A diffusion coefficient measuring device based on pulse technology and a control system thereof

Abstract

The application discloses the technical field of water body pollutant characteristic research, and discloses a dispersion coefficient measuring device based on pulse technology and a control system thereof, which comprises a water pump, a mixing box, a culvert, a plurality of measuring wells, a plurality of probes, a height adjusting device, a buffer tank, a first electromagnetic valve and a second electromagnetic valve. The dispersion coefficient measuring device based on pulse technology and the control system thereof can improve the inversion precision of the dispersion coefficient, synchronously acquire dispersion parameters under different hydraulic gradients, realize high-sensitivity and rapid-response radioactivity measurement, greatly reduce manual operation errors, and improve experimental efficiency.

Description

Technical Field

[0001] This invention relates to the field of water pollutant characteristic research technology, specifically to a diffusion coefficient measuring device and its control system based on pulse technology. Background Technology

[0002] With the advancement of a series of projects in the Anhui irrigation area, the region's socio-economic development has led to a shift in water demand patterns from primarily agricultural production to a combination of urban domestic water use, industrial water use, and agricultural water use. This presents new requirements for determining the dispersion performance parameters of water bodies, the purification effect of water pollutants, and the migration patterns of pollutants. The dispersion coefficient is an indicator characterizing the strength of the dispersion phenomenon of soluble substances through a permeable medium. In the study of pollutant characteristics, investigating the dispersion of pollutants in different water bodies plays a crucial role in obtaining the dispersion performance parameters of water bodies, as well as the purification effect and migration patterns of pollutants. The determination of the dispersion coefficient mostly relies on the dispersion curve of tracers in aquifers. However, field measurements are time-consuming, labor-intensive, and difficult to obtain relevant data, easily leading to measurement errors. Therefore, it is necessary to design a dispersion coefficient measuring device based on pulse technology to simulate the pollutant dispersion process under different hydrological conditions and water depths indoors, in order to solve the aforementioned technical problems. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dispersion coefficient measuring device and its control system based on pulse technology, which can simulate the dispersion process of pollutants under different hydrological conditions and water depths indoors, thereby improving the accuracy of dispersion coefficient inversion.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides a diffusion coefficient measuring device based on pulse technology, comprising: a water pump, a mixing tank, a culvert, several measuring wells, several probes, a height adjustment device, a buffer tank, a first solenoid valve, a second solenoid valve, and several blocking mechanisms;

[0006] The water pump is connected to the input end of the mixing tank, the output end of the mixing tank is connected to one end of the culvert, the water pump is used to provide test water, the mixing tank is used to store and mix the radioactive tracer with the test water to obtain tracer water, the other end of the culvert is connected to the input end of the buffer tank, the output end of the buffer tank is connected to the outlet, the first solenoid valve is installed on the connecting pipe between the mixing tank and the culvert, and the second solenoid valve is installed on the connecting pipe between the culvert and the outlet.

[0007] The culvert is horizontal, and several measuring wells are installed parallel to each other and perpendicular to the culvert on its upper surface. The height of the measuring wells gradually decreases from the side near the mixing tank to the side near the buffer tank. Several blocking mechanisms are installed one-to-one at the bottom of each measuring well to block the water flow. Each blocking mechanism works independently. Each measuring well is equipped with a probe, which is suspended inside the measuring well by a height adjustment device. The probe is a solid-state scintillation detector used to calculate the activity concentration of radioactive tracers in the water.

[0008] Furthermore, the mixing tank includes a storage compartment, an inlet pipe, a mixing compartment, a gate, and an outlet pipe;

[0009] The outlet of the storage chamber is installed on the upper end of the mixing chamber via a slide rail, and the storage chamber is higher than the mixing chamber in the vertical direction. The gate is installed on the outlet of the storage chamber. The inlet pipe is installed on one side of the mixing chamber, and the outlet pipe is installed on the other side of the mixing chamber. The inlet end of the inlet pipe is connected to the outlet end of the water pump, and the outlet end of the outlet pipe is connected to the inlet end of the culvert.

