A coal seam water injection disaster prevention system and method based on ultrasonic resonance

Abstract

The present invention discloses a coal seam water injection disaster prevention system based on ultrasonic resonance, comprising a crack development degree monitoring unit, an ultrasonic transmitting unit, an ultrasonic receiving unit, a driving power supply, a control unit, a water injection unit and three basic supports built on the surface of the coal seam; the present invention also discloses a coal seam water injection disaster prevention method based on ultrasonic resonance, comprising the following steps: step S1, starting an ultrasonic sensor and a water injection unit, and the ultrasonic sensor detects a target area; step S2, performing a preliminary detection of the natural frequency of the coal body and receiving ultrasonic waves; step S3, performing a second detection and reception of the natural frequency of the coal body; step S4, exciting the coal body to resonate; step S5, performing cyclic resonance fracture on the coal body cracks until the target is met; step S6, re-detecting the coal body cracks and the distribution of the injected water; the system has the advantages of greatly enhancing the water injection effect, improving the water injection efficiency, high data accuracy, and fully automatic control.

Description

Technical Field

[0001] The invention belongs to the technical field of coal seam water injection disaster prevention, and in particular relates to a coal seam water injection disaster prevention system based on ultrasonic resonance. Background Art

[0002] Over 90% of the gas in a coal seam is adsorbed within its pores and fissures. In unmined or undisturbed coal seams, gas maintains a dynamic adsorption equilibrium. Once mined, however, the fissures within the seam are exposed, disrupting this equilibrium. Large quantities of gas are continuously desorbed from the coal seam and transported through the pores, microcracks, and fissures within the seam into tunnels or working faces. Currently, most coal mines utilize high-powered shearers and fully mechanized top-coal caving mining techniques. This, combined with low water content in each layer, leads to increased coal dust generation, posing a threat to production safety and directly harming worker health due to a deteriorating production environment. Therefore, ineffective gas and coal dust control measures can lead to gas and coal dust explosions.

[0003] Water injection into coal seams is the most commonly used method. However, using water injection alone still has problems such as poor water injection effect, low water injection efficiency, and the water injected into the coal seam cannot fully penetrate the coal seam. Summary of the Invention

[0004] The present invention aims to provide a coal seam water injection disaster prevention system and method based on ultrasonic resonance, which uses ultrasonic resonance to promote the development of coal seam cracks and enhance the water injection effect, thereby solving the problems of poor water injection effect, low water injection efficiency, and inability of the water injected into the coal seam to fully penetrate the coal seam when only water injection is used.

[0005] To this end, the technical solution adopted by the present invention is: a coal seam water injection disaster prevention system based on ultrasonic resonance, including a crack development degree monitoring unit, an ultrasonic transmitting unit, an ultrasonic receiving unit, a driving power supply, a control unit, a water injection unit and three basic supports built on the surface of the coal seam, the crack development degree monitoring unit includes an ultrasonic sensor installed on a single basic support for detecting the initial development of coal seam cracks; the ultrasonic transmitting unit includes a lifting device with a lifting end placed in the water injection hole, an ultrasonic resonance transmitting component circumferentially around the lifting end of the lifting device and evenly spaced up and down, and an initial detection ultrasonic transmitter, a signal generator, and an ultrasonic transmitting amplifier installed on a single basic support in sequence from top to bottom, the ultrasonic The sound wave receiving unit includes a primary ultrasonic receiver, a filter and an ultrasonic receiving amplifier installed in sequence from top to bottom on a single basic bracket. The ultrasonic resonance transmitting component includes a shell and a secondary ultrasonic transmitter, a secondary ultrasonic receiver, a position detection radar, and a resonant ultrasonic transmitter all built into the shell; the driving power supply and the control unit are both connected to the crack development degree monitoring unit, the ultrasonic transmitting unit, and the ultrasonic receiving unit circuits; the water injection unit includes a water injection pipeline, a water injection water pressure sensor, a water pump, a water tank and a water injection operating table connected to the control unit; the water injection pipeline starts from the water tank and is connected to the water pump and the water injection operating table in sequence and then extends to the bottom of the water injection hole; the water injection water pressure sensor is placed in the water injection pipeline.

