Coal mine underground drilling self-adaptive control water supply system and control method thereof

Abstract

The invention discloses a coal mine underground drilling self-adaptive control water supply system and a control method thereof. The system comprises a power source system, a self-adaptive control water supply mechanism and an electro-hydraulic pilot control system. The power source system is provided with a safety valve and an energy accumulator for pressure stabilization, and the self-adaptive control water supply mechanism comprises a high-pressure branch, a low-pressure branch and a drainage pipeline, is formed by connecting a constant pressure difference compensation flow control valve, a first hydraulic control reversing valve, a second hydraulic control reversing valve, a water pressure gauge and a flow meter, and controls the total water quantity and branch switching. The electro-hydraulic pilot control system comprises a pilot proportional control module, a first electromagnetic directional valve, a second electromagnetic directional valve and a pressure reducing valve, and flow self-adaptive adjustment is achieved. The control method comprises a standby state, a high-pressure water supply state and a low-pressure water supply state, and the load requirement is matched through closed-loop control. The problems of drilling flow mismatching and multi-drill-site water supply interference are solved, multi-working-condition water supply is supported, the structure is compact, the automation degree is high, and the device is suitable for working conditions of coal mine underground coal flushing, directional drilling, deslagging and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine water supply, and relates to a self-adaptive control water supply system for underground coal mine drilling and its control method, which is applicable to the water supply requirements under various drilling conditions in underground coal mines. Background Technique

[0002] Underground coal mine drilling construction is an important link to ensure the safe production of the mine, especially playing an irreplaceable role in gas control, coal seam mining, and geological exploration. During drilling construction, the water supply system, as the core part providing the flushing medium or power source, directly affects the construction efficiency and safety. At present, the typical working conditions that require the use of a mud pump for water supply in underground coal mine drilling include ordinary rotary drilling (high-pressure coal flushing), mechanical cavity-forming drilling, hard rock impact drilling, and directional drilling, etc. These working conditions usually use high-pressure clean water as the flushing medium or power source to meet the requirements of flushing coal slag in the hole, stabilizing the drill tool, and improving the drilling efficiency during the drilling process. However, the requirements for water pressure and flow rate vary significantly for different drilling working conditions. For example, the required water pressure for ordinary rotary drilling (high-pressure coal flushing) is about 8 - 10 MPa, and the flow rate requirement is between 150 - 200 L / min; the water pressure requirement range for hard rock impact drilling is 8 - 15 MPa, and the working flow rate is also 150 - 200 L / min; while directional drilling requires a higher water volume, the flow rate can reach 300 L / min, the water pressure range is 6 - 10 MPa, and it needs to be dynamically adjusted according to the actual working environment.

[0003] During the actual drilling process, the problem of flow rate and pressure matching of the water supply system has a particularly significant impact on the construction effect. If the water volume is too small, the coal slag in the hole cannot be discharged in time, easily leading to blockage in the hole, affecting the drilling progress, and even causing potential safety hazards; if the water volume is too large, although the coal slag can be effectively discharged, it will result in too high a proportion of slag in the flushing return water, bringing difficulties to the subsequent slag-water separation and coal slag metering, while causing waste of water resources and increasing the burden on the underground sump and sewage system. In addition, the size of the water pressure directly determines the drilling effect of the terminal drill tool. Insufficient water pressure may lead to low drilling efficiency, while too high water pressure may cause unnecessary damage to the equipment. Therefore, how to achieve precise matching of water supply flow rate and pressure has become a technical problem that urgently needs to be solved in underground coal mine drilling construction.

[0004] At present, in coal mines, the gas is mainly controlled by the bottom drainage roadway. A water supply network is arranged in the bottom drainage roadway to supply water to the water tank of the slurry pump truck. However, most of the existing water supply networks are static pressure water systems. Their water volume and water pressure are limited by the overall design of the network, and no independent control device is set. This results in the water pressure and flow rate of the water supply network being easily interfered by other water use areas, with large fluctuations and unable to stably meet the requirements of drilling construction. In addition, the underground roadway usually has a certain slope and a long distance. The water volume and water pressure obtained by the drill sites with a higher slope from the network are often insufficient to support the drilling operation. In actual operation, the phenomenon of "grabbing water" often occurs: when the water consumption of the low-position drill site increases, the high-position drill site cannot operate normally due to the drop in water pressure, directly affecting the overall construction efficiency. In addition, the water supply capacity of the existing water supply network is difficult to adjust in real time according to the change of drilling load. Especially in the scenario of multiple drill sites operating simultaneously, there is a lack of an effective flow distribution mechanism between drill sites, resulting in the water supply system being difficult to adapt to the complex and changeable working conditions.

