Chemical phosphorus removal dosing control method and system

Abstract

The invention belongs to the technical field of environment-friendly sewage treatment and automatic control, and particularly relates to a chemical phosphorus removal dosing control method and system. The method comprises the following steps: collecting data in a control period, modeling phosphorus removal capacity maintained by sludge and solid surface sediments after drug withdrawal or drug reduction as a phosphorus capacity state, online updating the phosphorus capacity according to a difference value between a drug feeding theoretical phosphorus removal amount and an actual phosphorus removal amount in combination with a sludge discharge amount, and establishing an effluent phosphorus prediction model taking the phosphorus capacity as input by utilizing regression. And constructing an optimization function containing the water outlet deviation and dosing, and solving the dosing amount under the dosing constraint to control the dosing pump. The phosphorus capacity memory effect is obviously introduced and estimated online, the contribution of the residual medicament can be objectively described, and the medicament utilization efficiency is improved, short-term excessive dosing is avoided, and the stability and robustness of effluent total phosphorus control are enhanced while effluent standard reaching, capacity safety redundancy and dosing stability are considered.

Description

Technical Field

[0001] This invention belongs to the field of environmental wastewater treatment and automatic control technology, specifically relating to a chemical phosphorus removal dosing control method and system. Background Technology

[0002] With increasingly stringent water discharge standards, wastewater treatment plants commonly employ a combined process of "biological phosphorus removal + chemical phosphorus removal" to achieve long-term stable compliance with total phosphorus (TP) standards. Chemical phosphorus removal removes dissolved phosphorus from wastewater by adding metal salts such as iron and aluminum salts to form phosphate precipitates or co-precipitates.

[0003] Existing chemical dosing methods mostly employ intelligent dosing based on PID or fuzzy control: using the effluent TP deviation as the main control variable, the dosing amount is automatically adjusted through algorithms such as PID, fuzzy control, and neural networks. The control object of this chemical dosing method is the relationship between the "current" instantaneous water quality and the "current" dosing amount. The typical approach is: if the current instantaneous effluent TP is high, the dosing amount is increased; if the current instantaneous effluent TP is low, the dosing amount is decreased.

[0004] However, practical engineering and literature studies show that residual sludge, the surface of structures, and residual sediments in wastewater treatment systems still have a certain "phosphorus adsorption capacity." For example, residual iron and aluminum precipitates and adsorption sites on the surface of iron oxides still have the ability to adsorb phosphorus in the water for a period of time after the dosing is stopped.

[0005] However, existing chemical dosing methods do not include "phosphorus adsorption capacity" as a time-varying state variable in the dosing control model. Therefore, when the system phosphorus capacity is too high, the control system still administers the drug based on the "no capacity assumption," resulting in long-term waste of the drug. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: Firstly, a chemical phosphorus removal dosing control method is proposed, which includes the following steps in each control cycle: collecting operational data of the wastewater treatment system; operational data includes: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and residual sludge discharge flow rate; initializing the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle; phosphorus capacity is used to characterize the phosphorus removal capacity maintained by the system based on sludge and solid surface deposits after the dosing is stopped or reduced; updating the phosphorus capacity of the current control cycle online based on the operational data; online updating includes: calculating the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage, obtaining the phosphorus removal capacity contributed by the phosphorus capacity and the residual phosphorus removal capacity; calculating the phosphorus capacity after sludge discharge loss based on the residual sludge discharge flow rate, and calculating it in conjunction with a preset memory time parameter. The phosphorus capacity after natural decay is calculated. The phosphorus capacity for the next control cycle is obtained by combining the phosphorus removal contribution from the phosphorus capacity, the phosphorus removal capacity of residual chemicals, the phosphorus capacity lost after sludge discharge, and the phosphorus capacity after natural decay. A prediction model for the total phosphorus concentration in the effluent, using phosphorus capacity as input, is established through multi-parameter linear regression and sliding window least squares. The total phosphorus concentration in the effluent is output using this prediction model. The deviation of the total phosphorus concentration in the effluent, the deviation of the phosphorus capacity for the next control cycle, and the deviation of the current dosage are obtained. An objective function is constructed that includes the deviation of the total phosphorus concentration in the effluent, the deviation of the phosphorus capacity, and the deviation of the current dosage. Under the condition of satisfying the upper and lower limits of the dosage, the target dosage for the current control cycle is calculated by solving an optimization problem that minimizes the objective function. The operating frequency of the dosing pump is controlled according to the target dosage to complete the chemical phosphorus removal dosing control.

[0007] Secondly, a chemical phosphorus removal dosing control system is proposed, comprising: an operation data acquisition module for acquiring operation data of the wastewater treatment system; the operation data includes: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and residual sludge discharge flow rate; a phosphorus capacity initialization module for initializing the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle; phosphorus capacity is used to characterize the phosphorus removal capacity maintained by the system relying on sludge and solid surface deposits after the dosing is stopped or reduced; and a phosphorus capacity update module for updating the phosphorus capacity of the current control cycle online based on the operation data; comprising: a first numerical calculation unit for calculating the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage, obtaining the phosphorus removal capacity contributed by the phosphorus capacity and the residual phosphorus removal capacity; a second numerical calculation unit for calculating the phosphorus capacity after sludge discharge loss based on the residual sludge discharge flow rate; a third numerical calculation unit for calculating the phosphorus capacity after natural decay in combination with a preset memory time parameter; and a fourth numerical calculation unit. The system comprises the following modules: a unit for synthesizing phosphorus removal capacity contributed by phosphorus capacity, residual chemical phosphorus removal capacity, phosphorus capacity after sludge discharge, and phosphorus capacity after natural decay, to obtain the phosphorus capacity for the next control cycle; a prediction model construction module for establishing a prediction model for effluent total phosphorus concentration using phosphorus capacity as input through multi-parameter linear regression and sliding window least squares method; a prediction model calling module for outputting the effluent total phosphorus concentration using the effluent total phosphorus concentration prediction model; a normalized deviation calculation module for obtaining the effluent total phosphorus concentration deviation, the phosphorus capacity deviation for the next control cycle, and the current dosage deviation; an objective function construction module for constructing an objective function that includes the effluent total phosphorus concentration deviation, phosphorus capacity deviation, and current dosage deviation; a target dosage calculation module for calculating the target dosage for the current control cycle by solving an optimization problem that minimizes the objective function under the condition of satisfying the upper and lower limits of dosage; and a dosing pump control module for controlling the operating frequency of the dosing pump according to the target dosage to complete the chemical phosphorus removal dosing control.

