A sewage treatment plant carbon source dosage control method, device, equipment and medium

Abstract

The application discloses a sewage treatment plant carbon source adding amount control method, device, equipment and medium, relates to the sewage treatment automatic control technical field, and carries out pretreatment to the multi-source control data of the sewage treatment process; the nitrogen index emission load and the water yield of the current control period are updated rolling, the cumulative nitrogen index emission load and the cumulative water yield between the starting control period and the current control period are obtained; based on the cumulative nitrogen index emission load, the cumulative water yield, the residual water yield prediction value between the next control period and the end control period of the current control period, the dynamic control set value is determined; the target carbon source adding amount is determined by using the water nitrogen index concentration and the dynamic control set value, the target carbon source adding amount is converted into a control instruction and is issued to an executing mechanism, so that the executing mechanism controls the carbon source adding amount, solves the problem that it is difficult to consider the constraints and dynamically adjusts according to the cumulative emission margin, and realizes the automatic control of the carbon source adding amount.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology for wastewater treatment, and in particular to a method, device, equipment and medium for controlling the amount of carbon source added in a wastewater treatment plant. Background Technology

[0002] Existing wastewater treatment plants typically face two types of constraints simultaneously: one is the daily average constraint within the environmental assessment cycle, such as the daily average total nitrogen in the effluent not exceeding the prescribed limit; the other is the constraint of instantaneous severe exceedances, such as the upper limit of instantaneous extreme values, loss values, or abnormal values ​​specified in online data or regulatory rules not exceeding the prescribed range. In actual production, penalties or assessments not only focus on a single instantaneous reading, but also on whether the daily average value calculated over the assessment cycle meets the standards, while simultaneously prohibiting serious exceedances of instantaneous data.

[0003] Most existing carbon source control methods have fixed control objectives, such as requiring the total nitrogen or nitrate nitrogen in the effluent from the biological treatment tank to be below a certain fixed set value in the long term. Although this method is easy to implement, if the cumulative average concentration is already significantly lower than the limit, the system will continue to add carbon sources according to the conservative target, which can easily lead to carbon source waste and may cause problems such as increased chemical oxygen demand in the effluent, increased sludge production, and increased operating costs. When the influent flow or nitrogen load fluctuates, the system cannot reallocate the allowable discharge margin according to the established cumulative discharge load and the remaining assessment time, resulting in a lack of dynamic adaptability in the control objective.

[0004] Some control methods dynamically adjust the carbon source dosage based on parameters such as influent load, carbon-nitrogen ratio, nitrate-nitrogen concentration, DO (dissolved oxygen), and ORP (oxidation-reduction potential). However, their dynamic adjustment mainly serves the denitrification process itself and does not simultaneously use the cumulative average constraint of the assessment period and the instantaneous extreme value hard constraint as the solution conditions for the real-time control target.

[0005] As can be seen from the above, how to solve the problem of not being able to dynamically adjust according to the cumulative emission margin and the difficulty in taking constraints into account, and how to achieve automated control of carbon source addition in wastewater treatment plants, is a problem that needs to be solved in this field. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a method, apparatus, equipment, and medium for controlling the carbon source dosage in wastewater treatment plants, which can solve the problems of being unable to dynamically adjust according to cumulative emission margins and the difficulty in simultaneously considering constraints, thereby achieving automated control of the carbon source dosage in wastewater treatment plants. The specific solution is as follows: In a first aspect, this application discloses a method for controlling the carbon source dosage in a wastewater treatment plant, including: Acquire multi-source control data of the wastewater treatment process, and preprocess the multi-source control data; Based on the preprocessed data, the nitrogen emission load and effluent volume for the current control period are calculated. The nitrogen emission load and effluent volume for the current control period are then updated on a rolling basis to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control period to the current control period. The nitrogen index includes total nitrogen and nitrate nitrogen. The preprocessed data is used to predict the water output to obtain the predicted value of the remaining water output between the next control cycle and the end of the control cycle. Based on the cumulative nitrogen emission load, the cumulative water discharge, and the predicted remaining water discharge, determine the dynamic control setpoint for the nitrogen index to be achieved for the current control cycle. Using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint, the target carbon source dosage is determined. The target carbon source dosage is converted into a control command and sent to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the control cycle ends, thereby completing the carbon source dosage control.

[0007] Optionally, the step of acquiring multi-source control data of the wastewater treatment process and preprocessing the multi-source control data includes: Acquire multi-source control data for the wastewater treatment process; the multi-source control data includes water quality status data, water quantity and hydraulic status data, actuator action data, and discharge assessment constraint parameters. The multi-source control data is resampled and timestamp aligned to obtain sampled and aligned data; The sampled and aligned data are cleaned of outliers, filled with missing values, and standardized to obtain preprocessed data.

[0008] Optionally, the step of calculating the nitrogen emission load and effluent flow rate for the current control period based on the preprocessed data, and continuously updating the nitrogen emission load and effluent flow rate for the current control period, includes: Extract the effluent nitrogen concentration and effluent flow rate for the current control cycle from the pre-processed data; Based on the effluent nitrogen concentration and the effluent flow rate, calculate the nitrogen emission load for the current control cycle; The outflow rate is used to calculate the outflow volume for the current control cycle; The nitrogen emission load and the effluent volume for the current control cycle are updated on a rolling basis.

[0009] Optionally, based on the cumulative nitrogen emission load, the cumulative effluent volume, and the predicted remaining effluent volume, a dynamic control setpoint for the nitrogen index to be achieved corresponding to the current control cycle is determined, including: Obtain the daily average emission limits for nitrogen; Based on the daily average emission limit of nitrogen index, cumulative nitrogen index emission load, cumulative water discharge and the predicted value of remaining water discharge, the average nitrogen index concentration between the next control cycle and the end of the control cycle of the current control cycle is determined. Construct daily average value constraints and instantaneous extreme value constraints, and set a dynamic daily average safety margin; By using the daily average constraint, the instantaneous extreme value constraint, and the dynamic daily average safety margin, the average nitrogen index concentration is constrained to obtain the dynamic control setpoint value of the nitrogen index to be achieved corresponding to the current control cycle.

[0010] Optionally, determining the target carbon source dosage using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint includes: Calculate the control deviation between the pre-acquired effluent nitrogen concentration and the dynamic control setpoint; The effective volume of water to be treated for denitrification control is determined based on the pretreated data. The concentration of nitrate nitrogen to be removed is determined based on the real-time or predicted effluent nitrate nitrogen concentration and the corresponding dynamic control setpoint. Using the effective water volume and the concentration of nitrate nitrogen to be removed, the theoretical carbon requirement for denitrification is determined; The feedforward carbon source dosage is determined based on the theoretical carbon requirement of denitrification, and the feedback correction carbon source dosage is determined based on the control deviation. The feedforward carbon source dosage and the feedback correction carbon source dosage are fused to obtain the target carbon source dosage.

[0011] Optionally, the target carbon source dosage is converted into a control command, including: By limiting the dosage and rate of change of the target carbon source dosage, the carbon source dosage control amount is obtained; The carbon source dosing control quantity is converted into control commands; the control commands include metering pump frequency control commands, metering pump stroke control commands, dosing valve opening control commands, and carbon source volume dosing flow rate control commands.

[0012] Optionally, control commands are sent to the actuator, so that the actuator controls the carbon source dosage based on the control commands, and the process of acquiring multi-source control data is repeated until the control cycle ends, including: Control commands are issued to the actuators so that the actuators can control the amount of carbon source added based on the control commands; Obtain the current nitrogen concentration in the effluent, as well as the actual carbon source dosage reported by the implementing agency after controlling the carbon source dosage; Based on the current effluent nitrogen concentration, the operational risk status of the wastewater treatment process is determined; Based on the operational risk status, the dynamic control setpoint and target carbon source dosage are adjusted, and then the process of acquiring multi-source control data is repeated until the control cycle ends.

