Desulfurization wastewater recycling treatment system and method for thermal power plant based on automation control

Abstract

The application provides a thermal power plant desulfurization wastewater recycling treatment system and method based on automatic control, relates to the technical field of wastewater treatment, and sets a form control area on a desulfurization wastewater recycling main pipeline. By adding a form control agent and introducing an induced crystal seed, scaling ions such as calcium ions, magnesium ions and sulfate ions in the wastewater are converted into stable fine suspended crystals. By changing the existing form of the scaling ions, the scaling ions enter the subsequent pipeline in the form of non-deposited microcrystals, eliminating the hidden danger of scaling of the recycling main pipeline. Meanwhile, the wastewater treated by the form control treatment and other clean water sources are mixed in a water replenishing main pipeline according to a dynamically determined flow ratio, minimum cost constraints and other water quality parameter constraints, and the mixed water with stable comprehensive water quality enters a desulfurization tower as replenishing water. The in-situ treatment saves cost and space, improves resource utilization, reduces water resource consumption and comprehensive wastewater recycling cost while ensuring the safe operation of the desulfurization system.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an automated control-based system and method for the reuse and treatment of desulfurization wastewater from thermal power plants. Background Technology

[0002] The desulfurization wastewater generated by wet flue gas desulfurization (FGD) systems in thermal power plants is characterized by high salinity, high hardness, high suspended solids, and large fluctuations in water quality. When this wastewater is reused for coal yard washing, ash silo washing, and slag bin dust suppression, one of the key limiting factors is the high concentration of scaling ions in the reused water, primarily calcium, magnesium, and sulfate ions. These ions continuously deposit and crystallize in the reuse pipes and spray devices, forming scale, leading to equipment blockage, reduced flow, and frequent cleaning. Simultaneously, when the desulfurization wastewater is introduced into the desulfurization tower makeup water, its chloride ion concentration and suspended solids content must be strictly controlled. High chloride ion concentrations accelerate corrosion of the desulfurization system, and high suspended solids affect desulfurization efficiency. Therefore, the following technical problems exist in the reuse treatment of desulfurization wastewater: Problem 1: High concentrations of calcium, magnesium, and sulfate ions in desulfurization wastewater continuously precipitate and deposit during pipeline transportation, forming dense scale such as calcium sulfate and calcium carbonate. This leads to pipeline blockage, reduced flow, and failure of spray equipment. Traditional scale inhibition methods mainly rely on periodic addition of scale inhibitors. However, the dosage of scale inhibitors depends on manual experience, and there are often problems of insufficient or excessive addition when water quality fluctuates. At the same time, scale inhibitors have a slow treatment speed and long reaction time, requiring separate softening tanks and sedimentation tanks, which increases the footprint, reduces treatment efficiency, and increases production costs, making them unsuitable for practical use. Question 2: Directly introducing desulfurization wastewater into the desulfurization tower makeup water can lead to excessive concentrations of residual calcium, magnesium, sulfate, and chloride ions. This not only accelerates equipment corrosion but also reduces desulfurization efficiency. Existing technologies employ two approaches: one is to deeply soften the desulfurization wastewater, removing ions through chemical precipitation before reuse, but this deep treatment is costly; the other is to dilute it with fresh water, which is simple but increases water consumption, has low reliability, high cost, cannot dynamically adapt to the desulfurization system's operation, reduces overall plant water utilization, and increases maintenance costs. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a method for the reuse and treatment of desulfurization wastewater from thermal power plants based on automated control, the method comprising: Water quality parameters of desulfurization wastewater are continuously collected at the inlet of the main pipeline for desulfurization wastewater reuse. Based on the water quality parameters of desulfurization wastewater, the scaling tendency index and total scale load are calculated. Using the scaling tendency index and total scale load as inputs, and combined with a preset morphology control model, the initial dosage of the morphology control agent is obtained; the morphology control agent is continuously injected into the desulfurization wastewater according to the initial dosage to obtain morphology-controlled recycled water. The reclaimed water with controlled morphology and the multiple clean water sources are introduced into the water supply main pipe separately to obtain mixed water; The comprehensive water quality parameters of the mixed water are acquired in real time. The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal. The equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source are calculated as feedforward signals. The dosage of the form control agent and the introduction ratio of each clean water source are dynamically adjusted to keep the comprehensive water quality parameters of the mixed water within the preset safety threshold. The cost of the form control agent and the cost of each clean water source per unit time are obtained. With the goal of minimizing the total operating cost, the dosage of the form control agent and the introduction ratio of each clean water source are periodically and continuously optimized. When abnormal operating conditions are detected, safety interlock protection is automatically activated.

