A pressure dosing method and system for wastewater treatment

Abstract

The application relates to the technical field of sewage treatment, in particular to a pressure dosing method and system for sewage treatment. The application first establishes a stable gas pressure environment in a dosing device, and uses a high-precision pressure sensor to collect pressure data in real time; based on Bernoulli equation, a total pressure-dosing flow relationship model and a dosing pipe static pressure-dosing flow relationship model of the dosing device are constructed, and the applicable flow intervals of the two models are determined; after a target flow value is input, the corresponding model is selected according to the interval to calculate the target total pressure or static pressure value; the system adopts a hierarchical PID control strategy, a primary PID is responsible for total pressure adjustment, and a secondary PID is responsible for static pressure fine adjustment, so that the rapidity and accuracy of pressure control are cooperatively ensured; meanwhile, the actual dosing amount is continuously monitored through a flow measurement unit, and when the flow deviation exceeds the set range, a calibration program is automatically started, and the pressure-flow model parameters are optimized in real time; finally, through closed-loop control of pressure and flow, high-precision adjustment of the dosing flow is realized.

Description

A pressurized dosing method and system for wastewater treatment Technical Field

[0001] This application relates to the technical field of wastewater treatment, and in particular to a pressure dosing method and system for wastewater treatment. Background Technology

[0002] The dosing system is a crucial component of wastewater treatment processes, and its operational status directly impacts treatment effectiveness and operating costs. Currently, wastewater treatment projects primarily employ gravity dosing, metering pump dosing, and integrated dosing equipment, with metering pump dosing and gravity dosing being the most widely used. Large-scale wastewater treatment plants, on the other hand, often utilize intelligent dosing control systems.

[0003] Existing gravity dosing methods involve gravity-fed dosing from elevated tanks / storage basins, while metering pump dosing relies on mechanical lifting to transport the liquid. Integrated dosing equipment combines a dedicated stirring device with a metering device. Intelligent dosing control systems achieve precise adjustment of the dosing rate through a combination of online monitoring and automatic control, but require a large number of monitoring and measuring devices.

[0004] Existing technologies suffer from the following problems: First, dosing stability is poor, gravity dosing is difficult to control precisely, and metering pump dosing is easily affected by pipe scaling; second, flow measurement relies on contact sensors, which are prone to corrosion and scaling over long periods, leading to decreased accuracy; third, metering pumps have a limited flow range, impellers are prone to wear, and energy consumption is high; fourth, maintenance costs are high, flow meters require regular calibration, dosing pump failures are difficult to repair, and system operation requires advanced maintenance techniques. Therefore, there is an urgent need for a stable, reliable, and easy-to-maintain dosing method to overcome the technical problems of unstable dosing, flow measurement susceptible to corrosion and scaling, short metering pump lifespan, and high maintenance costs in existing technologies, so as to achieve precise control of the dosing process and long-term stable operation of the system. Summary of the Invention

[0005] To address the problem of unstable dosing in existing dosing methods, this application provides a pressure dosing method and system for wastewater treatment, employing the following technical solution:

[0006] In a first aspect, this application provides a pressurized dosing method for wastewater treatment, comprising the following steps:

[0007] Establish a stable gas pressure within the dosing device, and obtain the real-time pressure value within the dosing device through a pressure sensor;

[0008] Based on the real-time pressure value, a total pressure-dosing flow rate relationship model and a static pressure-dosing flow rate relationship model of the dosing device and a dosing pipe static pressure-dosing flow rate relationship model are established based on Bernoulli's equation, and the flow rate ranges corresponding to the two relationship models are determined respectively.

[0009] Based on the two relational models mentioned above, the target flow rate value is input, the corresponding flow range is determined according to the input target flow rate value, one of the relational models is selected, and the corresponding target total pressure or dosing pipe static pressure value is calculated.

[0010] Real-time monitoring of changes in the dosage within the dosing device; dynamic adjustment of the actual total pressure or the static pressure of the dosing pipe to maintain the target pressure value based on the changes in the dosage; wherein, the actual total pressure or the static pressure of the dosing pipe is adjusted by PID graded control.

[0011] The real-time dosing flow rate is calculated by measuring the dosage. When the flow rate deviation exceeds the preset range, automatic calibration is performed.

[0012] By adopting the above technical solution, this application first establishes a stable gas pressure environment within the dosing device and uses a high-precision pressure sensor to collect pressure data in real time. Then, based on Bernoulli's equation, it establishes a total pressure-dosing flow rate relationship model and a static pressure-dosing flow rate relationship model for the dosing device, and determines the flow rate range corresponding to each of the two relationship models. Based on the two relationship models, the target flow rate value is input, and the corresponding flow rate range is determined according to the input target flow rate value. One of the relationship models is selected to calculate the corresponding target total pressure or static pressure value of the dosing pipe. Subsequently, the system adopts a PID hierarchical control strategy, where the first-level PID controller is responsible for total pressure regulation, and the second-level PID controller is responsible for static pressure fine-tuning. The two controllers work together to ensure the speed and accuracy of pressure control. At the same time, the system continuously monitors the actual dosing amount through devices such as level gauges or mass flow meters. When the flow rate deviation is detected to exceed the set range, the calibration program is automatically started to optimize the pressure-flow rate model parameters in real time. Through closed-loop control of pressure and flow rate, combined with the hierarchical PID control strategy, high-precision regulation of the dosing flow rate is achieved.

[0013] Optionally, the real-time dosing flow rate can be calculated by measuring the dosage, including any of the following methods:

[0014] The liquid level change value is monitored at fixed time intervals, the liquid level change value is converted into a volume variable, and the actual dosing flow rate is calculated based on the volume variable.

[0015] The weight change value is monitored at fixed time intervals, the weight change value is converted into a volume variable, and the actual dosing flow rate is calculated based on the volume variable.