[0006] As a preferred embodiment of the above scheme, the control unit includes a data acquisition and control computer connected to the ultrasonic transmitting unit and the ultrasonic receiving unit, and a crack development data computer connected to the crack development degree monitoring unit. The data acquisition and control computer and the crack development data computer are interconnected to avoid excessive load on one control computer. By dividing the data into two computers for separate calculations, the operation is convenient and not messy.

[0007] It is further preferred that the secondary ultrasonic transmitter and the resonant ultrasonic transmitter are both connected to the driving power supply and the control unit circuit and are integrated and installed in parallel, which has high space utilization; the rear-end circuits of the secondary ultrasonic transmitter and the resonant ultrasonic transmitter are respectively provided with closed-circuit switches, and the corresponding secondary ultrasonic transmitter and the resonant ultrasonic transmitter are started and stopped by controlling the closed-circuit switches, and the route design is reasonable.

[0008] It is further preferred that the lower part of the vertical section of the water injection pipe extending into the water injection hole is provided with water outlet holes at upper and lower intervals on the side away from the lifting device, and the multiple holes are facing away from the water outlet to ensure that the water outlet is gentle. When the multiple holes outlet water, it will not interfere with the ultrasonic resonance emission component on the lifting device, and avoid the single hole water outlet from flushing, lifting and shaking left and right, resulting in instability when moving up and down. The design is reasonable.

[0009] Further preferably, a water-proof sealing strip is laid on the top of the water injection hole to prevent dust and debris from entering the water injection hole and blocking the cracks.

[0010] More preferably, a secondary receiving filter is installed at the end of the secondary ultrasonic receiver to shield some useless ultrasonic waves, reduce ultrasonic receiving errors, and have a reasonable design.

[0011] The present invention also adopts a coal seam water injection disaster prevention method based on ultrasonic resonance, which includes the following steps:

[0012] Step S1: Using the above-mentioned coal seam water injection disaster prevention system based on ultrasonic resonance, first start the ultrasonic sensor and the water injection unit. The control unit receives water pressure data from the water injection pressure sensor. When the water pressure data changes, the water pump is started to inject water until the water pressure stabilizes. The ultrasonic sensor detects coal body cracks in the target area and the distribution of water injected by the water injection unit. The data is then transmitted to the control unit for processing and imaging. Finally, the ultrasonic sensor is turned off.

[0013] Step S2: Synchronously start the ultrasonic transmitter, signal generator, and ultrasonic transmitter amplifier for initial detection to conduct preliminary detection of the natural frequency of the coal body; synchronously start the ultrasonic receiver, filter, and ultrasonic receiver amplifier for initial detection to receive ultrasonic waves; and send the received ultrasonic wave data to the control unit. The control unit performs waveform imaging and searches for peaks in the frequencies observed in the waveform. These peaks are the natural frequencies of the coal body. The waveform data is recorded and processed, and the ultrasonic transmitter and receiver units are turned off.

[0014] Step S3: Start the position detection radar to accurately detect the crack location, then start the lifting device to move the ultrasonic resonance transmitting assembly up and down so that it is aligned with the target crack area, and start the secondary ultrasonic transmitter and secondary ultrasonic receiver to re-detect and receive the natural frequency of the coal body;

[0015] Step S4, turning off the secondary ultrasonic transmitter and the secondary ultrasonic receiver, starting the resonant ultrasonic transmitter to emit ultrasonic waves of the same natural frequency as the coal body in step S3, to excite the coal body to resonate and expand its cracks, and finally turning off the resonant ultrasonic transmitter;

[0016] Step S5: Restart the secondary ultrasonic transmitter and the secondary ultrasonic receiver to detect and receive the natural frequency of the coal body and transmit the data to the control unit. Compare the data with the previous waveform data to determine whether the crack development meets the target. If not, repeat step S4 to perform cyclic resonance cracking on the coal body until the target is met. If so, shut down the secondary ultrasonic transmitter and the secondary ultrasonic receiver.

