Automatic slurry control system for strengthening wet desulphurization

Abstract

The invention provides an automatic slurry control system for strengthening wet desulphurization. The automatic slurry control system comprises a state real-time fusion module, a slurry supply feedforward correction module, a circulating pump energy efficiency cost evaluation module and a circulating pump operation point tracing module which are coupled in sequence. According to the invention, through state prediction and deviation correction, the component content which is difficult to directly measure in the slurry is estimated, and the measurement noise and hysteresis interference of the sensor are inhibited; flue gas parameters are collected and calculated to pre-judge sulfur dioxide load, feed-forward adjustment of the supply amount is achieved, and system response delay is avoided; meanwhile, the effective calcium carbonate solid content is used as feedback control quantity, composite adjustment is constructed, limestone slurry supply adapts to external disturbance, the reaction environment of an absorption tower is stabilized, and the reagent utilization rate is increased; the economical efficiency of the circulating pump is evaluated by combining the mass transfer benefit and the real-time electricity price, the operation frequency of the circulating pump is iteratively optimized, and finally the energy consumption of the circulating pump is minimized while the desulfurization efficiency is guaranteed.

Description

Technical Field

[0001] This disclosure relates to the field of data acquisition and control technology, and in particular to an automatic control system and method for enhancing wet desulfurization of slurry. Background Technology

[0002] The field of data acquisition and control technology uses various sensors and measuring instruments to acquire key physical quantities such as temperature, pressure, flow rate, concentration, and position in real time during the operation of industrial sites, experimental equipment, or various physical systems. These raw data, which are usually analog signals, are transformed into digital information that can be recognized and processed by computers. Based on the data acquisition, the control system performs calculations and makes decisions according to preset control strategies or advanced algorithms.

[0003] In complex industrial processes such as wet desulfurization, existing data acquisition and control technologies rely solely on feedback from the pH value of the slurry to adjust the limestone supply. However, as a comprehensive macroscopic characterization of chemical reactions, pH changes lag behind the actual consumption of components within the slurry. When the flue gas load changes, the control system can only passively adjust after detecting a deviation of the pH value from the set point. This lag response often leads to momentary over- or under-dosage of reagents, wasting limestone and potentially causing short-term failures in desulfurization efficiency. Summary of the Invention

[0004] The purpose of this disclosure is to provide an automatic control system and method for enhancing wet desulfurization slurry, in order to solve the problems existing in the prior art.

[0005] The embodiments of this disclosure adopt the following technical solution: an automatic control system for slurry in enhanced wet desulfurization, comprising: a real-time state fusion module, used to generate a slurry state prediction vector based on the sulfur dioxide concentration at the absorber outlet, slurry pH value, densitometer reading, the state estimate value at the previous moment, and the current control input value; generate a measurement deviation vector based on the slurry state prediction vector and the slurry pH value; and adjust the components of the slurry state prediction vector based on the measurement deviation vector to generate an estimated slurry component value; and a slurry replenishment feedforward correction module, used to calculate the total sulfur dioxide load based on the inlet flue gas flow rate and sulfur dioxide concentration, determine the basic replenishment amount for disturbance compensation, and combine the effective calcium carbonate solid content in the estimated slurry component value as... The feedback control input generates a composite adjustment for the limestone slurry flow rate; the circulating pump energy efficiency cost assessment module is used to collect the inlet and outlet sulfur dioxide concentrations and the slurry circulating pump flow rate to calculate the mass transfer efficiency, establish mass transfer efficiency assessment parameters, and collect the input power of the slurry circulating pump and the real-time electricity price to calculate the electricity cost. Based on the mass transfer efficiency assessment parameters and the electricity cost, the current operating condition energy efficiency cost index is determined; the circulating pump operating point tracking module is used to apply frequency perturbation to the current frequency of the slurry circulating pump, obtain a new operating condition energy efficiency cost index after stabilization, determine the pump frequency perturbation adjustment direction by combining it with the operating condition energy efficiency cost index of the previous cycle, and update the frequency setpoint of the slurry circulating pump according to the pump frequency perturbation adjustment direction to establish the optimal slurry circulating pump operating frequency.

[0006] This disclosure also provides an automatic slurry control method for enhanced wet desulfurization, comprising: generating a slurry state prediction vector based on the sulfur dioxide concentration at the absorber outlet, slurry pH value, densitometer reading, previous state estimate, and current control input value; generating a measurement deviation vector based on the slurry state prediction vector and slurry pH value; adjusting the components of the slurry state prediction vector based on the measurement deviation vector to generate slurry component estimates; calculating the total sulfur dioxide load based on the inlet flue gas flow rate and sulfur dioxide concentration; determining the basic replenishment amount for disturbance compensation; and using the effective calcium carbonate solid content in the slurry component estimates as feedback. The controlled input is used to generate a composite regulation of limestone slurry flow rate; the inlet and outlet sulfur dioxide concentrations and slurry circulation pump flow rates are collected to calculate mass transfer efficiency, establish mass transfer efficiency evaluation parameters, and the input power of the slurry circulation pump and real-time electricity price are collected to calculate electricity cost. Based on the mass transfer efficiency evaluation parameters and the electricity cost, the current operating condition energy efficiency cost index is determined; a frequency disturbance is applied to the current frequency of the slurry circulation pump, and after stabilization, a new operating condition energy efficiency cost index is obtained. The pump frequency disturbance adjustment direction is determined by combining the operating condition energy efficiency cost index of the previous cycle, and the frequency setpoint of the slurry circulation pump is updated according to the pump frequency disturbance adjustment direction to establish the optimal slurry circulation pump operating frequency.

