Horizontal drilling steady flow water discharge automatic constant flow measurement and control system

Abstract

The application discloses a kind of horizontal drilling steady flow automatic constant flow measurement and control system, it is related to horizontal drilling field, including: butt joint module, for sealing butt joint with the water discharge pipeline of horizontal drilling, the closed overflow passage of test medium is built;Acquisition module is used to real-time acquisition water discharge flow data in pipeline, and the flow data collected is synchronously transmitted to control module;The present application can quickly complete sealing butt joint with the water discharge pipeline of horizontal drilling in the field implementation of downhole horizontal drilling steady flow water discharge test, and automatically realizes constant flow water discharge control throughout, without manual repeated adjustment valve, substantially reduce downhole field operation intensity and safety risk.

Description

Technical Field

[0001] This invention relates to the field of horizontal drilling technology, specifically to an automatic constant flow measurement and control system for stable water discharge in horizontal drilling. Background Technology

[0002] Water release tests are an important means of obtaining hydrogeological parameters of aquifers (such as permeability, hydraulic conductivity, and storage capacity). Traditional water release tests are mostly conducted on vertical boreholes. During the test, the flow rate is usually manually controlled by adjusting valves to try to maintain a constant flow rate and meet the assumptions of steady-flow pumping tests. However, in actual operation, especially for horizontal boreholes or complex formation conditions, the water release flow rate will naturally decrease as the water level drops. Manually adjusting valves is difficult to maintain a constant flow rate in real time and accurately, causing the test data to deviate from the steady-flow theory and affecting the accuracy of parameter calculations.

[0003] Furthermore, existing flow control devices are mostly manual or simple electric valves, lacking a closed-loop control function that automatically adjusts the pipe flow area based on real-time flow feedback to maintain constant flow. For horizontal orifice tests, the device also needs to consider issues such as the sealing connection with the orifice and the synchronous and accurate measurement of the water level (water pressure) inside the orifice.

[0004] Therefore, there is an urgent need to develop a system that can automatically maintain a constant water flow rate and simultaneously and accurately record water pressure. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the present invention provides an automatic constant flow measurement and control system for stable water discharge in horizontal boreholes, which can effectively solve the problems of the existing technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions; This invention discloses an automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes, comprising: The docking module is used to seal and connect with the drain pipe of the horizontal borehole to create a closed flow channel for the test medium. The system comprises the following modules: a data acquisition module for real-time acquisition of water flow rate data within the pipeline and synchronous transmission of the acquired data to the control module; a monitoring module for real-time acquisition of water pressure data within the borehole test section and synchronous transmission of the acquired water pressure data to the storage module; a control module for receiving flow data from the real-time flow acquisition module, comparing it with a preset flow target value, generating and outputting adjustment control commands to the adjustment module; an adjustment module for receiving adjustment control commands from the closed-loop constant flow control module and changing its own valve port flow area to adjust the pipeline flow diameter; and a storage module for receiving and storing flow rate, water pressure data, and control command data to construct a test database. The acquisition module is interconnected with the monitoring module via a wireless network. The monitoring module is interconnected with the control module and the adjustment module via a wireless network. The adjustment module is interconnected with the storage module via a wireless network. The acquisition module and the adjustment module are connected in series in the test flow pipeline, and the monitoring module is installed in the target test section of the horizontal borehole.

[0007] Furthermore, the docking module includes an orifice docking flange, a multi-stage sealing assembly, a flow-through straight pipe section, and a pipe docking joint; The orifice flange is used to fix the orifice casing of the horizontal borehole. The multi-stage sealing assembly is nested in the gap between the orifice flange and the borehole drain pipe to block the external leakage channel of the test medium. Both ends of the straight flow pipe section are coaxially connected to the borehole drain pipe and the pipe connection joint, respectively. The pipe connection joint is used to seal the connection with the test flow pipe to form a continuous closed flow channel without abrupt changes in diameter.

[0008] Furthermore, the acquisition module includes a vortex flow sensing unit, a signal conditioning unit, and a data transmission unit; The vortex flow sensing unit is connected in series at the straight section of the test flow pipeline, and straight pipe sections that meet the flow stabilization requirements are provided upstream and downstream of it, for collecting the raw instantaneous flow signal of the test medium in the pipeline. The signal conditioning unit is used to filter, reduce noise, and perform linearization correction on the original signal, and output standard flow data; The data transmission unit is used to synchronously transmit standard traffic data to the control module and the storage module at a preset sampling frequency.