[0008] Thirdly, a computer device is proposed, comprising a memory, a processor, and a transceiver connected in sequence, wherein the memory is used to store a computer program, the transceiver is used to send and receive data, and the processor is used to read the computer program and execute a chemical phosphorus removal dosing control method as described in the first aspect.

[0009] Fourthly, a computer-readable storage medium is provided, on which instructions are stored, which, when executed on a computer, perform a chemical phosphorus removal dosing control method as described in the first aspect.

[0010] Fifthly, a computer program product containing instructions is proposed, which, when executed on a computer, causes the computer to perform a chemical phosphorus removal dosing control method as described in the first aspect; the computer includes: a general-purpose computer, a special-purpose computer, or a programmable device.

[0011] Compared with existing technologies, this invention has the following advantages and beneficial effects: By collecting operational data such as influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and residual sludge discharge flow rate in each control cycle, and initializing the phosphorus capacity of the current control cycle with the phosphorus capacity of the previous control cycle, the phosphorus capacity of "maintaining phosphorus removal capacity by relying on sludge and solid surface deposits after stopping or reducing dosage" is explicitly introduced as an online state quantity. Combining the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage, the phosphorus removal capacity contributed by the phosphorus capacity and the residual phosphorus removal capacity of the reagent are decomposed online. Then, the phosphorus capacity after sludge discharge loss is calculated based on the residual sludge discharge flow rate, and the phosphorus capacity after natural decay is obtained using a preset memory time parameter. Thus, the phosphorus capacity of the next control cycle is obtained comprehensively, realizing the residual phosphorus removal capacity of the system. The objective characterization and dynamic tracking of force are achieved. Based on this, a prediction model for total phosphorus concentration in effluent is established using multi-parameter linear regression and sliding window least squares method, with phosphorus capacity as one of the inputs. The model is then used to output the total phosphorus concentration in effluent. The predicted deviation of total phosphorus concentration in effluent, the deviation of phosphorus capacity in the next control cycle, and the deviation of current dosage are collectively constructed into an objective function. Under the condition of satisfying the upper and lower limits of dosage, the optimization problem that minimizes this objective function is solved to obtain the target dosage for the current control cycle. Based on this, the operating frequency of the dosing pump is controlled. Thus, without relying on a large number of manual experience coefficients, the effluent compliance requirements, the system phosphorus capacity safety redundancy, and the stability of dosing are unified into the same optimization framework. This avoids the over-dosing of chemicals caused by ignoring the contribution of residual chemicals, and improves the chemical utilization efficiency and the stability and robustness of total phosphorus control in effluent. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of the chemical phosphorus removal dosing control method provided in Embodiment 1 of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. The embodiments described below are some, but not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0014] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, materials, or methods are not specifically described to avoid obscuring the invention. Unless otherwise specified, the materials, instruments, and reagents used in the following embodiments are commercially available. Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art.

[0015] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0016] Example 1: Addressing the problem in existing technologies that neglect the "memory effect" (i.e., the residual phosphorus removal capacity of sludge and solid surface deposits formed after long-term dosing) in chemical phosphorus removal processes, leading to a delayed and difficult-to-control deterioration of effluent quality after discontinuation of treatment, this example provides a chemical phosphorus removal dosing control method. The overall technical framework is as follows: instead of relying solely on the current influent load for feedforward control, a closed-loop predictive model is constructed, incorporating "influent status, dosing amount, phosphorus capacity, and effluent quality." By calculating the difference between the theoretical and actual removal capacity of the reagent in real time, the phosphorus removal contribution from "newly added reagent" and "remaining phosphorus capacity of the system" is dynamically separated, thereby updating the system's phosphorus capacity for the current control cycle. Based on this, multi-parameter linear regression is used to predict the total phosphorus in the effluent, and an objective function is constructed encompassing three dimensions: water quality compliance, capacity maintenance, and stable dosing. The optimal dosing amount for the current cycle is obtained by solving the optimization problem.

[0017] Based on the above overall technical framework, a chemical phosphorus removal dosing control method is implemented in each control cycle. Figure 1 The following steps are shown: Step 1: Collect operational data of the wastewater treatment system.

[0018] The purpose of this step is to obtain physical quantities that describe the current operating conditions of the wastewater treatment system, providing a data foundation for subsequent state estimation and model prediction.

[0019] Sensors and flow meters installed on the process pipelines are used to measure real-time operating data of the wastewater treatment system, including: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current chemical dosage, and excess sludge discharge flow rate. Details are as follows: An electromagnetic flow meter is installed on the inlet pipe to collect the standard signal output by the electromagnetic flow meter, and the standard signal is converted into the inlet flow rate for the current control cycle. Q in ( k (Unit: m³ / h).

[0020] An electromagnetic flow meter is installed on the outlet pipe to collect the standard signal output by the electromagnetic flow meter, and the standard signal is converted into the outlet flow rate for the current control cycle. Q out ( k (Unit: m³ / h).

[0021] Install an online total phosphorus or orthophosphorus analyzer on the inlet pipe to obtain the total phosphorus concentration in the inlet water for the current control cycle. P in ( k (Unit: mg-P / L).

[0022] Install an online total phosphorus or orthophosphorus analyzer on the effluent pipe to obtain the total phosphorus concentration in the effluent during the current control cycle. P out ( k (Unit: mg-P / L).

[0023] A small flow meter is installed at the outlet of the metering pump for chemical phosphorus removal agents to obtain the volumetric flow rate of the agents. Q chem ( k (Unit: L / h); based on the reagent density (Unit: kg / L) and mass fraction of active ingredient w chem (e.g., the mass fraction of Fe ions in iron salts) to obtain the dosage (or active ingredient mass flow) for the current control cycle. The unit is kg-Fe / L.