[0004] On the other hand, this invention proposes an automated control-based desulfurization wastewater reuse treatment system for thermal power plants, used to implement the aforementioned automated control-based desulfurization wastewater reuse treatment method for thermal power plants. The system includes: The influent water quality monitoring module is used to continuously collect desulfurization wastewater quality parameters at the influent end of the desulfurization wastewater reuse main pipeline, and calculate the scaling tendency index and total scale load based on the desulfurization wastewater quality parameters. The morphology control module is used to obtain the initial dosage of the morphology control agent by taking the scaling tendency index and total scale load as inputs and combining them with a preset morphology control model. The agent is then added to the desulfurization wastewater to obtain morphology control recycled water. The supplementary mixing module is used to independently introduce the morphology-controlled reclaimed water and multiple clean water sources into the water supply header to obtain mixed water. The automated control module is used to acquire the comprehensive water quality parameters of the mixed water in real time. The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal. The equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source are calculated as feedforward signals. The dosage of the form control agent and the introduction ratio of each clean water source are dynamically adjusted. With the goal of minimizing the total operating cost, the dosage of the form control agent and the introduction ratio of each clean water source are periodically and continuously optimized. The safety interlock module is used to automatically execute safety interlock protection when abnormal operating conditions are detected.

[0005] This invention provides an automated control-based system and method for the reuse and treatment of desulfurization wastewater from thermal power plants. It offers the following advantages: 1. This invention establishes a morphology control zone on the main pipeline for desulfurization wastewater reuse. By continuously injecting a morphology control agent into the wastewater and pre-installing induced crystal seeds, the scale-forming ions in the wastewater are transformed into fine, smooth-surfaced micro-suspended crystals under the dual effects of molecular inhibition by the morphology control agent and heterogeneous nucleation on the crystal seed surface. These crystals remain stably suspended in the water in a harmless form, avoiding direct nucleation and deposition on the pipe wall surface. Unlike conventional softening methods that achieve scale prevention by removing a large number of scale-forming ions, this invention retains most of the scale-forming ions in the water, achieving scale prevention without removing scale simply by changing their crystal morphology. This is based on real-time calculations of the scaling tendency index and total scale load. As a result, the minimum dosage of reagent to meet the anti-scaling requirements was determined by the morphology control model pre-installed in the controller, avoiding the economic waste of excessive dosage. At the same time, the introduction of induced crystal seeds caused the heterogeneous nucleation of scale ions to occur preferentially on the surface of the crystal seeds rather than on the pipe wall surface, reducing the frequency of pipe cleaning and equipment maintenance costs. The scale prevention problem was transformed into a crystal morphology control problem, which was treated in situ, effectively reducing the footprint. It can be applied to the treatment of desulfurization wastewater of different coal types and seasons without large-scale equipment modification, saving costs and extending the service life of pipelines. While effectively solving the bottleneck of pipeline scaling, the reagent cost was optimized.