[0009] Furthermore, during the operation phase of the control module, it synchronously receives real-time flow data transmitted by the acquisition module and real-time water pressure data of the borehole test section transmitted synchronously by the monitoring module. Based on the received real-time data and the preset flow target value, it performs feedforward calculation and closed-loop correction calculation to generate opening adjustment parameters. The opening adjustment parameters are then converted into adjustment control commands that the adjustment module can recognize, and the adjustment control commands are synchronously output to the adjustment module and the storage module.

[0010] Furthermore, the feedforward solution and the closed-loop correction operation follow the following order: The theoretical relative valve opening that satisfies the preset flow target value is obtained through the feedforward calculation formula: ; The final valve opening adjustment increment is then obtained through a closed-loop correction formula: ; In the formula: This represents the theoretical relative opening of the valve during the k-th control cycle. The preset traffic target value; To regulate the valve's rated flow rate, i.e., when the valve is fully open and the pressure difference across the valve is the rated pressure difference. At that time, the flow rate of the medium passing through the valve; The effective real-time water pressure value of the borehole test section during the kth control cycle; This is the preset back pressure value at the outlet of the regulating valve; This represents the valve opening adjustment increment output during the k-th control cycle. This represents the actual relative opening degree of the valve during the (k-1)th control cycle; This refers to the real-time traffic data collected by the acquisition module during the k-th control cycle.

[0011] Furthermore, the regulating module includes an electric actuator, a sleeve-type regulating valve, and a valve position feedback unit; The sleeve-type regulating valve is connected in series in the test flow pipeline, and its valve stem is rigidly connected to the output end of the electric actuator unit on the same axis. The electric actuator is used to receive the adjustment control command output by the control module, drive the valve stem to make axial displacement, and change the flow area of ​​the valve port of the sleeve-type regulating valve. The valve position feedback unit is used to collect the actual valve position opening data of the regulating valve in real time and synchronously transmit the actual relative opening data back to the control module and the storage module.

[0012] Furthermore, the monitoring module includes at least three sets of water pressure sensing units, a signal synchronization unit, and a data uploading unit arranged at intervals along the axial direction of the horizontal borehole. Each set of water pressure sensing units is arranged at the front, middle, and rear ends of the borehole test section, respectively, to synchronously collect real-time water pressure data in the borehole at the corresponding locations. The signal synchronization unit is used to provide a unified time synchronization trigger signal for each set of water pressure sensing units, so that the timestamps of the water pressure data at each measuring point are consistent. The data uploading unit is used to synchronously transmit the synchronized water pressure data at each measuring point to the control module and the storage module. After receiving the water pressure data from each measuring point, the control module calculates the real-time water pressure value of the borehole test section used for feedforward calculation using the following formula: ; In the formula: The effective water pressure value of the borehole test section used in the kth control cycle; The total number of water pressure sensing units deployed is a positive integer not less than 3; The real-time water pressure data collected by the i-th water pressure sensing unit within the k-th control cycle; It is the arithmetic mean of the water pressure data at all measuring points within the k-th control cycle.

[0013] Furthermore, the storage module synchronously receives flow data from the acquisition module, water pressure data from the monitoring module, control command data from the control module, and valve position feedback data from the adjustment module. It aligns all the received multi-source data according to a unified timestamp to generate a multi-parameter associated dataset under the same time dimension, which serves as the storage content of the experimental database.

[0014] Compared with the known prior art, the technical solution provided by this invention has the following beneficial effects: This invention uses a leak-free closed flow channel to collect real-time water flow rate and water pressure data in the borehole test section. It can accurately compare the real-time flow rate with the preset target value and automatically adjust the pipe diameter to achieve closed-loop constant flow control during the water discharge process. This invention performs adaptive filtering, noise reduction, and linearization correction on flow data under complex operating conditions. While filtering out interference, it also ensures data smoothness and timely control response. It can simultaneously collect water pressure data from multiple points in the borehole and complete effective numerical calculations to support flow regulation. Furthermore, it can simultaneously store the entire process of test data and complete unified timestamp alignment to establish a test database, providing secure electronic data retention conditions for downhole borehole hydrogeological tests. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0016] Figure 1 This is a schematic diagram of an automatic constant flow measurement and control system for stable water discharge in horizontal boreholes. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] The present invention will be further described below with reference to embodiments.