[0007] The beneficial effects of this embodiment are as follows: By combining the state estimation of the previous moment with the current control input for state prediction, and then using the deviation between the current slurry pH measurement value and the predicted output for correction, it is possible to obtain an estimate of the content of components in the slurry that are difficult to measure directly, and suppress the interference caused by the measurement noise and hysteresis of a single sensor; in slurry replenishment regulation, real-time acquisition and calculation of the inlet flue gas flow rate and sulfur dioxide concentration can predict the total sulfur dioxide load in advance, realize rapid feedforward adjustment of the basic replenishment amount for disturbance compensation, and avoid system response lag caused by drastic load fluctuations; at the same time, the estimated effective carbon dioxide Calcium content, used as a feedback control variable, forms a composite regulation of feedforward and feedback, ensuring that the supply of limestone slurry can respond quickly to external disturbances while maintaining the stability of the chemical reaction environment inside the absorber, thus improving reagent utilization and reducing the risk of over-addition. The operating economy of the circulating pump is evaluated by establishing a dynamic correlation between mass transfer efficiency and electricity cost under real-time electricity price, and the frequency of the circulating pump is perturbed. Based on the changing trend of the energy efficiency cost index, iterative tracking is performed to continuously explore and lock the optimal operating frequency under the current operating conditions, thereby minimizing the energy consumption of the circulating pump while ensuring desulfurization efficiency. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the slurry automatic control system for enhancing wet desulfurization in the first embodiment of this disclosure; Figure 2 This is an operation flowchart of the automatic control process of slurry in the enhanced wet desulfurization of the system in the first embodiment of this disclosure; Figure 3 This is a flowchart of an automatic slurry control method for enhancing wet desulfurization in the second embodiment of this disclosure. Detailed Implementation

[0010] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0011] To address the problems existing in the prior art, the first embodiment of this disclosure provides an automatic slurry control system for enhanced wet desulfurization, the structural schematic diagram of which is shown below. Figure 1 As shown, it mainly includes a real-time state fusion module 10, a slurry replenishment feedforward correction module 20, a circulating pump energy efficiency cost assessment module 30, and a circulating pump operating point tracking module 40, which are coupled sequentially.

[0012] The real-time state fusion module 10 in this embodiment is mainly used to generate a slurry state prediction vector based on the sulfur dioxide concentration at the outlet of the absorption tower, the pH value of the slurry, the densitometer reading, the state estimate value at the previous moment, and the current control input value. It generates a measurement deviation vector based on the slurry state prediction vector and the slurry pH value, and adjusts the components of the slurry state prediction vector based on the measurement deviation vector to generate slurry component estimates.

[0013] In this embodiment, the real-time state fusion module 10 is specifically used to: collect the sulfur dioxide concentration, slurry pH value, and densitometer reading at the absorber tower outlet, and perform time alignment processing. First, according to a unified time base of once every 5 seconds, the sulfur dioxide concentration, slurry pH value, and densitometer reading at the absorber tower outlet collected by different sensors are aligned on the timestamp using linear interpolation to ensure that all data points correspond to the same moment; then, the effective calcium carbonate solid content, calcium sulfite solid content, gypsum solid content, and inert substance solid content in the state estimate value of the previous moment, as well as the limestone slurry replenishment flow rate and slurry... The frequency of the liquid circulation pump is measured. Then, the aligned measurement data is combined with the extracted state estimate from the previous moment and the current control input value, and concatenated according to the fixed field order of [outlet sulfur dioxide concentration, slurry pH value, densitometer reading, effective calcium carbonate solid content, calcium sulfite solid content, gypsum solid content, inert substance solid content, limestone slurry replenishment flow rate, and slurry circulation pump frequency] to form a temporary state vector. Next, each component in this temporary state vector is physically truncated. The truncation is based on the reasonable operating range of each physical quantity under actual working conditions. For example, the effective range of the sulfur dioxide concentration at the absorber outlet is set to 0. The effective range for slurry pH is set from 4.0 to 7.0, and the effective range for densitometer readings is set from 1050 kg / m³ to 1200 kg / m³. When a measured value exceeds its set physical boundary, its value is corrected to the closest boundary value. For example, a pH reading of 3.8 will be corrected to 4.0, and a sulfur dioxide concentration reading exceeding 200 mg / m³ will be corrected to 200 mg / m³. After truncation, a slurry state prediction vector is generated.

[0014] Furthermore, the real-time state fusion module 10, based on the slurry state prediction vector obtained in the previous step, utilizes a pre-established slurry pH process model function. This function is based on the chemical equilibrium relationship between the concentration of each component in the slurry and the pH value. It inputs chemical components such as the effective calcium carbonate content and calcium sulfite content from the slurry state prediction vector to calculate a predicted output value, namely the slurry pH prediction value. Subsequently, it reads the actual measured slurry pH value at the current moment, calculates the difference and its sign between the predicted and actual measured slurry pH values, obtains the deviation data, and then... Based on the sliding window, anomaly removal and difference limiting are performed on the deviation data within the sliding window to generate a measurement deviation vector. Specifically, the anomaly removal method maintains a sliding window containing the most recent 60 historical differences, calculates the average and standard deviation of the differences within the window, and sets a dynamic threshold. This threshold is the average difference plus 1.5 times the standard deviation. If the absolute value of the currently calculated difference exceeds this dynamic threshold, it is identified as an outlier, and its value is replaced with the average difference within the window. For example, if the average difference is 0.05 and the standard deviation is 0.02, then the dynamic threshold is 0.05. + 1.5 * 0.02 = 0.08. Any difference with an absolute value greater than 0.08 is considered an anomaly. After anomaly removal, the processed differences are then subjected to amplitude limiting. A fixed amplitude limiting threshold based on statistical analysis of historical operating data is set, which is ±0.25. This is because under stable operating conditions, the reasonable fluctuation of pH value caused by single-step adjustment usually does not exceed 0.25. If the difference exceeds ±0.25, it is forcibly corrected to ±0.25. Finally, according to the sampling order of data acquisition time, the differences after anomaly removal and difference limiting processing and their corresponding difference signs are organized to form a time series correspondence, generating a measurement deviation vector of slurry pH value.

[0015] Subsequently, based on the measurement deviation vector, the components in the slurry state prediction vector are weighted and adjusted. The weighting coefficients are preset according to the sensitivity of each component to pH. For example, the adjustment weighting coefficient K_c for effective calcium carbonate content is set to 0.15, and the adjustment weighting coefficient K_s for calcium sulfite content is set to -0.08. The adjustment formula is: New component content = Original component content + Weighting coefficient * pH deviation. When the pH measurement value is lower than the predicted value, the pH deviation is negative, so the effective calcium carbonate content as an alkaline buffer is increased, while the calcium sulfite content as a reaction product is decreased. After adjustment, a preliminary corrected state vector is obtained. Next, the consistency of the densitometer readings is checked. Based on the content of each solid component (effective calcium carbonate, calcium sulfite, gypsum, inert substances) in the preliminary corrected state vector, combined with the standard density of each component (e.g., calcium carbonate density is 2710 kg / m³, gypsum density is 2320 kg / m³), the results are adjusted. The density of the slurry (kg / m³) and water are used to calculate a theoretical slurry density through weighted averaging. This theoretical slurry density is then compared with the actual reading of the densitometer in the slurry state prediction vector. A consistency tolerance threshold of ±8 kg / m³ is set. This threshold is determined based on the accuracy of the densitometer itself and experience with process fluctuations. If the absolute value of the difference between the two exceeds this tolerance threshold, the adjustment amount of all solid components is reduced proportionally until the difference between the theoretical density and the actual reading is within the tolerance range.

