Coal Gangue Content Identification System and Method Based on High-Frequency Dynamic Pressure Sensor

Abstract

The present invention provides a coal gangue content identification system and method based on a high-frequency dynamic pressure sensor, belonging to the technical field of coal gangue content identification; it solves the problem that in the existing coal gangue identification methods, the coal gangue content cannot be accurately counted, resulting in the inability to accurately determine the closing time of coal discharging and thus low coal discharging efficiency; it includes multiple hydraulic supports, a high-frequency dynamic pressure sensor assembly is fixed below the rear flap of the hydraulic support, the high-frequency dynamic pressure sensor assembly is connected to the support controller, the support controller is connected to the solenoid valve group, and the solenoid valve group is connected to the cylinder on the hydraulic support through a hydraulic pipeline; the support controller is also connected to a host computer, and the host computer is used to analyze and process the pressure data collected by the high-frequency dynamic pressure sensor assembly, identify coal blocks and gangues and the percentage of gangue content through the pressure-time data, and then send a coal discharging signal to the support controller; the present invention is applied to fully mechanized mining faces.

Description

Technical Field

[0001] The present invention provides a coal gangue content identification system and method based on a high-frequency dynamic pressure sensor, belonging to the technical field of coal gangue content identification. Background Art

[0002] China is a major coal country, and automation in coal mining is an inevitable trend in the future. Automatic top coal caving is a case of fully mechanized mining automation. When to automatically close the coal discharge port during the coal caving process is of utmost importance for the following reasons: Closing the coal discharge port too early will result in unemptied coal; closing the coal discharge port too late will release a large amount of coal gangue, reducing the coal quality and affecting the calorific value of raw coal. It is very difficult to find a relatively mature solution on the market that can identify the coal gangue content during the coal caving process and stop the coal caving. For the above reasons, the present invention proposes a brand-new coal gangue content identification system and method, which can identify the percentage of coal gangue content in the current coal flow and apply to close the coal discharge port based on whether the identified gangue percentage reaches a threshold. Summary of the Invention

[0003] In order to solve the problem in the existing coal gangue identification method that the coal gangue content cannot be accurately counted, resulting in the inability to accurately determine the closing time of the coal discharge, thus reducing the coal caving efficiency, the present invention proposes a coal gangue content identification system and method based on a high-frequency dynamic pressure sensor.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A coal gangue content identification system based on a high-frequency dynamic pressure sensor includes multiple hydraulic supports placed in the fully mechanized mining face for supporting the roof. A rear insertion plate is connected to the inside of the rear tail beam of each hydraulic support through a jack. A support controller is provided on each hydraulic support. A high-frequency dynamic pressure sensor assembly is fixed below the rear insertion plate of the hydraulic support. The high-frequency dynamic pressure sensor assembly is used to detect the pressure of coal blocks and coal gangue during the coal caving process. The high-frequency dynamic pressure sensor assembly is connected to the support controller through a first connecting wire. The support controller is connected to a solenoid valve group through a second connecting wire. The solenoid valve group is connected to the cylinders of the rear tail beam and the rear insertion plate on the hydraulic support through a hydraulic pipeline, and is used to control the actions of the cylinders on the rear tail beam and the rear insertion plate of the hydraulic support.

[0005] The support controller is also connected to a host computer through a wire. The host computer is used to analyze and process the pressure data collected by the high-frequency dynamic pressure sensor assembly, identify coal blocks, gangue, and the percentage of gangue content through the pressure-time data, and then send a coal caving signal to the support controller.

[0006] The high-frequency dynamic pressure sensor assembly is composed of a number of high-frequency dynamic pressure sensors arranged longitudinally, and the acquisition frequency of each high-frequency dynamic pressure sensor is not less than 2 MHz.

[0007] After the rear tail beam and the rear insertion plate extend, they will abut against the rock to block the coal blocks.

[0008] A critical q value for judging coal blocks or gangue is preset in the host computer, and the critical q value is the ratio of the peak value of the pressure curve to the time when the inflection point appears.