[0024] Install a flow meter on the waste sludge discharge pipe to obtain the waste sludge discharge flow rate. Q w ( k (Unit: m³ / h).

[0025] It should be noted that the sampling period for the above-mentioned types of operational data is the current control period Δt, which can be set to 10 to 30 minutes, for example, 15 minutes. All the above-mentioned operational data are collected once in each sampling period. Median filtering and missing value imputation can be performed on the collected operational data to ensure that the input data is stable and reliable.

[0026] This step provides a comprehensive real-time data stream reflecting system load and response, ensuring the control system can sense environmental changes. This step serves as the input for all subsequent calculations; the collected operational data is directly used for phosphorus capacity updates in step S2 and the prediction model in step S3.

[0027] Step 2: Initialize the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle, and update the phosphorus capacity of the current control cycle online based on the operating data.

[0028] The phosphorus capacity described in this step is used to characterize the system's ability to maintain phosphorus removal capacity by relying on sludge and solid surface deposits after the dosing is stopped or reduced.

[0029] The purpose of this step is to quantify the "memory effect" of the system in the current control cycle, that is, to quantitatively calculate the active sites with phosphorus removal capabilities stored in the system in the current control cycle.

[0030] The basic principle of this step is based on the law of conservation of mass and reaction kinetics. Phosphorus removal in the system is achieved through the combined action of the "instantaneous chemical reaction" of all reagents and the "adsorption mechanism" of sludge and solid surface deposits. When the actual phosphorus removal exceeds the theoretical chemical removal capacity, it indicates that the phosphorus capacity stored in the sludge and solid surface deposits has been consumed; conversely, it indicates that there is a surplus of reagents, which is converted into new phosphorus capacity. Simultaneously, considering the physical losses caused by sludge discharge and the natural decay over time, the phosphorus capacity for the next control cycle is finally obtained. The phosphorus capacity of the current control cycle initialized in this step is the phosphorus capacity of the previous control cycle. Specifically, it includes the following steps: Step 2.1: Initialize the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle.

[0031] Step 2.2: Calculate the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage to obtain the phosphorus removal capacity contributed by phosphorus capacity and the residual phosphorus removal capacity of the pesticide. This includes the following steps: Step 2.2.1: Calculate the theoretical phosphorus removal capacity of the current dosage based on the dosage of the current control cycle and the phosphorus removal capacity coefficient per unit of the current control cycle.

[0032] The theoretical phosphorus removal capacity of the current dosage is Cap th ( k ), Cap th (k )= M chem ( k )× k stoich ( k );in, k Indicates the current control cycle. M chem ( k This represents the dosage for the current control cycle. k stoich ( k () represents the phosphorus removal capacity coefficient per unit of reagent in the current control cycle.

[0033] Phosphorus removal capacity coefficient per unit of reagent in the current control cycle k stoich ( k The determination was made through multiple beaker tests. The specific method was as follows: First, the total phosphorus in the influent and effluent was measured under different dosage conditions to obtain samples ( D i ,Δ P i );in, D i Indicates the first i The concentration of the reagent added under the conditions of the second beaker test is expressed in mg-Fe / L, Δ P i Indicates the first i The decrease in total phosphorus concentration per unit volume of water under the second beaker test condition was expressed in mg-P / L; then, the ΔP / L value was fitted using the least squares method. P i and D i The linear relationship, i.e., Δ P i = k stoich ( k )× D i Thus, the phosphorus removal capacity per unit of reagent is obtained. k stoich ( k (Unit: mg-P / mg-Fe).

[0034] Step 2.2.2: Calculate the actual phosphorus removal amount of the current dosage based on the influent flow rate, total phosphorus concentration of the influent, total phosphorus concentration of the effluent, and total phosphorus concentration of the effluent in the current control cycle.

[0035] The actual phosphorus removal rate at the current dosage is R obs ( k ), Robs ( k )=( Q in ( k )× P in ( k )− Q out ( k )× P out ( k ))×Δ t ;in, Q in ( k () represents the influent flow rate for the current control cycle. P in ( k () represents the total phosphorus concentration in the influent during the current control cycle. Q out ( k () represents the outflow rate for the current control cycle. P out ( k ) represents the total phosphorus concentration in the effluent during the current control cycle, Δ t This represents the duration of the current control cycle.

[0036] Step 2.2.3: Compare the theoretical phosphorus removal amount of the current dosage with the actual phosphorus removal amount of the current dosage.

[0037] If the actual phosphorus removal rate is greater than the theoretical phosphorus removal rate, it indicates that the dosage of chemicals used in the current control cycle is insufficient to remove phosphorus from the influent. Besides the phosphorus removed by the added chemicals, the remaining phosphorus is removed by the phosphorus capacity of the current control cycle. In this case, the difference between the theoretical and actual phosphorus removal rates can be taken as the residual phosphorus removal capacity, and the residual dosage is equal to zero (i.e., the residual phosphorus removal capacity is zero). Conversely, if the actual phosphorus removal rate is less than the theoretical phosphorus removal rate, it indicates that an excessive amount of chemicals was added. The unreacted chemicals are converted into residual phosphorus removal capacity. In this case, the difference between the actual and theoretical phosphorus removal rates can be taken as the phosphorus removal rate contributed by the phosphorus capacity, and the residual phosphorus removal capacity is converted into the phosphorus capacity for the next control cycle. Specifically, the residual phosphorus removal capacity is... Cap res ( k ), Cap res ( k )=max(0, Cap th ( k )− R obs ( k The amount of phosphorus removed by phosphorus capacity is Rmem ( k ), R mem ( k )=min( R obs ( k ), Cap th ( k )).

[0038] Step 2.3: Calculate the phosphorus capacity after sludge discharge loss based on the excess sludge discharge flow rate. This includes the following steps: Step 2.3.1: Obtain the amount of residual sludge discharged based on the residual sludge discharge flow rate.

