Constant-pressure Fracture Grouting Control System and Control Method

Abstract

The present invention discloses a constant-pressure fissure grouting control system, which includes a piston container. The slurry outlet of the piston container is connected to a grouting fissure platform. One end of the piston container away from the grouting fissure platform is connected to a plunger pump. A pressure sensor and a flow sensor are arranged on the grouting fissure platform. The pressure sensor and the flow sensor are respectively connected to a data acquisition instrument. The data acquisition instrument is connected to a central processor. The central processor is connected to the plunger pump, and it can grout multiple fissures with different sizes simultaneously and can observe the flow of the grouting material in the fissures. The present invention also discloses a method for controlling constant-pressure fissure grouting using the above control system, which can monitor the pressure and flow information in real time, control the opening degree of the plunger pump, and is easy to operate.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal seam gas control, relates to a constant-pressure fissure grouting control system, and specifically also relates to a constant-pressure fissure grouting control method. Background Art

[0002] With the increase of coal seam mining depth in China, the difficulty of controlling coal and gas outburst disasters is increasing day by day. At present, the most commonly used measure for controlling gas disasters in coal mines is gas drainage, and the borehole sealing effect is one of the key factors affecting the gas drainage effect. After the drainage borehole is formed, due to the absence of coal body in the middle of the borehole, the stress in the borehole and its surrounding area will change accordingly, and various fissures of different sizes will be formed at the same time. Poor borehole sealing effect will cause the weakening of the drainage effect. Therefore, it is necessary to further study the grouting mechanism of fissures of different sizes and the flow mechanism of different sealing materials in fissures of different sizes during the grouting process. Conducting experimental research on grouting of fissures of different sizes has great significance and engineering application value for coal mine gas control.

[0003] At present, most experimental devices can only realize the grouting experiment of a single fissure and cannot realize the grouting experiment of multiple fissures of different sizes at the same time. Therefore, in order to meet the experimental requirements, simulate the grouting process of actual fissures of different sizes and observe the flow distance of the grouting material in the fissures, and realize the timely adjustment of the grouting pressure during the grouting process, it is urgent to establish a constant-pressure fissure grouting control system, which has the characteristics of high automation degree and high control precision. Summary of the Invention

[0004] The purpose of the present invention is to provide a constant-pressure fissure grouting control system, which can grout multiple fissures of different sizes at the same time and can observe the flow of the grouting material in the fissures.

[0005] The technical solution adopted by the present invention is that the constant-pressure fissure grouting control system includes a piston container. The slurry outlet of the piston container is connected to a grouting fissure platform. One end of the piston container far from the grouting fissure platform is connected to a plunger pump. A pressure sensor and a flow sensor are arranged on the grouting fissure platform. The pressure sensor and the flow sensor are respectively connected to a data acquisition instrument. The data acquisition instrument is connected to a central processor, and the central processor is connected to the plunger pump.

[0006] The present invention is further characterized in that

[0007] The grouting fissure platform is composed of two pieces of plexiglass arranged up and down. Semi-circular main grooves are arranged on the inner walls of the two pieces of plexiglass near the piston container and are in corresponding positions, forming a circular main channel; a number of auxiliary grooves are arranged at equal intervals on the inner walls of the two pieces of plexiglass and are in corresponding positions, forming a number of circular branch channels. One end of the number of branch channels is communicated with the main channel, and the other end of the number of branch channels is communicated with the atmosphere.

[0008] The main channel is vertically arranged with several branch channels.

[0009] The number of branch channels is 13, and their inner diameters are 5mm, 4mm, 3mm, 2mm, 1mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm respectively; the inner diameter of the main channel is 20mm.

[0010] On each branch channel, a pressure sensor, a solenoid valve, and a flow sensor are sequentially arranged in the flowing direction of the grouting material.

[0011] The data acquisition instrument includes a pressure acquisition module and a flow acquisition module. The pressure acquisition module is connected to the pressure sensor, and the flow acquisition module is connected to the flow sensor.