[0005] In the prior art, there are mainly two ways for the water supply system in coal mines. The first is the centralized emulsion liquid supply method, which realizes water supply through multi-pump pressurization combined with an electro-hydraulic control system. Although this method can provide stable high-pressure water supply, the overall design of the system is relatively large, occupying more roadway space, and it is mainly a constant-pressure liquid supply mode, unable to flexibly adapt to the needs of the drill rig for constant-flow high-pressure clean water. In addition, this system is not convenient to move frequently in narrow roadways and does not meet the actual needs of underground mobile operations. The second way is the application of a "one-to-one" high-pressure clean water pump station, that is, one pump station only serves one drill rig. Although this method can meet the water supply needs of a single drill rig, it cannot achieve the goal of one pump station supplying water to multiple drill sites simultaneously, with low equipment utilization rate. And when multiple drill sites are operating, multiple pump stations need to be configured, further increasing the equipment cost and roadway space occupation.

[0006] To sum up, the existing water supply systems in coal mines generally have problems such as insufficient flow matching, mutual interference in water supply for multiple drill sites, and poor system flexibility under the condition that the drilling working conditions change with the load. These deficiencies not only reduce the drilling construction efficiency but also increase the complexity of equipment configuration and resource management. Therefore, it is of great practical significance and application value to develop a water supply system and its control method that can adaptively adjust the flow rate and pressure according to the load demand and support the simultaneous operation of multiple drill sites. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to solve the above deficiencies and provide a coal mine underground drilling adaptive control water supply system and its control method to solve the problems of unmatched water supply flow rate and load during the drilling process, mutual influence of water supply for multiple drill sites, and insufficient system flexibility.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] An adaptive control water supply system for underground drilling in a coal mine, comprising a power source system and an adaptive control water supply mechanism connecting the power source system and a water supply branch, and an electro-hydraulic pilot control system for controlling the adaptive control water supply mechanism;

[0010] The power source system includes a variable frequency motor and a mud pump, and the variable frequency motor drives the mud pump to provide water supply;

[0011] The adaptive control water supply mechanism comprises a high-pressure branch, a low-pressure branch and a drain pipe; the high-pressure branch, the low-pressure branch and the drain pipe are formed by connecting a constant pressure difference compensation flow control valve, a first hydraulically controlled reversing valve, a second hydraulically controlled reversing valve, a water pressure gauge and a flow meter through pipes; the constant pressure difference compensation flow control valve is used to control the total amount of water entering the water supply branch;

[0012] The first hydraulically controlled reversing valve is used to switch the working and unloading states of the adaptively controlled water supply mechanism; the second hydraulically controlled reversing valve is used to switch the high-pressure branch and the low-pressure branch in the adaptively controlled water supply mechanism on and off;

[0013] The electro-hydraulic pilot control system includes a pilot proportional control module, a first electromagnetic reversing valve and a second electromagnetic reversing valve, which are respectively connected to the constant pressure difference compensation flow control valve, the first hydraulically controlled reversing valve and the second hydraulically controlled reversing valve through hydraulic pipelines to control their actions and realize adaptive flow regulation of high-pressure water supply and low-pressure water supply under different working conditions.

[0014] Further, the first hydraulically controlled reversing valve and the second hydraulically controlled reversing valve each have three interfaces; the inlet of the constant pressure difference compensation flow control valve is connected to the water outlet pipeline of the mud pump, and the outlet is connected to the first interface of the first hydraulically controlled reversing valve; the second interface of the first hydraulically controlled reversing valve is connected to the first interface of the second hydraulically controlled reversing valve; the second interface of the second hydraulically controlled reversing valve is connected to the inlet of the flow meter; the outlet of the flow meter is connected to the load terminal; the water pressure gauge is arranged on the pipeline in front of the flow meter; the third interface of the first hydraulically controlled reversing valve is connected to the drain pipeline;

[0015] The third interface of the second hydraulically controlled reversing valve is connected to the inlet of the throttle valve; the outlet of the throttle valve is connected to the inlet of the one-way valve, and the outlet of the one-way valve is also connected to the inlet of the flow meter; the overflow valve is connected in parallel between the third interface of the second hydraulically controlled reversing valve and the drain pipeline;

[0016] When the first hydraulically controlled reversing valve is switched to the working state and the second hydraulically controlled reversing valve is switched to the high-pressure state, water is delivered to the load terminal through the high-pressure branch; when the first hydraulically controlled reversing valve is switched to the working state and the second hydraulically controlled reversing valve is switched to the low-pressure state, water is delivered to the load terminal through the low-pressure branch;

[0017] When the first hydraulic control reversing valve switches to the unloading state, the water flow is unloaded through the drain pipeline.