[0013] Secondly, this application discloses a carbon source dosage control device for a wastewater treatment plant, comprising: The preprocessing module is used to acquire multi-source control data of the wastewater treatment process and preprocess the multi-source control data. The rolling update module is used to calculate the nitrogen emission load and effluent volume of the current control cycle based on the preprocessed data, and to perform rolling updates on the nitrogen emission load and effluent volume of the current control cycle to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control cycle to the current control cycle; the nitrogen index includes total nitrogen and nitrate nitrogen; The water output prediction module is used to predict the water output of the preprocessed data and obtain the remaining water output prediction value between the next control cycle and the end control cycle of the current control cycle. The dynamic control setpoint determination module is used to determine the dynamic control setpoint that the nitrogen index should reach for the current control cycle based on the cumulative nitrogen index emission load, the cumulative water discharge, and the predicted value of the remaining water discharge. The carbon source dosage control module is used to determine the target carbon source dosage by using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint, convert the target carbon source dosage into a control command and send it to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the end of the control cycle is reached to complete the carbon source dosage control.

[0014] Thirdly, this application discloses an electronic device, including: Memory, used to store computer programs; A processor is used to execute the computer program to implement the aforementioned method for controlling the carbon source dosage in a wastewater treatment plant.

[0015] Fourthly, this application discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned disclosed method for controlling the carbon source dosage in a wastewater treatment plant.

[0016] Beneficial Effects: This application provides a method for controlling carbon source dosage in wastewater treatment plants. This includes acquiring multi-source control data of the wastewater treatment process and preprocessing the data, thus improving the consistency of control data from different sources and sampling periods. Based on the preprocessed data, the method calculates the nitrogen emission load and effluent volume for the current control period, and continuously updates these data to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control period to the current control period. This improves the matching degree between nitrogen emission assessment results and actual pollutant emission loads, avoiding the judgment of daily average emission risk based solely on single-point concentrations. Furthermore, the method predicts effluent volume from the preprocessed data to obtain the predicted value of the remaining effluent volume from the next control period to the end of the control period, thus improving the dynamic adaptability of the remaining emission margin calculation and ensuring dynamic... The dynamic control setpoint changes with the remaining assessment period and remaining water volume. Based on the cumulative nitrogen emission load, cumulative effluent volume, and predicted remaining effluent volume, the dynamic control setpoint for the nitrogen index corresponding to the current control cycle is determined. Therefore, it can improve the coordinated control capability of daily average constraints and instantaneous extreme value constraints, and avoid long-term use of fixed and conservative nitrogen index control targets. Using the pre-acquired effluent nitrogen concentration and dynamic control setpoint, the target carbon source dosage is determined. The target carbon source dosage is converted into a control command and issued to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the end of the control cycle is reached to complete the carbon source dosage control. Therefore, it can reduce unnecessary denitrification carbon source dosage, reduce the operational risks caused by sudden changes or over-dosing, and ensure that carbon source dosage control is rolled over with the assessment cycle. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This application discloses a flowchart of a method for controlling the carbon source dosage in a wastewater treatment plant. Figure 2 This is a schematic diagram of a carbon source dosage control device for a wastewater treatment plant disclosed in this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in this application. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Existing wastewater treatment plants typically face two types of constraints simultaneously: one is the daily average constraint within the environmental assessment cycle, such as the daily average total nitrogen in the effluent not exceeding the prescribed limit; the other is the constraint of instantaneous severe exceedances, such as the upper limit of instantaneous extreme values, loss values, or abnormal values ​​specified in online data or regulatory rules not exceeding the prescribed range. In actual production, penalties or assessments not only focus on a single instantaneous reading but also on whether the daily average value calculated over the assessment cycle meets the standards, while simultaneously prohibiting severe exceedances in instantaneous data. Most existing carbon source control methods have fixed control objectives, such as long-term requirements that the total nitrogen or nitrate nitrogen in the effluent from the biological treatment tank be less than a certain fixed set value. Although this method is easy to implement, when the daily cumulative average concentration is already significantly lower than the limit, the system continues to add carbon sources according to the conservative target, which can easily lead to carbon source waste and may cause problems such as increased chemical oxygen demand in the effluent, increased sludge production, and increased operating costs. When the influent flow or nitrogen load fluctuates, the system cannot reallocate the allowable discharge margin according to the already formed cumulative discharge load and the remaining assessment time, resulting in a lack of dynamic adaptability in the control objectives. While some control methods dynamically adjust carbon source dosage based on parameters such as influent load, carbon-to-nitrogen ratio, nitrate concentration, DO, and ORP, these dynamic adjustments primarily serve the denitrification process itself and do not simultaneously incorporate the cumulative average constraint over the assessment period and the instantaneous extreme value hard constraint as solution conditions for the real-time control objective. Therefore, how to solve the problem of not being able to dynamically adjust based on cumulative discharge margin while simultaneously considering constraints, and how to achieve automated control of carbon source dosage in wastewater treatment plants, is a problem that needs to be solved in this field.

[0021] See Figure 1 As shown in the figure, this invention discloses a method for controlling the carbon source dosage in a wastewater treatment plant, which may specifically include: Step S11: Obtain multi-source control data of the wastewater treatment process and preprocess the multi-source control data.

[0022] In this embodiment, multi-source control data of the wastewater treatment process is acquired; the multi-source control data is resampled and timestamped to obtain sampled and aligned data; outlier cleaning, missing value supplementation and standardization are performed on the sampled and aligned data to obtain preprocessed data; the multi-source control data includes water quality status data, water quantity and hydraulic status data, actuator action data and discharge assessment constraint parameters.

[0023] The method proposed in this application can be deployed in the host computer, PLC (Programmable Logic Controller), edge computing device, or intelligent dosing control system of a wastewater treatment plant. The controlled object is the external carbon source dosing device in the anoxic zone, denitrification zone, or post-denitrification unit of the biological treatment tank. This method uses a discharge assessment cycle as the basic optimization cycle, for example, from 0:00 to 24:00 of a natural day. Other cycles can also be set according to regulatory requirements or plant management requirements. It can also be applied to biological nitrogen removal systems in municipal wastewater treatment plants, industrial park wastewater treatment plants, or reclaimed water plants. It is suitable for processes such as A / O (Anoxic / Oxic), A² / O (Anaerobic / Anoxic / Oxic), modified A² / O, multi-stage A / O, oxidation ditches, and MBR (Membrane Bioreactor) that have anoxic denitrification zones and require the addition of sodium acetate, methanol, glucose, or a composite carbon source.

[0024] In this embodiment, the multi-source control data includes online instrument data, process operation data, equipment execution data, and emission assessment parameters. The control system operates according to a preset sampling period. Collect water quality status data.

[0025] The water quality status data includes, but is not limited to, total nitrogen in the influent. Ammonia nitrogen in influent - Chemical oxygen demand of influent nitrate nitrogen in influent - Nitrate nitrogen in the anoxic zone or denitrification zone of the biological treatment tank - Total nitrogen in the effluent from the end of the biological treatment tank or the secondary sedimentation tank effluent nitrate nitrogen - Ammonia nitrogen in effluent - Chemical oxygen demand of effluent Dissolved oxygen pH Water temperature Oxidation-reduction potential and MLSS (Mixed Liquor Suspended Solids).

[0026] Water volume and hydraulic status data include, but are not limited to, inflow rate. Outflow rate Internal recirculation flow External return flow , Equalization tank level The system includes information on pump operating status, rainy or dry season indicators, and plant scheduling plans. The water volume and hydraulic status data are used to calculate the cumulative water output within the assessment period and the predicted water output for the remaining period.