[0010] The storage chamber is used to store radioactive tracers.

[0011] Furthermore, it also includes a stirrer, installed inside the mixing chamber, for mixing the test water and the radioactive tracer.

[0012] Furthermore, the tracer includes Br 82 and I 131 .

[0013] Furthermore, the height adjustment device includes pulleys, cables, brackets, and a motor;

[0014] The pulley is fixed to the top of the measuring well by a bracket. The cable passes around the pulley, with one end connected to the probe and the other end connected to the motor. The motor pulls the probe up and down along the measuring well by pulling the cable and the pulley's rotation.

[0015] Furthermore, it also includes water quality monitoring instruments, which are installed inside the culvert to monitor the water quality inside the culvert.

[0016] Furthermore, the buffer tank includes a tank body, several guide plates, an overflow port, and a drain port;

[0017] The guide vanes are arranged alternately inside the tank to reduce the water flow velocity and eliminate turbulence;

[0018] The overflow outlet is located at the top of the tank to maintain a stable water level; the drain outlet is located at the bottom of the tank to discharge sediment particles.

[0019] Secondly, the present invention provides a control system for the aforementioned pulse-based dispersion coefficient measuring device, comprising:

[0020] Data acquisition module; used for data acquisition;

[0021] The PLC control module is used to perform pulse injection, flow regulation, and probe lifting control.

[0022] The host computer analysis module is used to generate concentration-time curves and calculate the diffusion coefficient;

[0023] The communication module is used to achieve remote data synchronization and early warning.

[0024] Thirdly, the present invention provides a monitoring system, including the aforementioned control system, for dynamic early warning and prediction of water quality and hydrological processes.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0026] The dispersion coefficient measuring device and its control system based on pulse technology provided by this invention can simulate the dispersion process of pollutants under different hydrological conditions and water depths indoors by injecting tracer in a pulsed manner and combining it with the detection of multiple measuring wells under different working conditions, thereby improving the accuracy of dispersion coefficient inversion. During the experiment, only one measuring well is opened at a time, allowing the tracer to enter the corresponding measuring well, while the other measuring wells remain closed, thus avoiding crosstalk of water flow and cross-influence of tracer between different measuring wells, ensuring clear boundary conditions and independent and reliable measurement results for each experiment. By setting measuring wells with different heights or water depths, the concentration-time change process under different working conditions can be obtained, and the corresponding dispersion parameters can be inverted. Through the coordinated control of the buffer tank and the solenoid valve, the experimental water flow and water level conditions can be stabilized, reducing the impact of unstable disturbances on the experimental results. The probe continuously monitors the change in tracer concentration, realizing rapid response and continuous recording of the tracer migration process. The control system realizes experimental process control, data acquisition and analysis, reducing human operation errors and improving experimental efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the diffusion coefficient measuring device based on pulse technology provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of a measuring well provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the mixing box provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the buffer box provided in an embodiment of the present invention.

[0031] In the diagram: 1. Water pump; 2. Mixing tank; 31. First solenoid valve; 32. Second solenoid valve; 4. Measuring well; 5. Underground channel; 6. Buffer tank; 7. Pulley; 8. Cable; 9. Support; 10. Probe; 11. Water quality monitor; 12. Motor; 13. Switch; 14. Storage tank; 15. Inlet pipe; 16. Mixing tank; 17. Gate; 18. Agitator; 19. Outlet pipe; 20. Guide plate; 21. Overflow port; 22. Sewage outlet; 23. Blocking mechanism. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0033] In this embodiment of the invention, considering factors such as actual processing effect and the deformation coefficients of materials such as metal, plastic, and wood, as well as material price and quality, ABS plastic is selected to make the mixing chamber and buffer box, while PVC plastic is used to make the culvert and measuring well. Solenoid valves, water pumps, etc., are all commonly available models, but can also be customized according to requirements.