[0012] The central processor includes a central processing module and a valve control module. The central processing module is respectively connected to the pressure acquisition module, the flow acquisition module, and the valve control module, and the valve control module is connected to the piston pump.

[0013] Another technical solution adopted by the present invention is a constant-pressure crack grouting control method, which uses the above-mentioned constant-pressure crack grouting control system. The specific process is as follows:

[0014] Step 1: Prepare the grouting material, load the grouting material into one end of the piston container close to the grouting crack platform, and set the grouting pressure and the solenoid valves to be opened in the central processing module.

[0015] Step 2: Start the system. The piston pump injects water into the end of the piston container away from the grouting crack platform, pushing the piston in the piston container to inject the grouting material into the grouting crack platform. The grouting material first passes through the main channel and then through the branch channels with the solenoid valves opened.

[0016] Step 3: The pressure sensor and the flow sensor monitor the pressure and flow of the branch channels in real time and convert the data into digital signals through the pressure acquisition module and the flow acquisition module respectively and transmit them to the central processing module. The central processing module compares the received pressure with the set pressure threshold. If it is lower than the set pressure threshold, the central processing module controls the valve opening in the piston pump through the valve control module to increase the thrust of the piston pump pushing the piston container. When the pressure collected by the pressure sensor reaches the set threshold, the valve opening in the piston pump is maintained, so that the grouting material in the piston container is injected into each branch channel at a constant pressure. Repeat Step 3 until the grouting is completed.

[0017] Step 4: After the grouting is completed, replace the grouting material in the piston container with clear water. The piston pump pushes the piston in the piston container to inject the clear water into the grouting crack platform, and then the clear water flushes out the grouting material in the grouting crack platform.

[0018] The beneficial effects of the present invention are as follows: The constant-pressure fissure grouting control system of the present invention is used for the grouting process of different-sized fissures on the grouting fissure platform. The whole process has the characteristics of being transparent and visible. During the constant-pressure grouting process, the migration distance of the grouting material in different fissures can be observed. It is particularly suitable for the current constant-pressure grouting experiment of coal seam fissures. This control system only needs to select the required grouting fissure size and set the required grouting pressure parameters to achieve automatic control of constant-pressure grouting under different fissure conditions and meet the requirements of constant-pressure grouting. The constant-pressure fissure grouting control method of the present invention can perform automatic control after setting the parameters, which is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the constant-pressure fissure grouting control system of the present invention;

[0020] Figure 2 is a schematic structural diagram of the grouting fissure platform in the constant-pressure fissure grouting control system of the present invention;

[0021] Figure 3 is the control principle diagram of the constant-pressure fissure grouting control system of the present invention.

[0022] In the figure, 1. Grouting fissure platform, 2. Piston container, 3. Plunger pump, 4. Pressure sensor, 5. Flow sensor, 6. Solenoid valve, 7. Data acquisition instrument, 8. Central processing unit, 9. Main channel, 10. Branch channel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0024] The present invention provides a constant-pressure fissure grouting control system, the structure of which is as Figure 1 shown, including a piston container 2. The slurry outlet of the piston container 2 is connected to a grouting fissure platform 1. One end of the piston container 2 away from the grouting fissure platform 1 is connected to a plunger pump 3. A pressure sensor 4, a solenoid valve 6, and a flow sensor 5 are arranged on the grouting fissure platform 1. The pressure sensor 4 and the flow sensor 5 are respectively connected to a data acquisition instrument 7. The data acquisition instrument 7 is connected to a central processing unit 8. The central processing unit 8 is connected to the plunger pump 3. During the experimental grouting process, by real-time monitoring and feedback of the grouting parameters in the grouting fissure platform 1, the grouting pressure can be adjusted automatically in a timely manner to achieve automatic constant-pressure fissure grouting. At the same time, the grouting fissure platform has the characteristics of being transparent and visible, and the flow state and flow distance of the grouting liquid in the grouting fissure platform 1 can be observed in real time during the experiment.