[0016] Furthermore, the effective calcium carbonate content in the adjusted slurry state prediction vector is subjected to constrained projection based on sulfur dioxide concentration to generate slurry component estimates. Specifically, using a simplified desulfurization efficiency model, a predicted outlet sulfur dioxide concentration is recalculated based on the adjusted effective calcium carbonate solid content and the current liquid-to-gas ratio. This predicted concentration is then compared with the actual outlet sulfur dioxide concentration in the slurry state prediction vector. If the predicted sulfur dioxide concentration trend contradicts the adjustment direction of the effective calcium carbonate content (e.g., the calcium carbonate content is increased but the predicted sulfur dioxide concentration rises), the adjustment amount of the effective calcium carbonate solid content is reversed until it conforms to the basic chemical laws of the desulfurization reaction. After iterative correction through three steps—component-by-component adjustment, density consistency check, and sulfur dioxide concentration constrained projection—the final slurry component estimates are generated.

[0017] The slurry replenishment feedforward correction module 20 is used to calculate the total sulfur dioxide load based on the inlet flue gas flow rate and sulfur dioxide concentration, determine the basic replenishment amount for disturbance compensation, and combine the effective calcium carbonate solid content in the estimated slurry composition as the input of feedback control to generate a composite regulated limestone slurry flow rate. Specifically, the slurry replenishment feedforward correction module 20 first collects the inlet flue gas flow rate and sulfur dioxide concentration, and performs time alignment processing. In actual execution, the two asynchronously collected signals can be time aligned according to a unified time base of 10 seconds. The specific method is to use the forward filling method, that is, if flue gas flow data is missing at a certain time point, the most recent valid reading before that time point is used to fill it, and vice versa. Next, the measurement units are unified, converting the inlet flue gas flow rate from operating condition cubic meters per hour (m³ / h) to standard condition dry flue gas flow rate kilograms per second (kg / s), and converting the sulfur dioxide concentration from milligrams per cubic meter (mg / m³) to mass fraction (dimensionless). For any missing points that may exist in the data sequence, linear interpolation is used to fill them in, but the number of consecutive data points filled in does not exceed 3. That is, data segments that are missing for more than 30 seconds will be marked as invalid and will not be included in the calculation. Subsequently, at each aligned time point, the converted standard dry flue gas flow rate is multiplied by the mass fraction of sulfur dioxide to obtain the instantaneous sulfur dioxide mass flow rate (in kg / s) at that moment. Finally, using a preset calculation period of 5 minutes, all (i.e., 30) instantaneous sulfur dioxide mass flow rates within this period are summed and then multiplied by the sampling time interval of 10 seconds to calculate the total mass of sulfur dioxide entering the absorption tower during these 5 minutes, thus generating the total sulfur dioxide load.

[0018] Furthermore, the slurry replenishment feedforward correction module 20, based on the total sulfur dioxide load obtained in the previous step, first reads the preset stoichiometric parameters from the system configuration, including the molecular weight of calcium carbonate (CaCO3) (set to 100.09 g / mol), the molecular weight of sulfur dioxide (SO2) (set to 64.07 g / mol), and a calcium-sulfur ratio correction coefficient to compensate for incomplete reactions and the influence of impurities. This coefficient is set based on historical operating data statistics and process requirements, for example, set to 1.05. Then, according to the chemical reaction equation CaCO3 + SO2 → CaSO3 + CO2, it performs dimensional conversion according to the reaction ratio of sulfur and calcium carbonate, converting the total sulfur dioxide load (in kg) into the theoretically required mass of pure calcium carbonate. The calculation method is: required mass of calcium carbonate = total sulfur dioxide load * (100.09 / 64.07 g / mol). Then, the calculation results are truncated and anomaly removed based on the time period boundaries. The time period boundaries refer to the upper and lower limits of the physical delivery capacity of the limestone slurry supply pump. For example, based on the pump's performance curve, the upper limit of a single supply is set to 200 kg and the lower limit to 10 kg. If the calculated required calcium carbonate mass exceeds 200 kg, its value is truncated to 200 kg. If it is less than 10 kg, it is accumulated to the next calculation period and not supplied immediately. Anomaly removal is achieved by comparing the calculation results with the previous period. If the change rate between the current calculated value and the value of the previous period exceeds 50%, it is judged as an anomaly, and the value of the previous period is used to replace the current value. Finally, the processed required calcium carbonate mass value is used as the demand scale for that period and cumulatively allocated by period, that is, it is converted into the average mass flow rate (kg / s) within the corresponding period to generate the disturbance compensation base supply.

[0019] Subsequently, the slurry replenishment feedforward correction module 20, based on the disturbance compensation base replenishment amount generated in the previous steps, simultaneously retrieves the effective calcium carbonate solid content from the estimated slurry composition as the input for feedback control, compares the effective calcium carbonate solid content with the preset target solid content, and determines the solid content deviation. The preset target solid content is determined based on a trade-off between desulfurization efficiency and economy, for example, set to 12% (mass fraction). Then, based on the direction (positive or negative) and magnitude of the solid content deviation, the slurry flow rate adjustment value of the feedback control output is obtained by consulting a preset two-dimensional mapping table. This mapping table is based on a large amount of historical working data and establishes the relationship between the deviation and the replenishment adjustment value through regression analysis. For example, when the deviation is -2% (i.e., the actual value is 10%, which is lower than the target value of 2%), the feedback control output obtained from the table is to increase the slurry flow rate by 1.5 m³ / h. When the deviation is +1% (i.e., the actual value is 13%, which is higher than the target value of 1%), the feedback control output obtained from the table is to decrease the slurry flow rate by 0.8 m³ / h. When the absolute value of the deviation is less than 0.2%, it is considered a control dead zone, and the feedback control output is 0.

