An intelligent control and evaluation method for coal seam weakening in coal mining working face

Abstract

The present invention relates to the field of mining technology, and in particular to a method for intelligent control and evaluation of coal seam weakening in a coal mining working face, including: determining the working face for weakening the coal seam, and monitoring the sinking amount and support force of the support column during the operation of the coal mining machine in real time; determining the initial optimal sinking amount through experiments, comparing the real-time sinking amount of the support column of the coal mining machine with the initial optimal sinking amount, and adjusting the support force according to the comparison result until the real-time sinking amount of the support column is greater than the initial optimal sinking amount; monitoring the working parameters of the coal mining machine, adjusting the initial optimal sinking amount in real time according to the working parameters, obtaining the optimal sinking amount, and performing pressure control according to the optimal sinking amount. The present invention clarifies the parameters required to be measured for coal seam weakening, which is of great significance to coal seam weakening, intelligent monitoring of working faces, etc.

Description

Technical Field

[0001] The present invention relates to the field of mining technology, and in particular to an intelligent control and evaluation method for coal seam weakening at a coal mining working face. Background Art

[0002] Coal mines in western my country generally have the characteristics of shallow coal seams and hard coal bodies. During the mining process, the cutting machine speed is low, the coal mining machine vibrates greatly, and the drill bit is seriously damaged. Even with the use of high-strength drill bits and high-power coal mining machines, the efficiency and output cannot be significantly improved. Weakening the coal seam at the working face is conducive to improving the mineability and fracture rate of the coal seam. The use of coal seam weakening technology can effectively improve the production environment of the mine, improve mining efficiency and safety factor, and reduce the incidence of gas accidents. It is an important technical approach to achieve efficient utilization of coal resources.

[0003] Existing research and practice have shown that increasing the support strength of hydraulic supports is conducive to improving the stability of the coal wall of the working face and preventing spalling; conversely, reducing the support strength will cause the support pressure to be transferred to the front of the coal wall, increasing the degree of coal body crushing and the range of the plastic zone. At the same time, according to field observation data, during the period of periodic pressure on the working face, the coal cutting speed of the coal mining machine is significantly higher than that during the non-pressure period. It can be seen that if the support strength is reasonably controlled to promote the transmission of mining pressure to the coal wall while ensuring the safety of the working face roof, the purpose of weakening the coal body and improving coal mining efficiency can be achieved.

[0004] Based on this background, the present invention provides a method for intelligent control and evaluation of coal seam weakening in a coal mining working face to solve the above-mentioned problems existing in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide an intelligent control and evaluation method for coal seam weakening in a coal mining working face, which can find a roof subsidence control target value suitable for a certain working face and realize intelligent control and evaluation of the coal seam weakening effect of the coal mining working face, which is of great significance for improving coal mining efficiency.

[0006] To achieve the above object, the present invention provides a method for intelligent control and evaluation of coal seam weakening in a coal mining working face, comprising:

[0007] Determine the working face for weakening the coal seam, and monitor the sinking amount of the support column and the support force of the support in real time during the operation of the coal mining machine;

[0008] Determine an initial optimal sinking amount, compare the real-time sinking amount of the coal mining machine support column with the initial optimal sinking amount, and adjust the support force of the support according to the comparison result until the real-time sinking amount of the support column is greater than the initial optimal sinking amount;

[0009] The working parameters of the coal mining machine are monitored, the initial optimal sinking amount is adjusted in real time according to the working parameters to obtain the optimal sinking amount, and the pressure is controlled according to the optimal sinking amount.

[0010] Preferably, by installing a sensor device and a data transmission device on the coal mining machine support, the sinking amount of the support column and the support force of the support during the working process of the coal mining machine can be monitored in real time.

[0011] Preferably, adjusting the support force of the bracket according to the comparison result includes:

[0012] If the real-time sinking amount is less than the initial optimal sinking amount, the support force of the bracket is adjusted to change the real-time sinking amount until the real-time sinking amount is greater than the initial optimal sinking amount; wherein the maximum limit of changing the real-time sinking amount does not exceed the preset threshold value of the sinking amount to prevent the top plate from becoming unstable.