[0019] Example: This embodiment provides an automatic constant flow measurement and control system for stable water discharge in horizontal boreholes, such as... Figure 1 As shown, it includes: The docking module is used to seal and connect with the drain pipe of the horizontal borehole to form a closed flow channel for the test medium and complete the sealed connection between the borehole opening and the test pipe. The docking module includes an orifice flange, a multi-stage sealing assembly, a flow straight pipe section, and a pipe docking joint; The orifice flange is used to fix the orifice casing of the horizontal borehole. The multi-stage sealing assembly is nested in the gap between the orifice flange and the borehole drain pipe to block the external leakage channel of the test medium. Both ends of the straight flow section are coaxially connected to the borehole drain pipe and the pipe butt joint, respectively. The pipe butt joint is used to seal the connection with the test flow pipe to form a continuous closed flow channel without abrupt changes in diameter. The data acquisition module is used to collect water flow data in the pipeline in real time and transmit the collected flow data synchronously to the control module. The acquisition module includes a vortex flow sensing unit, a signal conditioning unit, and a data transmission unit; The vortex flow sensing unit is connected in series at the straight section of the test flow pipeline, and straight pipe sections that meet the flow stabilization requirements are set both upstream and downstream of it, in order to collect the raw instantaneous flow signal of the test medium in the pipeline. The signal conditioning unit is used to filter, reduce noise, and linearize the raw signal, and output standard flow data; The data transmission unit is used to synchronously transmit standard traffic data to the control module and the storage module at a preset sampling frequency; The filtering process is a variable-step adaptive sliding window filtering process adapted to the drilling and water discharge conditions. The window length and update step size of the filtering sliding window are matched with the control cycle of the control module as the reference. When the real-time flow fluctuation is within the preset steady-state range, a long window length and small step size mode is used to smooth the small steady-state fluctuations. When the real-time flow change rate exceeds the preset dynamic threshold, it automatically switches to a short window length and large step size mode to filter out transient disturbances and spike interference while avoiding the introduction of control phase deviation, thus balancing data smoothness and control response timeliness. The noise reduction process is a coherent noise reduction process based on flow characteristic frequency matching and multi-source parameter linkage. Based on the calibration parameters of the vortex flow sensor unit, a mapping relationship between the flow value and the characteristic frequency of the Karman vortex street is established, and the effective signal characteristic frequency band that matches the current flow is locked in real time. Simultaneously linked with the water pressure data of the borehole test section and the real-time opening data of the regulating valve, stray noise that does not match the effective frequency band and is incoherent with water pressure and valve position changes is eliminated. Narrowband amplitude-preserving noise reduction is performed on the effective frequency band signal to improve the data signal-to-noise ratio without distorting the effective flow signal. The linearization correction process is a full-parameter linkage adaptive linearization correction process adapted to varying operating conditions: A baseline curve of the instrument coefficient for the vortex flow sensor unit under standard calibration conditions is pre-stored, where the instrument coefficient is the number of output pulses from the sensor unit corresponding to a unit volume flow rate. Simultaneously, real-time borehole water pressure data, medium temperature data collected by the monitoring module, and real-time valve opening data fed back by the regulation module are acquired. First, the density and kinematic viscosity of the test medium under the current operating conditions are calculated based on fluid dynamics characteristics to correct the instrument coefficient deviation caused by changes in medium properties. Then, the current flow Reynolds number is calculated based on real-time flow and pipeline parameters, and piecewise linear correction is performed for the inherent nonlinearity of the instrument in the low Reynolds number range. At the same time, the measurement deviation caused by upstream and downstream flow field distortion is corrected by combining the valve opening data, completing the basic linearization correction for all operating conditions. The monitoring module is used to collect water pressure data in the borehole test section in real time and transmit the collected water pressure data synchronously to the storage module. The monitoring module includes at least three sets of water pressure sensing units, a signal synchronization unit, and a data uploading unit arranged at intervals along the axial direction of the horizontal borehole. Each set of water pressure sensing units is arranged at the front, middle, and rear ends of the borehole test section, respectively, to synchronously collect real-time water pressure data in the borehole at the corresponding locations. The signal synchronization unit is used to provide a unified time synchronization trigger signal for each set of water pressure sensing units, so that the timestamps of the water pressure data at each measuring point are consistent. The data uploading unit is used to synchronously transmit the synchronized water pressure data at each measuring point to the control module and the storage module. After receiving water pressure data from each measuring point, the control module calculates the real-time water pressure value of the borehole test section used for feedforward calculation using the following formula: ; In the formula: The effective water pressure value of the borehole test section used in the kth control cycle; The total number of water pressure sensing units deployed is a positive integer not less than 3; The real-time water pressure data collected by the i-th water pressure sensing unit within the k-th control cycle; This is the arithmetic mean of the water pressure data from all measuring points within the kth control cycle; This formula takes the preset flow target value, the factory-calibrated rated flow and rated pressure difference of the regulating valve as the core benchmark, and synchronously links the real-time water pressure of the borehole