[0020] After obtaining the slurry flow rate adjustment value from the feedback control output, the disturbance compensation base supply amount (pure calcium carbonate mass flow rate, kg / s) of the feedforward part is first converted into the base slurry flow rate (m³ / h) based on the calibrated concentration (e.g., 20% solid content) and density (e.g., 1100 kg / m³) of the limestone slurry. Then, this base slurry flow rate is summed with the slurry flow rate adjustment value from the feedback control output at time points to obtain a preliminary composite regulating flow rate. Finally, the flow rate is limited, and its upper and lower limits are determined by the minimum starting flow rate and the maximum rated flow rate of the limestone slurry pump, for example, set to 2 m³ / h and 25 m³ / h. If the summed result exceeds this range, the corresponding boundary value is taken to generate the final composite regulating limestone slurry flow rate.

[0021] In this embodiment, the circulating pump energy efficiency cost assessment module 30 is mainly used to collect inlet and outlet sulfur dioxide concentrations and slurry circulating pump flow rates to calculate mass transfer benefits, establish mass transfer benefit assessment parameters, and collect the input power of the slurry circulating pump and real-time electricity prices to calculate electricity costs. Based on the mass transfer benefit assessment parameters and electricity costs, the current operating condition energy efficiency cost index is determined. Specifically, the circulating pump energy efficiency cost assessment module 30 is used to: collect inlet sulfur dioxide concentration, outlet sulfur dioxide concentration, and slurry circulating pump flow rates, and perform time alignment processing; calculate the difference between the inlet sulfur dioxide concentration and the outlet sulfur dioxide concentration at each time point to obtain the instantaneous removal concentration; calculate the instantaneous mass transfer benefit quantification value based on the instantaneous removal concentration and slurry circulating pump flow rate; and sum all instantaneous mass transfer benefit quantification values ​​within a preset time period, using the sum as the mass transfer benefit assessment parameter for the preset time period.

[0022] Specifically, the circulating pump energy efficiency cost assessment module 30 collects the inlet sulfur dioxide concentration, outlet sulfur dioxide concentration, and slurry circulating pump flow rate. First, based on a unified 5-second time reference, it aligns the three signals collected from different sensors, which may have slight timestamp discrepancies. This is done using nearest neighbor interpolation, assigning the data value of each time point to the nearest 5-second grid point. Then, at each aligned time point, the difference between the inlet and outlet sulfur dioxide concentrations is calculated to obtain the instantaneous removal concentration. Finally, the instantaneous removal concentration, in milligrams per cubic meter (mg / m³), is converted to a unit value (from m³ / h). Multiplying the slurry circulation pump flow rate (m³ / s, i.e., divided by 3600) by the slurry circulation pump flow rate, we obtain a quantitative value representing the instantaneous mass transfer efficiency. Its physical meaning is approximately the mass of sulfur dioxide removed per unit time. Finally, a calculation period of 5 minutes (i.e., 300 seconds) is set, and the quantitative values ​​of all 60 instantaneous mass transfer efficiencies within this period are summed. This sum serves as the overall mass transfer efficiency assessment for this 5-minute period. The setting of this period length is based on an empirical trade-off, which can smooth out second-level measurement noise and small fluctuations, and can also sensitively reflect changes in desulfurization demand caused by changes in operating conditions (such as boiler load changes), thus generating mass transfer efficiency assessment parameters.

[0023] Subsequently, the circulating pump energy efficiency cost assessment module 30 synchronously collects the input power and real-time electricity price of the slurry circulating pump at each time point within a preset time period to obtain the instantaneous power cost at each time point; it sums all instantaneous power costs within the preset time period to obtain the total electricity cost consumed by the slurry circulating pump during the preset time period as the electricity cost; and it calculates the energy efficiency cost index for the current operating condition based on the electricity cost. Specifically, based on the obtained mass transfer benefit assessment parameters, it synchronously collects input power data from the slurry circulating pump motor control center and real-time electricity price data from the power grid dispatch system or a preset peak-valley-flat electricity price meter. First, it synchronizes these two new time series data and aligns them with the 5-second time base used in the mass transfer benefit assessment parameters. If the update frequency of the real-time electricity price is less than 5 seconds (e.g., updated every 15 minutes), the same electricity price value is used for all 5-second time points within that update cycle. At each aligned time point, the slurry circulating pump input power in kilowatts (kW) and the input power in kilowatts (kW) are compared with the ... The instantaneous power cost is obtained by multiplying the real-time electricity price (yuan / kWh) by the actual electricity cost within the 5-second time interval. Then, the unit is converted to the actual electricity cost within the 5-second time interval. Specifically, the instantaneous power cost is multiplied by the time interval (5 seconds) and then divided by 3600 (seconds / hour), thus converting the unit from "yuan / hour" to "yuan". Finally, within a 5-minute calculation period with the same parameters as the mass transfer benefit assessment, the actual electricity costs at all 60 time points within the period are summed to obtain the total electricity cost consumed by the slurry circulation pump during the period, thus generating the electricity cost.

[0024] In this embodiment, the formula for calculating the energy efficiency cost index under the current operating condition is as follows:

[0025] in, This represents the energy efficiency cost index under current operating conditions. This is a dynamic compliance weighting factor used to adjust the mass transfer benefit weights under different emission concentrations. This refers to the inlet sulfur dioxide concentration. For the concentration of sulfur dioxide at the export site, This refers to the flow rate of the slurry circulation pump. This refers to the input power of the slurry circulation pump. For real-time electricity prices, To calculate the start time, To calculate the end time, This indicates the conversion of electricity consumption from kilowatt-hours to cost per second, using a dynamic compliance weighting factor. The calculation expression is: , To adjust the constant of the weighting intensity, To set the target sulfur dioxide emission concentration, To set the upper limit for permissible sulfur dioxide emission concentrations.

[0026] In the above formula, environmental benefits (numerator) and economic costs (denominator) are directly linked to form a cost-benefit ratio indicator, and a dynamic compliance weighting factor is introduced. This factor is expressed through an exponential function, such that when the outlet sulfur dioxide concentration... Approaching environmental limits When the weight increases dramatically, the calculated mass transfer efficiency is amplified. This makes the entire evaluation system not only focus on economic efficiency, but also give higher weight to the boundary area of ​​environmental compliance, guiding the control system to prioritize stronger desulfurization operations when there is a risk of exceeding the standard, even if doing so will temporarily increase energy consumption costs.