[0034] Example 1

[0035] This embodiment provides a diffusion coefficient measuring device based on pulse technology, including: a water pump 1, a mixing tank 2, a culvert 5, three measuring wells 4, three probes 10, a height adjustment device, a buffer tank 6, a first solenoid valve 31, a second solenoid valve 32, a water quality monitor 11, and a blocking mechanism 23.

[0036] The water quality monitor 11 is used to monitor parameters such as flow velocity, temperature, conductivity, pH value, and turbidity in the culvert in real time. By monitoring the stability of flow velocity and the baseline change of conductivity, it is determined whether the background conditions of the water body are stable. When the flow velocity fluctuation is less than ±3% and the conductivity change rate is less than ±1%, the water body is considered to have reached a stable operating condition. Conducting tracer experiments under stable hydraulic and background water quality conditions can avoid interference from unsteady hydrodynamics on the concentration-time curve, thereby improving the accuracy of dispersion coefficient calculation.

[0037] The water pump is used to provide test water, and the mixing tank 2 is used to store and mix the radioactive tracer with the test water to obtain tracer water.

[0038] In this embodiment, the workpiece specifications are set taking into account factors such as device size and load-bearing capacity, and can be set according to requirements.

[0039] The mixing tank 2 has dimensions of 50cm × 50cm × 50cm and includes two storage chambers 14, an inlet pipe 15, a mixing chamber 16, two gate valves 17, a stirrer 18, and an outlet pipe 19. The storage chambers 14 are designed to be 10cm × 10cm × 10cm in size. The outlet of the storage chamber 14 is mounted on the upper part of the mixing chamber 16 via a slide rail, and the storage chamber 14 is vertically higher than the mixing chamber 16. The two storage chambers 14 are symmetrically distributed. The two gate valves 17 are installed one-to-one on the outlet of the storage chamber 14. The inlet pipe 15 is installed on one side of the mixing chamber 16, and the outlet pipe 19 is installed on... On the other side of the mixing chamber 16; the input end of the inlet pipe 15 is connected to the output end of the water pump 1, and the output end of the outlet pipe 19 is connected to the input end of the culvert 5; the other end of the culvert 5 is connected to the input end of the buffer tank 6, and the output end of the buffer tank 6 is connected to the outlet. The first solenoid valve 31 is installed on the connecting pipe between the mixing chamber 2 and the culvert 5, and the second solenoid valve 32 is installed on the connecting pipe between the culvert 5 and the outlet. The stirrer 18 is installed inside the mixing chamber 16 for mixing test water and radioactive tracer. The storage chamber 14 is used to store radioactive tracer, commonly Br. 82 and I 131 As a tracer. Br 82 The half-life is 36 hours, and the peak energy is 0.78~1.47 MeV; I 131 The half-life is 8.04 days, and the energy peak is 0.3~0.64 MeV. These tracers have the following characteristics: ① no harm to personnel and the environment; ② very short half-life and low activity; ③ good measurability; ④ do not change the density of water. Similarly, other tracers can be used as substitutes.

[0040] The buffer tank 6 has dimensions of 70cm × 50cm × 50cm and is a rectangular box structure. It contains several guide vanes 20, some of which act as energy dissipation baffles. The guide vanes are arranged in a staggered pattern to reduce water flow velocity and eliminate turbulence. An overflow port 21 is located at the top of the tank to maintain a stable water level, and a drain port 22 is located at the bottom to discharge sediment particles. By adjusting the internal hydraulic conditions, the buffer tank changes the flow state at the outlet of the culvert from turbulent to a stable laminar flow, thereby ensuring that the water level fluctuation in the measuring well is controlled within ±2mm, improving the accuracy of dispersion parameter calculation. The buffer tank 6 can buffer the water flow within the device, stabilizing the water level in the measuring well 4.