[0027] Actuator action data includes, but is not limited to, the frequency of the external carbon source metering pump. Pump stroke rate Valve opening Actual flow rate Effective COD concentration of carbon source reagents Aeration fan frequency, internal recirculation ratio and external reflux ratio The actuator motion data is used to verify the deviation between the actual dosage and the target dosage, and is used for feedback correction.

[0028] Emission assessment constraint parameters are collected, including the daily average emission limit for total nitrogen. Daily average control limit for nitrate nitrogen The upper limit of the instantaneous extreme value or loss value of total nitrogen. and the upper limit of instantaneous extreme values ​​or loss values ​​of nitrate and nitrogen. The system can input the emission assessment constraint parameters, or read them from the regulatory parameter table or the plant's internal parameter table. If the regulator only assesses the daily average total nitrogen value, while nitrate nitrogen is used as an internal process control indicator, then the daily average nitrate nitrogen control limit is... and the upper limit of instantaneous extreme values ​​or loss values ​​of nitrate and nitrogen It can be determined by in-plant experience, historical data, or the ratio between total nitrogen and nitrate nitrogen.

[0029] Since the sampling periods of the feedback signals from the total nitrogen meter, nitrate nitrogen meter, flow meter, dissolved oxygen meter, oxidation-reduction potential meter, and carbon source pump may differ, the control system operates according to a unified control cycle. Resampling and timestamp alignment are performed. For data with shorter sampling periods, the period mean or median is used; for data with longer sampling periods, the previous valid value is preserved, linear interpolation is used, or model prediction is used to fill in the gaps.

[0030] When online data contains negative values, over-range values, communication interruption values, instrument maintenance marker values, or abrupt values ​​that clearly contradict process knowledge, the system marks the data as abnormal. Abnormal data is replaced with the moving average of a sliding window, the historical average for the same period, the predicted value from a soft measurement model, or a manually set conservative value, and the confidence level of the corresponding data is lowered. .

[0031] For data that needs to be included in the prediction model or soft sensor model, the system uses Z-Score (Z-Score Standardization) to bring variables of different dimensions to a similar scale. Specifically: ; in, For the first The original variable in the th... Standardized value for each control cycle. For the first The original variable in the th... The value of each control cycle, For the first The average of the original variables in the historical sample. For the first The standard deviation of each original variable in the historical sample.

[0032] Standardized parameters and It is calculated from historical data during the system debugging phase and saved during deployment.

[0033] In addition, the system establishes a data cache table based on the assessment cycle. The cache table includes at least the timestamp, effluent flow rate, effluent total nitrogen, effluent nitrate nitrogen, cumulative effluent volume, cumulative total nitrogen load, cumulative nitrate nitrogen load, dynamic control setpoint, target dosage, and actual dosage for each control cycle. This cache table is used for daily average constraint calculation and rolling optimization.

[0034] This application does not use a fixed instantaneous total nitrogen or nitrate nitrogen upper limit as the sole control target, but continuously calculates the accumulated emission load and remaining available emission margin within each control cycle. Therefore, cycle initialization needs to be completed at the beginning of each control cycle.

[0035] The system sets the start time of the assessment cycle. and end time When the assessment cycle is based on calendar days, It is 00:00 on that day. The deadline is 00:00 the following day. Assume there are a total of [number missing] people within the assessment period. There are [number] control cycles, with a control cycle length of [length]. ,but: ; in, To control the cycle length, it can be set to 1 minute, 5 minutes, 10 minutes or other reasonable values ​​according to the instrument sampling cycle and the control system response speed.

[0036] At the start of the assessment period, the system initializes the cumulative water output to: ; in, This refers to the cumulative water output at the start of the assessment period.

[0037] The system initializes the cumulative total nitrogen emission load and cumulative nitrate nitrogen emission load as follows: ; =0; in, The cumulative total nitrogen emission load at the start of the assessment period. This refers to the cumulative nitrogen and nitrate emission load at the start of the assessment period.

[0038] If the system starts midway through the assessment cycle, it reads the historical data generated in the current cycle from the database and restores the cumulative water discharge, cumulative total nitrogen discharge load, and cumulative nitrate nitrogen discharge load.

[0039] For the In each control cycle, the system defines the current effluent flow rate as... The current total nitrogen concentration in the effluent is The current effluent nitrate concentration is The current target carbon source injection amount is The current dynamic control setpoint for total nitrogen is The current dynamic control setpoint for nitrate and nitrogen is .

[0040] The system defines daily average constraint safety margins respectively. , and instantaneous extreme value safety margin , The daily average constraint safety margin is used to prevent the daily average value from exceeding the limit at the end of the period, while the instantaneous extreme value safety margin is used to prevent the extreme value or the upper limit of the loss value from being triggered at any time.

[0041] The system sets dynamic control setpoints upper and lower limits based on process stability and equipment capacity. , , and And set upper and lower limits for carbon source input. , and the maximum change in a single period This is to avoid over-dosing due to excessively low control targets or insufficient denitrification due to excessively high control targets.

[0042] Step S12: Based on the preprocessed data, calculate the nitrogen emission load and effluent volume for the current control cycle, and perform rolling updates on the nitrogen emission load and effluent volume for the current control cycle to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start control cycle to the current control cycle; the nitrogen index includes total nitrogen and nitrate nitrogen.

[0043] In this embodiment, the effluent nitrogen concentration and effluent flow rate for the current control period are extracted from the preprocessed data; the nitrogen emission load for the current control period is calculated based on the effluent nitrogen concentration and the effluent flow rate; the effluent volume for the current control period is calculated using the effluent flow rate; and the nitrogen emission load and effluent volume for the current control period are updated on a rolling basis to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start control period to the current control period.

[0044] The system calculates the discharge load for each control cycle based on the current effluent nitrogen concentration and flow rate. The total nitrogen discharge load for the current control cycle is: ; in, For the first Total nitrogen emission load for each control cycle For the first The total nitrogen concentration in the effluent during each control cycle, For the first The outflow rate for each control cycle To control the cycle length.

[0045] The nitrate and nitrogen emission load for the current control cycle is: ; in, For the first Nitrogen emission load for each control cycle For the first The effluent nitrate and nitrogen concentration for each control cycle For the first The outflow rate for each control cycle.

[0046] In practical engineering, a unified unit is used, for example, when the concentration unit is... The unit of flow rate is The time unit is At that time, it can be done according to equal Perform the conversion.

[0047] The system updates the outflow rate for the current control cycle on a rolling basis, specifically as follows: ; in, From the start of the assessment period to the [number]th [period] The cumulative water discharge at the end of each control cycle From the start of the assessment period to the [number]th [period] The cumulative water discharge at the end of each control cycle.

[0048] The system performs rolling updates on the total nitrogen emission load for the current control cycle, specifically as follows: ; in, From the start of the assessment period to the [number]th [period] The cumulative total nitrogen emission load at the end of each control cycle, From the start of the assessment period to the [number]th [period] The cumulative total nitrogen emission load at the end of each control cycle.

[0049] The system updates the nitrate and nitrogen emission loads for the current control cycle on a rolling basis, specifically as follows: ; in, From the start of the assessment period to the [number]th [period] The cumulative nitrogen and nitrate emission load at the end of each control cycle From the start of the assessment period to the [number]th [period] The cumulative nitrogen emission load at the end of each control cycle.

[0050] Based on the cumulative nitrogen emission load and cumulative effluent volume, the system calculates the existing flow-weighted average concentration. The existing total nitrogen flow-weighted average concentration is: ; in, From the start of the assessment period to the [number]th [period] The total nitrogen flow weighted average concentration at the end of each control cycle.