[0027] What needs to be understood is that The inlet sulfur dioxide concentration was collected online by a continuous emission monitoring system (CEMS) installed on the inlet flue of the absorption tower. This system reports measurement data every 5 seconds, with the unit being mg / m³. In this embodiment, data from a single time point is selected. =1250mg / m³. The sulfur dioxide concentration at the outlet was collected online by a continuous emission monitoring system (CEMS) installed in the flue gas duct at the absorber outlet (before the chimney). The sampling frequency was also once every 5 seconds, and the data unit was mg / m³. In this embodiment, data from the same time point as the inlet concentration was selected. =28mg / m³. The flow rate of the slurry circulation pump is measured in real time by an electromagnetic flow meter installed on the main outlet pipe of the circulation pump. The data is transmitted to the control system via an industrial bus. The sampling frequency is once per second, and after processing, it is aligned with a 5-second time base. The unit is m³ / h. In this embodiment, data from a single time point is selected. =4200m³ / h. The input power of the slurry circulation pump is measured by a smart power meter installed in the pump motor distribution cabinet. This meter records the motor's real-time active power. The data is uploaded to the control system via the Modbus protocol, with a sampling frequency of once per second. After processing, the data is aligned with a 5-second time base, and the unit is kW. In this embodiment, data from a single time point is selected. =850kW. The real-time electricity price is obtained from the data interface of the local electricity trading market or determined based on the time-of-use price table pre-entered into the system. The price table divides a 24-hour day into peak, flat, and valley periods. At the time of calculation in this example, it falls within the flat price period, and its value is... =0.75 yuan / kWh. and An integration time domain is defined, representing the start and end times of the calculation. The length of this time domain is set according to the stationarity requirements of the system response, typically representing the stability evaluation phase after a complete optimization perturbation cycle. Here, it is set to an evaluation cycle of 5 minutes. Second. The constant used to adjust the weighting intensity determines the sensitivity of the weighting factor to changes in outlet concentration. Its value is determined through regression analysis of historical operating data, analyzing the outlet concentration and corresponding energy efficiency cost index under different operating conditions over a month, and adjusting through simulation. Values ​​(from 0.5 to 10.0, in steps of 0.5), observe The impact of value changes on the final operating point selection aims to choose a point that provides a sufficiently strong penalty when the concentration approaches the limit, while also minimizing the impact on economic efficiency during the normal operating range. The value is determined based on the analysis results. The value is 4.5. The target sulfur dioxide emission concentration is an internal control target set by the power plant's operation and management department based on environmental requirements and operational margins. It is typically lower than the legal emission limit to allow for safety margins in operational adjustments. This value is read from the system's operating parameter configuration library and is set to [value missing]. =20mg / m³. This value, set according to the regulations for the emission standards of this type of unit, is a limit on the permissible concentration of sulfur dioxide. =35mg / m³.

[0028] Based on the values ​​of the above parameters in this embodiment, the following calculation process can be obtained: Since the formula is in integral form, in actual discrete control systems, an approximate calculation is performed using a summation method, with the calculation period set to 300 seconds. ), sampling interval The sampling points are 60 in total, and for example, all parameter values ​​remain stable within 300 seconds, which is the instantaneous value obtained above.

[0029] First, calculate the dynamic compliance weighting factor. Value: ; Next, the numerator (total weighted desulfurization mass) is calculated, i.e., the integral. Approximate value: Instantaneous weighted desulfurization mass rate = : = ; Total weighted desulfurization mass = Instantaneous weighted desulfurization mass rate : = ; Then calculate the denominator (total electricity cost), i.e., the integral. Approximate value: Instantaneous electricity cost rate = ; Total electricity cost = Instantaneous electricity cost rate ; = ; Finally, calculate the energy efficiency cost index under the current operating conditions. : ; The results indicate that, under current operating conditions, for every 1 yuan of electricity cost, 0.12136 kg of weighted sulfur dioxide removal can be achieved. After adjustments to the system operation, if the calculated new... If the value is greater than 0.12136 kg / yuan, it indicates that the adjustment has improved the system's energy efficiency and cost-effectiveness; conversely, if the new value is less than 0.12136 kg / yuan, it indicates that the adjustment has improved the system's energy efficiency and cost-effectiveness. If the value is less than 0.12136 kg / yuan, it indicates that the adjustment has led to a decrease in the cost-effectiveness ratio.

[0030] The circulating pump operating point tracking module 40 is used to apply frequency disturbance to the current frequency of the slurry circulating pump, obtain the new operating condition energy efficiency cost index after stabilization, determine the pump frequency disturbance adjustment direction by combining the operating condition energy efficiency cost index of the previous cycle, and update the frequency setting value of the slurry circulating pump according to the pump frequency disturbance adjustment direction to establish the optimal operating frequency of the slurry circulating pump. Specifically, the circulating pump operating point tracking module 40 is used to apply frequency disturbance to the current frequency of the slurry circulating pump, set the disturbance amplitude and duration, monitor the fluctuation amplitude of outlet sulfur dioxide concentration, slurry pH value, and slurry circulating pump input power, and calculate the new operating condition energy efficiency cost index after stabilization; determine the change in energy efficiency cost index based on the difference between the new operating condition energy efficiency cost index and the operating condition energy efficiency cost index of the previous cycle; determine the comparison result between the absolute value of the change in energy efficiency cost index and the preset dead zone threshold; if the absolute value is greater than the preset dead zone threshold, determine the pump frequency disturbance adjustment direction as the current disturbance direction; if the absolute value is less than or equal to the negative preset dead zone threshold, determine the pump frequency disturbance adjustment direction as the reverse direction of the current disturbance direction. Furthermore, the circulating pump operating point tracking module 40 is also used to update the slurry circulating pump frequency setting value according to the pump frequency disturbance adjustment direction, perform frequency upper and lower limit constraints and frequency change rate constraints, verify the stable state of outlet sulfur dioxide concentration, slurry pH value, and slurry circulating pump input power, record the frequency setting value that meets the energy efficiency improvement conditions, and form the optimal slurry circulating pump operating frequency.