[0009] A method for identifying the coal gangue content based on a high-frequency dynamic pressure sensor, using a system for identifying the coal gangue content based on a high-frequency dynamic pressure sensor, includes the following steps:

[0010] The first step: Complete the connection of each component in the coal gangue content identification system;

[0011] The second step: The host computer configures relevant thresholds;

[0012] The third step: Open the coal discharge port and start discharging coal;

[0013] The fourth step: The mixture of coal blocks and gangue falls, and part of it hits the high-frequency dynamic pressure sensor assembly;

[0014] The fifth step: The high-frequency dynamic pressure sensor transmits the sampling data to the support controller;

[0015] The sixth step: After the impact ends, the support controller forwards the impact data to the host computer;

[0016] The seventh step: The host computer judges the impact material according to the impact data and the configured threshold data and calculates whether the percentage of gangue content exceeds the threshold;

[0017] The eighth step: If the percentage of gangue content judged in the sixth step exceeds the threshold, the host computer sends a signal to the support controller to close the coal discharge port;

[0018] The ninth step: After receiving the signal to close the coal discharge port, the support controller sends an electrical signal corresponding to the action of closing the coal discharge port to the solenoid valve group;

[0019] The tenth step: The solenoid valve group controls the hydraulic pipeline to realize the action of the hydraulic support;

[0020] The eleventh step: The process of gangue content identification and closing the coal discharge port is completed.

[0021] The relevant thresholds configured in the second step include: the critical q value of coal blocks and gangue, the gangue content percentage threshold, and the time range for calculating the gangue percentage, where the critical q value of coal blocks and gangue is the ratio of the peak value of the pressure curve to the time when the inflection point appears.

[0022] The high-frequency dynamic pressure sensor assembly is composed of multiple high-frequency dynamic pressure sensors. When different hard objects impact, the corresponding high-frequency dynamic pressure sensors will be triggered respectively to collect pressure values. When calculating the percentage of gangue content, the pressure values collected by the high-frequency dynamic pressure sensors within a certain time range are selected for calculation.

[0023] The beneficial effects of the present invention compared with the prior art are as follows: A coal-gangue content identification system and method based on high-frequency dynamic pressure sensors provided by the present invention, according to the difference in the hardness properties of coal and gangue, resulting in the difference in the peak value and inflection point time on the pressure curve. The pressure values of coal blocks and gangue on the coal flow are collected by the high-frequency dynamic pressure sensor assembly for identification and judgment, and the percentage of gangue content is calculated. According to the percentage of gangue content, the automatic closing of the coal discharge port is realized. The process is simple and the cost is low. It can realize the automation of coal discharge while improving the quality of coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the drawings:

[0025] Figure 1 It is a schematic structural diagram before coal discharge when applying the system of the present invention;

[0026] Figure 2 It is a schematic structural diagram during coal discharge when applying the system of the present invention;

[0027] Figure 3 It is a schematic structural diagram for closing the coal discharge port after the coal discharge is completed when applying the system of the present invention;

[0028] Figure 4 It is a curve graph showing the change of impact force with time when two objects with different hardnesses, soft and hard, are used;

[0029] Figure 5 It is a schematic diagram of an embodiment of an object impacting the high-frequency dynamic pressure sensor assembly;

[0030] In the figure: 1 is a hydraulic support, 2 is a rear insert plate, 3 is a rear tail beam, 4 is a coal block to be discharged, 5 is a rock stratum, 6 is a high-frequency dynamic pressure sensor assembly, 7 is a first connecting wire, 8 is a support controller, 9 is a host computer, 10 is a second connecting wire, 11 is a solenoid valve, and 12 is a hydraulic pipeline. DETAILED DESCRIPTION OF THE INVENTION

[0031] As Figures 1 to 5As shown in the figure, the present invention provides a coal gangue content identification system based on a high-frequency dynamic pressure sensor, including a hydraulic support 1, a rear insertion plate 2, a rear tail beam 3, a coal block to be discharged 4, a rock stratum 5, a high-frequency dynamic pressure sensor assembly 6, a first connecting wire 7 connecting the high-frequency dynamic pressure sensor assembly 6 and a support controller 8, a support controller 8, a host computer 9, a second connecting wire 10 connecting the support controller 8 and a solenoid valve group 11, a solenoid valve group 11, and a hydraulic pipeline 12 connecting the solenoid valve group 11 and a hydraulic support cylinder.

[0032] The descriptions and functions of each component used in the present invention are as follows:

[0033] Hydraulic support 1: The main supporting equipment in the fully mechanized coal mining face, used to support the roof and prevent collapse.