[0041] The water quality monitoring instrument 11 is installed inside the culvert 5. It monitors parameters such as flow velocity, water temperature, conductivity, pH, and turbidity in real time to detect the water quality within the culvert 5. Flow velocity characterizes the intensity of convective transport, water temperature corrects for the molecular diffusion coefficient, conductivity monitors the stability of background ion concentration, and turbidity assesses the disturbance of suspended particles. The water body is considered to have reached steady-state conditions when the monitored parameters meet the following criteria: flow velocity fluctuation less than ±3%, conductivity change rate less than ±1%, and water temperature fluctuation less than ±0.5℃. Experiments are then conducted only after the water body reaches steady-state conditions. Conducting pulse tracer experiments under steady-state hydrodynamic and stable background water quality conditions ensures that the tracer concentration-time curve meets the steady-state assumptions of the convection-dispersion model, avoiding interference from unsteady hydrodynamics on the breakthrough curve morphology, thereby improving the accuracy and repeatability of the dispersion coefficient inversion calculation.

[0042] The culvert 5 is horizontal, with dimensions of 1.5m × 0.5m × 0.1m. Three measuring wells 4 are parallel to each other and installed perpendicular to the upper surface of the culvert 5. The height of the measuring wells 4 decreases uniformly from the side near the mixing tank 2 to the side near the buffer tank 6. Measuring wells at different heights are used to create different hydraulic residence times and head gradient conditions, thereby simulating the dispersion process of actual water at different spatial scales. By observing the differences in tracer concentration-time curves within wells at different heights, the accuracy of dispersion coefficient inversion can be improved, and spatial resolution can be enhanced. The upper limit of the measuring well height is preferably 1.5m, and the lower limit is preferably 0.2m. The specific height can be adjusted according to the experimental scale and hydraulic conditions. The three measuring wells 4 each have a radius of 20 cm and heights of 1 m, 0.6 m, and 0.3 m, respectively. Three blocking mechanisms 23 are installed one-to-one at the bottom of each measuring well 4 to block water flow. Each blocking mechanism 23 operates independently. Each measuring well 4 is equipped with a probe 10, which is suspended inside the measuring well 4 by a height adjustment device. The probe 10 is a solid-state scintillation detector with a NaI(Tl) scintillation crystal inside. When the γ-rays generated by the decay of the radioactive tracer enter the crystal, they interact with the crystal to generate scintillation photons, which are converted into electrical pulse signals by a photomultiplier tube. The activity concentration of the radioactive tracer in the water is calculated based on the pulse count rate per unit time.

[0043] In this embodiment, the height adjustment device includes a pulley 7, a cable 8, a bracket 9, and a motor 12. The pulley 7 is fixed to the top of the measuring well 4 by the bracket 9. The cable 8 passes around the pulley 7, with one end connected to the probe 10 and the other end connected to the motor 12. The motor 12 pulls the probe 10 up and down along the measuring well 4 by pulling the cable 8 and under the steering action of the pulley 7.

[0044] In this embodiment, a switch 13 is also provided to control the opening and closing of the motor 12.

[0045] The method of using the diffusion coefficient measuring device based on pulse technology provided in this embodiment includes:

[0046] Before use, put the radioactive tracer particles or stock solution used in the experiment into the storage chamber 14, and prepare enough water for testing. Select one measurement well to be tested as the current test well, and keep the other measurement wells closed by the blocking mechanism so that the tracer only enters the test space corresponding to the current test well, avoiding water flow crosstalk and tracer cross-influence between different measurement wells.