[0031] Specifically, a preset frequency disturbance is applied to the current frequency of the slurry circulation pump. The amplitude and duration of this disturbance are preset based on historical operating data and process characteristics. The disturbance amplitude is set to a fixed value, such as 0.5Hz. This value is selected to ensure that it can cause measurable changes in key parameters such as outlet sulfur dioxide concentration, slurry pH value, and input power, without impacting the stability of the entire desulfurization system. The disturbance duration is set to 15 minutes, which is determined based on 1.5 times the average time required for the system to reach a new steady state, as analyzed after a step response test. After applying the disturbance, the three key parameters—outlet sulfur dioxide concentration, slurry pH value, and slurry circulation pump input power—are continuously monitored with a sampling period of 5 seconds, and the system is judged in real time. Whether the system has reached a stable state is determined by the stability criterion, which is defined as follows: within a continuous 3-minute sliding time window, the standard deviation of each of the above three parameters at 60 sampling points is continuously less than its corresponding stability threshold. These thresholds are obtained by analyzing the data fluctuations of the equipment under undisturbed stable operating conditions for 24 hours. For example, the stability threshold for the outlet sulfur dioxide concentration is set to 1.2 mg / m³, the stability threshold for the slurry pH value is set to 0.03, and the stability threshold for the input power is set to 0.8% of its current reading. Once the stability criterion is met, the system enters a 5-minute evaluation phase. Using all the data collected during this phase, the energy efficiency cost index under the new operating condition after the disturbance is calculated according to the calculation formula defined in the previous steps, and a new operating condition energy efficiency cost index is generated.

[0032] Based on the new operating condition energy efficiency cost index generated in the previous step, the operating condition energy efficiency cost index of the previous cycle is first retrieved from the records of the previous optimization cycle. Then, the difference between these two indices is calculated to obtain the change in the energy efficiency cost index. Next, this change is compared with a preset dead zone threshold. The purpose of this dead zone threshold is to filter out meaningless index changes caused by measurement noise or minor operating condition fluctuations. The method for setting its value is as follows: during the stable operation of the system, the operating condition energy efficiency cost index is continuously calculated for 10 cycles. The difference between the maximum and minimum values ​​among these 10 values ​​is found, and 150% of this difference is taken as the dead zone threshold. For example, if the continuously calculated index value fluctuates between 0.1210 kg / yuan and 0.1214 kg / yuan, the maximum difference is 0.0004 kg / yuan, and the dead zone threshold is 0.0004 * 1.5 = 0.0006 kg / yuan. Subsequently, the results are... The change direction rule is used for judgment. This rule is based on the optimization logic of the hill-climbing algorithm: retrieve the disturbance direction (increase frequency or decrease frequency) of the previous cycle. If the absolute value of the change in the energy efficiency cost index is less than the dead zone threshold, it is judged that the change is not significant, and the disturbance direction of the previous cycle is maintained to continue exploring. If the change in the energy efficiency cost index is greater than the dead zone threshold, it means that the disturbance of the previous cycle has brought about an improvement in efficiency, and the disturbance direction is maintained. If the change in the energy efficiency cost index is less than the negative dead zone threshold, it means that the disturbance of the previous cycle has led to a decrease in efficiency, and the disturbance direction needs to be reversed. For example, if the previous cycle increased the frequency by 0.5Hz, and the new index is 0.001kg / yuan higher than the old index (greater than the dead zone threshold), then the direction is judged to continue to increase. If the new index is 0.001kg / yuan lower than the old index, then the direction is judged to be reversed, that is, the frequency is changed to decrease next time, generating the pump frequency disturbance adjustment direction.

[0033] Based on the generated pump frequency disturbance adjustment direction, the frequency setpoint of the slurry circulation pump is updated. The specific update logic involves adding or subtracting the current frequency setpoint from the adjustment amount calculated based on the disturbance direction and amplitude (e.g., 0.5Hz) to obtain a new frequency setpoint. Before outputting this setpoint, two constraint checks are performed. First, there are upper and lower frequency limit constraints: the new setpoint is compared with the equipment's mechanical and technological safe operating range. This range is provided by the equipment manufacturer or set by the process engineer based on actual conditions; for example, the lower limit is 35Hz and the upper limit is 48.5Hz. If the calculated new setpoint exceeds this range, it is forcibly set to the closest boundary value. Second, there is a frequency change rate constraint: the rate of change of the frequency setpoint is limited to not exceeding a preset value, such as 0.1Hz. To avoid excessive mechanical or hydraulic shock to the pump body and pipeline system, the system sends the new frequency setpoint after constraint processing to the frequency converter. Then, the system re-enters the monitoring state and verifies whether the outlet sulfur dioxide concentration, slurry pH value, and slurry circulation pump input power have reached a new stable state based on the same stability criteria as mentioned above. At the same time, the system maintains a record table containing all historically tested frequency points and their corresponding operating condition energy efficiency cost indexes. Whenever a new frequency point is evaluated, if its corresponding energy efficiency cost index is higher than the highest value in the current record table, the frequency point is updated to the current optimal operating frequency. Through this continuous perturbation-evaluation-update cycle, the system continuously tracks and approaches the optimal energy efficiency point under the current load and operating conditions, thus forming the optimal slurry circulation pump operating frequency.

[0034] Figure 2 The diagram illustrates the operation flow chart of the system in this embodiment during the actual automatic control process of slurry in enhanced wet desulfurization. During the actual operation of the system, key data at the inlet and outlet of the absorption tower are collected and the slurry state is predicted and corrected based on the preset sampling frequency. Then, the replenishment amount is calculated and the regulating flow rate is generated. Next, a frequency disturbance is applied, and the operating condition energy efficiency cost index after the disturbance is applied is used to determine whether pump frequency adjustment is required. If adjustment is required, the new operating condition energy efficiency cost index is compared with the operating condition energy efficiency cost index of the previous cycle. If so, the new pump frequency setting is updated; otherwise, the original pump frequency value is maintained.

[0035] This embodiment combines the state estimation from the previous moment with the current control input for state prediction, and then uses the deviation between the current slurry pH measurement value and the predicted output for correction. This allows for the estimation of the content of components in the slurry that are difficult to measure directly, suppressing interference caused by noise and hysteresis from single sensor measurements. In slurry replenishment regulation, real-time acquisition and calculation of inlet flue gas flow rate and sulfur dioxide concentration can predict the total sulfur dioxide load in advance, enabling rapid feedforward adjustment of the basic replenishment amount to compensate for disturbances, avoiding system response lag caused by drastic load fluctuations. Simultaneously, the estimated effective calcium carbonate solid content is used as... To provide feedback control, a composite regulation of feedforward and feedback is formed, ensuring that the supply of limestone slurry can respond quickly to external disturbances while maintaining the stability of the chemical reaction environment inside the absorption tower. This improves reagent utilization and reduces the risk of over-addition. The operating economy of the circulating pump is evaluated by establishing a dynamic correlation between mass transfer efficiency and electricity cost under real-time electricity price. The frequency of the circulating pump is perturbed, and iterative tracking is performed based on the changing trend of the energy efficiency cost index to continuously explore and lock the optimal operating frequency under the current operating conditions. This minimizes the energy consumption of the circulating pump while ensuring desulfurization efficiency.