[0039] The amount of residual sludge discharged is Q w ( k )×Δt.

[0040] Step 2.3.2: Based on the proportion of the remaining sludge discharge to the effective volume of the system, obtain the phosphorus capacity loss caused by sludge discharge in the current control cycle.

[0041] The proportion of residual sludge discharge to the effective volume of the system is Q w ( k )×Δt / V tank ;in, Q w ( k () represents the remaining sludge discharge flow rate for the current control cycle. V tank This refers to the volume of the reaction tank.

[0042] The phosphorus capacity loss caused by sludge discharge during the current control cycle is: C eff ( k )× Q w ( k )×Δt / V tank ;in, C eff ( k ) represents the phosphorus capacity for the current control cycle, initialized.

[0043] Step 2.3.3: Subtract the phosphorus capacity loss from the phosphorus capacity of the current control cycle to obtain the phosphorus capacity after sludge discharge loss.

[0044] Phosphorus capacity after sludge discharge loss is C eff,1 ( k ), Ceff,1 ( k )= C eff ( k )×(1− Q w ( k )×Δt / V tank ).

[0045] Step 2.4: Calculate the phosphorus capacity after natural decay by combining the preset memory time parameters.

[0046] Using a preset memory time parameter, the phosphorus capacity after sludge discharge loss is calculated using an exponential decay method to obtain the phosphorus capacity after natural decay. The phosphorus capacity after natural decay is: C eff,2 ( k ), C eff,2 ( k )= C eff,1 ( k )×exp(-Δ t / T mem );in, T mem This is the preset memory time parameter.

[0047] Furthermore, the preset memory time parameters T mem The time required for the total phosphorus concentration in the effluent to rise from the normal level to the level exceeding the standard is determined by conducting a drug withdrawal test and using this time as the memory time parameter.

[0048] Step 2.5: By combining the phosphorus removal amount contributed by phosphorus capacity, the phosphorus removal capacity of residual reagents, the phosphorus capacity lost after sludge discharge, and the phosphorus capacity after natural decay, the phosphorus capacity for the next control cycle is obtained.

[0049] The phosphorus capacity for the next control cycle is C eff ( k +1), C eff ( k +1)= C eff,2 ( k )+ Cap res ( k )− C used ( k );in, k +1 indicates the next control cycle. C eff,2 ( k() represents the phosphorus capacity after decay during the current control cycle. Cap res ( k This represents the residual phosphorus removal capacity of the reagents during the current control cycle. C used ( k This indicates the actual phosphorus capacity consumed during the current control cycle; C used ( k )=min( C eff ( k ), R mem ( k ));in, C eff ( k () represents the phosphorus capacity for the current control cycle. R mem ( k This indicates the amount of phosphorus removed by phosphorus capacity during the current control cycle. C used ( k )Pick C eff ( k )and R mem ( k The smaller value in the equation means that if the phosphorus capacity in the current control cycle is large enough ( C eff ( k )≥ R mem ( k The phosphorus capacity actually consumed in the current control cycle is the amount of phosphorus removed by the phosphorus capacity. R mem ( k If the phosphorus capacity of the current control cycle is insufficient ( C eff ( k )< R mem ( k Then, the maximum amount of phosphorus capacity actually consumed in the current control cycle is... C eff ( k ).

[0050] Step 2 above converts the phosphorus removal capacity of sludge and solid surface deposits into a calculable phosphorus capacity, providing input features for the subsequent effluent total phosphorus concentration prediction model.

[0051] Step 3: Establish a prediction model for total phosphorus concentration in effluent using phosphorus capacity as input through multi-parameter linear regression and sliding window least squares method.

[0052] The purpose of this step is to establish a mapping relationship between input variables (total phosphorus concentration in the influent, influent flow rate, dosage and phosphorus capacity) and output water quality, and to predict the total phosphorus concentration in the effluent under the current operating conditions and the current system dosing strategy.

[0053] Multi-parameter linear regression (such as the ARX model structure) was used to characterize the linear correlation between the total phosphorus concentration in the effluent and the total phosphorus concentration in the influent, the influent flow rate, the dosage of chemicals, and the phosphorus capacity. Sliding window least squares (RLS) was used to identify model parameters to accommodate the slow drift of water plant characteristics.

[0054] First, the expression for the prediction model of total phosphorus concentration in effluent is established as follows: P out,pred ( k )= a 0+ a 1× P in ( k )+ a 2× Q in ( k )+ a 3× M chem ( k )+ a 4× C eff ( k );in, P out,pred ( k This represents the predicted total phosphorus concentration in the effluent during the current control period. a 0 to a 1 represents the model parameter vector.

[0055] Then, select the running data from N sampling times within the current control cycle to establish a data sample: ( P in ( j ), Q in ( j ), M chem ( j ), C eff ( j ), P out ( j )), j Indicates the first [number]th ... jEach sampling time, j =1,…,N, P in ( j ) indicates the first j The total phosphorus concentration in the influent at each sampling time. Q in ( j ) indicates the first j The inflow rate at each sampling time. M chem ( j ) indicates the first j The dosage at each sampling time. C eff ( j ) is the first j Phosphorus capacity at each sampling time, P out ( j ) indicates the first j Total phosphorus concentration in the effluent at each sampling time.

[0056] Finally, the parameter vector is solved using the least squares method. a 0 to a 1. Minimize the objective function. The objective function is: .

[0057] Step 4: Use the effluent total phosphorus concentration prediction model to output the effluent total phosphorus concentration.

[0058] Based on the total phosphorus concentration prediction model established in step 3, phosphorus capacity is explicitly introduced. C eff As a predictor, the total phosphorus concentration in the effluent is automatically fitted using the collected operational data and used to construct the objective function.

[0059] Step 5: Obtain the deviation of total phosphorus concentration in the effluent, the phosphorus capacity deviation for the next control cycle, and the current dosage deviation; construct an objective function that includes the deviation of total phosphorus concentration in the effluent, the phosphorus capacity deviation, and the current dosage deviation.