[0006] 2. This invention employs a method of mixing morphology-controlled reclaimed water with multiple clean water sources in a main water supply pipe. The deviation between the overall water quality parameters of the mixed water and a preset safety threshold serves as feedback, while the equivalent scale ion concentrations of the morphology-controlled reclaimed water and each clean water source serve as feedforward signals. A composite mode of feedforward pre-adjustment and feedback micro-correction dynamically adjusts the proportion of each water source introduced. Closed-loop correction of the mixing ratio is performed based on real-time water quality monitoring data, enabling automatic adaptation to significant fluctuations in desulfurization wastewater quality. Furthermore, with the optimization objective of minimizing the sum of the costs of morphology control agents and each clean water source per unit time, the minimum dilution ratio is obtained by calculating the relevant conditions for meeting the safety constraints of the mixed water quality. This achieves joint economic optimization of water consumption and chemical consumption, compressing the consumption of clean water sources to the minimum required to meet safety constraints. While ensuring the safe operation of the desulfurization system, this reduces water resource consumption and the overall cost of wastewater reuse, achieving automated control of the entire wastewater reuse process. Attached Figure Description

[0007] Figure 1 This is a flowchart of the automated control-based desulfurization wastewater reuse treatment method for thermal power plants according to the present invention. Figure 2 This is an architecture diagram of the automated control-based desulfurization wastewater reuse treatment system for thermal power plants according to the present invention. Detailed Implementation

[0008] 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.

[0009] like Figure 1 A method for the reuse and treatment of desulfurization wastewater from thermal power plants based on automated control, the method including: In step S100, water quality parameters of the desulfurization wastewater are continuously collected at the inlet of the main pipeline for desulfurization wastewater reuse. Based on these parameters, the scaling tendency index and total scale load are calculated. The scaling tendency index characterizes the current scaling risk level of the desulfurization wastewater, i.e., the thermodynamic trend and kinetic rate of hard scale formation on the inner wall of the pipeline without intervention, determining whether or not to add chemicals and at what concentration. The total scale load characterizes the total amount of scale ions that need to be treated per unit time, i.e., the instantaneous treatment pressure faced by the system. The magnitude of the total scale load directly determines the replenishment rate of induced crystals in step S204 and the expected pressure difference growth trend of the entire system, determining how much total crystallization the system needs to withstand and how many induced crystals need to be prepared.

[0010] In step S200, using the scaling tendency index and total scale load as inputs, and combining them with a preset morphology control model, the initial dosage of the morphology control agent is obtained. The morphology control agent is continuously injected into the desulfurization wastewater according to the initial dosage to obtain morphology-controlled recycled water. The morphology-controlled recycled water harmlessly transforms the morphology of scale-causing ions in the desulfurization wastewater. Under high temperature and high supersaturation conditions, scale-causing ions in the original desulfurization wastewater easily nucleate directly on the metal surface of pipes and grow into a hard, dense, plate-like scale layer, leading to pipe blockage. After morphology control treatment, the originally scale-causing wastewater with a strong deposition tendency is transformed into a stable suspension slurry that, although still containing a large number of scale-causing ions, has a crystalline form that is easy to transport and does not stick to the walls. This creates fundamental prerequisites for subsequent safe mixing with clean water sources and long-distance transportation.

[0011] In step S300, the reclaimed water controlled by form and multiple clean water sources are independently introduced into the water supply header to obtain mixed water. By diluting the reclaimed water controlled by form with clean water, the overall water quality indicators of the mixed water meet the preset safety thresholds for downstream processes (such as desulfurization system process water tanks, demister flushing water, etc.) or environmental discharge reuse. By uniformly mixing the reclaimed water controlled by form with multiple clean water sources such as fresh water and circulating wastewater in the water supply header, key indicators such as equivalent scale ion concentration, turbidity, and conductivity can be reduced and stably controlled within safe limits.

[0012] Step S400: Real-time acquisition of comprehensive water quality parameters of the mixed water; using the deviation between the comprehensive water quality parameters and the preset safety threshold as a feedback signal; using the equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source as feedforward signals; dynamically adjusting the dosage of the form control agent and the introduction ratio of each clean water source to maintain the comprehensive water quality parameters of the mixed water within the preset safety threshold. By calculating the comprehensive water quality parameters of the mixed water in real time, deviations are identified and feedback signals are provided to determine whether the final mixed water meets safety requirements. By adjusting the dosage of speciation control agents, scaling risk is controlled at the source. When feedback signals indicate a deteriorating trend in the quality of the mixed water, or when feedforward signals indicate an increase in the equivalent scale ion concentration of the speciation control reclaimed water, increasing the dosage of the agent can more thoroughly convert scale ions into microcrystals, thereby reducing the scaling potential of the reclaimed water itself. By adjusting the proportion of each clean water source introduced, rapid correction is achieved. When the feedback deviation is large or the adjustment of speciation control agents has reached its economic limit, dynamically increasing the proportion of clean water sources can quickly bring the mixed water quality back to the safe zone. This forms a two-dimensional control architecture of feedforward adjustment of the source dosage and feedback correction of the end dilution ratio, ensuring that the mixed water meets the standards in real time.