[0016] The inlet and outlet water time values ​​are monitored by a flow measuring device, and the actual dosing flow rate is calculated based on the fixed volume of the flow measuring device and the time values.

[0017] By adopting the above technical solutions, the system provides three optional measurement methods: The first is the liquid level measurement method, which uses a high-precision liquid level sensor to monitor the liquid level changes in the medicine storage tank at fixed time intervals, and converts the liquid level changes into volume changes based on the geometric parameters of the storage tank, thereby calculating the actual flow rate; the second is the weight measurement method, which uses a weighing sensor to monitor the weight changes in the medicine storage tank, and converts the weight changes into volume changes considering the density of the medicine, thus obtaining the actual flow rate; the third is the constant volume method, which uses a specially designed flow measuring device with a metering chamber of fixed volume, and calculates the actual flow rate by accurately measuring the time required for the medicine to fill and empty the metering chamber, combined with the known volume of the metering chamber. The liquid level method and the weight method avoid direct contact with the medicine, reducing the risk of equipment blockage and corrosion; the constant volume method has a simple structure and an intuitive and reliable measurement principle.

[0018] Optionally, automatic calibration can be performed, which includes the following steps:

[0019] The deviation rate between the actual dosing flow rate and the target flow rate value was calculated.

[0020] Adjust the total pressure of the dosing device or the static pressure of the dosing pipe according to the deviation rate to obtain a new target total pressure or static pressure of the dosing pipe to correct the flow deviation.

[0021] By adopting the above technical solution, the system first obtains the actual dosing flow rate through the aforementioned flow measurement method, compares it with the set target flow rate, and calculates the deviation rate. When the system detects that the deviation rate exceeds a preset threshold, it will automatically start the calibration procedure. During the calibration process, the system uses a progressive adjustment strategy to correct the total pressure of the dosing device or the static pressure of the dosing pipe based on the magnitude and direction of the deviation rate. If the actual flow rate is lower than the target value, the pressure is appropriately increased; otherwise, the pressure is decreased. Through multiple iterative adjustments, the flow deviation is adjusted until it returns to the allowable range. The pressure value at this point will be used as the new target pressure for subsequent dosing control. The system can autonomously identify and respond to flow deviations, and can complete parameter optimization without manual intervention. It has strong adaptability and can cope with various changes in operating conditions.

[0022] Optionally, the method may also include the following steps:

[0023] Establish separate historical databases for total pressure and chemical dosing flow rate, and for static pressure and chemical dosing flow rate in the dosing pipe.

[0024] Based on the data in the total pressure-dosing flow rate historical database, parameter fitting is performed to obtain an optimized total pressure-dosing flow rate model and a total pressure-dosing flow rate calibration range, which are used for overall flow rate regulation.

[0025] Based on the data in the historical database of static pressure and flow rate of the dosing pipe, the parameters are fitted to obtain the optimized static pressure and flow rate model of the dosing pipe and the calibration range of static pressure and flow rate of the dosing pipe. The static pressure and flow rate model of the dosing pipe is fine-tuned based on the minimum value of the total pressure and flow rate calibration range.

[0026] During automatic dosing operation, when it is necessary to adjust the dosing flow rate, the total pressure-dosing flow rate model is used first for flow rate adjustment; when the flow rate adjustment range is lower than the total pressure-dosing flow rate calibration range, the static pressure-dosing flow rate model of the dosing pipe is switched to be used for flow rate adjustment.

[0027] Adjust the total pressure value and fix it at the minimum value within the total pressure-dosing flow rate calibration range;

[0028] With a fixed total pressure parameter, the dosing flow rate can be further adjusted by changing the static pressure in the dosing pipe.

[0029] By adopting the above technical solution, the system first establishes historical databases for total pressure-flow rate and static pressure-flow rate, respectively, recording the pressure and flow rate correspondence under different operating conditions. Then, through data analysis and parameter fitting, optimized total pressure-flow rate models and static pressure-flow rate models are established, and their respective calibration ranges are determined. Among them, the static pressure-flow rate model uses the minimum value of the total pressure calibration range as the benchmark point for more precise flow rate adjustment. In actual operation, when a large range of flow rate adjustment is required, the total pressure-flow rate model is used first for rapid response. When the flow rate adjustment range is small and below the total pressure calibration range, the system first adjusts and fixes the total pressure to the minimum value of its calibration range, and then automatically switches to the static pressure-flow rate model to achieve more precise control by adjusting the static pressure of the dosing pipe. Through the graded control of total pressure and static pressure, both rapid response for large-range adjustments and high-precision control for small-range adjustments are ensured. The graded adjustment strategy avoids frequent adjustments of total pressure and improves the stability of the system.

[0030] Optionally, the method may also include the following steps:

[0031] A characteristic model of abnormal pressure fluctuations is established based on the aforementioned pressure-flow history database;

[0032] The real-time pressure value is compared with the abnormal pressure fluctuation feature model to identify pipeline leakage, pipeline blockage, or valve sticking.

[0033] The corresponding maintenance instructions are triggered based on the identification results.

[0034] By adopting the above technical solution, the system first extracts pressure fluctuation characteristics when different types of faults occur based on the historical pressure-flow database, and establishes an abnormal pressure fluctuation characteristic model. The model includes characteristic parameters of typical faults such as pipeline leakage, pipeline blockage, and valve jamming, such as pressure drop, pressure fluctuation frequency, and pressure rise rate. During operation, the system collects pressure data in real time and performs pattern matching and correlation analysis with the abnormal characteristic model. When the system detects that the pressure fluctuation characteristics highly match a certain type of fault mode, the system automatically identifies the specific fault type. Based on the identification results, the system then triggers corresponding maintenance instructions, such as alarm prompts, emergency response suggestions, or automatic protection measures.