[0013] Preferably, the support force of the bracket is adjusted by adjusting the pressure of the pump station, the method being:

[0014] P n =λ n P n-1

[0015] In the formula, λ n is the pressure adjustment coefficient of the first pump station, 0<λ n <1; P n is the support force of the bracket after adjustment; P n-1 is the initial support force before adjustment.

[0016] Preferably, the working parameters of the coal mining machine include coal mining speed, coal mining machine current, tunnel spalling rate and large block rate.

[0017] Preferably, adjusting the initial optimal sinking amount in real time according to the working parameters includes:

[0018] The coal mining speed is compared with the target optimal speed. If the coal mining speed is greater than or equal to the target optimal speed, the coal mining machine current is continued to be compared with the target optimal current. If the coal mining machine current is less than or equal to the target optimal current, there is no need to adjust the initial optimal sinking amount.

[0019] Preferably, adjusting the initial optimal sinking amount in real time according to the working parameters further comprises:

[0020] The spalling rate and large block rate of the laneway are compared with the target optimal spalling rate and target optimal large block rate respectively. If the spalling rate of the laneway is greater than or equal to the target optimal spalling rate and the large block rate is greater than or equal to the target optimal large block rate, pressurization is performed through the pump station to increase the support force of the bracket.

[0021] Preferably, if the coal mining speed is less than the target optimal speed, the coal mining machine current is greater than the target optimal current, the spalling rate of the roadway is less than the target optimal spalling rate and the large block rate is less than the target optimal large block rate, the initial optimal sinking amount is adjusted by:

[0022] ΔS n =λ' n ΔS n-1

[0023] In the formula, λ' n is the first optimal sinking adjustment coefficient, 0<λ' n <1; ΔS n is the optimal sinking amount; ΔS n-1 is the initial optimal sinking amount.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects:

[0025] Based on the intelligent monitoring and evaluation of coal seam weakening, the present invention clarifies the parameters required to measure coal seam weakening, and compares them with the optimal parameters obtained from experience to perform intelligent regulation and obtain the optimal parameters most suitable for the working face. The research results are of great significance to coal seam weakening, intelligent monitoring of working faces, and improving coal mining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0027] Figure 1 A schematic diagram of the roof structure of a coal mining working face during a non-pressure period according to an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the roof structure during the coal mining working face pressure period according to an embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of weakening the coal seam by reducing the support pressure to regulate the roof during the non-pressure period of the coal mining working face according to an embodiment of the present invention;

[0030] Figure 4 This is a flow chart of a method for intelligent control and evaluation of coal seam weakening in a coal mining face according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] The present invention proposes an intelligent control and evaluation method for coal seam weakening in coal mining working face, such as Figure 4 ,include:

[0034] Determine the working face for weakening the coal seam, and monitor the sinking amount of the support column and the support force of the support in real time during the operation of the coal mining machine;

[0035] The initial optimal sinking amount is determined by experiment, the real-time sinking amount of the coal mining machine support column is compared with the initial optimal sinking amount, and the support force of the support is adjusted according to the comparison result until the real-time sinking amount of the support column is greater than the initial optimal sinking amount;

[0036] Monitor the working parameters of the coal mining machine, adjust the initial optimal sinking amount in real time according to the working parameters, obtain the optimal sinking amount, and regulate the pressure according to the optimal sinking amount.

[0037] Furthermore, by installing a sensor device and a data transmission device on the coal mining machine support, the sinking amount of the support column and the support force of the support during the working process of the coal mining machine can be monitored in real time.

[0038] Adjust the support force of the bracket according to the comparison results, including:

[0039] If the real-time sinking amount is less than the initial optimal sinking amount, the bracket support force is adjusted to change the real-time sinking amount until the real-time sinking amount is greater than the initial optimal sinking amount; wherein the maximum limit of changing the real-time sinking amount does not exceed the preset threshold of the sinking amount to prevent the top plate from becoming unstable.