[0060] The purpose of this step is to use a dosage, phosphorus capacity, and effluent prediction model to solve a small-scale optimization problem in each sampling period to obtain the optimal dosage for the current period.

[0061] First, the deviations in total phosphorus concentration in the effluent, phosphorus capacity deviation in the next control cycle, and current dosage deviation are normalized. This yields the normalized deviations in total phosphorus concentration in the effluent, phosphorus capacity deviation, and current dosage deviation.

[0062] The deviation of normalized total phosphorus concentration in effluent is: ;in, The deviation in total phosphorus concentration in the effluentP out,pred ( k +1) represents the predicted total phosphorus concentration in the effluent for the next control cycle. P set The target concentration of total phosphorus in the effluent. P limit This represents the upper limit of total phosphorus concentration in the effluent. Normalized phosphorus capacity deviation is: ;in, For the phosphorus capacity deviation in the next control cycle, C eff , pred ( k +1) represents the phosphorus capacity for the next control cycle. C max For maximum safe phosphorus capacity, C min Minimum safe phosphorus capacity; The normalized deviation of the current dosage is: ;in, The deviation in the current dosage is due to... M chem ( k- 1) This refers to the dosage in the previous control cycle. M chem,scale This is a standardized measure of drug dosage. M chem,scale The dosage set according to the typical dosage of the water plant represents the "dosing range for normal operation" of the water plant. This serves as a benchmark to reflect the "drastic degree of change in dosage relative to the normal dosage." Normalization is used to convert dosage deviations into relative change rates relative to the normal dosage. For example, a change of 2 kg-Fe / h corresponds to a relative change rate of 0.1 (dimensionless), thus avoiding differences in magnitude.

[0063] Then, construct an objective function that includes the deviation of total phosphorus concentration in the effluent, the deviation of phosphorus capacity, and the deviation of the current dosage: .

[0064] Step 6: Under the condition of satisfying the upper and lower limits of drug dosage, calculate the target drug dosage for the current control cycle by solving the optimization problem that minimizes the objective function.

[0065] The conditions for upper and lower limits of dosage constraints are: M min ≤ M chem ( k )≤ M max , M min This is the lower limit of the dosage. M maxThe upper limit of the dosage is defined as the upper limit of the dosage, while the lower limit is determined by the equipment capacity and process requirements.

[0066] Solving the upper and lower limits of the dosage constraint makes J ( M chem Minimize M chem ( k ).

[0067] By solving the optimization problem that minimizes the objective function, the excessive or insufficient addition caused by simply pursuing the effluent standard in traditional PID control is avoided. At the same time, it prevents sudden phosphorus removal failure caused by ignoring capacity reserves, and achieves the comprehensive optimization of "effluent quality, operating cost and system robustness".

[0068] Step 7: Control the operating frequency of the dosing pump according to the target dosage to complete the chemical phosphorus removal dosing control.

[0069] The purpose of this step is to convert the calculated digital signal into the action of the physical equipment, completing the control closed loop. The controller converts the calculated target dosage into the operating frequency (Hz) or stroke percentage of the dosing pump, and sends commands via industrial control protocols (such as 4-20mA or Modbus) to drive the dosing pump, controlling the frequency converter of the metering pump to perform dosing. The system's execution results will then be monitored and evaluated in the next control cycle, forming a complete closed-loop control.

[0070] Example 2: Corresponding to Example 1, this example provides a chemical phosphorus removal dosing control system, including: The operation data acquisition module is used to collect the operation data of the wastewater treatment system. The operation data includes: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and excess sludge discharge flow rate. The phosphorus capacity initialization module is used to initialize the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle; phosphorus capacity is used to characterize the phosphorus removal capacity of the system after the dosing is stopped or reduced, relying on sludge and solid surface deposits. The phosphorus capacity update module is used to update the phosphorus capacity online for the current control cycle based on operating data; it includes: The first numerical calculation unit is used to calculate the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage, and to obtain the phosphorus removal capacity contributed by the phosphorus capacity and the phosphorus removal capacity of the residual agent. The second numerical calculation unit is used to calculate the phosphorus capacity after sludge discharge loss based on the excess sludge discharge flow rate; the phosphorus capacity after sludge discharge loss is: C eff,1 ( k ), Ceff,1 ( k )= C eff ( k )×(1− Q w ( k )×Δt / V tank );in, C eff ( k () represents the phosphorus capacity initialized for the current control cycle. Q w ( k () represents the remaining sludge discharge flow rate for the current control cycle. V tank The volume of the reaction tank; The third numerical calculation unit is used to calculate the phosphorus capacity after natural decay by combining preset memory time parameters; the phosphorus capacity after natural decay is... C eff,2 ( k ), C eff,2 ( k )= C eff,1 ( k )×exp(-Δ t / T mem );in, T mem Preset memory time parameters The fourth numerical calculation unit is used to comprehensively calculate the phosphorus capacity for the next control cycle by combining the phosphorus removal amount contributed by phosphorus capacity, the phosphorus removal capacity of residual reagents, the phosphorus capacity after sludge discharge loss, and the phosphorus capacity after natural decay; the phosphorus capacity for the next control cycle is... C eff ( k +1), C eff ( k +1)= C eff,2 ( k )+ Cap res ( k )− C used ( k );in, k +1 indicates the next control cycle. C eff,2 ( k This represents the phosphorus capacity decay during the current control cycle. Cap res ( k This represents the residual phosphorus removal capacity of the reagents during the current control cycle.C used ( k This indicates the actual phosphorus capacity consumed during the current control cycle; C used ( k )=min( C eff ( k ), R mem ( k ));in, C eff ( k () represents the phosphorus capacity for the current control cycle. R mem ( k This indicates the amount of phosphorus removed by phosphorus capacity during the current control cycle; The prediction model building module is used to establish a prediction model for total phosphorus concentration in effluent using phosphorus capacity as input, through multi-parameter linear regression and sliding window least squares method. The expression for the total phosphorus concentration prediction model in effluent is: P out,pred ( k )= a 0+ a 1× P in ( k )+ a 2× Q in ( k )+ a 3× M chem ( k )+ a 4× C eff ( k );in, P out,pred ( k This represents the predicted total phosphorus concentration in the effluent during the current control period. a 0 to a 1 represents the model parameter vector; The prediction model calling module is used to output the total phosphorus concentration in the effluent using the prediction model for the total phosphorus concentration in the effluent. The normalized deviation calculation module is used to obtain the deviation of total phosphorus concentration in the effluent, the phosphorus capacity deviation for the next control cycle, and the deviation of the current dosage. The expression for the deviation of total phosphorus concentration in the effluent is: ;in, The deviation in total phosphorus concentration in the effluent P out,pred ( k +1) represents the predicted total phosphorus concentration in the effluent for the next control cycle. Pset The target concentration of total phosphorus in the effluent. P limit This represents the upper limit of total phosphorus concentration in the effluent; the expression for the phosphorus capacity deviation in the next control cycle is: ;in, For the phosphorus capacity deviation in the next control cycle, C eff , pred ( k +1) represents the phosphorus capacity for the next control cycle. C max For maximum safe phosphorus capacity, C min The minimum safe phosphorus capacity; the expression for the current dosage deviation is: ;in, The deviation in the current dosage is due to... M chem ( k- 1) This refers to the dosage in the previous control cycle. M chem,scale Normalized table measurement of drug dosage The objective function construction module is used to construct an objective function that includes the deviations in effluent total phosphorus concentration, phosphorus capacity, and current dosage. The expression for the objective function is: ; The target dosage calculation module is used to calculate the target dosage for the current control cycle by solving an optimization problem that minimizes the objective function, under the condition of satisfying the upper and lower limits of the dosage. The dosing pump control module is used to control the operating frequency of the dosing pump according to the target dosage, thereby completing the chemical phosphorus removal dosing control.