[0034] Rear insertion plate 2: The main mechanical structure for top coal caving. This mechanism cooperates with the rear tail beam 3 to open the coal discharge port. After this mechanism retracts, the coal block to be discharged 4 will fall freely to achieve coal caving.

[0035] Rear tail beam 3: The main mechanical structure for top coal caving. This mechanism cooperates with the rear insertion plate 2 to open the coal discharge port. After this mechanism retracts, the coal block to be discharged 4 will fall freely to achieve coal caving.

[0036] Coal block to be discharged 4: The coal block to be discharged during the coal caving process.

[0037] Rock stratum 5: Natural rock stratum. After the rear insertion plate 2 and the rear tail beam 3 extend, they will abut against the rock stratum 5 to play a role in blocking coal blocks.

[0038] High-frequency dynamic pressure sensor assembly 6: Composed of several high-frequency dynamic pressure sensors along the longitudinal direction, and the acquisition frequency of each high-frequency dynamic pressure sensor can reach 2 MHz. During the falling process of coal blocks and gangues, they will hit a certain high-frequency dynamic pressure sensor in the longitudinal direction. The curve of pressure changing with time can be drawn through the dynamic acquisition data of the high-frequency dynamic pressure sensor. The pressure data during the impact process will be transmitted to the support controller 8, and the support controller 8 will synchronously transmit the data to the host computer 9, and the host computer 9 will process and analyze the data.

[0039] First connecting wire 7: Used to connect the high-frequency dynamic pressure sensor assembly 6 and the support controller 8 to achieve data communication between the two.

[0040] Support controller 8: First, it is used to send electrical signals to the solenoid valve group 11 to control the movement of the hydraulic support 1. Second, it serves as a data hub for the high-frequency dynamic pressure sensor assembly 6 and the host computer 9 for data interaction. The data of the high-frequency dynamic pressure sensor is forwarded to the host computer 9 through the support controller 8. After being processed by the host computer 9, the signal to close the coal discharging is sent to the support controller 8, and the support controller 8 sends the signal to close the coal discharging to the solenoid valve group 11. The solenoid valve group 11 controls the cylinder actions of the rear planker 2 and the rear tail beam 3 to complete the operation of closing the coal discharging port.

[0041] Host computer 9: It is used to analyze and process sensor data. The impact material and the percentage of gangue content can be analyzed through the pressure-time data. Based on the analysis results, it decides whether to close the coal discharging port. If necessary, the signal to close the coal discharging port is sent to the support controller 8, and then the support controller 8 performs corresponding actions.

[0042] Second connecting wire 10: It is used to connect the support controller 8 and the solenoid valve group 11 to achieve data communication between the two.

[0043] Solenoid valve group 11: It controls the corresponding cylinders through the electrical signals given by the support controller 8 to achieve the various actions of the hydraulic support 1.

[0044] Hydraulic pipeline 12: It is used to connect the solenoid valve group 11 and the cylinder. When the pipeline pressure rises, the cylinder connected to this pipeline will move.

[0045] The present invention also proposes a method for identifying the coal and gangue content based on a high-frequency dynamic pressure sensor, which is used to automatically close the coal discharging port during the top coal caving process. It mainly includes the following steps:

[0046] The first step: Complete Figure 1 the connection of each component shown.

[0047] The second step: The host computer 9 configures relevant thresholds (the critical q value of coal blocks and gangue, the gangue content percentage threshold calculate the time range Δt of the gangue percentage).

[0048] The third step: Open the coal discharging port and start coal discharging, as Figure 2 shown.

[0049] The fourth step: The mixture of coal blocks and gangue falls, and part of it hits the high-frequency dynamic pressure sensor assembly 6.

[0050] The fifth step: The high-frequency dynamic pressure sensor transmits the sampled data to the support controller 8.

[0051] The sixth step: After the impact ends, the support controller 8 forwards the impact data to the host computer 9.

[0052] Step 7: The host computer 9 determines the impact material based on the impact data and the configured threshold data, and calculates whether the percentage of gangue content exceeds the threshold.

[0053] Step 8: If the percentage of gangue content determined in Step 6 exceeds the threshold, the host computer 9 sends a signal to the support controller 8 to close the coal discharge.

[0054] Step 9: After receiving the signal to close the coal discharge port, the support controller 8 sends an electrical signal corresponding to the action of closing the coal discharge port to the solenoid valve group 11.