[0013] Step S500: Obtain the cost of the form control agent and the cost of each clean water source per unit time. With the goal of minimizing the total operating cost, periodically and continuously optimize the dosage of the form control agent and the introduction ratio of each clean water source. Periodic rolling optimization is used to break away from short-sighted control at a single moment, achieving a dynamic balance between safety and cost over time. This allows the system to adaptively follow long-term fluctuations in the quality of desulfurization wastewater (such as changes in coal type or seasons), always operating on the cost-optimal curve, avoiding the economic waste caused by fixed ratios or pure feedback control.

[0014] Step S600: When an abnormal operating condition is detected, the safety interlock protection is automatically executed.

[0015] In this embodiment, the steps for calculating the scaling tendency index and total scale load based on the desulfurization wastewater quality parameters include: Step S101: Obtain the desulfurization wastewater quality parameters at the inlet of the main desulfurization wastewater reuse pipeline. These parameters include calcium ion concentration, magnesium ion concentration, sulfate ion concentration, pH value, conductivity, and temperature. All desulfurization wastewater quality parameters are continuously acquired using an online water quality sensor array installed at the inlet of the main desulfurization wastewater reuse pipeline. Specifically, calcium ion concentration, magnesium ion concentration, and sulfate ion concentration are measured in real-time using ion-selective electrode sensors or an online inductively coupled plasma atomic emission spectrometer. pH value is obtained using an online glass electrode pH meter. Conductivity is obtained using a conductivity meter, reflecting the total dissolved solids content in the wastewater; sudden changes in conductivity can trigger more intensive sampling or an early warning system. Temperature is obtained using a platinum resistance temperature sensor.

[0016] Step S102: Calculate the supersaturation ratio of each sparingly soluble salt component based on the water quality parameters of the desulfurization wastewater, and perform a weighted summation of each supersaturation ratio to obtain the scaling tendency index, which characterizes the overall scaling risk of the desulfurization wastewater. The saturation ratio is the ratio of the actual ion product to the solubility product of the salt ions in the solution. For calcium sulfate, the supersaturation ratio is obtained by dividing the product of its calcium ion concentration and sulfate ion concentration by the solubility product of calcium sulfate. For calcium carbonate, the supersaturation ratio is obtained by solving the carbonate ion concentration using the carbonate balance equation based on pH and alkalinity, and then dividing the product of its calcium ion concentration and carbonate ion concentration by the solubility product of calcium carbonate. When the saturation ratio is greater than 1, it indicates that the salt is in a supersaturated state in the solution, and there is a thermodynamic driving force for scaling. The larger the saturation ratio, the stronger the scaling tendency, the faster the crystal nucleation rate, and the higher the scaling tendency index. The calculated supersaturation ratios of calcium sulfate, calcium carbonate, and other sparingly soluble salts are weighted. Each weight coefficient is pre-calibrated during the system commissioning phase based on the main scale composition of the desulfurization wastewater. The sum of all weight coefficients is 1. The scaling tendency index is calculated by weighting. The larger the scaling tendency index, the stronger the overall scaling tendency of the desulfurization wastewater.

