A coal seam pressure-stabilizing water injection system

Abstract

The invention discloses a coal seam pressure-stabilizing water injection system, comprising a water injection unit, a water replenishment unit and a pressure-stabilizing control unit; the water replenishment unit comprises a pressure-stabilizing water storage tank, a pressure-stabilizing water replenishment pump, a pressure tank and a water replenishment pipeline; the pressure-stabilizing control unit comprises a gravity valve, a pre-valve water pressure sensor, a post-valve water pressure sensor and a PC receiving terminal; an air bag is vertically installed in the pressure tank, the top of the air bag is connected to the pressure-stabilizing water storage tank through a second water replenishment pipeline, the bottom of the air bag is connected to the water injection pipeline through a "U"-shaped first water replenishment pipeline, the gravity valve is installed at the front end of the first water replenishment pipeline near the water injection pipeline, the pre-valve water pressure sensor at the upper end of the gravity valve is used to monitor the water pressure of the water injection pipeline in real time, and the post-valve water pressure sensor at the lower end of the gravity valve is used to monitor the water pressure of the water replenishment pipeline. It can avoid the influence of "water leakage", "ultra-low flow", "ultra-low water pressure" and other phenomena on the disaster prevention effect of coal seam water injection, and stabilize the water injection pressure.

Description

Technical Field

[0001] The invention belongs to the field of mine dust prevention and control, in particular to coal seam water injection to improve the dust reduction effect of water injection, and specifically relates to a coal seam pressure-stabilizing water injection system. Background Art

[0002] Dust in coal mining production includes both rock dust and coal dust, which is one of the major hazards of coal mining production. With the improvement of the mechanization degree of coal mining, the amount of dust production has also increased dramatically. The quality of dust control is directly related to the safe production of coal mines and the health of miners. Coal seam water injection is the most basic and effective dust prevention measure for mining working faces, and has been widely used in various coal mines in recent years. Hydraulic fracturing, as a key technology in the process of coal seam water injection, can transform the macro-micro structure of the coal body, promote the development of secondary pores, enhance the wetting effect of the coal body, and effectively reduce the coal dust content in the production process of the working face. In the actual practice of hydraulic fracturing engineering, water injection pressure is a relatively critical parameter. At present, the mine water injection system generally adopts underground static pressure water injection or high-pressure water pump pressurized water injection. Once the water pump has problems and cannot operate, or the water volume in the water tank is too low, it will cause the water injection pressure to drop sharply, seriously affecting the water injection effect. In addition, during the coal seam water injection process, if there are large cracks or faults, "water leakage" will occur, which will also lead to a decrease in water injection pressure and unsatisfactory fracturing effect. Therefore, in order to avoid the impact of "water leakage", "ultra-low flow" and "ultra-low water pressure" on the disaster prevention effect of coal seam water injection, further improvements need to be made to the existing coal seam water injection system. Summary of the invention

[0003] In order to avoid the influence of "water leakage", "ultra-low flow" and "ultra-low water pressure" on the disaster prevention effect of coal seam water injection, further stabilize the water injection pressure and improve the disaster prevention effect of water injection, the present invention is committed to developing a coal seam water injection system that can achieve pressure stabilization.

[0004] To this end, the technical solution adopted by the present invention is: a coal seam pressure-stabilizing water injection system, including a water injection unit, the water injection unit including a main water storage tank, a water injection pipeline and a water injection pump, and also including a water replenishment unit and a pressure-stabilizing control unit; the water replenishment unit includes a pressure-stabilizing water storage tank, a pressure-stabilizing water replenishment pump, a pressure tank, and a water replenishment pipeline composed of a first water replenishment pipeline and a second water replenishment pipeline; the pressure-stabilizing control unit includes a gravity valve, a water pressure sensor before the valve, a water pressure sensor after the valve, a PC receiving terminal and a central controller;