[0055] Step 10: The solenoid valve group 11 controls the hydraulic pipeline 12 to actuate the hydraulic support 1 to close the coal discharge port, as Figure 3 shown.

[0056] Step 11: The process of gangue content identification and closing the coal discharge port is completed.

[0057] The principle of using a high-frequency dynamic pressure sensor to identify coal blocks and gangue in the present invention is as follows:

[0058] The purpose of the present invention is to identify the content of gangue in the coal flow.

[0059] The significant characteristics of gangue and coal are: gangue is hard in texture and high in hardness; coal is softer in texture and low in hardness.

[0060] When two objects with different hardnesses impact the pressure sensor, the pressure value will have the following characteristics:

[0061] 1. When the object with higher hardness impacts, the pressure value can quickly reach the peak, and can also quickly reach the inflection point of pressure drop. The duration from the start of pressure increase to the pressure tending to 0 is short. The entire pressure-time curve is "tall and thin".

[0062] 2. When the object with lower hardness impacts, the pressure value reaches the peak slower than the object with higher hardness, and reaches the inflection point of pressure drop slower. The duration from the start of pressure increase to the pressure tending to 0 is longer. The entire pressure-time curve is "short and fat".

[0063] The curve of the impact force of hard and soft objects changing with time is basically as follows Figure 4 shown.

[0064] According to the above principle, record the peak value on the pressure curve of coal blocks and gangue as F', and the time when the pressure appears at the inflection point as T'. The ratio of the peak value to the inflection point time Obviously, the Q value of gangue is large, and the Q value of coal blocks is small. Thus, by judging the size of the Q value, it is possible to determine whether it is gangue or coal blocks.

[0065] A critical q value for coal and gangue can be set in the host computer 9 software. When Q>q, it is considered gangue, and when Q<q, it is considered coal. How to determine the q value exactly needs to be measured through experiments according to the actual situation of each site. The hardness and texture of coal and gangue are different in different environments and geological conditions, so q needs to be obtained through on-site testing.

[0066] In summary, after the support controller 8 forwards the data of the pressure changing with time collected by the high-frequency dynamic pressure sensor to the host computer 9, the analysis software of the host computer 9 can analyze and calculate the Q value of this impact. By comparing with the threshold q configured in the host computer 9, it can be determined whether it is a coal block or gangue.

[0067] The principle of analyzing the percentage of gangue content in the present invention is as follows:

[0068] Figure 1 The high-frequency dynamic pressure sensor assembly 6 in [reference] is composed of a number of high-frequency dynamic pressure sensors longitudinally, as follows Figure 5 shown. In the figure, the high-frequency dynamic pressure sensor assembly 6 is composed of 9 pressure sensors. When the three objects a, b, and c in the figure impact the high-frequency dynamic pressure sensor assembly 6, they trigger the No. 1, No. 5, and No. 8 high-frequency dynamic pressure sensors respectively. During the impact process, the high-frequency dynamic pressure sensor will collect the pressure value at a high frequency. Through the pressure data, the host computer 9 identifies the material of this impact and stores the identification result and the impact time.

[0069] Because the time when each high-frequency dynamic pressure sensor receives the impact is different, a calculation time range Δt needs to be known to calculate the percentage of gangue content. According to the identification results stored in the host computer 9, the percentage of gangue content within a Δt can be known. When reaches the configured threshold the host computer 9 sends a signal to the support controller 8 to close the coal discharge port (open the rear tail beam 3 and the rear insert plate 2). The support controller 8 sends an action signal to the solenoid valve group 11, and the solenoid valve group 11 drives the hydraulic pipeline 12 to complete the action. Thus, the entire process of identifying the percentage of coal and gangue content and closing the coal discharge port is completed.

[0070] The key point protected by the present invention is to collect pressure data at a high frequency through the high-frequency dynamic pressure sensor, identify the impact material through the different impact curves of different materials, and then control the hydraulic support to act to close the coal discharge port according to the identification result. As for how the structures such as the support controller, the solenoid valve group, and the high-frequency dynamic pressure sensor operate and what the principle is, no detailed description is made because these devices are commonly used in the industry.