[0071] Furthermore, the first numerical calculation unit includes: The theoretical phosphorus removal calculation subunit calculates the theoretical phosphorus removal capacity for the current dosage based on the dosage and the unit phosphorus removal capacity coefficient of the current control cycle. The theoretical phosphorus removal capacity for the current dosage is: Cap th ( k ), Cap th ( k )= M chem ( k )× k stoich ( k );in, k Indicates the current control cycle. M chem ( k This represents the dosage for the current control cycle. kstoich ( k () represents the phosphorus removal capacity coefficient per unit of reagent in the current control cycle; The actual phosphorus removal calculation subunit is used to calculate the actual phosphorus removal rate of the current dosage based on the influent flow rate, influent total phosphorus concentration, effluent flow rate, and effluent total phosphorus concentration of the current control cycle. The actual phosphorus removal rate of the current dosage is: R obs ( k ), R obs ( k )=( Q in ( k )× P in ( k )− Q out ( k )× P out ( k ))×Δ t ;in, Q in ( k () represents the influent flow rate for the current control cycle. P in ( k () represents the total phosphorus concentration in the influent during the current control cycle. Q out ( k () represents the outflow rate for the current control cycle. P out ( k ) represents the total phosphorus concentration in the effluent during the current control cycle, Δ t This is the duration of the current control cycle; The numerical analysis subunit compares the theoretical phosphorus removal amount of the current dosage with the actual phosphorus removal amount. If the actual phosphorus removal amount is greater than the theoretical phosphorus removal amount, the difference between the actual and theoretical phosphorus removal amounts is taken as the phosphorus removal amount contributed by phosphorus capacity. If the actual phosphorus removal amount is less than the theoretical phosphorus removal amount, the difference between the theoretical and actual phosphorus removal amounts is taken as the residual phosphorus removal capacity of the pesticide. The phosphorus removal amount contributed by phosphorus capacity is... R mem ( k ), R mem ( k )=min( R obs ( k ), Cap th ( k The residual phosphorus removal capacity is... Cap res ( k ), Cap res ( k )=max(0, Cap th ( k )− R obs ( k )).

[0072] Furthermore, the second numerical unit includes: The sludge discharge calculation subunit is used to obtain the amount of residual sludge discharge based on the residual sludge discharge flow rate. The phosphorus capacity loss calculation subunit is used to obtain the phosphorus capacity loss caused by sludge discharge in the current control cycle based on the proportion of residual sludge discharge to the effective volume of the system. The remaining phosphorus capacity calculation subunit is used to subtract the phosphorus capacity loss from the phosphorus capacity of the current control cycle to obtain the phosphorus capacity after sludge discharge loss.

[0073] Example 3: Based on the method provided in Example 1 and the system provided in Example 2, this example provides a computer device that executes the method described in Example 1 or any other method that may involve the method described in Example 1. The device includes a memory, a processor, and a transceiver connected in sequence. The memory stores a computer program, the transceiver sends and receives messages, and the processor reads the computer program and executes the method described in Example 1 or any other method that may involve the method described in Example 1. Specifically, the memory may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or last-in-first-out (FILO) memory, etc.; the processor may include, but is not limited to, a microprocessor of the STM32F105 series. Furthermore, the computer device may also include, but is not limited to, a power module, a display screen, and other necessary components.

[0074] The working process, working details and technical effects of the aforementioned computer device provided in this embodiment can be found in the method described in Embodiment 1 or any method that may involve the method described in Embodiment 1, and will not be repeated here.

[0075] Example 4: This example provides a computer-readable storage medium that stores instructions that include the method described in Example 1 or any other method that may involve the method described in Example 1. Specifically, the computer-readable storage medium stores instructions that, when executed on a computer, perform the method described in Example 1 or any other method that may involve the method described in Example 1. The computer-readable storage medium refers to a data storage medium, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or Memory Sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0076] The working process, working details and technical effects of the aforementioned computer-readable storage medium provided in this embodiment can be found in the method described in Embodiment 1 or any method that may be related to Embodiment 1, and will not be repeated here.