[0051] The established flow-weighted average concentration of nitrate and nitrogen is: ; in, From the start of the assessment period to the [number]th [period] The nitrate-nitrogen flow-weighted average concentration at the end of each control cycle.

[0052] The above average concentration is a flow-weighted average concentration, used to reflect the actual emission load level and to determine the daily average emission risk within the current assessment period.

[0053] Step S13: Predict the outflow rate of the preprocessed data to obtain the predicted value of the remaining outflow rate between the next control cycle and the end control cycle of the current control cycle.

[0054] In this embodiment, the system predicts the remaining outflow between the next control cycle and the end of the control cycle. The prediction method can be based on historical flow rates, current inflow rates, changes in the regulating tank level, the operating status of the booster pump, weather conditions, plant scheduling plans, or machine learning prediction models.

[0055] The specific predicted value of the remaining water discharge is as follows: ; in, For the first The predicted value of remaining water discharge between the next control cycle of the current control cycle and the end control cycle of the assessment cycle. For the first Predicted outflow rate for each future control cycle.

[0056] If the remaining water output cannot be accurately predicted, the system adopts a conservative estimate and increases the safety margin.

[0057] Step S14: Based on the cumulative nitrogen emission load, the cumulative water discharge, and the predicted remaining water discharge, determine the dynamic control setpoint for the nitrogen index to be achieved for the current control cycle.

[0058] In this embodiment, the daily average emission limit of nitrogen index is obtained; based on the daily average emission limit of nitrogen index, cumulative nitrogen index emission load, cumulative effluent volume, and predicted remaining effluent volume, the average nitrogen index concentration between the next control cycle and the end of the control cycle is determined; daily average value constraints and instantaneous extreme value constraints are constructed, and a dynamic daily average safety margin is set; using the daily average value constraints, the instantaneous extreme value constraints, and the dynamic daily average safety margin, the average nitrogen index concentration is constrained to obtain the dynamic control setpoint value of nitrogen index to be achieved corresponding to the current control cycle.

[0059] Based on the daily average total nitrogen emission limit, cumulative total nitrogen emission load, cumulative effluent volume, and predicted remaining effluent volume, the system calculates the theoretically permissible average total nitrogen concentration between the next control cycle of the current control cycle and the end control cycle of the assessment cycle, assuming that the daily average total nitrogen concentration does not exceed the limit at the end of the assessment cycle. Specifically: ; in, For the first The average total nitrogen concentration between the next control cycle of a control cycle and the end control cycle of the assessment cycle, i.e. the average total nitrogen concentration allowed for the remaining period. The higher the value, the more ample the remaining emissions margin. The lower the value, the higher the cumulative emission load. The remaining period is the [number missing]. The period between the next control cycle of a control cycle and the end control cycle of the assessment cycle.

[0060] Based on the daily average control limit for nitrate and nitrogen, the cumulative nitrate and nitrogen emission load, the cumulative effluent volume, and the predicted remaining effluent volume, the system calculates the theoretically permissible average nitrate and nitrogen concentration between the next control cycle of the current control cycle and the end control cycle of the assessment cycle. Specifically: ; in, For the first The average nitrate concentration between the next control cycle of a control cycle and the end control cycle of the assessment cycle, i.e. the average nitrate concentration allowed for the remaining period. It can be the daily average limit for nitrate nitrogen stipulated by regulations, or the process control limit for nitrate nitrogen calculated by the plant based on the total nitrogen control requirements.

[0061] The system determines the current daily average constraint risk level based on the remaining permissible average concentration and a preset threshold: (1) When At that time, it was determined that the daily average margin was sufficient; (2) When At that time, it was determined that the daily average margin was normal; (3) When At that time, the daily average risk was judged to be high.

[0062] in, For traditional fixed control targets, To determine the threshold for margin, This is the daily average risk safety threshold. The same method is used to assess the risk of nitrate and nitrogen.

[0063] The system uses the predicted flow-weighted average concentration at the end of the assessment period not exceeding the daily average emission limit for nitrogen as the daily average constraint. The daily average constraint for total nitrogen is: ; in, In the first The weighted average concentration of total nitrogen flow for the assessment period obtained from the prediction of each control cycle. For the cumulative total nitrogen emission load, For the first The total nitrogen emission load predicted between the next control cycle and the end of the assessment cycle.

[0064] The daily average constraint for nitrate nitrogen is: ; in, In the first The weighted average concentration of nitrate and nitrogen flow rate for the assessment period is obtained from the prediction of each control cycle. To calculate the cumulative nitrogen and nitrate emission load, For the first The predicted nitrogen and nitrate emission load between the next control cycle and the end of the assessment cycle.

[0065] The system uses the instantaneous extreme value constraint that the predicted effluent concentration within any control cycle does not exceed the instantaneous extreme value or the upper limit of the loss value. This constraint is a hard constraint, and its priority is higher than the carbon source conservation target. The instantaneous extreme value constraint for total nitrogen is: ; in, For from the first Forward prediction of the first control cycle The instantaneous total nitrogen concentration at each control step size This represents the instantaneous extreme value or upper limit of total nitrogen loss. This represents the total number of control steps for forward prediction.

[0066] The instantaneous extremum constraint conditions for nitrate nitrogen are: ; in, For from the first Forward prediction of the first control cycle Instantaneous concentration of nitrate nitrogen at a control step size This represents the instantaneous extreme value or upper limit of the loss value of nitrate and nitrogen.

[0067] Even if the daily average still has a margin, as long as it is predicted that the instantaneous extreme value limit may be exceeded in a certain short period of time in the future, the system will also reduce the dynamic control setpoint and enter the safety control.

[0068] To avoid daily average exceedances caused by instrument errors, prediction errors, and influent load surges, the system is configured with a dynamic daily average safety margin, specifically: ; in, For the first The dynamic daily average safety margin for each control cycle. Based on the safety margin, For the first Historical prediction error for each control cycle For the first Data confidence level for each control cycle For the first The influent load fluctuation coefficient for each control cycle For the first The remaining time risk coefficient for each control cycle. , , , These are the weighting coefficients for the corresponding items.

[0069] The larger the prediction error, the lower the data confidence level, the stronger the load fluctuation, or the shorter the remaining time, the greater the dynamic daily average safety margin.

[0070] The system also sets an instantaneous extreme value safety margin, specifically: ; in, ) is the first Instantaneous extreme value safety margin for each control cycle Based on the instantaneous safety margin, For the first Instantaneous prediction error per control cycle For the first Impact load risk coefficient for each control cycle For the first Instrument uncertainty coefficient for each control cycle , , These are the weighting coefficients for the corresponding items.

[0071] The system calculates the original dynamic control setpoint for total nitrogen under daily average constraints based on the allowable average total nitrogen concentration for the remaining time period and the dynamic daily average safety margin. Specifically: ; in, For the first The initial dynamic control setpoint for total nitrogen for each control cycle. The average total nitrogen concentration allowed for the remaining period. This represents the dynamic daily average safety margin for total nitrogen. This setpoint indicates the total nitrogen control target allowed in the current control period, provided that the daily average constraint is met.

[0072] The system calculates the original dynamic control setpoint for nitrate nitrogen under the daily average constraint based on the allowable average nitrate nitrogen concentration for the remaining time period and the dynamic daily average safety margin. Specifically: ; in, For the first The original dynamic control setpoints for nitrate and nitrogen for each control cycle. The average nitrate concentration allowed for the remaining period. This represents the dynamic daily average safety margin for nitrate nitrogen. Since nitrate nitrogen typically has a faster online detection response than total nitrogen, the system prioritizes adjusting the carbon source dosage based on the dynamic control setpoint for nitrate nitrogen and uses the cumulative total nitrogen value for long-term correction.