[0036] Based on the same inventive concept, the second embodiment of this disclosure provides an automatic slurry control method for enhanced wet desulfurization, the flowchart of which is shown below. Figure 3 As shown, it mainly includes: S10: Generate a slurry state prediction vector based on the sulfur dioxide concentration at the absorber outlet, slurry pH value, densitometer reading, previous state estimate, and current control input value. Generate a measurement deviation vector based on the slurry state prediction vector and slurry pH value. Adjust the components of the slurry state prediction vector based on the measurement deviation vector to generate slurry component estimates. S20: Calculate the total sulfur dioxide load based on the inlet flue gas flow rate and sulfur dioxide concentration, determine the basic supply amount for disturbance compensation, and combine the effective calcium carbonate solid content in the estimated slurry composition as the input for feedback control to generate a composite regulated limestone slurry flow rate. S30: Collect the inlet and outlet sulfur dioxide concentrations and the flow rate of the slurry circulation pump to calculate the mass transfer efficiency, establish mass transfer efficiency evaluation parameters, and collect the input power of the slurry circulation pump and the real-time electricity price to calculate the electricity cost. Based on the mass transfer efficiency evaluation parameters and the electricity cost, determine the energy efficiency cost index under the current operating conditions. S40: Apply frequency disturbance to the current frequency of the slurry circulation pump, obtain the new operating condition energy efficiency cost index after stabilization, determine the pump frequency disturbance adjustment direction by combining the operating condition energy efficiency cost index of the previous cycle, and update the frequency setpoint of the slurry circulation pump according to the pump frequency disturbance adjustment direction to establish the optimal operating frequency of the slurry circulation pump.

[0037] The specific implementation process of the above steps has been described in detail in the first embodiment of this disclosure, and will not be repeated here.

[0038] This embodiment combines the state estimation from the previous moment with the current control input for state prediction, and then uses the deviation between the current slurry pH measurement value and the predicted output for correction. This allows for the estimation of the content of components in the slurry that are difficult to measure directly, suppressing interference caused by noise and hysteresis from single sensor measurements. In slurry replenishment regulation, real-time acquisition and calculation of inlet flue gas flow rate and sulfur dioxide concentration can predict the total sulfur dioxide load in advance, enabling rapid feedforward adjustment of the basic replenishment amount to compensate for disturbances, avoiding system response lag caused by drastic load fluctuations. Simultaneously, the estimated effective calcium carbonate solid content is used as... To provide feedback control, a composite regulation of feedforward and feedback is formed, ensuring that the supply of limestone slurry can respond quickly to external disturbances while maintaining the stability of the chemical reaction environment inside the absorption tower. This improves reagent utilization and reduces the risk of over-addition. The operating economy of the circulating pump is evaluated by establishing a dynamic correlation between mass transfer efficiency and electricity cost under real-time electricity price. The frequency of the circulating pump is perturbed, and iterative tracking is performed based on the changing trend of the energy efficiency cost index to continuously explore and lock the optimal operating frequency under the current operating conditions. This minimizes the energy consumption of the circulating pump while ensuring desulfurization efficiency.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An automatic control system for slurry in enhanced wet desulfurization, characterized in that, include: The real-time state fusion module is used to generate a slurry state prediction vector based on the sulfur dioxide concentration at the absorber outlet, slurry pH value, densitometer reading, state estimate value at the previous moment, and current control input value; generate a measurement deviation vector based on the slurry state prediction vector and slurry pH value; and adjust the components of the slurry state prediction vector based on the measurement deviation vector to generate slurry component estimate values. The slurry replenishment feedforward correction module is used to calculate the total sulfur dioxide load based on the inlet flue gas flow rate and sulfur dioxide concentration, determine the basic replenishment amount for disturbance compensation, and combine the effective calcium carbonate solid content in the estimated slurry composition as the input of feedback control to generate a composite regulated limestone slurry flow rate. The circulating pump energy efficiency cost assessment module is used to collect the inlet and outlet sulfur dioxide concentrations and the flow rate of the slurry circulating pump to calculate the mass transfer efficiency, establish mass transfer efficiency assessment parameters, and collect the input power of the slurry circulating pump and the real-time electricity price to calculate the electricity cost. Based on the mass transfer efficiency assessment parameters and the electricity cost, the current operating condition energy efficiency cost index is determined. The circulating pump operating point tracking module is used to apply frequency disturbance to the current frequency of the slurry circulating pump, obtain a new operating condition energy efficiency cost index after stabilization, determine the pump frequency disturbance adjustment direction by combining the operating condition energy efficiency cost index of the previous cycle, and update the frequency set value of the slurry circulating pump according to the pump frequency disturbance adjustment direction to establish the optimal operating frequency of the slurry circulating pump.

2. The automatic slurry control system according to claim 1, characterized in that, The real-time state fusion module is specifically used for: Collect the sulfur dioxide concentration, slurry pH value, and densitometer reading at the outlet of the absorption tower, and perform time alignment processing; Obtain the effective solid content of calcium carbonate, solid content of calcium sulfite, solid content of gypsum, and solid content of inert substances from the state estimate of the previous time step; Obtain the limestone slurry replenishment flow rate and slurry circulation pump frequency from the current control input values; The aligned sulfur dioxide concentration, slurry pH value, densitometer reading, and the effective calcium carbonate solid content, calcium sulfite solid content, gypsum solid content, inert substance solid content, limestone slurry replenishment flow rate, and slurry circulation pump frequency are spliced ​​together in a preset order and truncated by physical boundaries to form the slurry state prediction vector.

3. The automatic slurry control system according to claim 2, characterized in that, The real-time state fusion module is specifically used for: The preset slurry pH value process model function is called, and the slurry pH prediction value is calculated based on the effective calcium carbonate solid content and calcium sulfite solid content in the slurry state prediction vector. The deviation data is obtained based on the difference between the predicted pH value of the slurry and the actual pH value of the slurry, and the sign of the difference. Based on the sliding window of deviation data, anomaly removal and difference limiting are performed on the deviation data within the sliding window to generate a measurement deviation vector. Based on the measurement deviation vector, the components in the slurry state prediction vector are weighted and adjusted, and the adjusted slurry state prediction vector is subjected to a consistency check based on densitometer readings. The effective calcium carbonate content in the adjusted slurry state prediction vector is subjected to constrained projection based on sulfur dioxide concentration to generate slurry component estimates.