[0018] Furthermore, the constant differential pressure compensation flow control valve is an electro-hydraulic proportional control valve, and the signal of the pilot proportional control module is used to adjust the opening of the valve port to achieve stepless flow regulation.

[0019] Furthermore, the power source system further includes a safety valve and an accumulator. The safety valve is connected to the water outlet pipeline of the mud pump to limit the system pressure, and the accumulator is connected to the water outlet pipeline to stabilize the water supply pressure.

[0020] Furthermore, a pressure sensor is also provided in the power source system.

[0021] Furthermore, there is one or more adaptive control water supply mechanisms, and each adaptive control water supply mechanism corresponds to a water supply branch, and the flow of each branch is independently controlled.

[0022] Furthermore, the electro-hydraulic pilot control system further includes a pressure reducing valve. The pressure reducing valve takes oil from the drilling rig or hydraulic equipment and supplies hydraulic oil to the pilot proportional control module, the first electromagnetic reversing valve and the second electromagnetic reversing valve. The oil supply flow is not less than 15 L / min, and the oil supply pressure is not less than 5 MPa.

[0023] A control method for the adaptive control water supply system for underground coal mine drilling as described above. The working states of the adaptive control water supply system for underground coal mine drilling include a standby state, a high-pressure water supply state, and a low-pressure water supply state. The control methods for each working state are as follows:

[0024] Standby state: The pilot proportional control module outputs the minimum signal, the first electromagnetic reversing valve loses power, the first hydraulic control reversing valve switches to connect to the drain pipeline, and the water flow is unloaded through the drain pipeline.

[0025] High-pressure water supply state: The first electromagnetic reversing valve is powered on, the first hydraulic control reversing valve switches to the working state, the second electromagnetic reversing valve loses power, the second hydraulic control reversing valve switches to the high-pressure branch, the water flow is transported to the load terminal through the high-pressure branch, and the electro-hydraulic pilot control system forms a closed-loop control with the flow meter through the pilot proportional control module, and adaptively adjusts the water supply flow according to the demand of the load terminal.

[0026] Low-pressure water supply state: The first electromagnetic reversing valve is powered on, the first hydraulic control reversing valve switches to the working state, the second electromagnetic reversing valve is powered on, the second hydraulic control reversing valve switches to the low-pressure branch, the water flow is transported to the load terminal through the low-pressure branch, and the electro-hydraulic pilot control system forms a closed-loop control with the flow meter through the pilot proportional control module, and adaptively adjusts the water supply flow according to the demand of the load terminal.

[0027] Furthermore, in the low-pressure water supply state, the opening of the overflow valve is adjusted to limit the low-pressure water supply pressure.

[0028] Furthermore, the high-pressure water supply state is used for working conditions such as coal flushing in coal mines, mechanical cavity formation drilling, hard rock impact drilling, directional drilling, or other high-pressure and large-flow water supply.

[0029] Furthermore, the low-pressure water supply state is used for working conditions such as borehole slag discharge in coal mines or other low-pressure and small-flow water supply.

[0030] The beneficial effects of the present invention are as follows:

[0031] A self-adaptive control water supply system and its control method for boreholes in coal mines proposed by the present invention significantly improve the performance and adaptability of the water supply system in borehole construction in coal mines by introducing constant pressure difference compensation flow control technology and an electro-hydraulic pilot control system. Compared with the prior art, it has the following significant technical advantages and beneficial effects:

[0032] 1. Achieve self-adaptive and precise adjustment of water supply flow rate, and solve the problem of flow rate matching under load changes

[0033] The present invention uses a constant pressure difference compensation flow control valve as the core control element, and forms a closed-loop control system in cooperation with a pilot proportional control module and a flow meter, which can adaptively adjust the water supply flow rate according to the real-time change of the drilling load. Whether it is a high-pressure and large-flow working condition (such as coal flushing, hard rock impact drilling, directional drilling, water pressure requirement 6 - 15 MPa, flow rate 150 - 300 L / min), or a low-pressure and small-flow working condition (such as borehole slag discharge), the system can ensure the precise matching of water volume and actual demand through the stepless adjustment function of the electro-hydraulic proportional control valve. This characteristic effectively solves the problems in the prior art such as blockage of coal slag in the borehole due to insufficient water volume, or waste of resources and difficulty in back-end slag-water separation caused by excessive water volume, thereby improving the stability and efficiency of borehole construction.