[0017] Step S6: Start the ultrasonic sensor and re-detect the coal body cracks in the target area after resonance and the distribution of water injected by the water injection unit. The data is transmitted back to the control unit for comparison with the expected data. If the expected data is met, the entire coal seam water injection disaster prevention system is shut down. If not, steps S1-S6 are repeated until the standard is met.

[0018] As a preferred embodiment of the above solution, in step S4, starting and stopping the secondary ultrasonic transmitter and the resonant ultrasonic transmitter are both achieved by controlling the closed-circuit switches on the corresponding lines by the control unit, which is a reasonable operation.

[0019] Beneficial effects of the present invention:

[0020] (1) Compared with the simple use of water injection, there are problems such as poor water injection effect, low water injection efficiency, and the water injected into the coal seam cannot fully penetrate the coal seam. This scheme is based on the coal seam water injection disaster prevention system of ultrasonic resonance. It uses ultrasonic resonance to promote the development of coal seam fissures to enhance the water injection effect. The design is ingenious and can greatly enhance the water injection effect, improve the water injection efficiency, and ensure the effect of coal seam water injection in controlling gas and coal dust explosions.

[0021] (2) The crack development degree monitoring unit is used to detect the initial state of coal seam cracks and the initial water injection distribution. The primary detection ultrasonic transmitter in the ultrasonic transmitting unit is used to perform preliminary detection of the natural frequency of the coal body. The primary ultrasonic receiver is used to receive ultrasonic waves and send the received ultrasonic data to the control unit. Waveform imaging is performed in the control unit to roughly obtain the data of the natural frequency of the coal seam to facilitate the subsequent parameter setting of the secondary ultrasonic transmitter and the secondary ultrasonic receiver. Then, by starting the lifting device, the ultrasonic resonance transmitting component is driven up and down to align it with the target crack area. The secondary ultrasonic transmitter and the secondary ultrasonic receiver are used to realize accurate data detection of the natural frequency of the coal seam. The natural frequency of the coal seam is detected twice, and the data accuracy is high, which effectively avoids the situation of poor resonance effect and is precisely designed.

[0022] (3) The control unit determines the ultrasonic frequency emitted by the automatic control ultrasonic transmitter and processes the data signal of the ultrasonic sensor to control the start and shut down of the entire facility. It also controls the water injection pressure by controlling the water pump switch through the water injection console, thereby realizing the automation of the entire process and achieving the optimal effect of coal body fissure development, thereby improving the effect of promoting water injection by expanding coal seam fissures. The system is fully automated and easy to operate.

[0023] In summary, it has the advantages of greatly enhancing the water injection effect, improving the water injection efficiency, ensuring the coal seam water injection to control gas and coal dust explosions, high data accuracy, and fully automated automatic control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is a structural diagram of the coal seam water injection disaster prevention system based on ultrasonic resonance.

[0025] Figure 2 Schematic diagram of the structure inside the water injection hole.

[0026] Figure 3 It is a structural diagram of the ultrasonic resonance emission component. DETAILED DESCRIPTION

[0027] The present invention will be further described below by way of examples and in conjunction with the accompanying drawings:

[0028] Combine Figure 1 — Figure 3 As shown, a coal seam water injection disaster prevention system based on ultrasonic resonance is composed of a crack development degree monitoring unit 1, an ultrasonic transmitting unit 2, an ultrasonic receiving unit 3, a driving power supply 4, a control unit 5, a water injection unit 6 and three basic supports 7 built on the surface of the coal seam.

[0029] The fracture development degree monitoring unit 1 is composed of an ultrasonic sensor 11 mounted on a single basic support 7 for detecting the initial development of coal seam fractures.

