. According to the determination method of the reasonable position of the net hanging in the retraction stage of the working face under high-intensity mining, the basic parameters of the last expected cycle of the working face, the starting position of the pressure, the length of the flexible net, the continuous length of the pressure, and the minimum position of the net The size is compared, and the calculation expression of the hanging net position is summarized according to the comparison result;

S2. According to the last 4 to 6 cycles of step distance before hanging the net on the working face, calculate the average cycle step distance and the distance from the starting position of the next cycle to the main withdrawal channel;

S3. According to the comparison result, substitute the average cycle step distance and the distance between the starting position of the next cycle and the main withdrawal channel into the corresponding calculation expression to calculate a reasonable hanging net length.

Preferably, in step S1, the calculation expression specifically includes:

X＝X _min ～X ₀ (1),

X=L _Z +n×s (2),

X = L _Z - L _C (3);

Among them, in formula (1) ~ formula (3):

X——reasonable hanging net length, m;

X _min - the minimum hanging net length, m;

X ₀ ——The actual length of the flexible net is the maximum hanging net length, m;

L _Z ——the distance from the starting position of the last cycle to the main retracement channel, m;

L _C ——Cycle pressure duration length, m;

n——surplus coefficient, the value is 2~4;

s—cut depth of shearer, m;

In step (1), the relationship between the comparison result and the hanging net position is specifically:

(1) When the starting position of the last cycle is less than the minimum hanging net length, select formula (1);

(2) When the starting position of the last cycle is greater than the minimum hanging net length but less than the flexible net length, select formula (2);

(3) When the starting position of the last cycle of pressing is greater than the length of the flexible net but the end position of the pressing is greater than the minimum length of the hanging net, select formula (3);

(4) When the starting position of the last cycle of pressing is greater than the length of the flexible net but the end position of the pressing is less than the minimum length of the hanging net, select formula (2).

The present invention overcomes the deficiencies of the prior art and provides a method for determining the position of the hanging net in the retraction stage of the working face under high-intensity mining in the mine. Firstly, the basic parameters such as the periodical pressure of the working face and the prediction of the position of the pressure and the length of the flexible net are analyzed. , established 3 different calculation expressions, and then according to the comparison results of the average cycle pressure step distance, pressure continuous length, flexible net length and minimum net hanging position, the average cycle pressure step distance and The distance from the starting position of the last cycle to the main retracement channel is substituted into the corresponding calculation expression to calculate a reasonable hanging net length. The invention realizes the scientific and reasonable determination of the net hanging position, ensures that there is no heavy pressure during the net hanging period of the fully mechanized mining face, ensures the safety and smoothness of the net hanging operation, and provides a guarantee for safe production in the withdrawal stage. At the same time, this method has good guiding significance for enterprises to determine the length of flexible nets required. Considering that the cost of a flexible net can reach several million, if the length of flexible nets can be saved by 0.1 to 0.2 times, it can save large economic benefits for enterprises. .

Description of drawings

Fig. 1 is the flow chart of the steps of the method for determining the position of the hanging net at the retraction stage of the working face under the high-intensity mining of the mine of the present invention;

Fig. 2 is a schematic diagram of selecting a reasonable position for hanging the net during the withdrawal stage in the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

A method for determining the position of the hanging net in the retraction stage of the working face under high-intensity mining in a mine, as shown in Figure 1, includes the following steps:

S1. According to the determination method of the reasonable position of the net hanging in the retraction stage of the working face under high-intensity mining, the basic parameters of the last expected cycle of the working face, the starting position of the pressure, the length of the flexible net, the continuous length of the pressure, and the minimum position of the net The size is compared, and the calculation expression of the hanging net position is summarized according to the comparison result;

In step S1, as shown in Figure 2, the spatial relationship between the influencing factors involved in the net-hanging stage is uncertain, and there are three situations:

(1) The starting position of the last cycle of pressing is less than the minimum hanging net length, that is, L _Z < X _min , at this time

X＝X _min ～X ₀ formula (1)

X——The position of hanging the net, that is, the distance from the starting point of hanging the net to the main withdrawal channel, m.

That is, the net hanging position at this time can be arbitrarily selected between the minimum net hanging position and the length of the flexible net, because even the minimum net hanging distance is outside the pressure area at this time, which can ensure the safety and smooth progress of the net hanging.

(2) The starting position of the last cycle of pressing is greater than the minimum length X _min of the hanging net but less than the actual length X ₀ of the flexible net, that is, X _min ≤ L _Z < X ₀ , and formula 2 is used for calculation at this time:

X＝L _Z +n×s formula (2)

n——surplus coefficient, 2 to 4, usually 3.

s—cut depth of shearer, m; the cut depth of fully mechanized mining face in Shendong mining area is generally 0.8m.