[0034] 2. Support simultaneous operation of multiple drill fields, and eliminate water supply interference and "water grabbing" phenomenon

[0035] The self-adaptive control water supply mechanism of the present invention designs independent high-pressure and low-pressure branches, and realizes flexible switching and independent control between branches through the first hydraulic control reversing valve and the second hydraulic control reversing valve. The system supports the parallel operation of one or more self-adaptive control water supply mechanisms, each mechanism corresponding to a water supply branch, and the flow rates of each branch do not interfere with each other. This design completely eliminates the water pressure fluctuation and "water grabbing" phenomenon in the traditional water supply network caused by multiple drill fields sharing the same water source. Especially in the operation of high-position drill fields with a large slope and long distance in the bottom extraction roadway, it can ensure stable water pressure and flow rate supply. Compared with the existing "one-to-one" high-pressure pump station or centralized liquid supply system, the present invention significantly improves the equipment utilization rate and the collaborative operation ability of multiple drill fields.

[0036] 3. Optimize the system structure to reduce the occupation of roadway space and the burden of equipment transfer

[0037] The present invention integrates the design of the power source system (frequency conversion motor and mud pump) and the adaptive control water supply mechanism, with a compact structure and small floor area, which is particularly suitable for the mobile operation requirements in narrow underground roadways. Compared with the existing centralized emulsion liquid supply system, this system avoids the equipment complexity and space occupation problems brought by multi-pump pressurization; compared with the "one-to-one" pumping station mode, it reduces the configuration requirements of multiple pumping stations, reduces the number of equipment transfers and maintenance costs. In addition, the design of the drain pipe of the system enables the water flow to be quickly unloaded in the standby state, further simplifying the operation process and improving the switching efficiency of the equipment under different working conditions.

[0038] 4. Improve the level of automatic control, with simple operation and safe and reliable

[0039] The present invention realizes the automatic management of the water supply process through the electro-hydraulic pilot control system. The pilot proportional control module combines the first electromagnetic directional valve and the second electromagnetic directional valve, which can automatically adjust the state of the hydraulic control directional valve according to the preset working conditions (such as standby, high-pressure water supply, low-pressure water supply), without frequent manual intervention, reducing the operation difficulty and the risk of human error. At the same time, the safety valve and accumulator equipped in the power source system respectively limit the system pressure and stabilize the water supply pressure to ensure the safety of the system during high-pressure operation; the pressure reducing valve provides stable hydraulic oil for the electro-hydraulic control components (oil supply flow ≥ 15L / min, pressure ≥ 5MPa), ensuring the control accuracy and reliability. These characteristics make the system operate more stably and have stronger adaptability in complex underground environments.

[0040] 5. Save water resources and reduce the burden on the underground sewage system

[0041] The present invention avoids the waste problem caused by excessive water volume in the traditional constant-pressure water supply system through the flow rate adaptive adjustment function. In the low-pressure water supply state, the opening adjustment of the overflow valve further limits the water supply pressure to ensure that the water volume output is consistent with the actual demand, reducing the situation of too high slag-water ratio in the punching return slag water. This not only facilitates the separation of slag and water and the measurement of coal slag at the back end, but also reduces water resource consumption and the operation load of the underground sump and sewage system, with significant environmental and economic benefits.

[0042] 6. Widely applicable to various working conditions and improve the construction flexibility

[0043] The water supply system of the present invention can flexibly switch between the high-pressure water supply state and the low-pressure water supply state to meet the requirements of various drilling conditions in coal mines. For example, the high-pressure water supply state is suitable for high-pressure and large-flow scenarios such as coal washing, mechanical cavity formation drilling, hard rock impact drilling, and directional drilling; while the low-pressure water supply state is suitable for low-pressure and small-flow scenarios such as drilling slag discharge. The versatility of the system enables it to cover a wide range of applications from ordinary rotary drilling to complex directional drilling. Compared with the single-function water supply systems in the prior art, it has higher construction flexibility and adaptability.

[0044] In summary, through the innovative application of the constant pressure difference compensation flow control technology and the electro-hydraulic pilot control system, the present invention realizes the dynamic matching of the water supply flow and the load demand, independent water supply for multiple drill fields, system structure optimization, and automatic control. Compared with the prior art, this system not only improves the drilling construction efficiency and safety, but also reduces the equipment cost, water resource waste, and environmental burden, showing significant technological progress and practical value, and providing an efficient and reliable water supply solution for drilling operations in coal mines.

[0045] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0047] Figure 1 is the schematic diagram of the adaptive control water supply system for underground coal mine drilling in the present invention.

[0048] Figure 2 is the schematic diagram of the electro-hydraulic pilot control system in the present invention.

[0049] Figure 3 is the schematic diagram of the constant pressure difference compensation flow control valve in the present invention.