[0035] Optionally, the method may also include the following steps:

[0036] The pressure energy released during the dosing process is converted into electrical energy through a micro-turbine energy recovery device.

[0037] The compressed air released during the dosing process is collected into the air storage tank to provide an auxiliary air source for the dosing process.

[0038] By adopting the above technical solution, a micro turbine energy recovery device is installed in the liquid decompression stage of the system. When the high-pressure liquid passes through the device, the pressure energy drives the turbine to rotate, which in turn drives the generator to generate electricity. This recovered electricity can be used to power the system's instruments or operate other auxiliary equipment. At the same time, the system is equipped with a compressed air recovery device, which collects the compressed air released during the dosing process into the air storage tank. The compressed air in the air storage tank can serve as a backup air source for the system, providing supplementation when the air pressure is insufficient.

[0039] Optionally, the actual total pressure or the static pressure of the dosing line can be adjusted through PID control in a graded manner, specifically including the following steps:

[0040] Step 1: Obtain the target pressure value and the real-time pressure value;

[0041] Step 2: When the deviation between the real-time pressure value and the target pressure value exceeds the first preset range, the fast adjustment mode is activated, and the pressure is adjusted using the first set of PID parameters;

[0042] Step 3: When the deviation between the real-time pressure value and the target pressure value is within the first preset range, the fine adjustment mode is activated, and the pressure is adjusted using the second set of PID parameters. The proportional coefficient and integral coefficient of the second set of PID parameters are less than the proportional coefficient and integral coefficient of the first set of PID parameters.

[0043] Step 4: Detect the duration of the real-time pressure value within the first preset range. When the duration reaches the preset duration, the pressure is determined to be stable. If the pressure fluctuation exceeds the second preset range in the fine adjustment mode, return to step 2.

[0044] Step 5: Continuously monitor the real-time pressure value. When the real-time pressure value exceeds the third preset range, finely adjust the opening of the dosing valve according to the preset time interval to keep the pressure within the third preset range.

[0045] By adopting the above technical solution, the system first collects pressure data in real time and compares it with the target pressure value. When the pressure deviation exceeds the first preset range, the system automatically starts the rapid adjustment mode, using a larger proportional and integral coefficient to ensure that the system can quickly approach the target value. When the pressure deviation enters the first preset range, the system switches to the fine adjustment mode, using smaller PID parameters for fine-tuning to avoid overshoot and oscillation. The system continuously monitors the stability of the pressure value. When the pressure remains within the first preset range for a preset time, it is determined that the pressure has reached a stable state. If the pressure fluctuation exceeds the second preset range during the fine adjustment process, the system automatically switches back to the rapid adjustment mode to readjust. After reaching a stable state, the system continues to monitor the pressure value. When it exceeds the third preset range, the system maintains the pressure within the allowable range by periodically fine-tuning the opening of the dosing valve. By using different control parameters at different stages, both the speed of adjustment and the accuracy of control are ensured, giving the system strong adaptive capabilities. At the same time, the periodic fine-tuning mechanism ensures the long-term stability of the system.

[0046] Secondly, this application provides a pressurized dosing system for wastewater treatment, comprising:

[0047] A dosing device, comprising a dosing tank and a pressure sensor disposed within the dosing tank, for detecting and acquiring real-time pressure values ​​within the dosing device;

[0048] The controller, electrically connected to the pressure sensor, is used to calculate the relationship model between total pressure or static pressure and dosing flow rate based on Bernoulli's equation, and to calculate the target total pressure or dosing pipe static pressure according to the relationship model.

[0049] A liquid level sensor is installed inside the dosing tank to monitor the liquid level in the dosing device in real time and calculate the actual amount of medicine added to the dosing tank; a weight sensor is installed at the bottom of the dosing tank to monitor the weight change of the medicine in the dosing device in real time and calculate the actual amount of medicine added to the dosing tank.

[0050] An electric proportional valve, electrically connected to the controller, is used to adjust the actual total pressure according to changes in liquid level via PID graded control; a proportional regulating valve, electrically connected to the controller, is used to adjust the static pressure of the dosing pipe according to changes in liquid level via PID graded control; and a flow measuring device is used to monitor and calculate the actual dosing flow rate of the dosing pipe.

[0051] The controller is also used to automatically calibrate by adjusting the actual dosing flow rate of the dosing pipe when a flow deviation is detected to exceed a preset range.

[0052] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the pressure dosing method for wastewater treatment described above.

[0053] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the pressure dosing method for wastewater treatment described above.

[0054] In summary, this application includes at least one of the following beneficial technical effects:

[0055] 1. This application first establishes a stable gas pressure environment within the dosing device, and uses a high-precision pressure sensor to collect pressure data in real time; based on Bernoulli's equation, it constructs a total pressure-dosing flow rate relationship model and a static pressure-dosing flow rate relationship model for the dosing device, and clarifies the applicable flow rate ranges for both; after inputting the target flow rate value, it selects the corresponding model to calculate the target total pressure or static pressure value according to its range; the system adopts a hierarchical PID control strategy, with the first-level PID responsible for total pressure regulation and the second-level PID responsible for static pressure fine-tuning, working together to ensure the speed and accuracy of pressure control; simultaneously, it continuously monitors the actual dosing amount through a flow measurement unit (level gauge method, weighing method, constant volume method, etc.), and automatically initiates a calibration program when the flow deviation exceeds the set range, optimizing the pressure-flow rate model parameters in real time; Ultimately, high-precision regulation of the dosing flow rate is achieved through closed-loop control of pressure and flow rate; 2. This application establishes a flow control system at two levels: total pressure and static pressure; the system first establishes an optimized historical database of total pressure-flow rate and static pressure-flow rate, and establishes corresponding models and calibration ranges through data analysis and parameter fitting, wherein the static pressure model is based on the minimum value of the total pressure calibration range; during operation, a hierarchical adjustment strategy is adopted: for large-range flow rate regulation, the total pressure model is used for rapid response; when the adjustment range is lower than the total pressure calibration range, the total pressure is fixed at the minimum value of the calibration range, and the static pressure model is switched to precise control; this hierarchical control scheme ensures both the speed of large-range adjustment and the high precision of small-range adjustment, while avoiding frequent adjustments of total pressure and improving system stability;