[0047] In operation, open the first solenoid valve 31 and the second solenoid valve 32, and use water pump 1 to pump water into the culvert 5 through the pipeline. Monitor the water quality using the water quality monitor 11 continuously. Once the water quality stabilizes, adjust the first solenoid valve 31 and the second solenoid valve 32 to control the water flow rate, ensuring the water level in the measuring well 4 remains relatively constant. Start the mixing tank 2, and according to the preset concentration parameters, open the gate 17 to release the target amount of particles or the target volume of radioactive tracer stock solution into the mixing chamber 16. Simultaneously, turn on the stirrer 18 to thoroughly mix the tracer and water. The mixed tracer water flows into the culvert 5 through the pipeline. After a period of time, close the gate 17 and use water pump 1 to pump the same flow rate of non-tracer water into the culvert 5 to propel the tracer water. After injecting tracer water, the motor 12 is started, the cable 8 is pulled, and the probe 10 is continuously moved up and down by the fixed pulley 7 fixed on the bracket 9. The probe 10 is used to measure the radioactivity. The probe 10 measures the activity through the scintillation process of the solid medium. The emitted pulse is transmitted to the computer through the cable 8 to observe the change of tracer content in the water over time.

[0048] During the experiment, the motor pulls the cable and drives the probe to move up and down synchronously via pulleys, ensuring that the probe and the water quality monitor maintain a relatively fixed position. The water quality monitor is used to observe the positional changes of the tracer water mass within the measurement well in real time, while the probe is used to simultaneously detect the tracer concentration or radioactivity at the corresponding location.

[0049] The probe movement employs a control method combining "preset survey + real-time tracking". Initially, the control system drives the probe and water quality monitor to perform vertical surveys along the depth of the measurement well according to preset time intervals, acquiring background signals and initial concentration distributions at different depths within the well. When the water quality monitor detects tracer water masses entering the measurement well, or when the probe detects a significant increase in tracer concentration, the control system switches from survey mode to tracking mode.

[0050] In tracking mode, the water quality monitor identifies the leading edge, main body, or areas of significant color / brightness change of the tracer water mass in real time. The control system adjusts the probe height based on the image recognition results, allowing the probe to move synchronously with the tracer water mass. Simultaneously, the probe provides real-time feedback on the tracer concentration change at its current location. When the probe detects a continued increase in concentration, it indicates that the probe is approaching the main tracer area. When the concentration reaches near its peak, the control system reduces the probe's movement speed, allowing the probe to continuously collect data near the high-concentration area. When the concentration begins to decrease, the control system continues to drive the probe to follow the tracer water mass backward or to the next monitoring location based on the water quality monitor's identification results and concentration change trend.

[0051] Throughout the test, the control system continuously records data such as probe height, test time, tracer concentration or radioactivity, tracer location detected by the water quality monitor, and water flow velocity, forming concentration-time data of the tracer migration process in the current measuring well. The single-well test is considered complete once the tracer concentration in the current measuring well returns to the background value or falls below a preset threshold.

[0052] After the current well test is completed, the well and connecting pipelines are flushed until the probe readings return to the background level. The current well is then closed, and the next well is opened, and the next set of tests under the same hydrological or water depth conditions is conducted using the same method. By sequentially conducting asynchronous tests on different wells, tracer migration and diffusion data under different hydrological and water depth conditions can be obtained, and the corresponding dispersion coefficients can be further retrieved.

[0053] During the tracer experiment, the probe, under the action of the height adjustment device, performs layered scanning along the depth direction of the measuring well. Indicates the distance along the direction of water flow. Indicates the vertical depth inside the measuring well. Indicates time, This represents the tracer activity concentration after background subtraction and detection efficiency correction. Data on the change of radioactive tracer activity concentration over time at different depths is continuously acquired. For the [missing information]... Each measurement well can generate concentration-time data. ,in Indicates the first Concentration data from individual measurement wells; after multiple measurement wells have been tested sequentially under the same or comparable hydraulic conditions, they can be further combined to form concentration-time datasets at different spatial locations. ,in For the first The distance between each measuring well along the direction of water flow.