[0050] Reference numerals: 1 - constant pressure difference compensation flow control valve; 2 - first hydraulic control reversing valve; 3 - second hydraulic control reversing valve; 4 - overflow valve; 5 - throttle valve; 6 - check valve; 7 - water pressure gauge; 8 - flowmeter; 9 - safety valve; 10 - pressure reducing valve; 11 - pilot proportional control module; 12 - first electromagnetic reversing valve; 13 - second electromagnetic reversing valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0052] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, rather than physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0053] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0054] Embodiment 1: Single-branch high-pressure directional drilling water supply system

[0055] Please refer to Figures 1 to 3 , in this embodiment, the present invention provides a coal mine underground drilling adaptive control water supply system, which is applicable to the single-branch water supply for directional drilling in coal mines. The specific technical solutions are as follows:

[0056] 1. Power source system

[0057] The power source system includes a variable-frequency motor, a mud pump, a safety valve 9 and an accumulator. The power of the variable-frequency motor is 75 kW, which drives the mud pump to supply water. The designed water supply pressure range is 6 - 10 MPa, and the maximum flow rate is 300 L / min. The safety valve 9 is connected to the outlet pipeline of the mud pump, and the set pressure is 12 MPa to limit the system pressure. The capacity of the accumulator is 10 L, which is connected to the outlet pipeline to stabilize the water supply pressure and eliminate pressure pulsation. The system is also equipped with a pressure sensor (accuracy ±0.1 MPa) to monitor the outlet water pressure in real time.

[0058] 2. Adaptive control water supply mechanism

[0059] The adaptive control water supply mechanism includes a high-pressure branch, a low-pressure branch and a drain pipe, which are formed by connecting a constant differential pressure compensated flow control valve 1, a first hydraulic control reversing valve 2, a second hydraulic control reversing valve 3, a water pressure gauge 7, a flow meter 8, a throttle valve 5, a check valve 6 and a relief valve 4 through pipelines. The specific structure and functions are as follows:

[0060] Constant differential pressure compensated flow control valve 1: An electro-hydraulic proportional control valve with a maximum flow rate of 300 L / min. Its inlet is connected to the outlet pipeline of the mud pump, and its outlet is connected to the first interface of the first hydraulic control reversing valve 2, used to control the total water volume entering the water supply branch.

[0061] First hydraulic control reversing valve 2: Designed with three interfaces. The first interface is connected to the outlet of the constant differential pressure compensated flow control valve 1, the second interface is connected to the first interface of the second hydraulic control reversing valve 3, and the third interface is connected to the drain pipe, used to switch between the working and unloading states.

[0062] Second hydraulic control reversing valve 3: Designed with three interfaces. The first interface is connected to the second interface of the first hydraulic control reversing valve 2, the second interface is connected to the inlet of the flow meter 8, and the third interface is connected to the inlet of the throttle valve 5, used to switch the on-off of the high-pressure branch and the low-pressure branch.

[0063] Throttle valve 5: Its inlet is connected to the third interface of the second hydraulic control reversing valve 3, and its outlet is connected to the inlet of the check valve 6, used to adjust the flow rate of the low-pressure branch.

[0064] Check valve 6: Its inlet is connected to the outlet of the throttle valve 5, and its outlet is connected to the inlet of the flow meter 8, used to prevent the reverse flow of high-pressure water.

[0065] Relief valve 4: Connected in parallel between the third interface of the second hydraulic control reversing valve 3 and the drain pipe, with a set pressure range of 1 - 5 MPa, used to limit the pressure of the low-pressure branch.

[0066] Water pressure gauge 7: With a measuring range of 0 - 15 MPa, installed on the pipeline in front of the flow meter 8, used to display the system water pressure.

[0067] Flow meter 8: With a measuring range of 0 - 350 L / min and an accuracy of ±1%, used to monitor the water supply flow rate in real time and feedback it to the control system.

[0068] 3. Electro-hydraulic pilot control system

[0069] The electro-hydraulic pilot control system includes a pilot proportional control module 11, a first electromagnetic directional control valve 12, a second electromagnetic directional control valve 13, and a pressure reducing valve 10. The pressure reducing valve 10 draws oil from the drilling rig hydraulic system, with an oil supply flow rate of 20 L / min and an oil supply pressure of 6 MPa. It reduces the pressure to 3 MPa and supplies it to the subsequent components. The pilot proportional control module 11 controls the valve opening of the constant differential pressure compensation flow control valve 1 through a current signal (4 - 20 mA). The first electromagnetic directional control valve 12 (a two-position four-way valve) controls the switching of the first hydraulic control directional control valve 2, and the second electromagnetic directional control valve 13 (a two-position four-way valve) controls the switching of the second hydraulic control directional control valve 3 to achieve flow adaptive adjustment under different working conditions.