[0005] An airbag is installed vertically in the center of the pressure tank, the top of the airbag is connected to the pressure-stabilizing water tank through a second water supply pipeline, and a pressure-stabilizing water supply pump is installed on the second water supply pipeline to transport the water in the pressure-stabilizing water tank to the airbag, so that the gas in the pressure tank on both sides of the airbag is compressed, and the bottom of the airbag is connected to the water injection pipeline through a "U"-shaped bent first water supply pipeline, and the gravity valve is installed at the front end of the first water supply pipeline close to the water injection pipeline. The pre-valve water pressure sensor at the upper end of the gravity valve is used to monitor the water pressure of the water injection pipeline in real time, and the post-valve water pressure sensor at the lower end of the gravity valve is used to monitor the water pressure of the water injection pipeline in real time. The pressure sensor is used to monitor the water pressure in the water supply pipeline. When the water pressure before the gravity valve is less than the water pressure after the valve, the gravity valve opens to supply water. When the water pressure before the gravity valve is greater than the water pressure after the valve, the gravity valve automatically closes. The water pressure sensor before the valve and the water pressure sensor after the valve can remotely send the water pressure information to the PC receiving terminal through the wireless transmission module. Once the water pressure monitored by the water pressure sensor after the valve exceeds the limit pressure of the gravity valve, or the water pressure monitored by the water pressure sensor before the valve is lower than the water pressure monitored by the water pressure sensor after the valve, an alarm signal is issued through the alarm.

[0006] As a preferred embodiment of the above scheme, a one-way valve is installed on the water injection pipeline at the front end of the intersection of the water supply pipeline and the water injection pipeline to prevent backflow.

[0007] Further preferably, when the water in the airbag is emptied, the pressure-stabilizing water supply pump starts to transport the water in the pressure-stabilizing water storage tank into the airbag until the gas on both sides of the airbag can no longer be compressed, and the pressure-stabilizing water supply pump automatically stops.

[0008] Further preferably, the pre-valve water pressure sensor and the post-valve water pressure sensor are respectively nested on their corresponding pipeline bodies through fastening sealing rings, and the detection head at one end thereof is located in the pipeline body.

[0009] Further preferably, the inner cavity of the air pressure tank is square, and gas injection ports are symmetrically arranged on the left and right sides of the air pressure tank for inflating gas into the corresponding gas filling spaces.

[0010] More preferably, the left and right inner walls of the pressure tank are respectively equipped with sensors and emulsion capsules, and the emulsion capsules are filled with sodium azide solid and a gas generator. The sensor is used to send the pressure information in the pressure tank to the PC receiving terminal in real time. When the measured gas pressure is lower than the normal working range, the central controller can send an ignition command to the gas generator. After ignition, the sodium azide solid in the emulsion capsule decomposes to produce nitrogen, and the emulsion capsule is burst to replenish the air pressure in the pressure tank. The pressure tank can be replenished with one-time air pressure as needed to adjust the water replenishment pressure of the water replenishment unit.

[0011] Beneficial effects of the present invention:

[0012] (1) The coal seam pressure-stabilized water injection system is equipped with a water replenishment unit and a pressure-stabilized control unit based on the original water injection unit. The water injection unit includes a main water storage tank, a water injection pump and a water injection pipeline. Under normal conditions, it is responsible for the water supply and pressurization of coal seam water injection. The water replenishment unit includes a pressure-stabilized water replenishment pump, a pressure-stabilized water storage tank, a pressure tank and a water replenishment pipeline. The pressure-stabilized water replenishment pump transports the water in the pressure-stabilized water storage tank to the pressure tank. The pressurized water is filled into the pressure tank, so that the air bag in the pressure tank is gradually compressed. When the air bag can no longer be compressed, the water replenishment pump automatically stops. Therefore, when the water pressure at the front end of the pipeline drops, the compressed gas in the pressure tank expands and quickly transports water to the pressure-stabilized control unit. The pressure-stabilized control unit includes a gravity valve, a water pressure sensor and a PC terminal. Under normal conditions, the water pressure before and after the gravity valve disc is balanced and the disc is closed. When the water pressure at the front end of the pipeline drops, the water pressure before the disc is greater than the water pressure after the disc, and the disc opens to supply water to the pipeline for pressure replenishment. Water pressure sensors are installed in the pipes at the upper and lower ends of the gravity valve. The water pressure sensor before the valve can monitor the water pressure of the water injection pipeline in real time, and the water pressure sensor after the valve can monitor the water pressure of the water supply pipeline, thereby realizing the monitoring of the ultimate pressure of the gravity valve and the air pressure tank; and a wireless transmission module is provided, which can remotely send the water pressure information to the PC receiving terminal. Once the water pressure monitored by the water pressure sensor after the valve exceeds the ultimate pressure of the gravity valve, or the water pressure in the water injection pipeline is abnormal (that is, the water pressure monitored by the water pressure sensor before the valve is lower than the water pressure monitored by the water pressure sensor after the valve), an alarm signal is issued.

[0013] (2) The present invention utilizes the force balance and the compressibility principle of gas, and through the coordination of the gravity valve and the air pressure tank, stabilizes the water injection pressure and improves the water injection effect. While saving energy and reducing emissions, it can also meet the requirements of simple operation and convenient maintenance.

[0014] (3) By stabilizing the water injection pressure, the water injection effect is improved, the impact of phenomena such as "water leakage", "ultra-low flow", and "ultra-low water pressure" on the disaster prevention effect of coal seam water injection is effectively reduced, and innovative coal seam water injection technology is developed.

[0015] (4) When designing the air pressure tank, the air bag is installed vertically in the center of the air pressure tank, and the water is replenished from the middle of the air pressure tank in a top-in and bottom-out manner. The symmetrical gas filling space exerts uniform pressure on the air bag, ensuring that the water replenishment process is stable and controllable. The first water replenishment pipeline adopts a "U"-shaped bending structure and is connected to the bottom of the air bag, which is more conducive to the installation and arrangement of the gravity valve. It is combined with a pressure stabilizing control unit composed of a water pressure sensor before the valve and a water pressure sensor after the valve to realize automatic alarm and automatic control, efficient, stable and reliable control, and the overall structure is compact, occupies a small space, and is easy to arrange and install on site.

[0016] (5) An air bag is installed in the air pressure tank. The air bag is not filled with air and is used as a water flow channel. Instead, the space on both sides of the air bag is inflated. The water flow channel is squeezed by the filling gas on the left and right sides to achieve water replenishment. This breaks away from the conventional design concept of inflating the air bag, and can better ensure that the water flow in the air pressure tank is evenly pressurized. The entire device has a simple structure, novel conception, ingenious design, and is easy to arrange. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 Schematic diagram of the water replenishment process for the air pressure tank. DETAILED DESCRIPTION

[0019] The present invention will be further described below by way of embodiments and in conjunction with the accompanying drawings:

[0020] like Figure 1 As shown, a coal seam pressure-stabilizing water injection system is mainly composed of three parts: a water injection unit, a water replenishment unit and a pressure-stabilizing control unit.

[0021] The water injection unit is mainly composed of a main water storage tank 1, a water injection pipeline 2 and a water injection pump 7, which is the same as the prior art and will not be described in detail here. The water replenishment unit and the pressure stabilization control unit are two additional parts.

[0022] The water replenishment unit is mainly composed of a pressure-stabilizing water storage tank 6, a pressure-stabilizing water replenishment pump 13, an air pressure tank 11, and a water replenishment pipeline. The water replenishment pipeline is composed of a first water replenishment pipeline 10 and a second water replenishment pipeline 12.

[0023] The pressure stabilizing control unit is mainly composed of a gravity valve 8, a water pressure sensor 4 before the valve, a water pressure sensor 9 after the valve, a PC receiving terminal and a central controller.