[0056] 3. This application employs a multi-level PID control strategy; the system compares pressure data with the target value in real time. When the deviation exceeds the first preset range, a fast adjustment mode is activated, using a larger PID parameter to quickly approach the target value; after entering the preset range, it switches to a fine adjustment mode, using a smaller PID parameter for fine-tuning; the system continuously monitors pressure stability, and when the pressure remains within the preset range for a certain period, it is determined to be stable; if a large fluctuation occurs during fine adjustment, it automatically switches back to the fast mode for readjustment; after reaching a stable state, when the pressure exceeds the third preset range, the valve opening is finely adjusted at regular intervals to maintain the pressure; by using different control parameters at different stages, a balance between rapid response and precise control is achieved, ensuring stable system operation. Attached Figure Description

[0057] Figure 1 is a schematic flowchart of a pressure dosing method for wastewater treatment according to an embodiment of this application;

[0058] Figure 2 is a schematic flowchart of step S140 in a pressure dosing method for wastewater treatment according to an embodiment of this application;

[0059] Figure 3 is a schematic flowchart of step S150 in a pressure dosing method for wastewater treatment according to an embodiment of this application;

[0060] Figure 4 is a schematic diagram of the dual-layer flow control process in a pressure dosing method for wastewater treatment according to an embodiment of this application;

[0061] Figure 5 is a schematic flowchart of a pressure dosing method for wastewater treatment according to an embodiment of this application for identifying faults;

[0062] Figure 6 is a schematic diagram of the energy recovery process in a pressure dosing method for wastewater treatment according to an embodiment of this application;

[0063] Figure 7 is a schematic diagram of a pressure dosing system for wastewater treatment according to an embodiment of this application;

[0064] Figure 8 is an internal structure diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0065] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to any or all possible combinations including one or more of the listed items.

[0066] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0067] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0068] In a first aspect, this application provides a pressure dosing method for wastewater treatment, referring to FIG1, which includes the following steps: S110, establishing a stable gas pressure in the dosing device, and obtaining the real-time pressure value in the dosing device by detecting the pressure sensor.

[0069] In this embodiment, the dosing device includes a dosing tank and a pressure sensor. The pressure sensor adopts a non-contact design and is installed in the gas phase space at the top of the dosing tank to avoid direct contact with the liquid drug.

[0070] Specifically, the system introduces compressed air into the dosing tank. A gradient air intake method is used, that is, the system first introduces air at a small flow rate to the initial pressure, and then gradually adjusts it to the target value after the pressure stabilizes. The pressure sensor continuously monitors the pressure inside the tank, and a stable state is considered reached when the pressure fluctuation value remains within a preset range.

[0071] S120. Based on the real-time pressure value, establish a total pressure-dosing flow rate relationship model and a static pressure-dosing flow rate relationship model for the dosing device based on Bernoulli's equation, and determine the flow rate range corresponding to the two relationship models respectively.

[0072] In this embodiment, the system is based on Bernoulli's equation. A pressure-flow relationship model was established. This model takes into account the effects of practical factors such as pipeline resistance and liquid level changes.

[0073] Specifically, pressure-flow calibration is performed before deployment. By changing the system pressure, the corresponding steady-state flow rate values ​​are recorded to establish a basic data set. A piecewise linear fitting method is used to establish the correspondence between pressure and flow rate. The fitting coefficient is set according to actual needs; in this embodiment, the fitting coefficient is set to 0.98.

[0074] S130. Input the target flow rate value based on two relational models, determine the corresponding flow range based on the input target flow rate value, select one of the relational models, and calculate the corresponding target total pressure or dosing pipe static pressure value.

[0075] In this embodiment, the system inputs the target flow rate value based on two relationship models, and calculates the required pressure value in reverse through the pressure-flow relationship.

[0076] Specifically, based on the input target flow rate value, the corresponding flow range is determined, and one of the relationship models is selected to calculate the corresponding target total pressure or dosing pipe static pressure value.

[0077] S140. Monitor the changes in the amount of chemical added in the dosing device in real time, and dynamically adjust the actual total pressure or the static pressure of the dosing pipe according to the changes in the amount of chemical added to maintain the target pressure value. The actual total pressure or the static pressure of the dosing pipe is adjusted by PID graded control.

[0078] In this embodiment, the system employs a two-stage regulation strategy of total pressure regulation and static pressure fine-tuning. Total pressure refers to the gas pressure inside the dosing tank, and static pressure refers to the liquid static pressure in the dosing pipe.

[0079] Specifically, the controller employs a PID hierarchical control strategy. When the pressure deviation is large, the total pressure is mainly changed by adjusting the air pressure regulating valve; when the pressure approaches the target value, precise control is achieved by fine-tuning the opening and closing angle of the dosing valve on the dosing pipe.

[0080] S150. The real-time dosing flow rate is calculated by measuring the dosing amount. When the flow rate deviation exceeds the preset range, automatic calibration is performed.

[0081] In step S150, the real-time dosing flow rate is calculated by measuring the dosage, including any of the following methods:

[0082] First, monitor the liquid level change value at fixed time intervals, convert the liquid level change value into a volume variable, and calculate the actual dosing flow rate based on the volume variable.