[0070] 4. Control Method

[0071] In this embodiment, for the high-pressure water supply requirement of directional drilling, the following working states are designed:

[0072] Standby state: The pilot proportional control module 11 outputs the minimum signal of 4 mA, the first electromagnetic directional control valve 12 is de-energized, and the first hydraulic control directional control valve 2 switches to connect to the drain pipe. The water flow is unloaded to the sump through the drain pipe.

[0073] High-pressure water supply state: The first electromagnetic directional control valve 12 is energized, and the first hydraulic control directional control valve 2 switches to the working state (left position); the second electromagnetic directional control valve 13 is de-energized, and the second hydraulic control directional control valve 3 switches to the high-pressure branch (left position). The water flow path is: mud pump → constant differential pressure compensation flow control valve 1 → first hydraulic control directional control valve 2 → second hydraulic control directional control valve 3 → flowmeter 8 → load terminal (drilling tool). The flowmeter 8 monitors the flow rate (target 300 L / min), forms a closed-loop control with the pilot proportional control module 11, dynamically adjusts the valve opening, and the water pressure is stabilized at 8 MPa to meet the requirements of directional drilling.

[0074] Low-pressure water supply state (standby): The first electromagnetic directional control valve 12 is energized, and the first hydraulic control directional control valve 2 switches to the working state; the second electromagnetic directional control valve 13 is energized, and the second hydraulic control directional control valve 3 switches to the low-pressure branch. The water flow path is: mud pump → constant differential pressure compensation flow control valve 1 → first hydraulic control directional control valve 2 → second hydraulic control directional control valve 3 → throttle valve 5 → check valve 6 → flowmeter 8 → load terminal. The flow rate target is 50 L / min, and the relief valve 4 limits the pressure to 3 MPa.

[0075] This embodiment realizes a high-pressure water supply of 300 L / min and 8 MPa, meets the flushing and power requirements of directional drilling, the flow rate accurately matches the load change, the construction efficiency is increased by about 20%, and the water resource utilization rate is increased by about 15%.

[0076] Embodiment 2: Dual-branch high-pressure coal washing and low-pressure slag discharging water supply system

[0077] In this embodiment, the present invention provides a dual-branch water supply system applicable to high-pressure coal flushing and low-pressure slag discharging simultaneously in coal mines. The specific technical solution is as follows:

[0078] 1. Power source system

[0079] The power source system includes a variable-frequency motor, a slurry pump, a safety valve 9, and an accumulator. The variable-frequency motor has a power of 90 kW, drives the slurry pump to supply water, with a maximum pressure of 15 MPa and a maximum flow rate of 400 L / min. The safety valve 9 has a set pressure of 16 MPa and is connected to the outlet pipeline to limit the system pressure. The accumulator has a capacity of 15 L to stabilize the water supply pressure, and a pressure sensor (accuracy ±0.1 MPa) monitors the outlet water pressure in real time.

[0080] 2. Adaptive control water supply mechanism

[0081] The system is configured with two parallel adaptive control water supply mechanisms (branch 1 for high-pressure coal flushing and branch 2 for low-pressure slag discharging). Each branch includes a high-pressure branch, a low-pressure branch, and a drain pipeline, which are connected by a constant differential pressure compensated flow control valve 1, a first hydraulic control reversing valve 2, a second hydraulic control reversing valve 3, a water pressure gauge 7, a flow meter 8, a throttle valve 5, a check valve 6, and a relief valve 4 through pipelines. The specific parameters are as follows:

[0082] Branch 1 (high-pressure coal flushing):

[0083] The constant differential pressure compensated flow control valve 1: The maximum flow rate is 200 L / min, and the inlet is connected to the outlet pipeline of the slurry pump.

[0084] The first hydraulic control reversing valve 2: The second interface is connected to the first interface of the second hydraulic control reversing valve 3, and the third interface is connected to the drain pipeline.

[0085] The second hydraulic control reversing valve 3: The second interface is connected to the inlet of the flow meter 8, and the third interface is connected to the inlet of the throttle valve 5.

[0086] The water pressure gauge 7: The measuring range is 0 - 15 MPa; the flow meter 8: The measuring range is 0 - 250 L / min.

[0087] Branch 2 (low-pressure slag discharging):

[0088] The constant differential pressure compensated flow control valve 1: The maximum flow rate is 150 L / min.

[0089] The first hydraulic control reversing valve 2 and the second hydraulic control reversing valve 3: Have the same structure as branch 1.

[0090] The throttle valve 5: The adjustment range is 0 - 100 L / min; the relief valve 4: The set pressure is 3 MPa; the check valve 6: Prevents reverse flow.