[0077] Example 5: This example provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the method described in Example 1 or any method that may involve the method described in Example 1. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0078] It should be understood that the terms "system," "device," "unit," and / or "module" as used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0079] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0080] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0081] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

Claims

1. A method for controlling chemical phosphorus removal dosage, characterized in that, The following steps are performed in each control cycle: Collect operational data of the wastewater treatment system; operational data includes: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and excess sludge discharge flow rate; The phosphorus capacity of the current control cycle is initialized using the phosphorus capacity of the previous control cycle; the phosphorus capacity is used to characterize the phosphorus removal capacity of the system after the dosing is stopped or reduced, relying on sludge and solid surface deposits. The phosphorus capacity for the current control cycle is updated online based on operational data. The online update includes: calculating the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage to obtain the phosphorus removal capacity contributed by the phosphorus capacity and the residual phosphorus removal capacity of the reagent; calculating the phosphorus capacity after sludge discharge loss based on the excess sludge discharge flow rate, and calculating the phosphorus capacity after natural decay in combination with the preset memory time parameter; and combining the phosphorus removal capacity contributed by the phosphorus capacity, the residual phosphorus removal capacity of the reagent, the phosphorus capacity after sludge discharge loss, and the phosphorus capacity after natural decay to obtain the phosphorus capacity for the next control cycle. A prediction model for total phosphorus concentration in effluent is established using multi-parameter linear regression and sliding window least squares method, with phosphorus capacity as input; the total phosphorus concentration in effluent is then output using the prediction model. Obtain the deviation of total phosphorus concentration in the effluent, the deviation of phosphorus capacity in the next control cycle, and the deviation of current dosage; construct an objective function that includes the deviation of total phosphorus concentration in the effluent, the deviation of phosphorus capacity, and the deviation of current dosage. Under the condition of satisfying the upper and lower limits of drug dosage, the target drug dosage for the current control cycle is calculated by solving the optimization problem that minimizes the objective function. The operating frequency of the dosing pump is controlled according to the target dosage to complete the chemical phosphorus removal dosing control.

2. The chemical phosphorus removal dosing control method according to claim 1, characterized in that, Obtaining the phosphorus removal capacity contributed by phosphorus capacity and the residual phosphorus removal capacity of the reagent includes the following steps: Based on the dosage of the current control cycle and the phosphorus removal capacity coefficient per unit of the current control cycle, calculate the theoretical phosphorus removal capacity of the current dosage. The actual phosphorus removal rate at the current dosage is calculated based on the influent flow rate, total phosphorus concentration in the influent, effluent flow rate, and total phosphorus concentration in the effluent during the current control cycle. The theoretical phosphorus removal amount of the current dosage is compared with the actual phosphorus removal amount of the current dosage. If the actual phosphorus removal amount is greater than the theoretical phosphorus removal amount, the difference between the actual and theoretical phosphorus removal amounts is taken as the phosphorus removal amount contributed by phosphorus capacity. If the actual phosphorus removal amount is less than the theoretical phosphorus removal amount, the difference between the theoretical and actual phosphorus removal amounts is taken as the residual phosphorus removal capacity of the pesticide.

3. The chemical phosphorus removal dosing control method according to claim 2, characterized in that, The theoretical phosphorus removal capacity of the current dosage is Cap th ( k ), Cap th ( k )= M chem ( k )× k stoich ( k ); in, k Indicates the current control cycle. M chem ( k This represents the dosage for the current control cycle. k stoich ( k () represents the phosphorus removal capacity coefficient per unit of reagent in the current control cycle; The actual phosphorus removal rate at the current dosage is R obs ( k ), R obs ( k )=( Q in ( k )× P in ( k )− Q out ( k )× P out ( k ))×Δ t ;in, Q in ( k () represents the influent flow rate for the current control cycle. P in ( k () represents the total phosphorus concentration in the influent during the current control cycle. Q out ( k () represents the outflow rate for the current control cycle. P out ( k ) represents the total phosphorus concentration in the effluent during the current control cycle, Δ t This is the duration of the current control cycle; The amount of phosphorus removed by phosphorus capacity is R mem ( k ), R mem ( k )=min( R obs ( k ), Cap th ( k )); The residual phosphorus removal capacity is Cap res ( k ), Cap res ( k )=max(0, Cap th ( k )− R obs ( k )).

4. The chemical phosphorus removal dosing control method according to claim 3, characterized in that, The calculation of phosphorus capacity after sludge discharge loss based on the residual sludge discharge flow rate includes the following steps: obtaining the residual sludge discharge volume based on the residual sludge discharge flow rate; obtaining the phosphorus capacity loss caused by sludge discharge in the current control cycle based on the proportion of residual sludge discharge volume to the effective volume of the system; and subtracting the phosphorus capacity loss from the phosphorus capacity in the current control cycle to obtain the phosphorus capacity after sludge discharge loss. The calculation of phosphorus capacity after natural decay, based on preset memory time parameters, includes the following steps: using preset memory time parameters to perform exponential decay calculation on phosphorus capacity after sludge discharge loss, to obtain phosphorus capacity after natural decay.

5. The chemical phosphorus removal dosing control method according to claim 4, characterized in that, Phosphorus capacity after sludge discharge loss is C eff,1 ( k ), C eff,1 ( k )= C eff ( k )×(1− Q w ( k )×Δt / V tank ); in, C eff ( k () represents the phosphorus capacity initialized for the current control cycle. Q w ( k () represents the remaining sludge discharge flow rate for the current control cycle. V tank The volume of the reaction tank; The phosphorus capacity after natural decay is C eff,2 ( k ), C eff,2 ( k )= C eff,1 ( k )×exp(-Δ t / T mem );in, T mem This is the preset memory time parameter.

6. The chemical phosphorus removal dosing control method according to claim 5, characterized in that, The phosphorus capacity for the next control cycle is C eff ( k +1), C eff ( k +1)= C eff,2 ( k )+ Cap res ( k )− C used ( k ); in, k +1 indicates the next control cycle. C eff,2 ( k This represents the phosphorus capacity decay during the current control cycle. Cap res ( k This represents the residual phosphorus removal capacity of the reagents during the current control cycle. C used ( k This indicates the actual phosphorus capacity consumed during the current control cycle; C used ( k )=min( C eff ( k ), R mem ( k ));in, C eff ( k () represents the phosphorus capacity for the current control cycle. R mem ( k This indicates the amount of phosphorus removed by phosphorus capacity during the current control cycle.