test section with the preset back pressure at the outlet of the regulating valve to directly calculate the theoretical relative opening of the valve that meets the flow target. It can provide the appropriate opening benchmark in advance based on the real-time operating parameters, minimize the flow disturbance caused by borehole water pressure fluctuations, and effectively improve the response speed of constant flow control and the adaptation accuracy of the initial operating conditions. The control module is used to receive the traffic data transmitted by the real-time traffic acquisition module, compare and calculate it with the preset traffic target value, and generate and output adjustment control commands to the adjustment module. During the operation phase of the control module, it synchronously receives real-time flow data transmitted by the acquisition module and real-time water pressure data of the borehole test section transmitted synchronously by the monitoring module. Based on the received real-time data and the preset flow target value, it performs feedforward calculation and closed-loop correction calculation to generate opening adjustment parameters. It then converts the opening adjustment parameters into adjustment control commands that the adjustment module can recognize, and then synchronously outputs the adjustment control commands to the adjustment module and the storage module. The feedforward solution and closed-loop correction operation follow the following rules: The theoretical relative valve opening that satisfies the preset flow target value is obtained through the feedforward calculation formula: ; Based on the theoretical valve opening obtained from the feedforward calculation, the above formula combines the deviation between the preset flow target and the real-time collected flow to make proportional adjustments, and simultaneously links the actual relative valve opening of the previous control cycle to make deviation corrections. Finally, it outputs the valve opening adjustment increment. This not only retains the fast response advantage of feedforward control, but also completely eliminates the theoretical deviation, operating condition drift and valve execution error of the feedforward calculation through closed-loop feedback. This enables a deep integration of fast feedforward prediction and precise closed-loop correction, allowing flow control to quickly adapt to changes in operating conditions and stably lock the preset target value, effectively avoiding the overshoot and oscillation problems that are prone to occur in traditional PID control. The final valve opening adjustment increment is then obtained through a closed-loop correction formula: ; The above formula for calculating the valve opening adjustment increment is based on water pressure data collected synchronously from multiple measuring points in the borehole. First, the arithmetic mean of all measuring point data is calculated, and then the standard deviation term of the measuring point data is subtracted to obtain the effective water pressure value used for feedforward calculation. This eliminates the random error of single measuring point data and the systematic deviation caused by uneven axial water pressure distribution in the borehole by using the average of multiple measuring points. It also avoids the interference of abnormally high measuring points on feedforward calculation by the deviation subtraction step, making the water pressure reference used for feedforward control more closely match the actual effective water supply pressure in the borehole. This improves the accuracy of feedforward calculation and the anti-interference ability of the system from the source. In the formula: The theoretical relative opening of the valve in the k-th control cycle is dimensionless and ranges from 0 to 1. The preset flow rate target value is expressed in m³ / h. To regulate the valve's rated flow rate, i.e., the valve is fully open (relative opening degree is 1) and the pressure difference across the valve is the rated pressure difference. At that time, the flow rate of the medium flowing through the valve is expressed in m³ / h, which is an inherent parameter specified by the valve manufacturer. The effective real-time water pressure value of the borehole test section during the kth control cycle is expressed in MPa. This is the preset back pressure value at the outlet of the control valve, in MPa, and is a preset fixed parameter of the system. This represents the valve opening adjustment increment output during the k-th control cycle. This represents the actual relative opening degree of the valve during the (k-1)th control cycle; This represents the real-time flow data collected by the acquisition module during the k-th control cycle, in m³ / h. The regulating module is used to receive the regulating control command output by the closed-loop constant current control module and change its own valve port flow area to regulate the flow diameter of the pipeline. The control module includes an electric actuator, a sleeve-type control valve, and a valve position feedback unit; A sleeve-type regulating valve is connected in series in the test flow pipeline, and its valve stem is rigidly connected to the output end of the electric actuator coaxially. The electric actuator is used to receive the regulation control commands output by the control module, drive the valve stem to make axial displacement, and change the flow area of ​​the valve port of the sleeve-type regulating valve. The valve position feedback unit is used to collect the actual valve position opening data of the control valve in real time and synchronously transmit the actual relative opening data back to the control module and the storage module. The storage module is used to receive and store flow rate, water pressure, and control command data to build an experimental database. The storage module synchronously receives flow data from the acquisition module, water pressure data from the monitoring module, control command data from the control module, and valve position feedback data from the regulation module. It aligns all the received multi-source data according to a unified timestamp to generate a multi-parameter associated dataset under the same time dimension, which serves as the storage content of the experimental database. The acquisition module and the adjustment module are connected in series in the test flow pipeline, and the monitoring module is installed in the target test section of the horizontal borehole. The data acquisition module is interconnected with the monitoring module via a wireless network. The monitoring module is interconnected with the control module and the adjustment module via a wireless network. The adjustment module is interconnected with the storage module via a wireless network.