[0073] The system integrates instantaneous extreme value hard constraints, process allowable lower limits, and process allowable upper limits to obtain the final dynamic control setpoint for total nitrogen, specifically: ; in, This is the final dynamic control setpoint for total nitrogen in the k-th control cycle. This is the lower limit of the dynamic control setpoint for total nitrogen. Set an upper limit for the dynamic control of total nitrogen. This represents the instantaneous extreme value or upper limit of total nitrogen loss. This represents the instantaneous extreme value safety margin corresponding to total nitrogen.

[0074] pass To prevent excessive dosing due to excessively low set values, by... and The difference forms an instantaneous extreme hard boundary, through Limit the maximum set value allowed by the process.

[0075] The system integrates instantaneous extreme value hard constraints, process allowable lower limits, and process allowable upper limits to obtain the final dynamic control setpoints for nitrate and nitrogen, specifically: ; in, This is the final dynamic control setpoint for nitrate and nitrogen in the k-th control cycle. This is the lower limit of the dynamic control setpoint for nitrate and nitrogen. Set an upper limit for dynamic control of nitrate and nitrogen. This represents the instantaneous extreme value or upper limit of the loss value of nitrate and nitrogen. This represents the instantaneous extreme value safety margin for nitrate and nitrogen. Consequently, the dynamic control setpoint for nitrate and nitrogen is simultaneously constrained by both the daily average and the instantaneous extreme value.

[0076] In this embodiment, the system expresses the dynamic control setpoint solution as a rolling constraint optimization problem. The optimization objective is to maximize the current dynamic control setpoint while satisfying daily average constraints, instantaneous extreme value constraints, and process upper and lower limit constraints. Since a higher allowable setpoint for effluent nitrogen typically requires less external carbon source, maximizing the dynamic control setpoint corresponds to reducing the carbon source dosage. The optimization objective is: ; in, Let be the objective function for the k-th control cycle. This is a penalty item for exceeding the risk limit. , , These are the weighting coefficients for the corresponding items.

[0077] The daily average total nitrogen constraint condition for the rolling constraint optimization problem is: ; Where st represents the constraint condition. The weighted average concentration of total nitrogen flow during the predicted assessment period, This represents the daily average emission limit for total nitrogen.

[0078] The daily average nitrogen value constraint condition for the rolling constraint optimization problem is: ; in, The weighted average concentration of nitrate and nitrogen flow rate for the predicted assessment period, This represents the daily average control limit for nitrate nitrogen.

[0079] The instantaneous extremum constraint condition for total nitrogen in the rolling constraint optimization problem is: ; in, For from the first Forward prediction of the first control cycle The instantaneous total nitrogen concentration at each control step size This represents the instantaneous extreme value or upper limit of total nitrogen loss.

[0080] The instantaneous extremum constraint condition for the nitrate nitrogen in the rolling constraint optimization problem is as follows: ; in, For from the first Forward prediction of the first control cycle Instantaneous concentration of nitrate nitrogen at a control step size This represents the instantaneous extreme value or upper limit of the loss value of nitrate and nitrogen.

[0081] The upper and lower bound constraints of the process in the rolling constraint optimization problem are: ; in, For the first Dynamic control setpoint for each control cycle This is the lower limit of the dynamic control setpoint allowed by the process. Set the upper limit of the dynamic control settings allowed by the process.

[0082] In actual operation, total nitrogen (TNO) is the final emission assessment indicator, while nitrate nitrogen (NNO) is the main rapid feedback indicator for the denitrification process. The system employs a coordinated strategy of long-cycle TNO constraint and short-cycle NNO control, using TNO constraint correction to the dynamic control setpoint for NNO. Specifically: ; in, This is the final dynamic control setpoint for nitrate nitrogen after total nitrogen constraint correction. These are the dynamic control setpoints for nitrate and nitrogen, determined by daily average constraints and instantaneous extreme value constraints. This is the final dynamic control setpoint for total nitrogen. The weighted average concentration of the total nitrogen flow rate. The daily average emission limit for total nitrogen. This is a conversion function for the dynamic control setpoint of nitrate nitrogen under total nitrogen constraint. The conversion function is determined based on historical data of the proportion of nitrate nitrogen to total nitrogen, residual organic nitrogen, residual ammonia nitrogen, and the relationship between total nitrogen and nitrate nitrogen in the effluent.

[0083] Step S15: Using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint, determine the target carbon source dosage, convert the target carbon source dosage into a control command and send it to the actuator, so that the actuator can control the carbon source dosage based on the control command. Repeat the process of acquiring multi-source control data until the end of the control cycle is reached to complete the carbon source dosage control.

[0084] In this embodiment, the control deviation between the pre-acquired effluent nitrogen index concentration and the dynamic control setpoint is calculated; the effective treated water volume for denitrification control is determined based on the pre-treated data; the concentration of nitrate nitrogen to be removed is determined based on the real-time or predicted effluent nitrate nitrogen concentration and the corresponding dynamic control setpoint; the theoretical carbon requirement for denitrification is determined using the effective treated water volume and the concentration of nitrate nitrogen to be removed; the feedforward carbon source dosage is determined based on the theoretical carbon requirement for denitrification, and the feedback correction carbon source dosage is determined based on the control deviation; the feedforward carbon source dosage and the feedback correction carbon source dosage are fused to obtain the target carbon source dosage; the target carbon source dosage is subject to dosage limits and change rate restrictions to obtain the carbon source dosage. The process involves: adding a control quantity; converting the carbon source addition control quantity into a control command; issuing the control command to the actuator so that the actuator can control the carbon source addition amount based on the control command; acquiring the current effluent nitrogen concentration and the actual carbon source addition amount fed back by the actuator after controlling the carbon source addition amount; determining the operational risk status of the wastewater treatment process based on the current effluent nitrogen concentration; adjusting the dynamic control setpoint and target carbon source addition amount based on the operational risk status, and then repeating the process of acquiring multi-source control data until the control cycle ends; the control commands include metering pump frequency control commands, metering pump stroke control commands, dosing valve opening control commands, and carbon source volume addition flow rate control commands.

[0085] After the dynamic control setpoint is determined, the system calculates the target carbon source dosage based on the deviation between the real-time or predicted effluent nitrogen concentration and the dynamic control setpoint. The control deviation for nitrate nitrogen is: ; in, For the first Nitrogen control deviation for each control cycle For the first Real-time or predicted effluent nitrate nitrogen concentration for each control cycle This is the corresponding final dynamic control setpoint for nitrate and nitrogen.

[0086] The control deviation for total nitrogen is: ; in, For the first Total nitrogen control deviation over one control cycle For the first Real-time or predicted total nitrogen concentration in effluent for each control cycle This is the corresponding final dynamic control setpoint for total nitrogen.

[0087] When the control deviation of nitrate nitrogen or total nitrogen is greater than zero, it indicates that the real-time or predicted concentration is higher than the dynamic control setpoint, and the carbon source needs to be increased; when the control deviation is less than zero and the daily average margin is sufficient, the carbon source can be reduced.

[0088] The system determines the concentration of nitrate nitrogen to be removed based on the real-time or predicted effluent nitrate nitrogen concentration and the corresponding dynamic control setpoint, specifically: ; in, For the first The concentration of nitrate nitrogen to be removed in each control cycle. To determine the real-time or predicted effluent nitrate nitrogen concentration, This corresponds to the final dynamic control setpoint for nitrate and nitrogen.