[0040] The support force of the bracket is adjusted by adjusting the pressure of the pump station. The method is as follows:

[0041] P n =λ n P n-1

[0042] In the formula, λ n is the pressure adjustment coefficient of the first pump station, 0<λ n <1; P n is the support force of the bracket after adjustment; P n-1 is the initial support force before adjustment.

[0043] Specifically, the working parameters of the coal mining machine include coal mining speed, coal mining machine current, tunnel spalling rate and large block rate.

[0044] The initial optimal sinking amount is adjusted in real time according to the working parameters, including:

[0045] The coal mining speed is compared with the target optimal speed. If the coal mining speed is greater than or equal to the target optimal speed, the coal mining machine current is continued to be compared with the target optimal current. If the coal mining machine current is less than or equal to the target optimal current, there is no need to adjust the initial optimal sinking amount.

[0046] Real-time adjustment of the initial optimal sinking amount according to working parameters, including:

[0047] The spalling rate and large block rate of the tunnel are compared with the target optimal spalling rate and target optimal large block rate respectively. If the spalling rate of the tunnel is greater than or equal to the target optimal spalling rate and the large block rate is greater than or equal to the target optimal large block rate, pressurization is performed through the pump station to increase the support force of the support.

[0048] If the coal mining speed is less than the target optimal speed, the coal mining machine current is greater than the target optimal current, the roadway spalling rate is less than the target optimal spalling rate and the large block rate is less than the target optimal large block rate, then adjust the initial optimal sinking amount by:

[0049] ΔS n =λ' n ΔS n-1

[0050] In the formula, λ' n is the first optimal sinking adjustment coefficient, 0<λ' n <1; ΔS n is the optimal sinking amount; ΔS n-1 is the initial optimal sinking amount.

[0051] In order to more clearly express the technical solution of the present invention, the following specific embodiments are provided to introduce the solution:

[0052] like Figure 1-Figure 3 In this embodiment, a method for intelligent control and evaluation of coal seam weakening in a coal mining working face is provided. It is necessary to install sensors on the coal mining machine support to monitor changes in pressure and stroke; and install data transmission components.

[0053] The following steps are involved:

[0054] S1. Determine the working face for weakening the coal seam, and monitor the sinking amount of the support column and the support force of the support in real time during the operation of the coal mining machine;

[0055] S2. Through experiments and a large amount of field data, the initial optimal sinking amount ΔS for the best weakening effect of the coal seam is concluded. The sinking amount S is compared with the initial optimal sinking amount ΔS. If S is less than ΔS, the pressure on the working face is adjusted to change the sinking amount S until the sinking amount S is greater than the initial optimal sinking amount ΔS.

[0056] S3. Monitor the speed, current, spalling rate and other parameters of the coal mining machine to determine whether ΔS is efficient, energy-saving and safe. If it is not the most suitable for the working face, adjust ΔS until it is the most suitable. Through creep yielding technology, the weakening of the coal seam is intelligently regulated. Using creep yielding technology, the support is used to bear and yield pressure, so that the roof sinks faster under safe conditions. Under the action of the roof sinking pressure, the coal seam is broken faster, the hardness of the coal seam is reduced, and it is easy to excavate.

[0057] In step S1 of this embodiment, after the coal mining machine has just finished cutting the coal, the scraper and the support must move forward. After moving forward, the support is designed according to the pressure of the pump station and the working surface, and a designed initial support force P0 is applied to the support. After the initial support force is applied, the sinking amount S and the support force P of the support column are intelligently monitored, and P is a variable.

[0058] In step S2 of this embodiment, determining the optimal sinking amount ΔS, the sinking amount S of the support column and the supporting force P includes the following steps:

[0059] S201: Through the creep yield test of hydraulic supports and a large amount of field data, the optimal sinking amount ΔS for achieving the best weakening effect of the coal seam is obtained.