[0054] When inverting the dispersion coefficient, the one-dimensional longitudinal convection-dispersion equation is preferentially used to describe the migration process of the tracer along the water flow direction:

[0055]

[0056] in, The average velocity in the direction of water flow. This represents the longitudinal dispersion coefficient. When it is necessary to consider the differences in concentration distribution at different depths within the measurement well, a two-dimensional convection-dispersion equation can be used for extension:

[0057]

[0058] in, This represents the vertical dispersion coefficient. If the vertical flow velocity is low during the experiment, the vertical convection term can be ignored; if significant vertical flow exists, it can be further introduced. The item needs to be revised.

[0059] In the specific calculation, firstly, based on the count rate or activity concentration data recorded by the probe, a breakthrough curve is extracted at a fixed measuring point or a fixed depth. Then, combining the measuring point location, flow rate, injection time, and initial tracer concentration, the peak concentration time, peak concentration, and curve broadening are calculated. Finally, the theoretical solution of the convection-diffusion equation is fitted using the least squares method or nonlinear regression method, with the goal of minimizing the residual between the measured concentration curve and the theoretical concentration curve, to invert and obtain the longitudinal diffusion coefficient. Furthermore, when multi-depth concentration data is available, the vertical dispersion coefficient can be estimated. .

[0060] Meanwhile, the probe's "real-time tracking" function is mainly used to capture the leading edge, main body, and peak region of the tracer water mass, avoiding missed detections in high-concentration areas. When performing breakthrough curve fitting, concentration-time series at fixed spatial locations or fixed depths should be used first to ensure that the inversion data is consistent with the fixed measurement point observation assumption of the convection-diffusion equation.

[0061] The practical application of this patented technology in the Sima Mountain Chuhe River Level IV Station Main Canal Project is mainly reflected in the following four specific implementation plans:

[0062] I. Regarding groundwater pollution prevention and control, for the risk of nitrate and pesticide leakage in densely populated agricultural areas within irrigation districts (such as fertilizer application areas), a group of pulsed test wells can be deployed, injecting appropriate amounts of tracers to simulate the pollutant migration process. Through a smart system, high-frequency monitoring and real-time recording of the spatiotemporal changes in tracer concentration can accurately quantify the pollutant transport path and rate. Then, an integrated GIS engine can simulate the impact range to identify high-risk pollution areas. Based on the obtained dispersion parameters and pollution range, the location of cutoff walls or the optimized layout of pumping wells can be scientifically guided, thereby significantly reducing groundwater treatment costs and effectively preventing drinking water source pollution.

[0063] II. Regarding the prevention and control of salinization in irrigation areas, single-well pulse devices are deployed in downstream saline-alkali land distribution areas to inject NaCl tracers and continuously monitor the dispersion parameters of salt ions such as Na⁺ and Cl⁻ in soil and groundwater. Combined with multi-source data access from the intelligent system, including radar precipitation, hydrological station API, and IoT sensors, the salt diffusion rate and accumulation trend are inverted. Then, the impact range is simulated using an integrated GIS engine. Based on this, the design of drainage ditch spacing and drainage schemes are optimized to improve salt removal efficiency and reduce the harm of salinity to crops.

[0064] Thirdly, regarding channel leakage assessment and repair, single-well pulse tests were conducted in key sections of the main canal. After injecting tracers, the concentration response of surrounding groundwater was monitored in real time. The leakage rate and range were inverted by analyzing the diffusion velocity and concentration decay characteristics. Combined with data quality monitoring in the intelligent system, missing values ​​were alerted, and abnormal values ​​were corrected, accurately locating severely leaking sections. Based on the test results, the priority and scope of anti-seepage lining projects can be guided, effectively reducing water conveyance losses and improving water resource utilization efficiency.