[0017] Step S103: Obtain the instantaneous flow rate of the desulfurization wastewater and calculate the total amount of scaling ions entering the reuse system per unit time based on the calcium ion concentration, which is taken as the total scale load. The instantaneous flow rate of the desulfurization wastewater is continuously obtained using an electromagnetic flowmeter or ultrasonic flowmeter installed at the inlet of the main desulfurization wastewater reuse pipeline, downstream of the water quality sensor group. All scaling ions, mainly calcium ions, are converted according to the molar mass of calcium sulfate to obtain the equivalent calcium sulfate concentration. The equivalent calcium sulfate concentration is multiplied by the instantaneous flow rate, and the resulting value is taken as the total scale load. The total scale load represents the total amount of scaling ions per unit time. The higher the total scale load, the greater the scaling ion load that the morphology control zone needs to bear, and the corresponding increase in the required dosage of morphology control agent and the replenishment of induced crystal seeds. To calculate the equivalent calcium sulfate concentration, then, M represents molar mass. Indicates calcium ion concentration. This indicates the magnesium ion concentration. If other ions, such as barium ions, are present, the concentration is increased based on their molar mass and barium ion concentration, using a conversion formula.

[0018] In this embodiment, the construction process of the preset morphology control model includes: Step S201: During the commissioning phase before operation, multiple sets of desulfurization wastewater samples with different calcium ion concentrations, magnesium ion concentrations, sulfate ion concentrations, and pH values ​​are configured. These desulfurization wastewater samples cover the entire fluctuation range that power plant desulfurization wastewater may experience during actual operation. Specifically, the configuration of desulfurization wastewater samples is based on the actual water quality fluctuation range that the desulfurization system of the thermal power plant may experience at the wastewater discharge outlet under different coal types, loads, and seasonal operating conditions throughout the year. By collecting historical water quality data of desulfurization wastewater for at least one consecutive calendar year (or one maintenance cycle), the minimum, maximum, and typical distribution range of each water quality parameter are identified. Then, within this range, multiple representative combination points are selected at equal or non-equal intervals. Real wastewater samples corresponding to these characteristic points are manually configured or collected from the field to ensure that the input space of the constructed morphological control model can completely cover all operating conditions that may be encountered in future actual operation, avoiding control failures caused by model extrapolation.

[0019] The particle size distribution of precipitated crystals and the scaling rate of pipe walls were measured for each desulfurization wastewater sample under different dosages of speciation control agents. The particle size distribution was obtained using an existing laser particle size analyzer. The scaling rate of the pipe walls was indirectly characterized by the rate of change of pressure difference in the test section. High-precision differential pressure sensors were installed at both ends of a transparent or metal test pipe section with the same material, inner diameter, and hydraulic conditions as the field test section. Wastewater treated with speciation control was continuously flowed through this test section, and the increase in pressure difference per unit time (e.g., per hour) was continuously recorded. The pressure difference increment per unit time was divided by the length of the test section to obtain the rate of change of pressure difference per unit pipe length. This rate of change is proportional to the scaling rate of the pipe walls, quantitatively evaluating whether scaling of the pipe walls was effectively inhibited under the given agent dosage. If the rate of change of pressure difference per unit pipe length was lower than a preset threshold, it indicated that the scaling rate of the pipe walls was effectively inhibited.

[0020] Using the scaling tendency index and total scale load as input variables, and the minimum dosage required to prevent scaling (where the scaling rate is below a preset threshold and the crystal particle size does not exceed the micrometer limit) as the output variable, a mapping relationship between the input and output is established. This mapping relationship is presented as a morphological control model in the form of a piecewise linear function or an interpolation table. The specific form of the morphological control model can be a two-dimensional interpolation table, such as using the scaling tendency index as the row index and the total scale load as the column index, with the data in the table representing the corresponding minimum dosage. During online operation, the scale tendency index and total scale load, calculated in real time, are used as query conditions. The minimum dosage required to prevent scaling is quickly obtained directly through table lookup and piecewise linear interpolation, avoiding complex online experiments or trial and error, and achieving precise and optimized dosage.