[0089] The system determines the effective treated water volume for denitrification control based on pretreated data, and uses the effective treated water volume and the concentration of nitrate nitrogen to be removed to determine the theoretical carbon requirement for denitrification, specifically: ; in, For the first The theoretical carbon requirement for denitrification per control cycle. To effectively treat the water volume involved in denitrification control, The concentration of nitrate nitrogen to be removed. It represents the chemical oxygen demand equivalent required to remove one unit of nitrate nitrogen. Determined based on influent flow rate, internal recirculation flow rate, or post-denitrification treatment water volume; Determined based on the type of carbon source and on-site calibration results.

[0090] The system determines the feedforward carbon source dosage based on the carbon requirement of denitrification theory, specifically as follows: ; in, For the first Feedforward carbon source addition amount per control cycle To effectively treat the water volume involved in denitrification control, The effective chemical oxygen demand concentration of the external carbon source, This refers to carbon source utilization efficiency or denitrification conversion efficiency.

[0091] The system determines the feedback correction of carbon source dosage based on control deviation, specifically as follows: ; in, For the first Feedback adjustment of carbon source dosage for each control cycle For proportional control parameters, For integral control parameters, These are differential control parameters. For the first Control deviation per control cycle For the first Control deviation per control cycle. Nitrogen and nitrate can be used to control deviation. Total nitrogen control deviation Or a weighted combination of the two.

[0092] The system fuses the feedforward carbon source dosage and the feedback-corrected carbon source dosage to obtain the target carbon source dosage, specifically: ; in, For the first The target carbon source injection amount for each control cycle This is the baseline dosage to maintain the system's basic denitrification capacity. If the system does not have a baseline dosage, then... Take zero.

[0093] The system limits the dosage and rate of change of the target carbon source to obtain the carbon source dosage control amount, specifically: ; in, For the first The final carbon source addition control amount issued for each control cycle. The minimum allowable dosage, For the maximum allowable dosage, This represents the maximum allowable variation in dosage within a single control cycle. This avoids process fluctuations caused by frequent start-ups and shutdowns of the metering pump or sudden changes in dosage.

[0094] The system converts the carbon source dosing control quantity into a metering pump frequency control command, specifically: ; in, For the first Metering pump frequency control command or metering pump control signal for each control cycle This is the calibration coefficient for the metering pump.

[0095] The system converts the carbon source dosing control quantity into a carbon source volume dosing flow rate control command, specifically: ; in, For the first Carbon source volume addition flow control commands for each control cycle This is a conversion factor for carbon source density or concentration. The system also generates metering pump stroke control commands and dosing valve opening control commands based on the carbon source dosage control amount.

[0096] The control system sends frequency control commands, stroke control commands, dosing valve opening control commands, and carbon source volume dosing flow rate control commands to the metering pump, frequency converter, or dosing valve. After execution, the system reads the actual carbon source dosage fed back by the actuator. It is used to determine whether the implementing agency is implementing the target carbon source addition amount.

[0097] The system obtains the current nitrogen concentration in the effluent and corrects the prediction error based on the actual effluent effect, specifically: ; in, For the first The prediction error for each control cycle, This refers to the actual online test value or the laboratory verification value. These are the model's predicted values.

[0098] When the actual value is consistently higher than the predicted value, it indicates that the model prediction result is too low, and the system increases the safety margin; when the actual value is consistently lower than the predicted value and the system is stable, the system gradually decreases the safety margin.

[0099] The system updates the dynamic daily average safety margin based on the prediction error, specifically as follows: ; in, This serves as the dynamic daily average safety margin for the next control cycle. This represents the dynamic daily average safety margin for the current control cycle. This is the daily average safety margin correction factor.

[0100] The system updates the instantaneous extreme value safety margin based on the instantaneous prediction error, specifically as follows: ; in, This provides a safety margin for the instantaneous extreme values ​​in the next control cycle. This represents the instantaneous extreme value safety margin for the current control cycle. This is the instantaneous extreme value safety margin correction factor. This represents the instantaneous prediction error for the current control cycle. By dynamically updating the safety margin, the system adaptively adjusts to different seasons, load levels, and instrument conditions.

[0101] The system determines the operational risk status of the wastewater treatment process based on the current effluent nitrogen concentration: like or ; and To provide advance warning for extreme values, the wastewater treatment process is determined to enter an instantaneous extreme value safety mode. In this instantaneous extreme value safety mode, the system stops dynamically adjusting the setpoint to conserve carbon sources, adopts a conservative setpoint, and increases the target carbon source dosage as needed.

[0102] like ;in, To determine the daily risk lead time, the wastewater treatment process is set to enter the daily risk protection mode. Under this mode, the system lowers the dynamic control setpoints for total nitrogen and nitrate nitrogen, prioritizing ensuring that the daily average values ​​do not exceed the standards at the end of the assessment period.

[0103] When the total nitrogen meter, nitrate meter, flow meter, carbon source metering pump, communication link, or programmable logic controller malfunctions, the system reduces the confidence level of the corresponding data. The system then switches to a conservative control strategy. This conservative control strategy uses manually set fixed values, historical safe dosage amounts, or backup instrument data until the anomaly is resolved.

[0104] The system writes water quality data, water quantity data, cumulative daily average, remaining allowable average concentration, dynamic control setpoint, target carbon source dosage, actual carbon source dosage, safety margin, risk level, and equipment status into the database for the purpose of tracing operational results, model correction, and verifying implementation effectiveness.

[0105] After completing the calculation, control, and recording of the current control cycle, the system enters the next control cycle and repeats the process of acquiring multi-source control data for the wastewater treatment process. As the cumulative nitrogen emission load, remaining assessment time, predicted remaining effluent volume, and operational risk status continuously change, the dynamic control setpoints also change accordingly. When the end of the control cycle is reached, the carbon source dosage control for the current assessment cycle is completed.

[0106] The core theme of this invention is: in the process of denitrification control in the biological treatment tank of a sewage treatment plant, based on the total nitrogen load, nitrate nitrogen load and effluent volume accumulated within an environmental assessment cycle, combined with the daily average emission limit and the upper limit of instantaneous extreme / loss value, the dynamic control setpoint of the total nitrogen and / or nitrate nitrogen in the effluent of the biological treatment tank at the current moment is solved on a rolling basis, and the amount of external carbon source added is controlled by the dynamic control setpoint.

[0107] This application couples the cumulative discharge load, cumulative effluent volume, remaining assessment period, predicted remaining effluent volume, and daily average discharge limit within the environmental assessment cycle to obtain the average discharge concentration that is still permissible for the remaining period. Then, it integrates the permissible average discharge concentration with the upper limit of instantaneous extreme values / loss values ​​to solve the dynamic control setpoints of total nitrogen and / or nitrate nitrogen in the effluent of the biological treatment tank at the current moment.

[0108] Within each control cycle, the system prioritizes determining whether there is still an emission margin in the current assessment cycle based on the daily average constraint. If the cumulative average is low and the remaining margin is large, the current total nitrogen / nitrate nitrogen control setpoint is appropriately increased to reduce carbon source addition. If the cumulative average is close to the daily limit or there is a risk of exceeding the daily average in the remaining period, the control setpoint is reduced to increase the denitrification intensity. At the same time, the system always sets a hard constraint on instantaneous extreme values. When the predicted or real-time nitrogen index approaches the upper limit of the instantaneous extreme value, the system immediately enters the safety control logic, restricts the setpoint from continuing to rise, and increases carbon source addition.

[0109] Therefore, this invention first solves for a dynamic setpoint that is jointly constrained by a "periodic cumulative average constraint" and an "instantaneous extreme value hard constraint", and then calculates the carbon source dosage based on the deviation between the dynamic setpoint and the actual effluent nitrogen index, thereby achieving synergistic optimization of compliance safety and carbon source economy.