[0083] Specifically, the liquid level change refers to the change in the height of the liquid solution inside the dosing tank, while the volume change refers to the change in the volume of the liquid solution calculated based on the geometry of the dosing tank. The system records the liquid level value at preset time intervals and calculates the difference between the two measurements. The liquid level change is converted into a volume change based on the cross-sectional area of ​​the dosing tank, and the average flow rate is obtained by dividing by the time interval. When the storage tank has a non-standard geometric shape, the system performs the conversion calculation according to a pre-calibrated liquid level-volume conversion table.

[0084] Second, monitor the weight change value at fixed time intervals, convert the weight change value into a volume variable, and calculate the actual dosing flow rate based on the volume variable.

[0085] Specifically, the weight change refers to the total weight change of the dosing tank and the liquid medicine inside, which needs to be converted to volume based on the density of the liquid medicine. A weighing sensor is installed at the bottom of the dosing tank. The system records the weight change within a fixed time window and converts the weight change into a volume change based on the current density of the liquid medicine. Alternatively, a fixed weight difference method can be used, which records the time required for the weight to decrease by a fixed value (e.g., 10 kg), and the flow rate is calculated based on this time. The gravimetric method is not affected by the shape of the dosing tank and is suitable for storage tanks of various sizes.

[0086] Third, the inlet and outlet water time values ​​are monitored by a flow measuring device, and the actual dosing flow rate is calculated based on the fixed volume of the flow measuring device and the time value.

[0087] Specifically, a flow measurement device refers to a metering chamber with a fixed volume, and the inflow / outflow time value refers to the time interval between the filling and emptying of the metering chamber by the chemical solution. A fixed-volume metering device is installed in parallel on the dosing pipeline, and the flow direction of the chemical solution is controlled by a three-way valve. When flow measurement is required, the chemical solution is switched to the metering device. Level switches are installed at the upper and lower ends of the metering device to record the time difference between the arrival and departure of the chemical solution at the upper and lower level switches. The actual flow rate is obtained by dividing the calibrated volume of the metering device by the time difference.

[0088] In one embodiment, referring to Figure 2, step S140, adjusting the actual total pressure or the static pressure of the dosing pipe through PID control in a graded manner, specifically includes the following steps:

[0089] S141. Obtain the target pressure value and the real-time pressure value.

[0090] In this embodiment, the target pressure value refers to the system pressure setpoint calculated based on the flow demand, and the real-time pressure value refers to the current system pressure collected by the pressure sensor.

[0091] Specifically, the controller continuously collects data from the pressure sensor and calculates the deviation between the real-time pressure value and the target pressure value. The system automatically selects different control modes based on the magnitude of the deviation.

[0092] S142. When the deviation between the real-time pressure value and the target pressure value exceeds the first preset range, the fast adjustment mode is activated, and the pressure is adjusted using the first set of PID parameters.

[0093] In this embodiment, the first preset range defines the activation conditions for the fast adjustment mode. The first set of PID parameters uses a large proportional coefficient and integral coefficient for the fast adjustment phase.

[0094] Specifically, when the pressure deviation exceeds the first preset range, the system activates the rapid adjustment mode. In this mode, the proportional and integral coefficients are relatively large, enabling the controller to generate a strong adjustment effect, quickly changing the opening of the air pressure regulating valve and driving the system pressure closer to the target value.

[0095] S143. When the deviation between the real-time pressure value and the target pressure value is within the first preset range, the fine adjustment mode is activated, and the pressure is adjusted using the second set of PID parameters.

[0096] Among them, the proportional coefficient and integral coefficient of the second group of PID parameters are smaller than those of the first group of PID parameters.

[0097] In this embodiment, the fine adjustment mode uses the second set of PID parameters, whose proportional coefficient and integral coefficient are smaller than those of the fast adjustment mode, in order to achieve a smooth transition.

[0098] Specifically, once the pressure enters the first preset range, the system automatically switches to fine-tuning mode. In this mode, the proportional and integral parameters are reduced to decrease the intensity of the control action and prevent overshoot or oscillation. The pressure is then gradually stabilized near the target value through smooth adjustment.

[0099] Furthermore, this embodiment employs an improved parameter tuning method, obtaining the system's first-order plus-delay model parameters through step response testing. These parameters include: system gain Kp, which is the ratio of pressure change to valve opening change; system time constant T, which is the time required for the step response to reach 63.2% of its final steady-state value minus the delay time, where 63.2% is the characteristic value of the first-order system response, equal to 1 - 1 / e; and delay time L, which is the time interval from receiving the control signal to the start of the response. In fast adjustment mode, the first set of PID parameters is calculated as follows: proportional coefficient Kp1 = 0.8 × T / (L × Kp), integral time Ti1 = 1.5L, and derivative time Td1 = 0.4L. In fine adjustment mode, i.e., when the pressure deviation is no greater than 10%, the second set of PID parameters is calculated as follows: proportional coefficient Kp2 = 0.3 × T / (L × Kp), integral time Ti2 = 2T, and derivative time Td2 = 0.4L.

[0100] S144. Detect the duration of the real-time pressure value within the first preset range. When the duration reaches the preset duration, the pressure is determined to be stable. If the pressure fluctuation exceeds the second preset range in the fine adjustment mode, return to step S142.

[0101] In this embodiment, the system monitors the stability of the pressure value. The system is deemed to have reached a stable state after the pressure remains within a preset range for a preset duration.

[0102] Specifically, the system records the duration of the pressure value within a first preset range. When the duration reaches the preset value, the pressure adjustment is considered complete. If the pressure fluctuation exceeds a second preset range during fine adjustment, the system automatically switches back to the fast adjustment mode and restarts the adjustment.

[0103] S145. Circularly detect the real-time pressure value. When the real-time pressure value exceeds the third preset range, finely adjust the opening of the dosing valve according to the preset time interval to keep the pressure within the third preset range.