[0021] In this embodiment, a speciation control agent is continuously injected into the desulfurization wastewater according to the initial dosage, resulting in speciation control reclaimed water, including: Step S202: Using the scaling tendency index and total scale load as query conditions, the morphology control model is invoked to locate the intervals to which the scaling tendency index and total scale load belong. The minimum dosage corresponding to the current scaling tendency index and total scale load is calculated using piecewise linear interpolation. The minimum dosage is then multiplied by a preset safety factor to obtain the initial dosage. The safety factor ranges from 1.10 to 1.20 and is set based on actual operating experience during the debugging phase in step S201. The morphology control agent is selected as a single component or a compound combination. It is a type of water-soluble organic polymer or compound mixture whose molecular structure contains highly polar active functional groups. It generally includes organophosphonic acids (such as hydroxyethylidene diphosphonic acid), polycarboxylic acids (such as polyacrylic acid and maleic acid copolymers), and their compound combinations; for example, only organophosphates or a mixture of organophosphonic acid and polycarboxylic acid at a mass ratio of 1:2 can be selected. In practical applications in power plants, polycarboxylic acid and organophosphonic acid compound agents are usually preferred based on wastewater quality and cost. The morphology control agent molecules, through active functional groups such as carboxylic acid groups and phosphonic acid groups, selectively adsorb onto active growth sites on the surface of crystals such as calcium sulfate and calcium carbonate, distorting the normal growth direction of the crystals and forcing the crystals to tend to form small, rounded particles, rather than coarse, plate-like crystals with strong deposition.

[0022] In step S203, the form control agent is continuously injected into the desulfurization wastewater according to the initial dosage. The form control agent and the desulfurization wastewater are rapidly mixed in a static mixer for a mixing time of less than or equal to 5 seconds. This allows the form control agent molecules to adsorb onto the surface of newly formed crystal nuclei and simultaneously onto the inner wall of the pipe, inhibiting the direct nucleation of crystal nuclei on the pipe wall and distorting the normal growth direction of the crystals. The form control agent molecules form an adsorption film on the surface of the metal pipe wall, shielding the active nucleation sites on the pipe wall surface and significantly reducing the catalytic effect of the pipe wall as a heterogeneous nucleation substrate, causing scale ions to preferentially migrate to the surface of the suspended seed crystals. The form control agent preferentially adsorbs onto the active growth points of specific crystal faces on the crystal surface, hindering the normal growth of those crystal faces and forcing the crystals to grow in a lateral or isotropic direction, ultimately forming smooth, fine-sized uniform particles, significantly reducing the tendency of crystals to adhere to and roll onto the pipe surface. The inhibitory effect of the form control agent is stably maintained during continuous flow, ensuring that the microcrystals remain suspended and stable without agglomeration and sedimentation during the long-distance transport from the form control zone to the water mixing zone.

[0023] Among them, a static mixer is a device that has no internal moving parts and relies on specially structured turbulent elements (such as spiral blades, corrugated plates, and cross guide vanes) to cause the fluid to generate splitting, merging, rotation, and turbulence, thereby achieving rapid and uniform mixing. The static mixer is installed on the reuse main pipeline after the shape control agent injection point and before the shape control zone, with the specific location being close to the downstream of the agent injection port. The length of the static mixer is designed according to the pipe diameter and flow rate, and is usually 3 to 5 times the pipe diameter. Once the morphology control agent is injected into the pipeline, it immediately enters the static mixer along with the high-speed turbulent wastewater. Under the forced action of multiple layers of turbulence-inducing elements inside the static mixer, the agent molecules and scale ions and suspended particles in the water achieve near-molecular-level uniform mixing in a very short time. This rapid mixing avoids the problem of excessively high or low concentrations of the agent in certain areas: excessively high concentrations would waste the agent, while excessively low concentrations would not effectively inhibit nucleation. This ensures that the agent molecules can be quickly adsorbed onto the surface of the crystal nucleus and the inner wall of the pipeline the moment the new crystal nucleus is formed. The static mixer accelerates the mixing and flow of the morphology control agent and the wastewater, shortening the mixing time and thus preventing the crystal nucleus from growing on the pipe wall.