[0071] Regarding the specific structure of the present invention, it should be noted that the connection relationships between the various component modules adopted by the present invention are definite and achievable. Except for the special descriptions in the embodiments, the specific connection relationships can bring corresponding technical effects, and on the premise of not relying on the execution of corresponding software programs, the technical problems proposed by the present invention can be solved. The models of the components, modules, and specific components, the connection methods between them, and the conventional usage methods and predictable technical effects brought by the above technical features, except for the specific descriptions, all belong to the publicly disclosed content in patents, journal papers, technical manuals, technical dictionaries, and textbooks that those skilled in the art can obtain before the filing date, or belong to the prior art such as the conventional techniques and common general knowledge in the art, and there is no need to elaborate. This makes the technical solution provided in this case clear, complete, and achievable, and the corresponding physical product can be reproduced or obtained according to this technical means.

[0072] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coal gangue content identification system based on a high-frequency dynamic pressure sensor, comprising a plurality of hydraulic supports placed in a fully-mechanized mining face for supporting the roof. A rear inserting plate is connected to the inside of the rear tail beam of each hydraulic support through a jack, and a support controller is arranged on each hydraulic support. It is characterized in that: A high-frequency dynamic pressure sensor assembly is fixed below the rear flap of the hydraulic support. The high-frequency dynamic pressure sensor assembly is used to detect the pressure of coal blocks and coal gangue during the coal caving process. The high-frequency dynamic pressure sensor assembly is connected to the support controller through a first connecting wire. The support controller is connected to the solenoid valve group through a second connecting wire. The solenoid valve group is connected to the cylinders of the rear tail beam and the rear flap of the hydraulic support through a hydraulic pipeline, and is used to control the actions of the cylinders on the rear tail beam and the rear flap of the hydraulic support. The support controller is also connected to a host computer through a wire. The host computer is used to analyze and process the pressure data collected by the high-frequency dynamic pressure sensor assembly, identify coal blocks, gangue, and the percentage of gangue content through the pressure-time data, and then send a signal to the support controller. The high-frequency dynamic pressure sensor assembly is composed of a number of high-frequency dynamic pressure sensors arranged longitudinally. The acquisition frequency of each high-frequency dynamic pressure sensor is not less than 2 MHz. The peak value of coal blocks and gangue on the pressure-time curve is F’, the time when the pressure appears at the inflection point is T’, and the ratio Q = F’ / T’. A critical q value for coal blocks and gangue is set in the host computer software. When Q>q, it is considered to be gangue, and when Q<q, it is considered to be coal.

2. The coal gangue content identification system based on a high-frequency dynamic pressure sensor according to claim 1, wherein: After the rear tail beam and the rear flap extend, they will press against the rock to block the coal blocks.

3. A method for identifying the coal gangue content based on a high-frequency dynamic pressure sensor, which uses the coal gangue content identification system based on a high-frequency dynamic pressure sensor as described in claim 1 or 2, and is characterized in that: It includes the following steps: The first step: Complete the connection of each component in the coal gangue content identification system. The second step: The host computer configures relevant thresholds, including: the critical q value of coal blocks and gangue, the gangue content percentage threshold, and the time range for calculating the gangue percentage. The third step: Open the coal caving port and start coal caving. The fourth step: The mixture of coal blocks and gangue falls, and some hit the high-frequency dynamic pressure sensor assembly. The fifth step: The high-frequency dynamic pressure sensor transmits the sampling data to the support controller. The sixth step: After the impact ends, the support controller forwards the impact data to the host computer. The seventh step: The host computer judges the impact material based on the impact data and the configured threshold data, and calculates whether the percentage of gangue content exceeds the threshold. The eighth step: If the percentage of gangue content judged in the sixth step exceeds the threshold, the host computer sends a signal to the support controller to close the coal caving. The ninth step: After receiving the signal to close the coal caving port, the support controller sends an electrical signal corresponding to the action of closing the coal caving port to the solenoid valve group. The tenth step: The solenoid valve group controls the hydraulic pipeline to realize the action of the hydraulic support. The eleventh step: The process of gangue content identification and closing the coal caving port is completed.

4. The coal gangue content identification method based on a high-frequency dynamic pressure sensor according to claim 3, characterized in that: The high-frequency dynamic pressure sensor assembly is composed of multiple high-frequency dynamic pressure sensors. When different hard objects impact, the corresponding high-frequency dynamic pressure sensors will be triggered to collect pressure values respectively. When calculating the percentage of gangue content, the pressure values collected by the high-frequency dynamic pressure sensors within a certain time range are selected for calculation.

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