[0104] In this embodiment, the system enters the pressure stabilization phase, maintaining pressure stability through periodic fine-tuning.

[0105] Specifically, the system continuously monitors the pressure value, and when the pressure exceeds the third preset range, it fine-tunes the opening of the regulating valve at fixed time intervals. For static pressure control in the dosing line, pressure stabilization is achieved by fine-tuning the opening angle of the dosing valve.

[0106] In one embodiment, referring to Figure 3, step S150, automatic calibration, specifically includes the following steps:

[0107] S151. Calculate the deviation rate between the actual dosing flow rate and the target flow rate.

[0108] In this embodiment, the deviation rate refers to the relative error between the actual dosing flow rate and the target flow rate value, which is used to characterize the system's operating accuracy.

[0109] Specifically, the system acquires the actual flow rate value based on any of the three flow measurement schemes mentioned above. The actual flow rate value is compared with the target flow rate value to calculate the relative deviation. For example, if the target flow rate is 100 units and the actual measured flow rate is 95 units, the deviation rate is -5%. The system sets a deviation rate threshold as a calibration trigger condition.

[0110] S152. Adjust the total pressure of the dosing device or the static pressure of the dosing pipe according to the deviation rate to obtain a new target total pressure or static pressure of the dosing pipe to correct the flow deviation.

[0111] In this embodiment, the system uses a progressive adjustment strategy to correct the pressure parameters based on the magnitude and direction of the deviation rate.

[0112] Specifically, when the detected deviation rate exceeds a threshold, the system initiates a calibration procedure. If the actual flow rate is lower than the target value, the pressure is increased by a preset step size; if the actual flow rate is higher than the target value, the pressure is decreased. After each adjustment, the flow rate is remeasured and the deviation rate is calculated until the deviation rate returns to the allowable range. The new pressure value will be used as the updated target pressure for subsequent control. This embodiment, through an automatic calibration mechanism, enables the system to adapt to the influence of operating conditions such as changes in pipeline resistance and changes in the properties of the liquid. The progressive adjustment strategy avoids drastic fluctuations during the calibration process, ensuring the stability of system regulation.

[0113] In one embodiment, referring to FIG4, the method further includes the following steps:

[0114] S410. Establish historical databases for total pressure and chemical dosing flow rate, and historical databases for static pressure and chemical dosing flow rate in the dosing pipe, respectively.

[0115] In this embodiment, the historical database consists of two independent parts: a total pressure-flow database and a static pressure-flow database, which record the pressure-flow correspondence under different operating conditions.

[0116] Specifically, the system continuously collects pressure and flow data during operation, and stores the data in categories. Total pressure data records the relationship between gas pressure and corresponding flow rate in the dosing tank, while static pressure data records the relationship between liquid static pressure and flow rate in the dosing pipe. The database is updated regularly to maintain data timeliness.

[0117] S420. Based on the data in the historical database of total pressure-dosing flow rate, perform parameter fitting to obtain the optimized total pressure-dosing flow rate model and the total pressure-dosing flow rate calibration range, which are used for overall flow rate regulation.

[0118] In this embodiment, the system analyzes and processes the total pressure-flow data to establish a basic model for wide-range adjustment.

[0119] Specifically, a piecewise linear fitting method is used to process historical data to determine the functional relationship between total pressure and flow rate. Simultaneously, based on the data distribution characteristics, the effective range of total pressure regulation is determined, i.e., the total pressure-flow rate calibration interval. This interval defines the applicable scope of the total pressure regulation method.

[0120] S430. Based on the data in the historical database of static pressure-dosing flow rate of the dosing pipe, perform parameter fitting to obtain the optimized static pressure-dosing flow rate model and the calibration range of static pressure-dosing flow rate of the dosing pipe. The static pressure-dosing flow rate model of the dosing pipe is fine-tuned based on the minimum value of the total pressure-dosing flow rate calibration range.

[0121] In this embodiment, the system establishes a static pressure-flow rate model for precise adjustment. This model uses the minimum value of the total pressure calibration range as a reference point.

[0122] Specifically, under the condition of minimum total pressure, the relationship between static pressure and flow rate is analyzed to establish a mathematical model for fine-tuning. The effective range of static pressure adjustment is determined, i.e., the static pressure-flow rate calibration interval. This model is mainly used for precise adjustment within a small range.

[0123] S440. During automatic dosing operation, when it is necessary to adjust the dosing flow rate, the total pressure-dosing flow rate model is used first for flow rate adjustment; when the flow rate adjustment range is lower than the total pressure-dosing flow rate calibration range, the static pressure-dosing flow rate model of the dosing pipe is switched to be used for flow rate adjustment.

[0124] In this embodiment, the system automatically selects the appropriate control model based on the adjustment requirements.

[0125] Specifically, when a wide range of flow rate adjustments is required, the total pressure-flow rate model is used first to achieve a rapid response by adjusting the gas pressure. When the adjustment range is small, it automatically switches to the static pressure-flow rate model to achieve precise control by adjusting the liquid static pressure.

[0126] S450, Adjust the total pressure value and fix it at the minimum value within the total pressure-dosing flow rate calibration range.

[0127] S460. Under fixed total pressure parameters, the dosing flow rate can be further adjusted by changing the static pressure of the dosing pipe.

[0128] In this embodiment, the system adopts a control strategy of fixed total pressure + static pressure fine-tuning.

[0129] Specifically, the total pressure is first adjusted to the minimum value within its calibrated range and kept constant. Based on this, the flow rate is precisely adjusted by changing the static pressure in the dosing pipe. This method avoids frequent adjustments to the total pressure and improves system stability.

[0130] In one embodiment, referring to FIG5, the method further includes the following steps:

[0131] S510. Establish an abnormal pressure fluctuation characteristic model based on the pressure-flow history database.