The reason why the position of the net should be added to the starting position of the pressure is to add a certain length of cutting depth because:

(a) In the coal cutting process of the working face, there is often a tendency of coming pressure before the cutting. The pressure of the working face is generally higher than that of the non-coming pressure, which may also lead to the aggravation of mine pressure. The operation is unfavorable, so a cutting depth of 1 to 2 knives must be added on the basis of the minimum distance;

(b) In the actual operation process, it takes a long time to hang the net. In addition to the maintenance shift, it often takes 1 to 2 production shifts or even more time. According to the actual measurement and statistical results, it may cause the working face to be pressed in advance. Therefore, an additional cutting depth of 1 to 2 knives should be added.

(3) When the starting position of the last cycle of pressing is greater than the flexible net length X ₀ (maximum net hanging distance), that is, L _Z ≥ X ₀ , the following situations are included at this time:

A. When L _Z -L _C ≥ X _min :

X＝L _Z -L _C formula (3)

L _C ——the continuous length of pressure, m; it can be obtained according to the actual measurement results of mine pressure, and the continuous length of continuous pressure of the fully mechanized mining face in Shendong mining area is generally 3-8s;

B. When L _Z -L _C <X _min :

X＝L _Z +n×s formula (2)

At this time, the length of the flexible net is less than the distance from the initial position of the hanging net to the withdrawal channel, and the calculation expression is the same as formula 2. The part of the hanging net whose length is insufficient should be continued with a metal net in the later stage.

S2. According to the last 4 to 6 cycles of step distance before hanging the net on the working face, calculate the average cycle step distance and the distance from the starting position of the next cycle to the main withdrawal channel;

In step S2, count the last 4 to 6 cycles to press the step distances L ₁ , L ₂ , L ₃ , L ₄ , L ₅ , and L ₆ before hanging the net, and calculate the average cycle to press the step distance L.

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 6</span>}}}{\mathrm{<span\; class="notranslate">\; 6</span>}}$

According to the calculated L, predict the position of the next cycle, that is, the distance d between the starting position of the previous cycle and the main retracement channel minus the average cycle step distance L, to obtain the starting point of the next cycle The starting position L _Z ; where, L _Z =dL.

S3. According to the comparison result, substitute the average cycle step distance and the distance between the starting position of the next cycle and the main withdrawal channel into the corresponding calculation expression to calculate a reasonable hanging net length.

Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects: For the previous method of estimating the position of the hanging net based on experience, the present invention first analyzes the periodic pressure of the working face and predicts the position of the pressure and the length of the flexible net. and other basic parameters, established three different calculation expressions, realized the scientific and reasonable determination of the net hanging position, ensured that there is no heavy pressure during the net hanging period of the fully mechanized mining face, and ensured the safety and smoothness of the net hanging operation. Safe production is guaranteed. At the same time, this method has good guiding significance for enterprises to determine the length of flexible nets required. Considering that the cost of a flexible net can reach several million, if the length of flexible nets can be saved by 0.1 to 0.2 times, it can save large economic benefits for enterprises. .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (2)

1. the lower work plane of mine high strength exploitation withdraws a stage linked network method for determining position, it is characterized in that comprising the following steps:

S1, according to the lower work plane of high strength exploitation in the definite method that withdraws stage linked network rational position, to this work plane estimate for the last time periodic weighting original position, flexible net length, press persistence length, minimum linked network position basic parameter size compares, and summarizes the calculation expression of linked network position according to comparative result;

S2, according to the periodic weighting step pitch of last 4～6 times before work plane linked network, calculate press average period step pitch and next time periodic weighting original position apart from the distance of main return channel;

S3, according to described comparative result, by press average period step pitch and next time periodic weighting original position apart from the corresponding calculation expression of distance substitution of main return channel, calculate rational linked network length.

2. the lower work plane of mine high strength exploitation as claimed in claim 1 withdraws stage linked network method for determining position, it is characterized in that, in step S1, described calculation expression specifically comprises:

X＝X _min～X ₀ (1)，

X＝L _Z+n×s (2)，

X＝L _Z-L _C (3)；

Wherein, in formula (1)～formula (3):

X---reasonable linked network length, m;

X _min---minimum linked network length, m;

X ₀---flexible net physical length is maximum linked network length, m;

L _z---last periodic weighting original position is apart from the distance of main return channel, m;

L _c---periodic weighting persistence length, m;

N---redundancy, value 2～4;

S---coal-winning machine cuts dark, m;

In step (1), the relation between described comparative result and linked network position is specially:

(1) when last periodic weighting original position is less than minimum linked network length, selecting type (1);

(2) when last periodic weighting original position is greater than minimum linked network length but is less than flexible net length, selecting type (2);

(3) when last periodic weighting original position is greater than flexible net length but presses end position to be greater than minimum linked network length, selecting type (3);

(4) when last periodic weighting original position is greater than flexible net length but presses end position to be less than minimum linked network length, selecting type (2).