[0030] The ultrasonic transmitting unit 2 consists of a lifting device 25 with the lifting end placed in the water injection hole A, an ultrasonic resonance transmitting component 24 circumferentially around the lifting end of the lifting device 25 and evenly spaced up and down, and a primary detection ultrasonic transmitter 21, a signal generator 22, and an ultrasonic transmitting amplifier 23 installed in sequence from top to bottom on a single basic bracket 7.

[0031] The ultrasonic receiving unit 3 is composed of a primary ultrasonic receiver 31 , a filter 32 and an ultrasonic receiving amplifier 33 which are sequentially mounted on a single base bracket 7 from top to bottom.

[0032] The ultrasonic resonance transmitting assembly 24 is composed of a shell 241 and a secondary ultrasonic transmitter 242 , a secondary ultrasonic receiver 243 , a position detection radar 244 , and a resonant ultrasonic transmitter 245 , all of which are built into the shell 241 .

[0033] A secondary receiving filter 247 is installed at the end of the secondary ultrasonic receiver 243 .

[0034] The driving power supply 4 and the control unit 5 are both connected to the crack development degree monitoring unit 1 , the ultrasonic transmitting unit 2 , and the ultrasonic receiving unit 3 .

[0035] The water injection unit 6 consists of a water injection pipeline 61 , a water injection pressure sensor 62 , a water pump 63 , a water tank 64 and a water injection operation console 65 connected to the control unit 5 .

[0036] The water injection pipeline 61 starts from the water tank 64 and is connected to the water pump 63 and the water injection operation table 65 in sequence, and then extends to the bottom of the water injection hole A.

[0037] The water injection pressure sensor 62 is placed in the water injection pipeline 61.

[0038] The control unit 5 is composed of a data acquisition and control computer 51 connected to the ultrasonic transmitting unit 2 and the ultrasonic receiving unit 3 , and a crack development data computer 52 connected to the crack development degree monitoring unit 1 .

[0039] The data acquisition and control computer 51 and the fracture development data computer 52 are in data communication with each other.

[0040] The secondary ultrasonic transmitter 242 and the resonant ultrasonic transmitter 245 are both connected to the driving power supply 4 and the control unit 5 and are integrated and installed in parallel.

[0041] The rear end circuits of the secondary ultrasonic transmitter 242 and the resonant ultrasonic transmitter 245 are respectively provided with closed-circuit switches 246 .

[0042] Water outlet holes 611 are provided at intervals above and below the lower part of the vertical section of the water injection pipe 61 extending into the water injection hole A and away from the lifting device 25 .

[0043] A water-proof sealing strip A1 is laid on the top of the water injection hole A.

[0044] A coal seam water injection disaster prevention method based on ultrasonic resonance, the specific implementation steps are as follows:

[0045] Step S1, using the above-mentioned coal seam water injection disaster prevention system based on ultrasonic resonance, first start the ultrasonic sensor 11 and the water injection unit 6, the control unit 5 receives the water pressure data from the water injection water pressure sensor 62, when the water pressure data changes, start the water pump 63 to inject water until the water pressure is stable, the ultrasonic sensor 11 detects the coal body cracks in the target area and the distribution of water injected by the water injection unit 6, and then transmits the data to the control unit 5 for processing and imaging, and finally turns off the ultrasonic sensor 11.

[0046] Step S2: Synchronously start the ultrasonic transmitter 21, signal generator 22, and ultrasonic transmitter amplifier 23 for initial detection to conduct preliminary detection of the natural frequency of the coal body; synchronously start the ultrasonic receiver 31, filter 32, and ultrasonic receiver amplifier 33 to receive ultrasonic waves, and send the received ultrasonic data to the control unit 5; perform waveform imaging in the control unit 5; search for peaks in the frequencies observed in the waveform, which are the natural frequencies of the coal body; record and process the waveform data; and then turn off the ultrasonic transmitter unit 2 and ultrasonic receiver unit 3.

[0047] Step S3: Start the position detection radar 244 to accurately detect the crack position, then start the lifting device 25 to drive the ultrasonic resonance transmitting component 24 to move up and down so that it is aligned with the target crack area, and start the secondary ultrasonic transmitter 242 and the secondary ultrasonic receiver 243 to re-detect and receive the natural frequency of the coal body.