[0024] Step S204: A morphology control zone is defined inside the main reuse pipeline. Induced crystal seeds are introduced into the morphology control zone to transform scale ions in the desulfurization wastewater into fine suspended crystals under the combined action of the morphology control agent and the induced crystal seeds. The sludge discharge valve is opened periodically to discharge the settled oversized particles, resulting in morphology-controlled reused water. Based on the total scale load calculated in S103, the number of newly generated microcrystals per unit time in the morphology control zone is estimated, and the replenishment rate required to maintain the effective concentration of induced crystal seeds is calculated. The control system quantitatively replenishes the induced crystal seeds according to a preset pulse or continuous replenishment method. The induced crystal seeds are micron-sized calcium sulfate dihydrate powder with a particle size between 2 and 8 microns after surface activation treatment (such as pickling, mechanical grinding, or surface coating). During the treatment process, scale ions in the desulfurization wastewater preferentially undergo heterogeneous nucleation and crystal growth on the surface of the induced crystal seed particles, rather than directly nucleating and depositing on the inner wall of the pipeline.

[0025] The morphology control zone is a specific functional section deliberately demarcated along the main pipeline for desulfurization wastewater reuse. It is typically located after the static mixer and before the water supply header. The top of the morphology control zone has an inlet for feeding induced crystals, and the bottom has a sludge discharge trough. The added induced crystals mix with the incoming desulfurization wastewater within the morphology control zone and then flow through the seed crystal suspension bed. As the wastewater flows through the seed crystal suspension bed, calcium and sulfate ions in the water preferentially undergo heterogeneous nucleation along the surface of the seed crystal particles. Since the surface free energy change required for nucleation on the induced crystal surface is much lower than that required for uniform nucleation or direct nucleation on the pipe wall, once a sufficient amount of induced crystals is present, the vast majority of the crystallization process will be completed on the induced crystal surface, effectively suppressing nucleation on the inner wall of the pipeline. The newly formed crystals grow layer by layer around the induced crystal as the core. The morphology control molecules adsorbed on the surface further inhibit their orderly accumulation on various crystal faces, ensuring that the final crystal particles maintain a smooth surface and small particle size, continuously suspended in the water flow.

[0026] No flow-throttling elements or static mixing devices are installed between the outlet of the morphology control zone and the main water supply pipe to ensure that the water flow in the pipe is in a stable turbulent state. The constant pressure operation of the recycled water pump ensures that the flow velocity in the pipe remains within the design velocity range. This ensures that the micro-suspended crystals, after morphology control transformation, are uniformly distributed in the pipe due to the carrying and shearing effects of turbulence, preventing crystal sedimentation and accumulation in low-velocity areas. The pressure difference between the differential pressure sensor before and after the morphology control zone is continuously monitored and sent to the control system for trend analysis. When an abnormal increase in the differential pressure value occurs, emergency response is initiated according to the blockage warning procedure in step S600.

[0027] As some of the grown seed crystals and deposited crystals settle to the bottom of the morphology control zone under gravity, the control system automatically opens the sludge discharge valve at the bottom of the morphology control zone at preset time intervals (e.g., every 24 hours of operation) to discharge the deposited oversized particles to the desulfurization wastewater sedimentation tank. After sludge discharge, the control system automatically replenishes an equal amount of seed crystals based on the estimated total scale load to maintain a stable seed crystal concentration in the morphology control zone.

[0028] The derivation and calculation process for the amount of seed crystals to be added includes: First, based on the total scale load calculated in step S103, assuming that during steady-state operation, most of the scale ions entering the system are converted into suspended microcrystals, the total mass of newly generated microcrystals per unit hour is approximately equal to the total scale load. To ensure that they preferentially grow on the seed crystals rather than nucleate on the pipe wall, the minimum total surface area provided by the suspended seed crystals needs to be proportional to the rate of new crystal formation, and a proportionality coefficient k is set. The proportionality coefficient is obtained through calibration during the commissioning phase. Therefore, the minimum total surface area = total scale load × proportionality coefficient. Then, given that the seed crystals are approximately spherical calcium sulfate dihydrate particles with a density of ρ (approximately 2.3 g / cm³) and a particle size of d (taking an intermediate value, such as 5 micrometers), the volume of a single seed crystal is... The quality is , surface area is Specific surface area provided by a unit mass of seed crystals , The unit is per square meter per kilogram; therefore, the total mass of seed crystals required is... , Where k represents the proportionality coefficient, which is calibrated through the scaling rate experiment in step S201, and is typically taken as 0.1~0.5. between; Indicates the minimum total surface area. This represents the total scale load; since the induced seed crystals continuously grow and enlarge during recycling, eventually settling and being discharged, continuous replenishment is necessary. Let the average residence time of the seed crystals in the morphology control zone be... The seed crystal mass required per unit time (hour) is obtained by dividing the volume of the morphology control region by the flow rate. , Finally, based on the current total scale load The real-time value, according to the preset and The proportional relationship is determined during the debugging phase and then placed into the controller to quantitatively add induced seed crystals to the morphology control region in a pulse or continuous manner.