[0020] In this embodiment, the acquisition module collects real-time water flow data in the pipeline and transmits the collected flow data synchronously to the control module. The monitoring module collects water pressure data in the borehole test section and transmits the collected water pressure data synchronously to the storage module. The control module receives the flow data transmitted by the real-time flow acquisition module, compares it with the preset flow target value, generates and outputs adjustment control commands to the adjustment module. The adjustment module further receives the adjustment control commands output by the closed-loop constant flow control module, changes its own valve port flow area to adjust the pipeline flow diameter, and finally receives and stores the flow rate, water pressure acquisition data and control command data through the storage module to construct the test database.

[0021] In the above embodiments, the system can quickly complete the sealing connection with the borehole water discharge pipeline during the on-site implementation of the stable flow water discharge test in the downhole horizontal borehole. It can automatically achieve constant flow water discharge control throughout the process without the need for repeated manual valve adjustment, which greatly reduces the intensity of on-site operation and safety risks in the well. It can also accurately collect and correct flow rate and water pressure data, and simultaneously complete the standardized storage of data throughout the entire process to ensure the accuracy of test data and the stability of the test process.

[0022] See the example of an application of this system in the above embodiments: To prevent water hazards from the Ordovician limestone aquifer in the 1202 longwall face of a coal mine, a stable flow water discharge test needs to be conducted on the completed horizontal exploration borehole. The borehole has a final depth of 260m, and the test section is set between 180m and 240m. The test requires a constant water discharge flow rate of 25m³ / h to accurately obtain the hydrogeological parameters of the aquifer, while ensuring stable and controllable water pressure inside the borehole during the water discharge process, and preventing safety risks caused by sudden changes in flow rate.

[0023] During the on-site construction phase, the system's docking module is first used to achieve a sealed connection with the borehole drainage pipeline. The borehole flange and borehole casing are securely fixed with bolts. A multi-stage sealing assembly is nested at the connection gap between the flange and the drainage pipeline to completely block the external leakage channel of the test medium. Then, the straight flow section is connected to the pipeline joint to complete the coaxial and sealed connection between the borehole drainage pipeline and the test pipeline, forming a continuous closed flow channel without abrupt changes in diameter, thus avoiding interference from flow field distortion on the accuracy of subsequent flow rate acquisition.

[0024] After completing the pipeline connection, the functional modules were deployed according to the system design requirements: the acquisition module and the regulation module were installed in series in the test flow pipeline, and straight pipe sections that meet the requirements of stable flow were reserved upstream and downstream of the acquisition module to ensure the stability of flow acquisition; the three sets of water pressure sensing units of the monitoring module were deployed at 180m (front end), 210m (middle end) and 240m (rear end) of the borehole test section, respectively, to synchronously acquire real-time water pressure data at different locations in the test section.