[0024] The airbag 5 is vertically installed in the center of the air pressure tank 11, and the top of the airbag 5 is connected to the pressure-stabilizing water storage tank 6 through the second water supply pipeline 12. The pressure-stabilizing water supply pump 13 is installed on the second water supply pipeline 12, and is used to transport the water in the pressure-stabilizing water storage tank 6 to the airbag 5, so that the gas in the air pressure tank 11 on both sides of the airbag 5 is compressed. The bottom of the airbag 5 is connected to the water injection pipeline 2 through the first water supply pipeline 10 with a "U" shape bend.

[0025] The gravity valve 8 is installed at the front end of the first water supply pipeline 10 near the water injection pipeline 2. The valve-front water pressure sensor 4 at the upper end of the gravity valve 8 is used to monitor the water pressure of the water injection pipeline 2 in real time, and the valve-back water pressure sensor 9 at the lower end of the gravity valve 8 is used to monitor the water pressure of the water supply pipeline. When the valve-front water pressure of the gravity valve 8 is less than the valve-back water pressure, the gravity valve 8 opens to supply water; when the valve-front water pressure of the gravity valve 8 is greater than the valve-back water pressure, the gravity valve 8 automatically closes and stops supplying water.

[0026] The water pressure sensor 4 before the valve and the water pressure sensor 9 after the valve can remotely send the water pressure information to the PC receiving terminal through the wireless transmission module. Once the water pressure monitored by the water pressure sensor 9 after the valve exceeds the limit pressure of the gravity valve 8, or the water pressure monitored by the water pressure sensor 4 before the valve is lower than the water pressure monitored by the water pressure sensor 9 after the valve, an alarm signal is issued through the alarm.

[0027] It is best to install a one-way valve on the water injection pipeline 2 at the front end of the intersection of the water supply pipeline and the water injection pipeline 2 to prevent backflow.

[0028] When the water in the airbag 5 is emptied, the pressure-stabilizing water supply pump 13 starts to transport the water in the pressure-stabilizing water storage tank 6 to the airbag 5 until the gas on both sides of the airbag can no longer be compressed, and the pressure-stabilizing water supply pump 13 automatically stops.

[0029] The pre-valve water pressure sensor 4 and the post-valve water pressure sensor 9 are respectively nested on their corresponding pipeline bodies through fastening sealing rings, and the detection head at one end thereof is located in the pipeline body.

[0030] The inner cavity of the air pressure tank 11 is square, and gas injection ports 11a are symmetrically arranged on the left and right sides of the air pressure tank 11 for filling gas into the corresponding gas filling spaces. The filling gas in the air pressure tank 11 can be nitrogen or other inert gases, but is not limited thereto.

[0031] Sensors and emulsion capsules are installed on the left and right inner walls of the pressure tank 11. Sodium azide solid and a gas generator are installed in the emulsion capsule. The sensor is used to send the pressure information in the pressure tank to the PC receiving terminal in real time. When the measured gas pressure is lower than the normal working range, the central controller can send an ignition command to the gas generator. After ignition, the sodium azide solid in the emulsion capsule decomposes to produce nitrogen, and the emulsion capsule is burst to replenish the air pressure in the pressure tank. Built-in sensors, emulsion capsules, sodium azide solid and gas generator can automatically replenish air pressure, with a high degree of automation.

[0032] The air pressure tank completes a water replenishment process, such as Figure 2 As shown, it is divided into four steps: after inflation, the airbag is compressed together by the pre-charged gas → the water in the pressure-stabilizing water tank enters the airbag, and the airbag gradually expands → the water in the airbag is gradually replenished to the water injection unit → the water in the airbag is fully replenished to the water injection unit.