[0132] In this embodiment, the abnormal pressure fluctuation feature model includes typical pressure change features of different types of faults.

[0133] Specifically, the system extracts pressure data characteristics at the time of various faults from the historical pressure-flow database. Pipeline leakage typically manifests as a continuous drop in pressure and difficulty in maintaining the target pressure; pipeline blockage manifests as a gradual increase in pressure and a decrease in flow; valve sticking manifests as a slow or abrupt change in pressure regulation response. The system parameterizes these characteristics to establish a fault feature library.

[0134] S520 compares real-time pressure values ​​with abnormal pressure fluctuation characteristic models to identify pipeline leaks, pipeline blockages, or valve jamming.

[0135] In this embodiment, the system compares the current pressure data with the fault characteristic model in real time.

[0136] Specifically, the controller continuously collects pressure data and calculates parameters such as pressure change trends, fluctuation frequency, and response characteristics. These parameters are then used for pattern matching against a fault feature database. When a pressure fluctuation characteristic is detected to be highly similar to a certain type of fault mode, the system determines that a corresponding fault may exist. For example, if a slow pressure increase and a continuous decrease in flow rate are detected, the system will identify it as a possible pipeline blockage.

[0137] S530: Trigger corresponding maintenance commands based on the identification results.

[0138] In this embodiment, the system triggers maintenance instructions of different levels according to the fault type.

[0139] Specifically, for pipeline leaks, the system issues an emergency alarm and automatically reduces system pressure; for pipeline blockages, the system recommends pipeline cleaning; for valve jamming, the system prompts for inspection of the valve mechanism. Maintenance commands can include alarm prompts, operational suggestions, or automatic protection measures. The system also records the time of failure and relevant parameters to provide a basis for subsequent maintenance.

[0140] In one embodiment, referring to FIG6, the method further includes the following steps:

[0141] S610 converts the pressure energy released during the dosing process into electrical energy through a micro turbine energy recovery device.

[0142] In this embodiment, the micro turbine energy recovery device is installed at the pressure relief point of the dosing pipeline to recover excess pressure.

[0143] Specifically, during the dosing process, pressure energy loss occurs as the chemical solution flows from the high-pressure zone to the low-pressure zone. The system installs a miniature turbine at the pressure drop point, using the pressure difference to drive its rotation. The turbine is connected to a small generator, converting mechanical energy into electrical energy. The recovered electrical energy can be used to power system instruments or stored in an energy storage device. The device is installed in the section of pipe with the greatest pressure drop to achieve optimal energy recovery efficiency.

[0144] S620: Collects compressed air released during the dosing process into an air storage tank to provide an auxiliary air source for the dosing process.

[0145] In this embodiment, the system is equipped with an air storage and recovery system for collecting and reusing compressed air.

[0146] Specifically, the compressed air released during the dosing process is dehumidified and filtered before being stored in a storage tank. The storage tank is equipped with a pressure sensor and control valve, automatically switching to use compressed air from the storage tank as an auxiliary air source when the main air supply pressure is insufficient. This design reduces the consumption of external compressed air while providing redundant air source protection. The volume of the storage tank is determined based on the system scale and operating characteristics to ensure sufficient air storage capacity.

[0147] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0148] Secondly, this application provides a pressure dosing system for wastewater treatment. The pressure dosing system for wastewater treatment of this application will be described below in conjunction with the pressure dosing method for wastewater treatment described above.

[0149] Referring to Figure 7, a pressurized dosing system for wastewater treatment includes:

[0150] A dosing device, comprising a dosing tank and a pressure sensor installed inside the dosing tank, for detecting and acquiring real-time pressure values ​​within the dosing device;

[0151] The controller, electrically connected to the pressure sensor, is used to calculate the relationship model between total pressure or static pressure and dosing flow rate based on Bernoulli's equation, and to calculate the target total pressure or dosing pipe static pressure based on the relationship model.

[0152] A liquid level sensor, installed inside the dosing tank, is used to monitor the liquid level in the dosing device in real time and calculate the actual amount of medicine added; a weight sensor, installed at the bottom of the dosing tank, is used to monitor the weight change of the medicine in the dosing device in real time and calculate the actual amount of medicine added.

[0153] An electro-proportional valve, electrically connected to the controller, is used to adjust the actual total pressure according to changes in liquid level via PID graded control.

[0154] A proportional control valve, electrically connected to the controller, is used to adjust the static pressure of the dosing pipe according to changes in liquid level via PID graded control; a flow measuring device is used to monitor and calculate the actual dosing flow rate of the dosing pipe.

[0155] The controller is also used to automatically calibrate by adjusting the actual dosing flow rate of the dosing pipe when a flow deviation is detected to exceed a preset range.

[0156] In one embodiment, this application provides an electronic device, which may be a server, and its internal structure diagram is shown in Figure 8. The electronic device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores data. The network interface communicates with external terminals via a network connection. When the computer program is executed by the processor, it implements a pressure dosing method for wastewater treatment.

[0157] Those skilled in the art will understand that the structure shown in Figure 8 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the electronic device to which the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0158] In one embodiment, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0159] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0160] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pressure dosing method for wastewater treatment, characterized in that, The process includes the following steps: establishing a stable gas pressure within the dosing device, and obtaining the real-time pressure value within the dosing device using a pressure sensor; based on the real-time pressure value, establishing a total pressure-dosing flow rate relationship model and a static pressure-dosing flow rate relationship model for the dosing device based on Bernoulli's equation, and determining the flow rate ranges corresponding to the two relationship models respectively; Based on the two relational models mentioned above, the target flow rate value is input, the corresponding flow range is determined according to the input target flow rate value, one of the relational models is selected, and the corresponding target total pressure or dosing pipe static pressure value is calculated. The system monitors changes in the dosage within the dosing device in real time and dynamically adjusts the actual total pressure or static pressure of the dosing pipe based on these changes to maintain the target pressure value. This adjustment is achieved through PID graded control. The real-time dosing flow rate is calculated by measuring the dosage, and automatic calibration is performed when a flow rate deviation exceeds a preset range.