[0025] The piston container 2 is made of 316 stainless steel, with a volume of 2000 ml and a pressure resistance of 16 MPa, which can ensure the constant pressure and flow rate of the grouting material output by the piston container 2;

[0026] The working pressure of the plunger pump 3 is 3.5 MPa, the flow rate is 60 L / h, and the power is 0.37 KW. It can transport various liquid media with high viscosity, high pressure, and high temperature. It has a simple structure and is convenient for maintenance.

[0027] The monitoring accuracy of the pressure sensor 4 is 0.1%, and the measuring range is 0 - 4 MPa. The monitoring accuracy of the flow sensor 5 is 0.2% F.S. Both the pressure sensor 4 and the flow sensor 5 adopt high-precision sensors to ensure the data accuracy during the experiment.

[0028] As Figure 2 shown, the grouting fracture platform 1 consists of two pieces of transparent plexiglass arranged up and down. The thickness of each piece of plexiglass is 40 mm. On the inner walls of one end of the two pieces of plexiglass close to the piston container 2, semi-circular main grooves are provided and the positions correspond to form a circular main channel 9; on the inner walls of the two pieces of plexiglass, a number of secondary grooves are provided at equal intervals and the positions correspond to form a number of circular branch channels 10. The number of branch channels 10 is used to simulate different fractures. The main channel 9 is perpendicular to the number of branch channels 10. One end of the number of branch channels 10 is connected to the main channel 9, and the other end of the number of branch channels 10 is connected to the atmosphere. On each branch channel 10, a pressure sensor 4, a solenoid valve 6, and a flow sensor 5 are arranged in sequence according to the flow direction of the grouting material, so as to monitor the pressure and flow rate of the grouting material in each branch channel 10 inside the grouting fracture platform 1 in real time. The edges of the two pieces of plexiglass are connected by bolts, and the two sides parallel to the branch channels 10 and the edges close to and parallel to the main channel 9 are sealed with sealant. By setting an opening and closing at the entrance of the branch channel 10, the grouting of different fractures is realized; the grouting fracture platform 1 can withstand a pressure of 3 Mpa. Using transparent plexiglass is convenient for observing the flow state and distance of the grouting material in different branch channels 10.

[0029] Specifically, the number of branch channels 10 is 13, and the inner diameters are 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm respectively; the inner diameter of the main channel 9 is 20 mm.

[0030] As Figure 3 shown, the data acquisition instrument 7 includes a pressure acquisition module and a flow acquisition module. The pressure acquisition module is connected to the pressure sensor 4, and the flow acquisition module is connected to the flow sensor 5. The central processor 8 includes a central processing module and a valve control module. The central processing module is respectively connected to the pressure acquisition module, the flow acquisition module, and the valve control module. The valve control module is connected to the plunger pump 3.

[0031] The present invention also provides a constant-pressure fracture grouting control method. Using the above constant-pressure fracture grouting control system, the specific process is as follows:

[0032] Step 1: Configure the grouting material. Load the grouting material into one end of the piston container 2 close to the grouting fissure platform 1, and set the grouting pressure and the solenoid valves 6 to be opened in the central processing module.

[0033] Step 2: Start the system. The plunger pump 3 injects water into the end of the piston container 2 away from the grouting fissure platform 1, pushing the piston in the piston container 2 to inject the grouting material into the grouting fissure platform 1. The grouting material first passes through the main channel 9 and then through the branch channel 10 of the opened solenoid valve 6.

[0034] Step 3: The pressure sensor 4 and the flow sensor 5 monitor the pressure and flow rate of the branch channel 10 in real time and convert the data into digital signals through the pressure acquisition module and the flow acquisition module respectively and transmit them to the central processing module. The central processing module compares the received pressure with the set pressure threshold. If it is lower than the set pressure threshold, the central processing module controls the valve opening of the plunger pump 3 through the valve control module to increase the thrust of the plunger pump 3 pushing the piston container 2. When the pressure collected by the pressure sensor reaches the set threshold, the valve opening in the plunger pump 3 is maintained, so that the grouting material in the piston container 2 is injected into each branch channel 10 at a constant pressure. Repeat Step 3 until the grouting is completed, so that the grouting material inside the grouting fissure platform 1 flows stably.