[0110] The key points of this application are: incorporating the cumulative average constraint of the assessment period into the solution of the real-time control setpoints for total nitrogen / nitrate nitrogen in the effluent of the biological treatment tank, eliminating the use of fixed single-point instantaneous control targets; simultaneously coupling the daily average constraint and the instantaneous extreme value / loss value hard constraint into the dynamic setpoint solution algorithm to achieve rolling optimization under dual constraints; the control logic is based on "first solving the maximum allowable SP, and then using SP to drive carbon source addition"; when the cumulative daily average margin is large, the system automatically increases the effluent nitrogen index SP and reduces carbon source addition; when the daily average exceeds the standard risk or the instantaneous extreme value is reached... When the risk increases, the system automatically reduces SP and enters safety control; it adopts a flow-weighted cumulative load calculation method, which is more in line with the pollutant emission load and daily average assessment logic; it supports the coordinated control of total nitrogen and nitrate nitrogen, where nitrate nitrogen can be used as a rapid feedback indicator, and total nitrogen can be used as a daily average assessment and long-term correction indicator; it improves the reliability of engineering operation by dynamically correcting the control target through safety margin, instrument confidence, prediction error and load fluctuation amplitude; the method is compatible with existing wastewater treatment plant central control systems, PLCs, online instruments and carbon source dosing pumps, which facilitates engineering implementation.

[0111] Therefore, this application provides a method for controlling carbon source dosage in wastewater treatment plants, including acquiring multi-source control data of the wastewater treatment process, preprocessing the multi-source control data to improve the consistency of control data from different sources and sampling periods; calculating the nitrogen emission load and effluent volume of the current control period based on the preprocessed data, and continuously updating the nitrogen emission load and effluent volume of the current control period to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start control period to the current control period, thus improving the matching degree between nitrogen index assessment results and actual pollutant emission load, avoiding the judgment of daily average emission risk based solely on single-point concentration; predicting the effluent volume from the preprocessed data to obtain the predicted value of the remaining effluent volume from the next control period to the end control period, thus improving the dynamic adaptability of the remaining emission margin calculation and ensuring dynamic control. The setpoint changes with the remaining assessment period and remaining water volume. Based on the cumulative nitrogen emission load, cumulative effluent volume, and predicted remaining effluent volume, the dynamic control setpoint for the nitrogen index corresponding to the current control cycle is determined. Therefore, it can improve the coordinated control capability of daily average constraints and instantaneous extreme value constraints, and avoid long-term use of fixed and conservative nitrogen index control targets. Using the pre-acquired effluent nitrogen concentration and dynamic control setpoint, the target carbon source dosage is determined. The target carbon source dosage is converted into a control command and issued to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the end of the control cycle is reached to complete the carbon source dosage control. Therefore, it can reduce unnecessary denitrification carbon source dosage, reduce the operational risks caused by sudden changes or over-dosing, and ensure that carbon source dosage control is rolled over with the assessment cycle.

[0112] See Figure 2 As shown in the figure, an embodiment of the present invention discloses a carbon source dosage control device for a wastewater treatment plant, which may specifically include: Preprocessing module 11 is used to acquire multi-source control data of the wastewater treatment process and preprocess the multi-source control data; The rolling update module 12 is used to calculate the nitrogen emission load and effluent volume of the current control cycle based on the preprocessed data, and to perform rolling updates on the nitrogen emission load and effluent volume of the current control cycle to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control cycle to the current control cycle; the nitrogen index includes total nitrogen and nitrate nitrogen; The water output prediction module 13 is used to predict the water output of the preprocessed data to obtain the remaining water output prediction value between the next control cycle and the end control cycle of the current control cycle. The dynamic control setpoint determination module 14 is used to determine the dynamic control setpoint that the nitrogen index should reach in the current control cycle based on the cumulative nitrogen index emission load, the cumulative water discharge, and the predicted value of the remaining water discharge. The carbon source dosage control module 15 is used to determine the target carbon source dosage by using the pre-acquired effluent nitrogen index concentration and the dynamic control set value, convert the target carbon source dosage into a control command and send it to the actuator, so that the actuator can control the carbon source dosage based on the control command, and repeat the process of acquiring multi-source control data until the end of the control cycle is reached to complete the carbon source dosage control.

[0113] In some specific embodiments, the preprocessing module 11 may specifically include: The data acquisition module is used to acquire multi-source control data of the wastewater treatment process; the multi-source control data includes water quality status data, water quantity and hydraulic status data, actuator action data, and discharge assessment constraint parameters; The sampling and alignment module is used to resample and timestamp-align the multi-source control data to obtain sampled and aligned data. The data cleaning and standardization module is used to clean outliers, fill in missing values, and standardize the sampled and aligned data to obtain preprocessed data.

[0114] In some specific embodiments, the rolling update module 12 may specifically include: The data extraction module is used to extract the effluent nitrogen concentration and effluent flow rate of the current control cycle from the preprocessed data. The nitrogen emission load calculation module is used to calculate the nitrogen emission load for the current control cycle based on the effluent nitrogen concentration and the effluent flow rate. The water output calculation module is used to calculate the water output of the current control cycle using the water output flow rate; The cumulative update module is used to continuously update the nitrogen emission load and the effluent volume for the current control cycle.

[0115] In some specific embodiments, the dynamic control setpoint determination module 14 may specifically include: The daily average emission limit acquisition module is used to acquire the daily average emission limit for nitrogen. The average nitrogen index concentration determination module is used to determine the average nitrogen index concentration between the next control cycle and the end of the control cycle based on the daily average nitrogen index emission limit, cumulative nitrogen index emission load, cumulative water discharge and the predicted value of remaining water discharge. The constraint construction module is used to construct daily average value constraints and instantaneous extreme value constraints, and to set dynamic daily average safety margins; The dynamic control setpoint determination module is used to constrain the average nitrogen index concentration using the daily average value constraint, the instantaneous extreme value constraint, and the dynamic daily average safety margin, so as to obtain the dynamic control setpoint that the nitrogen index should reach in the current control cycle.

[0116] In some specific embodiments, the carbon source dosage control module 15 may specifically include: The control deviation calculation module is used to calculate the control deviation between the pre-acquired effluent nitrogen concentration and the dynamic control setpoint. The effective treatment volume determination module is used to determine the effective treatment volume of water participating in denitrification control based on the pretreated data. The module for determining the concentration of nitrate nitrogen to be removed is used to determine the concentration of nitrate nitrogen to be removed based on the real-time or predicted effluent nitrate nitrogen concentration and the corresponding dynamic control setpoint. The theoretical carbon requirement for denitrification is determined using the effective treated water volume and the concentration of nitrate nitrogen to be removed. The feedforward and feedback dosage determination module is used to determine the feedforward carbon source dosage based on the theoretical carbon requirement for denitrification, and to determine the feedback correction carbon source dosage based on the control deviation. The target carbon source dosage determination module is used to fuse the feedforward carbon source dosage and the feedback correction carbon source dosage to obtain the target carbon source dosage.

[0117] The carbon source addition control quantity determination module is used to limit the addition amount and the rate of change of the target carbon source addition quantity to obtain the carbon source addition control quantity. The control command conversion module is used to convert the carbon source dosing control quantity into control commands; the control commands include metering pump frequency control commands, metering pump stroke control commands, dosing valve opening control commands, and carbon source volume dosing flow rate control commands.

[0118] The control command issuing module is used to issue control commands to the actuator, so that the actuator can control the amount of carbon source added based on the control commands; The feedback data acquisition module is used to acquire the current nitrogen concentration in the effluent, as well as the actual carbon source dosage fed back by the actuator after controlling the carbon source dosage. The operational risk status determination module is used to determine the operational risk status of the wastewater treatment process based on the current effluent nitrogen concentration. The rolling adjustment module is used to adjust the dynamic control setpoint and target carbon source dosage based on the operational risk status, and then repeatedly execute the process of acquiring multi-source control data until the end of the control cycle is reached.