[0025] After the system starts up, all modules enter the working state synchronously. The acquisition module acquires the instantaneous flow rate of the test medium in the pipeline in real time through the vortex flow sensor unit, and simultaneously completes filtering, noise reduction and linearization correction processing adapted to the field conditions, outputs standard flow data, and transmits it synchronously to the control module and storage module at the preset sampling frequency; the monitoring module provides a unified time synchronization trigger signal to the three sets of water pressure sensor units through the signal synchronization unit to ensure that the timestamps of the water pressure data at each measuring point are completely consistent. The synchronously acquired water pressure data at each measuring point is transmitted to the control module and storage module in real time through the data upload unit.

[0026] After receiving real-time flow data and water pressure data from various measuring points in the borehole, the control module first calculates the effective real-time water pressure value of the borehole test section within the corresponding control cycle based on the multi-measuring point water pressure data. Then, it completes the feedforward calculation by combining the preset flow target value of 25 m³ / h, directly obtaining the theoretical relative opening of the valve that meets the target flow requirement. Subsequently, it completes the closed-loop correction calculation by combining the actual relative opening of the valve in the previous control cycle and the deviation between the real-time collected flow and the target flow, obtaining the final valve opening adjustment increment, and converting it into an adjustment control command that the adjustment module can recognize, which is then synchronously output to the adjustment module and the storage module.

[0027] After receiving the control command, the regulating module drives the valve stem of the sleeve-type regulating valve to make precise axial displacement by the electric actuator, changing the flow area of ​​the valve port to adjust the flow diameter of the pipeline; at the same time, the valve position feedback unit collects the actual valve position opening data of the regulating valve in real time and transmits it back to the control module and the storage module to form a complete closed-loop constant flow control link.

[0028] During this 8-hour steady-flow water discharge test, the system achieved fully automatic constant flow control without manual intervention. Even when the water pressure fluctuated dynamically within the borehole test section, the system could quickly adjust and respond, consistently maintaining the actual discharge flow rate near the preset target value of 25 m³ / h. The steady-state flow control deviation did not exceed ±2%, fully meeting the specifications for hydrogeological tests in coal mines.

[0029] Throughout the experiment, the storage module synchronously receives flow data from the acquisition module, water pressure data from the monitoring module, control command data from the control module, and valve position feedback data from the regulation module. It aligns all the multi-source data according to a unified timestamp, generating a multi-parameter associated dataset under the same time dimension, thus completely preserving the original data of the entire experiment.

[0030] In summary, this embodiment of the system uses a leak-free, closed flow channel to collect real-time water flow rate and water pressure data in the borehole test section. It can accurately compare the real-time flow rate with the preset target value and automatically adjust the pipeline diameter to achieve closed-loop constant flow control during the water discharge process. At the same time, it performs adaptive filtering, noise reduction, and linearization correction on the flow data under complex operating conditions, filtering out interference while ensuring data smoothness and timely control response. It can simultaneously collect water pressure data from multiple points in the borehole and complete effective numerical calculations to support flow regulation. Furthermore, it can simultaneously store the entire process of test data and complete unified timestamp alignment to establish a test database, providing secure electronic data retention conditions for downhole borehole hydrogeological tests.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic constant flow measurement and control system for stable water discharge in horizontal boreholes, characterized in that, include: The docking module is used to seal and connect with the drain pipe of the horizontal borehole to create a closed flow channel for the test medium. The data acquisition module is used to collect water flow data in the pipeline in real time and transmit the collected flow data synchronously to the control module. The monitoring module is used to collect water pressure data in the borehole test section in real time and transmit the collected water pressure data synchronously to the storage module. The control module is used to receive the traffic data transmitted by the real-time traffic acquisition module, compare and calculate it with the preset traffic target value, and generate and output adjustment control commands to the adjustment module. The regulating module is used to receive the regulating control command output by the closed-loop constant current control module and change its own valve port flow area to regulate the flow diameter of the pipeline. The storage module is used to receive and store flow rate, water pressure, and control command data to build an experimental database. The acquisition module and the adjustment module are connected in series in the test flow pipeline, and the monitoring module is installed in the target test section of the horizontal borehole.

2. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The docking module includes an orifice flange, a multi-stage sealing assembly, a flow straight pipe section, and a pipe docking joint. The orifice flange is used to fix the orifice casing of the horizontal borehole. The multi-stage sealing assembly is nested in the gap between the orifice flange and the borehole drain pipe to block the external leakage channel of the test medium. Both ends of the straight flow pipe section are coaxially connected to the borehole drain pipe and the pipe connection joint, respectively. The pipe connection joint is used to seal the connection with the test flow pipe to form a continuous closed flow channel without abrupt changes in diameter.

3. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The acquisition module includes a vortex flow sensing unit, a signal conditioning unit, and a data transmission unit; The vortex flow sensing unit is connected in series at the straight section of the test flow pipeline, and straight pipe sections that meet the flow stabilization requirements are provided upstream and downstream of it, for collecting the raw instantaneous flow signal of the test medium in the pipeline. The signal conditioning unit is used to filter, reduce noise, and perform linearization correction on the original signal, and output standard flow data; The data transmission unit is used to synchronously transmit standard traffic data to the control module and the storage module at a preset sampling frequency.

4. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, During the operation phase of the control module, it synchronously receives real-time flow data transmitted by the acquisition module and real-time water pressure data of the borehole test section transmitted synchronously by the monitoring module. Based on the received real-time data and the preset flow target value, it performs feedforward calculation and closed-loop correction calculation to generate opening adjustment parameters. The opening adjustment parameters are then converted into adjustment control commands that the adjustment module can recognize, and the adjustment control commands are synchronously output to the adjustment module and the storage module.

5. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 4, characterized in that, The feedforward solution and closed-loop correction operation follow the following: The theoretical relative valve opening that satisfies the preset flow target value is obtained through the feedforward calculation formula: ； The final valve opening adjustment increment is then obtained through a closed-loop correction formula: ； In the formula: This represents the theoretical relative opening of the valve during the k-th control cycle. The preset traffic target value; To regulate the valve's rated flow rate, i.e., when the valve is fully open and the pressure difference across the valve is the rated pressure difference. At that time, the flow rate of the medium passing through the valve; The effective real-time water pressure value of the borehole test section during the kth control cycle; This is the preset back pressure value at the outlet of the regulating valve; This represents the valve opening adjustment increment output during the k-th control cycle. This represents the actual relative opening degree of the valve during the (k-1)th control cycle; This refers to the real-time traffic data collected by the acquisition module during the k-th control cycle.

6. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The regulating module includes an electric actuator, a sleeve-type regulating valve, and a valve position feedback unit; The sleeve-type regulating valve is connected in series in the test flow pipeline, and its valve stem is rigidly connected to the output end of the electric actuator unit on the same axis. The electric actuator is used to receive the adjustment control command output by the control module, drive the valve stem to make axial displacement, and change the flow area of ​​the valve port of the sleeve-type regulating valve. The valve position feedback unit is used to collect the actual valve position opening data of the regulating valve in real time and synchronously transmit the actual relative opening data back to the control module and the storage module.

7. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The monitoring module includes at least three sets of water pressure sensing units, a signal synchronization unit, and a data uploading unit arranged at intervals along the axial direction of the horizontal borehole. Each set of water pressure sensing units is arranged at the front, middle, and rear ends of the borehole test section, respectively, to synchronously collect real-time water pressure data in the borehole at the corresponding locations. The signal synchronization unit is used to provide a unified time synchronization trigger signal for each set of water pressure sensing units, so that the timestamps of the water pressure data at each measuring point are consistent. The data uploading unit is used to synchronously transmit the synchronized water pressure data at each measuring point to the control module and the storage module. After receiving the water pressure data from each measuring point, the control module calculates the real-time water pressure value of the borehole test section used for feedforward calculation using the following formula: ； In the formula: The effective water pressure value of the borehole test section used in the kth control cycle; The total number of water pressure sensing units deployed is a positive integer not less than 3; The real-time water pressure data collected by the i-th water pressure sensing unit within the k-th control cycle; It is the arithmetic mean of the water pressure data at all measuring points within the k-th control cycle.

8. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The storage module synchronously receives flow data from the acquisition module, water pressure data from the monitoring module, control command data from the control module, and valve position feedback data from the regulation module. It aligns all the received multi-source data according to a unified timestamp to generate a multi-parameter associated dataset under the same time dimension, which serves as the storage content of the experimental database.

9. The automatic constant flow measurement and control system for stable flow water discharge in horizontal boreholes according to claim 1, characterized in that, The acquisition module is interconnected with the monitoring module via a wireless network. The monitoring module is interconnected with the control module and the adjustment module via a wireless network. The adjustment module is interconnected with the storage module via a wireless network.

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