[0065] IV. Regarding the protection of ecologically sensitive areas, a pulse monitoring network will be deployed in the section of the Chuhe River wetland adjacent to the irrigation area to track the dispersion paths and spatiotemporal changes of pollutants such as nitrogen and phosphorus from agricultural non-point sources. By combining parameters such as adsorption coefficients and hysteresis factors with spatiotemporal data from the intelligent system, meteorological grid data will be matched with pump station locations to predict the residence time and migration patterns of pollutants in the wetland system, thus constructing a pollution early warning mechanism. This will ensure that the total phosphorus concentration in the wetland water is controlled below 0.2 mg / L, maintain biodiversity, and support the achievement of the "Clear Water Corridor" construction goal.

[0066] This patented technology provides a key scientific tool for the Sima Mountain irrigation system to overcome bottlenecks such as groundwater pollution, soil salinization, and canal leakage through in-situ, dynamic, and high-precision dispersion coefficient monitoring and transport simulation. It not only possesses strong engineering practicality and decision support capabilities but also demonstrates ecological sustainability, becoming a core technological support for the modernization and intelligent management of the irrigation area.

[0067] Example 2

[0068] This embodiment provides a control system for the diffusion coefficient measuring device based on pulse technology as described in Embodiment 1.

[0069] In this embodiment, the control system includes:

[0070] The system includes a data acquisition module, a PLC control module, a host computer analysis module, and a communication module.

[0071] The PLC control module is connected to the first solenoid valve 31, the second solenoid valve 32, the water pump 1, the agitator 18 and the motor 12 respectively, and is used to perform pulse injection, flow regulation and probe lifting control.

[0072] The data acquisition module is connected to the probe 10 and the water quality monitor 11 to collect radioactivity count rate and hydrodynamic parameters in real time.

[0073] The host computer analysis module has a built-in diffusion coefficient inversion algorithm (based on least squares fitting of one-dimensional convection diffusion equation), which automatically generates concentration-time curves and calculates the diffusion coefficient.

[0074] The communication module uses RS485 or wireless transmission to achieve remote data synchronization and early warning.

[0075] Example 3

[0076] This embodiment provides a monitoring system for dynamic early warning and prediction of water quality and hydrological processes. It includes a control system as described in Embodiment 2, which uses pulse technology to accurately measure the dispersion coefficient, enabling dynamic early warning and prediction of water quality and hydrological processes. Utilizing the dispersion coefficient and its derived transport laws, this system can be widely applied to groundwater pollution risk identification, salinization control, channel leakage assessment, and protection of ecologically sensitive areas, providing data support and decision-making basis for irrigation management, pollution control, and ecological protection. High-precision measurement of the dispersion coefficient is achieved specifically based on pulse testing technology. This module is deeply integrated into the system's underlying architecture, relying on real-time collected dispersion data to drive multiple intelligent analysis and early warning functions, including dynamic monitoring and trend analysis of multiple water quality parameters, data quality control (supporting missing value early warning and automatic correction of outliers), pollution diffusion simulation and spatial assessment (using a built-in GIS engine for multi-dimensional scenario simulation), and a real-time visualization dashboard for key indicators (dynamically updating core parameters such as dispersion rate and concentration distribution). By obtaining accurate dispersion coefficients, the system can further predict pollutant transport paths and make advanced assessments of ecological risks, providing quantitative decision support for regional water quality management, salinization control, seepage control, and early warning of ecological protection areas, and significantly improving the intelligence and responsiveness of the monitoring system.