7. A chemical phosphorus removal dosing control method according to claim 5 or 6, characterized in that, The expression for the prediction model of total phosphorus concentration in effluent is: P out,pred ( k )= a 0+ a 1× P in ( k )+ a 2× Q in ( k )+ a 3× M chem ( k )+ a 4× C eff ( k ); in, P out,pred ( k This represents the predicted total phosphorus concentration in the effluent during the current control period. a 0 to a 1 represents the model parameter vector.

8. The chemical phosphorus removal dosing control method according to claim 7, characterized in that, The expression for the deviation of total phosphorus concentration in the effluent is: ;in, The deviation in total phosphorus concentration in the effluent P out,pred ( k +1) represents the predicted total phosphorus concentration in the effluent for the next control cycle. P set The target concentration of total phosphorus in the effluent. P limit This represents the upper limit of total phosphorus concentration in the effluent. The expression for the phosphorus capacity deviation in the next control cycle is: ;in, For the phosphorus capacity deviation in the next control cycle, C eff , pred ( k +1) represents the phosphorus capacity for the next control cycle. C max For maximum safe phosphorus capacity, C min Minimum safe phosphorus capacity; The expression for the current dosage deviation is: ;in, The deviation in the current dosage is due to... M chem ( k- 1) This refers to the dosage in the previous control cycle. M chem,scale This is a normalized table measure of the dosage.

9. The chemical phosphorus removal dosing control method according to claim 8, characterized in that, The expression for the objective function is: .

10. A chemical phosphorus removal dosing control method according to any one of claims 4-6, characterized in that, The method for obtaining the memory time parameter is as follows: conduct a drug withdrawal test and use the time required for the total phosphorus concentration in the effluent to rise from the normal level to the level exceeding the standard as the memory time parameter.

11. A chemical phosphorus removal dosing control system, characterized in that, include: The operation data acquisition module is used to collect the operation data of the wastewater treatment system. The operation data includes: influent flow rate, effluent flow rate, influent total phosphorus concentration, effluent total phosphorus concentration, current dosage, and excess sludge discharge flow rate. The phosphorus capacity initialization module is used to initialize the phosphorus capacity of the current control cycle using the phosphorus capacity of the previous control cycle; phosphorus capacity is used to characterize the phosphorus removal capacity of the system after the dosing is stopped or reduced, relying on sludge and solid surface deposits. The phosphorus capacity update module is used to update the phosphorus capacity online for the current control cycle based on operating data; it includes: The first numerical calculation unit is used to calculate the difference between the theoretical phosphorus removal capacity and the actual phosphorus removal capacity of the current dosage, and to obtain the phosphorus removal capacity contributed by the phosphorus capacity and the phosphorus removal capacity of the residual agent. The second numerical calculation unit is used to calculate the phosphorus capacity after sludge discharge loss based on the residual sludge discharge flow rate. The third numerical calculation unit is used to calculate the phosphorus capacity after natural decay by combining the preset memory time parameters. The fourth numerical calculation unit is used to combine the phosphorus removal amount contributed by phosphorus capacity, the phosphorus removal capacity of residual reagents, the phosphorus capacity after sludge discharge loss, and the phosphorus capacity after natural decay to obtain the phosphorus capacity for the next control cycle. The prediction model building module is used to establish a prediction model for total phosphorus concentration in effluent using phosphorus capacity as input through multi-parameter linear regression and sliding window least squares method. The prediction model calling module is used to output the total phosphorus concentration in the effluent using the prediction model for the total phosphorus concentration in the effluent. The normalized deviation calculation module is used to obtain the deviation of total phosphorus concentration in the effluent, the phosphorus capacity deviation for the next control cycle, and the deviation of the current dosage. The objective function construction module is used to construct an objective function that includes the deviation of total phosphorus concentration in the effluent, the deviation of phosphorus capacity, and the deviation of the current dosage. The target dosage calculation module is used to calculate the target dosage for the current control cycle by solving an optimization problem that minimizes the objective function, under the condition of satisfying the upper and lower limits of the dosage. The dosing pump control module is used to control the operating frequency of the dosing pump according to the target dosage, thereby completing the chemical phosphorus removal dosing control.

12. A chemical phosphorus removal dosing control system according to claim 11, characterized in that, The first numerical calculation unit includes: The theoretical phosphorus removal calculation subunit calculates the theoretical phosphorus removal amount of the current dosage based on the dosage of the current control cycle and the unit phosphorus removal capacity coefficient of the current control cycle. The actual phosphorus removal calculation subunit is used to calculate the actual phosphorus removal amount of the current dosage based on the influent flow rate, total phosphorus concentration of the influent in the current control cycle, effluent flow rate and total phosphorus concentration of the effluent in the current control cycle. The numerical analysis subunit is used to compare the theoretical phosphorus removal amount of the current dosage with the actual phosphorus removal amount of the current dosage. If the actual phosphorus removal amount is greater than the theoretical phosphorus removal amount, the difference between the actual and theoretical phosphorus removal amounts is taken as the phosphorus removal amount contributed by phosphorus capacity. If the actual phosphorus removal amount is less than the theoretical phosphorus removal amount, the difference between the theoretical and actual phosphorus removal amounts is taken as the residual phosphorus removal capacity of the pesticide.

13. A chemical phosphorus removal dosing control system according to claim 12, characterized in that, The second numerical unit includes: The sludge discharge calculation subunit is used to obtain the amount of residual sludge discharge based on the residual sludge discharge flow rate. The phosphorus capacity loss calculation subunit is used to obtain the phosphorus capacity loss caused by sludge discharge in the current control cycle based on the proportion of residual sludge discharge to the effective volume of the system. The remaining phosphorus capacity calculation subunit is used to subtract the phosphorus capacity loss from the phosphorus capacity of the current control cycle to obtain the phosphorus capacity after sludge discharge loss.

Images