[0035] Step 4: After the grouting is completed, replace the grouting material in the piston container 2 with clean water. The plunger pump 3 pushes the piston in the piston container 2 to inject the clean water into the grouting fissure platform 1, and then the clean water flushes out the grouting material in the grouting fissure platform 1.

Claims

1. A constant-pressure fissure grouting control method, characterized in that Adopt a constant-pressure crack grouting control system, including a piston container (2). The slurry outlet of the piston container (2) is connected to a grouting crack platform (1). One end of the piston container (2) away from the grouting crack platform (1) is connected to a plunger pump (3). A pressure sensor (4) and a flow sensor (5) are arranged on the grouting crack platform (1). The pressure sensor (4) and the flow sensor (5) are respectively connected to a data acquisition instrument (7). The data acquisition instrument (7) is connected to a central processor (8). The central processor (8) is connected to the plunger pump (3); The grouting crack platform (1) is composed of two pieces of plexiglass arranged up and down. Semi-circular main grooves are arranged on the inner walls of the two pieces of plexiglass near the piston container (2) and are in corresponding positions, forming a circular main channel (9); A number of secondary grooves are arranged at equal intervals on the inner walls of the two pieces of plexiglass and are in corresponding positions, forming a number of circular branch channels (10). One end of the number of branch channels (10) is communicated with the main channel (9), and the other end of the number of branch channels (10) is communicated with the atmosphere; The specific process is as follows: Step 1, configure the grouting material, load the grouting material into one end of the piston container (2) close to the grouting crack platform (1), and set the grouting pressure and the solenoid valve (6) to be opened in the central processing module; Step 2, start the system, the plunger pump (3) injects water into one end of the piston container (2) away from the grouting crack platform (1), pushes the piston in the piston container (2) to inject the grouting material into the grouting crack platform (1). The grouting material first passes through the main channel (9), and then passes through the branch channel (10) with the solenoid valve (6) opened; Step 3, the pressure sensor (4) and the flow sensor (5) monitor the pressure and flow rate of the branch channel (10) in real time and transmit the data to the central processing module respectively through the pressure acquisition module and the flow acquisition module after converting them into digital signals. The central processing module compares the received pressure with the set pressure threshold. If it is lower than the set pressure threshold, the central processing module controls the valve opening of the plunger pump (3) through the valve control module, increases the thrust of the plunger pump (3) to push the piston container (2). When the pressure collected by the pressure sensor reaches the set threshold, keep the valve opening in the plunger pump (3), so that the grouting material in the piston container (2) is injected into each branch channel (10) at a constant pressure. Repeat Step 3 until the grouting is completed; Step 4, after the grouting is completed, replace the grouting material in the piston container (2) with clean water. The plunger pump (3) pushes the piston in the piston container (2) to inject the clean water into the grouting crack platform (1), then the clean water flushes and discharges the grouting material in the grouting crack platform (1).

2. The constant-pressure fissure grouting control method according to claim 1, characterized in that The main channel (9) is perpendicular to the number of branch channels (10).

3. The constant-pressure fissure grouting control method according to claim 1, characterized in that, The number of branch channels (10) is 13, and the inner diameters are 5mm, 4mm, 3mm, 2mm, 1mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm respectively; The inner diameter of the main channel (9) is 20mm.

4. The constant-pressure fissure grouting control method according to claim 1, characterized in that On each of the branch channels (10), a pressure sensor (4), a solenoid valve (6), and a flow sensor (5) are sequentially arranged in the flowing direction of the grouting material.

5. The constant-pressure fissure grouting control method according to claim 1, wherein The data acquisition instrument (7) includes a pressure acquisition module and a flow acquisition module. The pressure acquisition module is connected to the pressure sensor (4), and the flow acquisition module is connected to the flow sensor (5).

6. The constant-pressure fissure grouting control method according to claim 5, characterized in that, The central processor (8) includes a central processing module and a valve control module. The central processing module is respectively connected to the pressure acquisition module, the flow acquisition module, and the valve control module. The valve control module is connected to the plunger pump (3).

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