[0077] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to explain the relative positional relationship and movement between components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0078] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0079] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A device for measuring the dispersion coefficient based on pulse technology, characterized in that, include: Water pump (1), mixing tank (2), culvert (5), several measuring wells (4), several probes (10), height adjustment device, buffer tank (6), first solenoid valve (31), second solenoid valve (32) and several blocking mechanisms (23); Wherein, the water pump (1) is connected to the input end of the mixing tank (2), the output end of the mixing tank (2) is connected to one end of the culvert (5), the water pump is used to provide test water, the mixing tank (2) is used to store and mix the radioactive tracer with the test water to obtain tracer water, the other end of the culvert (5) is connected to the input end of the buffer tank (6), the output end of the buffer tank (6) is connected to the outlet, the first solenoid valve (31) is installed on the connecting pipe between the mixing tank (2) and the culvert (5), and the second solenoid valve (32) is installed on the connecting pipe between the culvert (5) and the outlet; The culvert (5) is horizontal, and several measuring wells (4) are parallel to each other and installed perpendicular to the culvert (5) on the upper surface of the culvert (5). The height of the measuring wells (4) gradually decreases from the side near the mixing box (2) to the side near the buffer box (6). Several blocking mechanisms (23) are installed one-to-one at the bottom of each measuring well (4) to block the water flow. Each blocking mechanism (23) works independently. Each measuring well (4) is equipped with a probe (10). The probe (10) is suspended in the measuring well (4) by a height adjustment device. The probe (10) is a solid scintillation detector used to calculate the activity concentration of radioactive tracers in the water.

2. The diffusion coefficient measuring device based on pulse technology according to claim 1, characterized in that: The mixing tank (2) includes a storage compartment (14), an inlet pipe (15), a mixing compartment (16), a gate (17), and an outlet pipe (19). The outlet of the storage chamber (14) is mounted on the upper end of the mixing chamber (16) via a slide rail, and the storage chamber (14) is higher than the mixing chamber (16) in the vertical direction. The gate (17) is mounted on the outlet of the storage chamber (14). The inlet pipe (15) is mounted on one side of the mixing chamber (16), and the outlet pipe (19) is mounted on the other side of the mixing chamber (16). The inlet end of the inlet pipe (15) is connected to the outlet end of the water pump (1), and the outlet end of the outlet pipe (19) is connected to the inlet end of the culvert (5). The storage compartment (14) is used to store radioactive tracers.

3. The diffusion coefficient measuring device based on pulse technology according to claim 2, characterized in that: It also includes a stirrer (18), installed inside the mixing chamber (16), for mixing test water and radioactive tracer.

4. The diffusion coefficient measuring device based on pulse technology according to claim 2, characterized in that: The tracer includes Br 82 and I 131 .

5. The diffusion coefficient measuring device based on pulse technology according to claim 1, characterized in that: The height adjustment device includes a pulley (7), a cable (8), a bracket (9), and a motor (12). The pulley (7) is fixed to the top of the measuring well (4) by the bracket (9). The cable (8) passes around the pulley (7). One end of the cable (8) is connected to the probe (10) and the other end is connected to the motor (12). The motor (12) pulls the cable (8) and, under the steering action of the pulley (7), pulls the probe (10) up and down along the measuring well (4).

6. The diffusion coefficient measuring device based on pulse technology according to claim 5, characterized in that: It also includes a water quality monitoring instrument (11), which is installed inside the culvert (5) to monitor the water quality inside the culvert (5).

7. The diffusion coefficient measuring device based on pulse technology according to claim 1, characterized in that: The buffer tank (6) includes a tank body, several guide plates (20), an overflow port (21), and a drain port (22); The guide plates (20) are staggered in the box to reduce the water flow velocity and eliminate turbulence; The overflow port (21) is located at the top of the tank to maintain a stable water level; the drain port (22) is located at the bottom of the tank to discharge sediment particles.

8. A control system for a diffusion coefficient measuring device based on pulse technology as described in any one of claims 1-7, characterized in that, include: Data acquisition module; Used for data collection; The PLC control module is used to perform pulse injection, flow regulation, and probe lifting control. The host computer analysis module is used to generate concentration-time curves and calculate the diffusion coefficient; The communication module is used to achieve remote data synchronization and early warning.

9. A monitoring system, comprising the control system as described in claim 8, characterized in that: Used for dynamic early warning and prediction of water quality and hydrological processes.

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