2. The pressure dosing method for wastewater treatment according to claim 1, characterized in that, The real-time dosing flow rate is calculated by measuring the dosage, including any of the following methods: monitoring liquid level changes within a fixed time interval, converting the liquid level changes into volume variables, and calculating the real-time dosing flow rate based on the volume variables; monitoring weight changes within a fixed time interval, converting the weight changes into volume variables, and calculating the real-time dosing flow rate based on the volume variables; or monitoring the inlet and outlet water time values ​​using a flow measuring device, and calculating the real-time dosing flow rate based on the fixed volume of the flow measuring device and the time values.

3. The pressure dosing method for wastewater treatment according to claim 1, characterized in that, Automatic calibration includes the following steps: calculating the deviation rate between the real-time dosing flow rate and the target flow rate; adjusting the total pressure of the dosing device or the static pressure of the dosing pipe according to the deviation rate to obtain a new target total pressure or static pressure of the dosing pipe to correct the flow deviation.

4. The pressure dosing method for wastewater treatment according to claim 1, characterized in that, The method further includes the following steps: establishing a historical database of total pressure-dosing flow rate and a historical database of static pressure-dosing flow rate in the dosing pipe; performing parameter fitting based on the data in the historical database of total pressure-dosing flow rate to obtain an optimized total pressure-dosing flow rate model and a total pressure-dosing flow rate calibration range for overall flow rate adjustment; performing parameter fitting based on the data in the historical database of static pressure-dosing flow rate in the dosing pipe to obtain an optimized static pressure-dosing flow rate model and a static pressure-dosing flow rate calibration range in the dosing pipe, wherein the static pressure-dosing flow rate model in the dosing pipe is fine-tuned based on the minimum value of the total pressure-dosing flow rate calibration range; During automatic dosing operation, when it is necessary to adjust the dosing flow rate, the total pressure-dosing flow rate model is used first for flow rate regulation. When the flow rate adjustment range is lower than the total pressure-dosing flow rate calibration range, the dosing pipe static pressure-dosing flow rate model is switched to be used for flow rate regulation. The total pressure value is adjusted and fixed at the minimum value of the total pressure-dosing flow rate calibration range. With the total pressure parameter fixed, the dosing flow rate is further adjusted by changing the static pressure of the dosing pipe.

5. The pressure dosing method for wastewater treatment according to claim 4, characterized in that, The method also includes the following steps: establishing an abnormal pressure fluctuation feature model based on the pressure-flow history database; comparing the real-time pressure value with the abnormal pressure fluctuation feature model to identify pipeline leakage, pipeline blockage, or valve jamming; and triggering corresponding maintenance commands based on the identification results.

6. The pressure dosing method for wastewater treatment according to claim 1, characterized in that, The method also includes the following steps: converting the pressure energy released during the dosing process into electrical energy through a micro turbine energy recovery device; collecting the compressed air released during the dosing process into an air storage tank to provide an auxiliary air source for the dosing process.

7. The pressure dosing method for wastewater treatment according to claim 1, characterized in that, Adjusting the actual total pressure or static pressure of the dosing line using PID control in a graded manner includes the following steps: Step 1: Obtain the target pressure value and the real-time pressure value; Step 2: When the deviation between the real-time pressure value and the target pressure value exceeds a first preset range, activate the rapid adjustment mode and use the first set of PID parameters for pressure adjustment; Step 3: When the deviation between the real-time pressure value and the target pressure value is within the first preset range, activate the fine adjustment mode and use the second set of PID parameters for pressure adjustment, wherein the proportional coefficient and integral coefficient of the second set of PID parameters are less than the proportional coefficient and integral coefficient of the first set of PID parameters; Step 4: Detect the duration of the real-time pressure value within the first preset range, and when the duration reaches a preset duration, determine that the pressure is stable; If the pressure fluctuation exceeds the second preset range in the fine adjustment mode, return to step 2; Step 5 The system continuously monitors the real-time pressure value. When the real-time pressure value exceeds the third preset range, the opening of the dosing valve is finely adjusted according to the preset time interval to keep the pressure within the third preset range.

8. A pressurized dosing system for wastewater treatment, characterized in that, include: The dosing device includes a dosing tank and a pressure sensor installed inside the dosing tank for detecting and acquiring real-time pressure values ​​within the dosing device; a controller electrically connected to the pressure sensor for calculating a relationship model between total pressure or static pressure and dosing flow rate based on Bernoulli's equation, and calculating a target total pressure or dosing pipe static pressure according to the relationship model; a level sensor installed inside the dosing tank for real-time monitoring of the liquid level within the dosing device and calculating the actual dosing amount in the dosing tank; a weight sensor installed at the bottom of the dosing tank for real-time monitoring of changes in the weight of the liquid in the dosing device and calculating the actual dosing amount in the dosing tank; an electro-proportional valve electrically connected to the controller for adjusting the actual total pressure according to changes in liquid level via PID graded control; a proportional regulating valve electrically connected to the controller for adjusting the dosing pipe static pressure according to changes in liquid level via PID graded control; and a flow measuring device for monitoring and calculating the actual dosing flow rate in the dosing pipe. The controller is also used for automatic calibration by adjusting the actual dosing flow rate in the dosing pipe when a flow deviation exceeding a preset range is detected.

9. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the pressure dosing method for wastewater treatment as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the pressure dosing method for wastewater treatment as described in any one of claims 1-7.

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