[0048] Step S4, close the secondary ultrasonic transmitter 242 and the secondary ultrasonic receiver 243, start the resonant ultrasonic transmitter 245 to transmit ultrasonic waves of the same natural frequency as the coal body in step S3, stimulate the coal body to resonate and expand its cracks, and finally close the resonant ultrasonic transmitter 245.

[0049] In step S4 , the start and stop of the secondary ultrasonic transmitter 242 and the resonant ultrasonic transmitter 245 are both achieved by the control unit 5 controlling the closed-circuit switch 246 on the corresponding line.

[0050] Step S5: Restart the secondary ultrasonic transmitter 242 and the secondary ultrasonic receiver 243 to detect and receive the natural frequency of the coal body and transmit the data to the control unit 5. Compare the data with the previous waveform data to determine whether the crack development meets the target. If not, repeat step S4 to perform cyclic resonance cracking on the coal body until the target is met. If so, turn off the secondary ultrasonic transmitter 242 and the secondary ultrasonic receiver 243.

[0051] Step S6, start the ultrasonic sensor 11, re-detect the coal body cracks in the target area after resonance and the distribution of water injected by the water injection unit 6, transmit the data back to the control unit 5 for comparison with the expected data, if the expected data is met, shut down the entire coal seam water injection disaster prevention system, if not, repeat steps S1-S6 until the standard is met.

Claims

1. A coal seam water injection disaster prevention system based on ultrasonic resonance, characterized by: The invention comprises a crack development degree monitoring unit (1), an ultrasonic transmitting unit (2), an ultrasonic receiving unit (3), a driving power supply (4), a control unit (5), a water injection unit (6) and three foundation supports (7) built on the surface of the coal seam. The crack development degree monitoring unit (1) comprises an ultrasonic sensor (11) installed on a single foundation support (7) for detecting the initial development of coal seam cracks; the ultrasonic transmitting unit (2) comprises a lifting device (25) whose lifting end is placed in a water injection hole (A), an ultrasonic resonance transmitting assembly (24) circumferentially around the lifting end of the lifting device (25) and uniformly spaced up and down, and a primary detection ultrasonic transmitter (21), a signal generator (22), and an ultrasonic transmitting amplifier (23) installed on the single foundation support (7) in sequence from top to bottom; the ultrasonic receiving unit (3) comprises a primary ultrasonic receiver (31), a filter (32), and a filter (33) installed on the single foundation support (7) in sequence from top to bottom. The ultrasonic resonance transmitting assembly (24) comprises a shell (241) and a secondary ultrasonic transmitter (242), a secondary ultrasonic receiver (243), a position detection radar (244), and a resonant ultrasonic transmitter (245), all of which are built into the shell (241); the driving power supply (4) and the control unit (5) are both connected to the crack development degree monitoring unit (1), the ultrasonic transmitting unit (2), and the ultrasonic receiving unit (3); the water injection unit (6) comprises a water injection pipeline (61), a water injection water pressure sensor (62), a water pump (63), a water tank (64), and a water injection operation table (65) connected to the control unit (5); the water injection pipeline (61) starts from the water tank (64), is connected to the water pump (63), the water injection operation table (65) in sequence, and then extends to the bottom of the water injection hole (A); the water injection water pressure sensor (62) is placed in the water injection pipeline (61).

2. The coal seam water injection disaster prevention system based on ultrasonic resonance according to claim 1, characterized in that: The control unit (5) comprises a data acquisition and control computer (51) connected to the ultrasonic transmitting unit (2) and the ultrasonic receiving unit (3) and a crack development data computer (52) connected to the crack development degree monitoring unit (1), and the data acquisition and control computer (51) and the crack development data computer (52) are interconnected.