[0060] S202: Compare the sinking amount S with the optimal sinking amount ΔS. If S<ΔS, the support pressure relief valve needs to be opened. According to the formula P n =λ n P n-1 Repeated multiple times, where λ n is the pressure adjustment coefficient of the first pump station, 0<λ n <1, P n is the support force of the bracket after adjustment, P n-1 is the initial support force before adjustment. By reducing the support force, the sinking amount S of the support column is increased until S ≥ ΔS.

[0061] S203: In order to prevent the top plate from becoming unstable, during the execution of S202, the stability of the top plate must also be monitored. If the top plate becomes unstable or the amount of top plate subsidence exceeds the set threshold, it is necessary to stop controlling the pressure relief valve and increase the support force P by controlling the pump station to increase the pressure. According to the formula P2=λ'1P1, λ'1 is the pressure adjustment coefficient of the second pump station, λ'1>1, P2 is the pressure after the first adjustment, and P1 is the pressure before the first adjustment. For safety reasons, the amount of top plate subsidence cannot be reduced indefinitely, regardless of whether it has been reduced to the target value. Once the top plate is monitored to be unstable or reaches the designed threshold, the support pressure should be stopped from being reduced, and the support pressure should be increased to control the top plate to continue to sink. At this time, according to the formula P m =λ'2Pm-1 Repeat several times to obtain the support force that can ensure the safety of the tunnel, where λ'2 is the pressure coefficient of the third pump station, λ'2>1, P m is the adjusted pressure, P m-1 is the pressure before adjustment.

[0062] After any pressure increase or pressure reduction adjustment in step S2, the parameters in S3 should be detected immediately, and whether to continue to implement the regulation in S2 is determined based on the detection results. In step S3 of this embodiment, the optimal shearer speed v, the optimal current L, the optimal slab rate and the optimal large block rate, and the optimal sinking amount ΔS that best suits the actual situation of the working face are determined, including the following steps:

[0063] S301: Monitor the coal mining speed, coal mining machine current, tunnel spalling rate and large block rate to determine whether the target optimal value is reached.

[0064] S302: Compare the measured coal mining machine speed v with the target optimal speed Δv. If v≥Δv, it means that the coal mining machine speed has reached the target optimal speed and does not need to be adjusted temporarily. Continue to compare the current of the coal mining machine with the target optimal current ΔL. If L≤ΔL, it means that the current of the coal mining machine has reached the target optimal current and does not need to be adjusted temporarily. Continue to compare the spalling rate k1 with the target spalling rate Δk1. If k1<Δk1, it means that the spalling rate meets the requirements and does not need to be adjusted temporarily. Continue to compare the large block rate k2 with the target large block rate Δk2. If k2<Δk2, it means that the large block rate meets the requirements and does not need to be adjusted temporarily. At this time, the regulation can be stopped to obtain the optimal sinking amount ΔS that best suits the actual situation of the working face.

[0065] S303: If the spalling rate k1 and the large block rate k2 are high, the belt will be blocked. It is necessary to use a pump station to increase the pressure to make the coal seam relatively hard, alleviate the spalling and reduce the large block rate.

[0066] Compare the measured spalling rate k1 with the target optimal spalling rate Δk1, and the large block rate k1 with the target optimal large block rate Δk1. If k1≥Δk1, k2≥Δk2, the spalling phenomenon is too serious and the large block rate is too high, which will block the belt and affect the working efficiency of the working face. At this time, it indicates that the previously determined optimal sinking amount ΔS is too large, resulting in excessive roof sinking and too soft coal wall, which should be adjusted and controlled. According to the formula: ΔS n =λ' n ΔS n-1 , where λ' n is the first optimal sinking adjustment coefficient, 0<λ' n <1,ΔS n is the optimal sinking amount; ΔS n-1is the initial optimal sinking amount; repeat several times until the appropriate optimal sinking amount is determined, and the flake rate and large block rate can be controlled to meet the requirements.