4. The automatic slurry control system according to claim 1, characterized in that, The slurry replenishment feedforward correction module is specifically used for: The inlet flue gas flow rate and sulfur dioxide concentration were collected and time-aligned. Calculate the instantaneous sulfur dioxide mass flow rate at each aligned time point, and calculate the total sulfur dioxide load within the preset calculation time period based on all instantaneous sulfur dioxide mass flow rates and sampling time intervals within the preset calculation time period; Based on the total sulfur dioxide content and stoichiometric parameters, determine the theoretical mass of calcium carbonate consumed; The theoretical calcium carbonate consumption is anomaly removed and truncation is performed to obtain the calcium carbonate mass demand value within the preset calculation time period. The calcium carbonate mass demand value is then converted into the average mass flow rate based on the preset calculation time period as the basic supply amount for disturbance compensation.

5. The automatic slurry control system according to claim 4, characterized in that, The slurry replenishment feedforward correction module is specifically used for: The effective calcium carbonate solid content in the estimated slurry composition is used as the input for feedback control, and compared with the preset target solid content to determine the solid content deviation. The adjustment value of the slurry flow rate output by the feedback control is determined based on the solid content deviation. The basic slurry flow rate is determined based on the disturbance compensation basic supply amount, and summed with the slurry flow rate adjustment value. The sum is then subjected to amplitude limiting processing to obtain the composite regulated limestone slurry flow rate.

6. The automatic slurry control system according to claim 4, characterized in that, The circulating pump energy efficiency cost assessment module is specifically used for: The concentrations of sulfur dioxide at the inlet and outlet of the slurry circulation pump were collected and time-aligned. Calculate the difference between the inlet sulfur dioxide concentration and the outlet sulfur dioxide concentration at each time point to obtain the instantaneous removal concentration; Calculate the instantaneous mass transfer efficiency based on the instantaneous removal concentration and the slurry circulation pump flow rate; All instantaneous mass transfer efficiency quantification values ​​within the preset time period are summed, and the sum is used as the mass transfer efficiency evaluation parameter within the preset time period.

7. The automatic slurry control system according to claim 6, characterized in that, The circulating pump energy efficiency cost assessment module is specifically used for: Based on each time point of the preset time period, the input power and real-time electricity price of the slurry circulation pump are collected synchronously to obtain the instantaneous power cost at each time point. The total power cost consumed by the slurry circulation pump during the preset time period is obtained by summing all the instantaneous power costs within the preset time period. Based on the aforementioned electricity cost, the energy efficiency cost index for the current operating conditions is calculated using the following formula: in, This represents the energy efficiency cost index under current operating conditions. This is a dynamic compliance weighting factor used to adjust the mass transfer benefit weights under different emission concentrations. This refers to the inlet sulfur dioxide concentration. For the concentration of sulfur dioxide at the export site, This refers to the flow rate of the slurry circulation pump. This refers to the input power of the slurry circulation pump. For real-time electricity prices, To calculate the start time, To calculate the end time, This indicates the conversion of electricity consumption from kilowatt-hours to cost per second, using a dynamic compliance weighting factor. The calculation expression is: , To adjust the constant of the weighting intensity, To set the target sulfur dioxide emission concentration, To set the upper limit for permissible sulfur dioxide emission concentrations.

8. The automatic slurry control system according to any one of claims 1 to 7, characterized in that, The circulating pump operating point tracking module is specifically used for: Apply frequency disturbance to the current frequency of the slurry circulation pump, set the disturbance amplitude and duration, monitor the fluctuation amplitude of outlet sulfur dioxide concentration, slurry pH value, and slurry circulation pump input power, and calculate the new operating condition energy efficiency cost index after stabilization. The change in the energy efficiency cost index is determined based on the difference between the new operating condition energy efficiency cost index and the operating condition energy efficiency cost index of the previous period. The absolute value of the change in the energy efficiency cost index is compared with a preset dead zone threshold. If the absolute value is greater than the preset dead zone threshold, the pump frequency disturbance adjustment direction is determined as the current disturbance direction. If the absolute value is less than or equal to a negative preset dead zone threshold, the pump frequency disturbance adjustment direction is determined as the reverse direction of the current disturbance direction.

9. The automatic slurry control system according to claim 8, characterized in that, The circulating pump operating point tracking module is specifically used for: Based on the direction of the pump frequency disturbance adjustment, update the frequency setting value of the slurry circulation pump, impose upper and lower limit constraints on the frequency and the rate of frequency change, verify the stable state of the outlet sulfur dioxide concentration, slurry pH value, and slurry circulation pump input power, record the frequency setting value that meets the energy efficiency improvement conditions, and form the optimal operating frequency of the slurry circulation pump.

10. An automatic control method for slurry in enhanced wet desulfurization, characterized in that, include: A slurry state prediction vector is generated based on the sulfur dioxide concentration at the absorber outlet, the slurry pH value, the densitometer reading, the state estimate value at the previous moment, and the current control input value. A measurement deviation vector is generated based on the slurry state prediction vector and the slurry pH value. The components of the slurry state prediction vector are adjusted based on the measurement deviation vector to generate slurry component estimates. The total sulfur dioxide load is calculated based on the inlet flue gas flow rate and sulfur dioxide concentration. The basic supply amount for disturbance compensation is determined, and the effective calcium carbonate solid content in the estimated slurry composition is used as the input for feedback control to generate a composite regulated limestone slurry flow rate. Collect the inlet and outlet sulfur dioxide concentrations and the flow rate of the slurry circulation pump to calculate the mass transfer efficiency, establish mass transfer efficiency evaluation parameters, and collect the input power of the slurry circulation pump and the real-time electricity price to calculate the electricity cost. Based on the mass transfer efficiency evaluation parameters and the electricity cost, determine the energy efficiency cost index under the current operating conditions. A frequency disturbance is applied to the current frequency of the slurry circulation pump. After stabilization, a new operating condition energy efficiency cost index is obtained. The direction of pump frequency disturbance adjustment is determined by combining the operating condition energy efficiency cost index of the previous cycle. The frequency setpoint of the slurry circulation pump is updated according to the pump frequency disturbance adjustment direction to establish the optimal operating frequency of the slurry circulation pump.

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