3. The coal seam water injection disaster prevention system based on ultrasonic resonance according to claim 1, characterized in that: The secondary ultrasonic transmitter (242) and the resonant ultrasonic transmitter (245) are both connected to the driving power supply (4) and the control unit (5) circuits and are integrated and installed in parallel. The rear end circuits of the secondary ultrasonic transmitter (242) and the resonant ultrasonic transmitter (245) are respectively provided with closed-circuit switches (246).

4. The coal seam water injection disaster prevention system based on ultrasonic resonance according to claim 1, characterized in that: The lower part of the vertical section of the water injection pipe (61) extending into the water injection hole (A) is provided with water outlet holes (611) spaced apart from each other on one side of the lifting device (25).

5. The coal seam water injection disaster prevention system based on ultrasonic resonance according to claim 1, characterized in that: A water-proof sealing strip (A1) is laid on the top of the water injection hole (A).

6. The coal seam water injection disaster prevention system based on ultrasonic resonance according to claim 1, characterized in that: A secondary receiving filter (247) is installed at the end of the secondary ultrasonic receiver (243).

7. A coal seam water injection disaster prevention method based on ultrasonic resonance, characterized in that: The following steps are involved: Step S1, using a coal seam water injection disaster prevention system based on ultrasonic resonance as described in any one of claims 1 to 6, first starting the ultrasonic sensor (11) and the water injection unit (6), the control unit (5) receives water pressure data from the water injection pressure sensor (62), when the water pressure data changes, starting the water pump (63) to inject water until the water pressure is stable, the ultrasonic sensor (11) detects the coal body cracks in the target area and the distribution of water injected by the water injection unit (6), then the data is transmitted to the control unit (5) for processing and imaging, and finally the ultrasonic sensor (11) is turned off; Step S2, synchronously starting the primary detection ultrasonic transmitter (21), the signal generator (22), and the ultrasonic transmission amplifier (23) to perform preliminary detection of the natural frequency of the coal body, synchronously starting the primary ultrasonic receiver (31), the filter (32), and the ultrasonic receiving amplifier (33), receiving ultrasonic waves, and sending the received ultrasonic wave data to the control unit (5), performing waveform imaging in the control unit (5), searching for peaks in the frequencies observed in the waveform, which are the natural frequencies of the coal body, recording and processing the waveform data, and shutting down the ultrasonic transmission unit (2) and the ultrasonic receiving unit (3); Step S3: Start the position detection radar (244) to accurately detect the crack position, then start the lifting device (25) to drive the ultrasonic resonance emission component (24) to move up and down so that it is aligned with the target crack area, and start the secondary ultrasonic transmitter (242) and the secondary ultrasonic receiver (243) to re-detect and receive the natural frequency of the coal body; Step S4, turning off the secondary ultrasonic transmitter (242) and the secondary ultrasonic receiver (243), starting the resonant ultrasonic transmitter (245) to transmit ultrasonic waves of the same natural frequency as the coal body in step S3, exciting the coal body to resonate and expand the cracks, and finally turning off the resonant ultrasonic transmitter (245); Step S5, restarting the secondary ultrasonic transmitter (242) and the secondary ultrasonic receiver (243), detecting and receiving the natural frequency of the coal body and transmitting the data to the control unit (5), comparing the data with the previous waveform data to determine whether the crack development condition meets the target; if not, looping step S4 to perform cyclic resonance cracking on the coal body cracks until the target is met; if so, shutting down the secondary ultrasonic transmitter (242) and the secondary ultrasonic receiver (243); Step S6, start the ultrasonic sensor (11), re-detect the coal body cracks in the target area after resonance and the distribution of water injected by the water injection unit (6), transmit the data back to the control unit (5) and compare it with the expected data. If the expected data is met, the entire coal seam water injection disaster prevention system is shut down. If not, the steps S1-S6 are repeated until the target is met.

8. The method for coal seam water injection disaster prevention based on ultrasonic resonance according to claim 7, characterized in that: In step S4, starting and stopping the secondary ultrasonic transmitter (242) and the resonant ultrasonic transmitter (245) are both achieved by the control unit (5) controlling the closed-circuit switch (246) on the corresponding line.

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