[0067] S304: Compare the shearer speed, shearer current, spalling rate and large block rate with the target optimal value. If v<Δv, L>ΔL, k1<Δk1, k2<Δk2, it means that the shearer speed and current have not reached the target optimal state, and the spalling rate and large block rate have not exceeded the standard, indicating that the previously determined optimal sinking amount ΔS is too small and should be adjusted. According to the formula: ΔS m =λ' m ΔS m-1 , where λ' m is the second optimal sinking adjustment coefficient, λ' m >1,ΔS m is the optimal sinking amount of the adjusted bracket, ΔS m-1 The optimal sinking amount of the bracket before adjustment. Repeat several times until the conditions in S302 or S303 appear, and then stop adjusting.

[0068] In this embodiment, the pump station is used to increase and release pressure, intelligently adjust the support force of the support, adjust the degree of coal seam crushing, reduce the hardness of the coal seam, and facilitate excavation. With the help of hydraulic supports, the bearing capacity of these supports is accurately monitored and adjusted, thereby achieving effective monitoring and management of the stability of the roof. At the same time, with the help of sensors installed on the hydraulic supports, data information on the support advancement stroke can be captured in real time, so as to more accurately evaluate the strength of the coal wall and possible risks.

[0069] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for intelligent control and evaluation of coal seam weakening in a coal mining working face, characterized in that: include: Determine the working face for weakening the coal seam, and monitor the sinking amount of the support column and the support force of the support in real time during the operation of the coal mining machine; Determine an initial optimal sinking amount, compare the real-time sinking amount of the coal mining machine support column with the initial optimal sinking amount, and adjust the support force of the support according to the comparison result until the real-time sinking amount of the support column is greater than the initial optimal sinking amount; Monitor the working parameters of the coal mining machine, adjust the initial optimal sinking amount in real time according to the working parameters, obtain the optimal sinking amount, and perform pressure control according to the optimal sinking amount; The working parameters of the coal mining machine include coal mining speed, coal mining machine current, tunnel spalling rate and large block rate; Adjusting the initial optimal sinking amount in real time according to the working parameters includes: Comparing the coal mining speed with the target optimal speed, if the coal mining speed is greater than or equal to the target optimal speed, then continuing to compare the coal mining machine current with the target optimal current, if the coal mining machine current is less than or equal to the target optimal current, then there is no need to adjust the initial optimal sinking amount; Compare the spalling rate and large block rate of the lane with the target optimal spalling rate and the target optimal large block rate respectively; if the spalling rate of the lane is greater than or equal to the target optimal spalling rate and the large block rate is greater than or equal to the target optimal large block rate, pressurize the pump station to increase the support force of the support; If the coal mining speed is less than the target optimal speed, the coal mining machine current is greater than the target optimal current, the roadway spalling rate is less than the target optimal spalling rate and the large block rate is less than the target optimal large block rate, then adjust the initial optimal sinking amount by: ΔS n =l' n ΔS n-1 In the formula, λ' n is the first optimal sinking adjustment coefficient, 0<λ' n <1; ΔS n is the optimal sinking amount; ΔS n-1 is the initial optimal sinking amount.

2. The method for intelligent control and evaluation of coal seam weakening in a coal mining working face according to claim 1 is characterized in that: By installing a sensor device and a data transmission device on the coal mining machine support, the sinking amount of the support column and the support force of the support during the working process of the coal mining machine can be monitored in real time.

3. The method for intelligent control and evaluation of coal seam weakening in a coal mining working face according to claim 1 is characterized in that: Adjusting the support force of the bracket according to the comparison result includes: If the real-time sinking amount is less than the initial optimal sinking amount, the support force of the bracket is adjusted to change the real-time sinking amount until the real-time sinking amount is greater than the initial optimal sinking amount; wherein the maximum limit of changing the real-time sinking amount does not exceed the preset threshold value of the sinking amount to prevent the top plate from becoming unstable.

4. The method for intelligent control and evaluation of coal seam weakening in a coal mining working face according to claim 3 is characterized in that: The support force of the support is adjusted by adjusting the pressure of the pump station, and the method is as follows: P n =λ n P n-1 In the formula, λ n is the pressure adjustment coefficient of the first pump station, 0<λ n <1; P n is the support force of the bracket after adjustment; P n-1 is the initial support force before adjustment.

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