[0091] The water pressure gauge 7: The measuring range is 0 - 5 MPa; the flow meter 8: The measuring range is 0 - 150 L / min.

[0092] Each branch is connected to the mud pump through an independent pipeline, and the flow rate is independently controlled.

[0093] 3. Electro-hydraulic pilot control system

[0094] The electro-hydraulic pilot control system includes a pressure reducing valve 10, a pilot proportional control module 11, a first electromagnetic directional control valve 12, and a second electromagnetic directional control valve 13. The pressure reducing valve 10 takes oil from the hydraulic equipment, with a supply flow rate of 25 L / min and a pressure of 7 MPa, which is reduced to 3 MPa. The pilot proportional control module 11 independently controls the constant differential pressure compensation flow control valves 1 of the two branches. The first electromagnetic directional control valve 12 and the second electromagnetic directional control valve 13 respectively control the first hydraulic control directional control valve 2 and the second hydraulic control directional control valve 3 of the two branches.

[0095] 4. Control method

[0096] This embodiment supports the simultaneous operation of two branches:

[0097] Standby state: The pilot proportional control module 11 outputs the minimum signal of 4 mA for both branches. The first electromagnetic directional control valve 12 is de-energized, and the first hydraulic control directional control valve 2 switches to the drain pipeline, and the water flow is unloaded.

[0098] High-pressure water supply (coal washing) for Branch 1: The first electromagnetic directional control valve 12 is energized, and the first hydraulic control directional control valve 2 switches to the working state; the second electromagnetic directional control valve 13 is de-energized, and the second hydraulic control directional control valve 3 switches to the high-pressure branch. The water flow path is: mud pump → constant differential pressure compensation flow control valve 1 → first hydraulic control directional control valve 2 → second hydraulic control directional control valve 3 → flowmeter 8 → load terminal. The flow rate is 200 L / min, the water pressure is 10 MPa, and it is adjusted by closed-loop control.

[0099] Low-pressure water supply (slag discharge) for Branch 2: The first electromagnetic directional control valve 12 is energized, and the first hydraulic control directional control valve 2 switches to the working state; the second electromagnetic directional control valve 13 is energized, and the second hydraulic control directional control valve 3 switches to the low-pressure branch. The water flow path is: mud pump → constant differential pressure compensation flow control valve 1 → first hydraulic control directional control valve 2 → second hydraulic control directional control valve 3 → throttle valve 5 → check valve 6 → flowmeter 8 → load terminal. The flow rate is 50 L / min, and the pressure is limited to 3 MPa by the overflow valve 4, and it is adjusted by closed-loop control.

[0100] This embodiment realizes simultaneous water supply for high-pressure coal washing at 200 L / min and 10 MPa and low-pressure slag discharge at 50 L / min and 3 MPa. Each branch does not interfere with each other, the construction efficiency is increased by about 25%, and the water resource utilization rate is increased by about 20%.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An adaptive control water supply system for underground drilling in coal mines, characterized in that: It includes a power source system and an adaptive control water supply mechanism connecting the power source system and a water supply branch, and an electro-hydraulic pilot control system for controlling the adaptive control water supply mechanism; The power source system includes a variable frequency motor and a mud pump, and the variable frequency motor drives the mud pump to provide water supply; The adaptive control water supply mechanism comprises a high-pressure branch, a low-pressure branch and a drain pipe; the high-pressure branch, the low-pressure branch and the drain pipe are formed by connecting a constant pressure difference compensation flow control valve, a first hydraulically controlled reversing valve, a second hydraulically controlled reversing valve, a water pressure gauge and a flow meter through pipes; the constant pressure difference compensation flow control valve is used to control the total amount of water entering the water supply branch; The first hydraulically controlled reversing valve is used to switch the working and unloading states of the adaptively controlled water supply mechanism; the second hydraulically controlled reversing valve is used to switch the high-pressure branch and the low-pressure branch in the adaptively controlled water supply mechanism on and off; The electro-hydraulic pilot control system includes a pilot proportional control module, a first electromagnetic reversing valve and a second electromagnetic reversing valve, which are respectively connected to the constant pressure difference compensation flow control valve, the first hydraulically controlled reversing valve and the second hydraulically controlled reversing valve through hydraulic pipelines to control their actions and realize adaptive flow regulation of high-pressure water supply and low-pressure water supply under different working conditions.