Claims

1. A coal seam pressure-stabilizing water injection system, comprising a water injection unit, wherein the water injection unit comprises a main water storage tank (1), a water injection pipeline (2) and a water injection pump (7), characterized in that: It also includes a water replenishment unit and a pressure stabilization control unit; the water replenishment unit includes a pressure stabilization water storage tank (6), a pressure stabilization water replenishment pump (13), an air pressure tank (11), and a water replenishment pipeline composed of a first water replenishment pipeline (10) and a second water replenishment pipeline (12); the pressure stabilization control unit includes a gravity valve (8), a pre-valve water pressure sensor (4), a post-valve water pressure sensor (9), a PC receiving terminal and a central controller; An air bag (5) is vertically installed in the center of the air pressure tank (11). The top of the air bag (5) is connected to the pressure-stabilizing water storage tank (6) through the second water supply pipeline (12). The pressure-stabilizing water supply pump (13) is installed on the second water supply pipeline (12) and is used to transport the water in the pressure-stabilizing water storage tank (6) into the air bag (5), so that the gas in the air pressure tank (11) located on both sides of the air bag (5) is compressed. The bottom of the air bag (5) is connected to the water injection pipeline (2) through the first water supply pipeline (10) with a "U" shape bend. The gravity valve (8) is installed at the front end of the first water supply pipeline (10) near the water injection pipeline (2). The valve front water pressure sensor (4) at the upper end of the gravity valve (8) is used to measure the water pressure of the water injection pipeline (2). Real-time monitoring is performed. The water pressure sensor (9) behind the gravity valve (8) is used to monitor the water pressure of the water supply pipeline. When the water pressure before the gravity valve (8) is less than the water pressure after the valve, the gravity valve (8) opens to supply water. When the water pressure before the gravity valve (8) is greater than the water pressure after the valve, the gravity valve (8) automatically closes. The water pressure sensor (4) before the valve and the water pressure sensor (9) after the valve can remotely send water pressure information to a PC receiving terminal through a wireless transmission module. Once the water pressure monitored by the water pressure sensor (9) after the valve exceeds the limit pressure of the gravity valve (8), or the water pressure monitored by the water pressure sensor (4) before the valve is lower than the water pressure monitored by the water pressure sensor (9) after the valve, an alarm signal is issued through the alarm.

2. The coal seam pressure-stabilizing water injection system according to claim 1, characterized in that: A one-way valve is installed on the water injection pipeline (2) at the front end of the intersection of the water supply pipeline and the water injection pipeline (2) to prevent backflow.

3. The coal seam pressure-stabilizing water injection system according to claim 1, characterized in that: When the water in the airbag (5) is emptied, the pressure-stabilizing water supply pump (13) is started to transport the water in the pressure-stabilizing water storage tank (6) into the airbag (5), until the gas on both sides of the airbag can no longer be compressed, and the pressure-stabilizing water supply pump (13) automatically stops.

4. The coal seam pressure-stabilizing water injection system according to claim 1, characterized in that: The pre-valve water pressure sensor (4) and the post-valve water pressure sensor (9) are respectively nested on their corresponding pipeline bodies through a tightening sealing ring, and a detection head at one end thereof is located inside the pipeline body.

5. The coal seam pressure-stabilizing water injection system according to claim 1, characterized in that: The inner cavity of the air pressure tank (11) is square, and gas injection ports (11a) are symmetrically arranged on the left and right sides of the air pressure tank (11) for inflating gas into the corresponding gas filling spaces.

6. The coal seam pressure-stabilizing water injection system according to claim 5, characterized in that: The filling gas in the air pressure tank (11) is nitrogen.

7. The coal seam pressure-stabilizing water injection system according to claim 1, characterized in that: The left and right inner walls of the pressure tank (11) are respectively provided with a sensor and an emulsion capsule, wherein the emulsion capsule contains sodium azide solid and a gas generator. The sensor is used to send the pressure information in the pressure tank to the PC receiving terminal in real time. When the measured gas pressure is lower than the normal working range, the central controller can send an ignition command to the gas generator. After ignition, the sodium azide solid in the emulsion capsule undergoes a decomposition reaction to generate nitrogen, and the emulsion capsule is burst to replenish the air pressure in the pressure tank.

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