[0119] Figure 3 This is a schematic diagram of an electronic device provided in an embodiment of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the carbon source dosage control method for a wastewater treatment plant, as disclosed in any of the foregoing embodiments.

[0120] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0121] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored on it include operating system 221, computer program 222 and data 223, etc., and the storage method can be temporary storage or permanent storage.

[0122] The operating system 221 manages and controls the various hardware devices on the electronic device 20 and the computer program 222 to enable the processor 21 to perform calculations and processing on the data 223 in the memory 22. It can be Windows, Unix, Linux, etc. The computer program 222, in addition to including a computer program capable of performing the carbon source dosage control method for a wastewater treatment plant executed by the electronic device 20 as disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the carbon source dosage control device of the wastewater treatment plant from external devices, as well as data collected by its own input / output interface 25.

[0123] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0124] Furthermore, this application also discloses a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, it implements the steps of the carbon source dosage control method for wastewater treatment plants disclosed in any of the foregoing embodiments.

[0125] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0126] The present invention provides a detailed description of a method, apparatus, equipment, and medium for controlling carbon source dosage in a wastewater treatment plant. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for controlling the carbon source dosage in a wastewater treatment plant, characterized in that, include: Acquire multi-source control data of the wastewater treatment process, and preprocess the multi-source control data; Based on the preprocessed data, the nitrogen emission load and effluent volume for the current control period are calculated. The nitrogen emission load and effluent volume for the current control period are then updated on a rolling basis to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control period to the current control period. The nitrogen index includes total nitrogen and nitrate nitrogen. The preprocessed data is used to predict the water output to obtain the predicted value of the remaining water output between the next control cycle and the end of the control cycle. Based on the cumulative nitrogen emission load, the cumulative water discharge, and the predicted remaining water discharge, determine the dynamic control setpoint for the nitrogen index to be achieved for the current control cycle. Using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint, the target carbon source dosage is determined. The target carbon source dosage is converted into a control command and sent to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the control cycle ends, thereby completing the carbon source dosage control.

2. The method for controlling carbon source dosage in a wastewater treatment plant according to claim 1, characterized in that, The acquisition of multi-source control data for the wastewater treatment process, and the preprocessing of the multi-source control data, include: Acquire multi-source control data for the wastewater treatment process; the multi-source control data includes water quality status data, water quantity and hydraulic status data, actuator action data, and discharge assessment constraint parameters. The multi-source control data is resampled and timestamp aligned to obtain sampled and aligned data; The sampled and aligned data are cleaned of outliers, filled with missing values, and standardized to obtain preprocessed data.

3. The method for controlling carbon source dosage in a wastewater treatment plant according to claim 1, characterized in that, The process of calculating the nitrogen emission load and effluent flow rate for the current control period based on preprocessed data, and then continuously updating the nitrogen emission load and effluent flow rate for the current control period, includes: Extract the effluent nitrogen concentration and effluent flow rate for the current control cycle from the pre-processed data; Based on the effluent nitrogen concentration and the effluent flow rate, calculate the nitrogen emission load for the current control cycle; The outflow rate is used to calculate the outflow volume for the current control cycle; The nitrogen emission load and the effluent volume for the current control cycle are updated on a rolling basis.

4. The method for controlling carbon source dosage in a wastewater treatment plant according to claim 1, characterized in that, Based on the cumulative nitrogen emission load, the cumulative effluent volume, and the predicted remaining effluent volume, the dynamic control setpoint for the nitrogen index corresponding to the current control cycle is determined, including: Obtain the daily average emission limits for nitrogen; Based on the daily average emission limit of nitrogen index, cumulative nitrogen index emission load, cumulative water discharge and the predicted value of remaining water discharge, the average nitrogen index concentration between the next control cycle and the end of the control cycle of the current control cycle is determined. Construct daily average value constraints and instantaneous extreme value constraints, and set a dynamic daily average safety margin; By using the daily average constraint, the instantaneous extreme value constraint, and the dynamic daily average safety margin, the average nitrogen index concentration is constrained to obtain the dynamic control setpoint value of the nitrogen index to be achieved corresponding to the current control cycle.

5. The method for controlling carbon source dosage in a wastewater treatment plant according to claim 1, characterized in that, The step of determining the target carbon source dosage by using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint includes: Calculate the control deviation between the pre-acquired effluent nitrogen concentration and the dynamic control setpoint; The effective volume of water to be treated for denitrification control is determined based on the pretreated data. The concentration of nitrate nitrogen to be removed is determined based on the real-time or predicted effluent nitrate nitrogen concentration and the corresponding dynamic control setpoint. Using the effective water volume and the concentration of nitrate nitrogen to be removed, the theoretical carbon requirement for denitrification is determined; The feedforward carbon source dosage is determined based on the theoretical carbon requirement of denitrification, and the feedback correction carbon source dosage is determined based on the control deviation. The feedforward carbon source dosage and the feedback correction carbon source dosage are fused to obtain the target carbon source dosage.

6. The method for controlling carbon source dosage in a wastewater treatment plant according to claim 1, characterized in that, Converting the target carbon source dosage into control commands includes: By limiting the dosage and rate of change of the target carbon source dosage, the carbon source dosage control amount is obtained; The carbon source dosing control quantity is converted into control commands; the control commands include metering pump frequency control commands, metering pump stroke control commands, dosing valve opening control commands, and carbon source volume dosing flow rate control commands.

7. The method for controlling carbon source dosage in a wastewater treatment plant according to any one of claims 1 to 6, characterized in that, Control commands are issued to the actuators so that the actuators can control the carbon source dosage based on the control commands. The process of acquiring multi-source control data is repeated until the control cycle ends, including: Control commands are issued to the actuators so that the actuators can control the amount of carbon source added based on the control commands; Obtain the current nitrogen concentration in the effluent, as well as the actual carbon source dosage reported by the implementing agency after controlling the carbon source dosage; Based on the current effluent nitrogen concentration, the operational risk status of the wastewater treatment process is determined; Based on the operational risk status, the dynamic control setpoint and target carbon source dosage are adjusted, and then the process of acquiring multi-source control data is repeated until the control cycle ends.

8. A carbon source dosage control device for a wastewater treatment plant, characterized in that, include: The preprocessing module is used to acquire multi-source control data of the wastewater treatment process and preprocess the multi-source control data. The rolling update module is used to calculate the nitrogen emission load and effluent volume of the current control cycle based on the preprocessed data, and to perform rolling updates on the nitrogen emission load and effluent volume of the current control cycle to obtain the cumulative nitrogen emission load and cumulative effluent volume from the start of the control cycle to the current control cycle; the nitrogen index includes total nitrogen and nitrate nitrogen; The water output prediction module is used to predict the water output of the preprocessed data and obtain the remaining water output prediction value between the next control cycle and the end control cycle of the current control cycle. The dynamic control setpoint determination module is used to determine the dynamic control setpoint that the nitrogen index should reach for the current control cycle based on the cumulative nitrogen index emission load, the cumulative water discharge, and the predicted value of the remaining water discharge. The carbon source dosage control module is used to determine the target carbon source dosage by using the pre-acquired effluent nitrogen concentration and the dynamic control setpoint, convert the target carbon source dosage into a control command and send it to the actuator, so that the actuator can control the carbon source dosage based on the control command. The process of acquiring multi-source control data is repeated until the end of the control cycle is reached to complete the carbon source dosage control.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the carbon source dosage control method for a wastewater treatment plant as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store computer programs; wherein, when the computer programs are executed by a processor, they implement the carbon source dosage control method for a wastewater treatment plant as described in any one of claims 1 to 7.

Images