2. The underground coal mine drilling adaptive control water supply system according to claim 1 is characterized by: The first hydraulically controlled reversing valve and the second hydraulically controlled reversing valve both have three interfaces; the inlet of the constant pressure difference compensation flow control valve is connected to the water outlet pipeline of the mud pump, and the outlet is connected to the first interface of the first hydraulically controlled reversing valve; the second interface of the first hydraulically controlled reversing valve is connected to the first interface of the second hydraulically controlled reversing valve; the second interface of the second hydraulically controlled reversing valve is connected to the inlet of the flow meter; the outlet of the flow meter is connected to the load terminal; the water pressure gauge is arranged on the pipeline in front of the flow meter; the third interface of the first hydraulically controlled reversing valve is connected to the drain pipeline; The third interface of the second hydraulically controlled reversing valve is connected to the inlet of the throttle valve; the outlet of the throttle valve is connected to the inlet of the one-way valve, and the outlet of the one-way valve is also connected to the inlet of the flow meter; the overflow valve is connected in parallel between the third interface of the second hydraulically controlled reversing valve and the drain pipeline; When the first hydraulically controlled reversing valve is switched to the working state and the second hydraulically controlled reversing valve is switched to the high-pressure state, water is delivered to the load terminal through the high-pressure branch; when the first hydraulically controlled reversing valve is switched to the working state and the second hydraulically controlled reversing valve is switched to the low-pressure state, water is delivered to the load terminal through the low-pressure branch; When the first hydraulically controlled reversing valve is switched to the unloading state, the water flow is unloaded through the drain pipeline.

3. The coal mine underground drilling adaptive control water supply system according to claim 2 is characterized by: The constant pressure difference compensation flow control valve is an electro-hydraulic proportional control valve, which adjusts the valve opening by the signal of the pilot proportional control module to achieve stepless flow regulation.

4. The underground coal mine drilling adaptive control water supply system according to claim 1, characterized in that: The power source system further comprises a safety valve and an accumulator, wherein the safety valve is connected to the water outlet pipeline of the mud pump to limit the system pressure, and the accumulator is connected to the water outlet pipeline to stabilize the water supply pressure.

5. The underground coal mine drilling adaptive control water supply system according to claim 4 is characterized by: The power source system is also provided with a pressure sensor.

6. The underground coal mine drilling adaptive control water supply system according to claim 1, characterized in that: There are one or more adaptively controlled water supply mechanisms, each of which corresponds to a water supply branch, and the flow of each branch is independently controlled.

7. The coal mine underground drilling adaptive control water supply system according to claim 1, characterized in that: The electro-hydraulic pilot control system also includes a pressure reducing valve, which is connected to a drilling rig or hydraulic equipment to take oil and provides hydraulic oil to a pilot proportional control module, a first solenoid reversing valve and a second solenoid reversing valve, with an oil supply flow rate of ≮15L / min and an oil supply pressure of ≮5MPa.

8. A control method for an underground coal mine borehole adaptive control water supply system according to any one of claims 1 to 7, characterized in that: The working states of the underground coal mine borehole adaptive control water supply system include standby state, high pressure water supply state, and low pressure water supply state. The control methods of each working state are: Standby state: the pilot proportional control module outputs a minimum signal, the first electromagnetic reversing valve loses power, the first hydraulically controlled reversing valve switches to connect to the drain pipe, and the water flow is unloaded through the drain pipe; High-pressure water supply state: the first electromagnetic reversing valve is energized, the first hydraulically controlled reversing valve is switched to the working state, the second electromagnetic reversing valve is de-energized, the second hydraulically controlled reversing valve is switched to the high-pressure branch, and the water flow is delivered to the load terminal through the high-pressure branch. The electro-hydraulic pilot control system forms a closed-loop control with the flow meter through the pilot proportional control module, and the water supply flow is adaptively adjusted according to the demand of the load terminal; Low-pressure water supply state: the first solenoid reversing valve is energized, the first hydraulically controlled reversing valve is switched to the working state, the second solenoid reversing valve is energized, the second hydraulically controlled reversing valve is switched to the low-pressure branch, and the water flow is delivered to the load terminal through the low-pressure branch. The electro-hydraulic pilot control system forms a closed-loop control with the flow meter through the pilot proportional control module, and adaptively adjusts the water supply flow according to the demand of the load terminal.

9. The control method according to claim 8, characterized in that: In the low-pressure water supply state, the low-pressure water supply pressure is limited by adjusting the opening of the overflow valve.

10. The control method according to claim 8, characterized in that: The high-pressure water supply state is used for coal flushing, mechanical hole drilling, hard rock impact drilling, directional drilling or other high-pressure and large-flow water supply conditions in coal mines.

11. The control method according to claim 8, characterized in that: The low-pressure water supply state is used for underground coal mine drilling and slag removal or other low-pressure and small-flow water supply conditions.

Images