[0029] In this embodiment, the steps for obtaining mixed water by independently introducing the morphology-controlled recycled water and multiple clean water sources into the water supply header include: The morphology-controlled reclaimed water obtained after steps S301 and S204, along with at least one clean water source (including fresh water, circulating water wastewater, reverse osmosis concentrate, etc.), are introduced into the makeup water main pipe through independent branch lines. A comprehensive water quality sensor group is installed at the end of the makeup water main pipe, including a scale ion concentration sensor, turbidity meter, pH meter, conductivity meter, etc., to continuously monitor the comprehensive water quality parameters of the mixed water. Based on the deviation between the mixed water quality parameters and the preset safety threshold, the opening of the electric regulating valves in each water source branch is adjusted to maintain the mixed water quality within the safe setting range.

[0030] When calculating the mixing ratio, the water quality parameters of each clean water source are not constant values. Following the same steps as step S100, the equivalent scaling ion concentration and scaling tendency index of each clean water source are calculated, and the calculation results are used as input parameters for the mixing ratio calculation. For clean water sources with small water quality fluctuations, after debugging and determination, their equivalent scaling ion concentration can be preset as a fixed value in the system. The measured value is compared with the stored value to determine whether the fixed value needs to be updated.

[0031] In this system, the reclaimed water, controlled by its morphology, directly enters the main inlet of the makeup water header. Typically, no regulating valve is installed before this inlet to ensure stable microcrystalline suspension. On each branch pipe of each clean water source, the water flows sequentially through a manual inspection valve, an electric regulating valve, an electromagnetic flowmeter, and a check valve, finally converging into the makeup water header. Based on the target introduction ratio calculated in step S400, current signals are output to drive the actuators of each electric regulating valve, matching the valve opening to the target flow rate. The electromagnetic flowmeter provides real-time feedback of the actual flow rate, performing a closed-loop comparison with the set value to correct the valve opening. Through independent branch design, the introduction flow rate and ratio of each clean water source can be independently and accurately controlled and measured without interference. The check valve prevents reclaimed water from flowing back into the clean water source branch due to pressure fluctuations, ensuring water purity. The makeup water header, as the final mixing hub, flexibly blends the wastewater treated at the source with various clean water sources of different costs and qualities, achieving precise compliance with end-point water quality standards and providing a physical basis for subsequent economic optimization.

[0032] In this embodiment, the steps for dynamically adjusting the dosage of the form control agent and the introduction ratio of each clean water source include: Step S401: Real-time acquisition of comprehensive water quality parameters of the mixed water, using the deviation between the comprehensive water quality parameters and preset safety thresholds as feedback signals. The comprehensive water quality parameters are continuously acquired online by a comprehensive water quality sensor array installed at the end of the water supply header. These parameters include calcium ion concentration, sulfate ion concentration, magnesium ion concentration, turbidity, pH value, and conductivity in the mixed water. The preset safety thresholds include upper limits for calcium ion concentration, sulfate ion concentration, the sum of calcium and magnesium ion concentrations, turbidity, the allowable upper and lower ranges for pH, and conductivity.

[0033] The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal to trigger a closed-loop correction of the clean water source introduction ratio. The measured comprehensive water quality parameters are compared with the corresponding preset safety threshold. If the comprehensive water quality parameters are less than the preset safety threshold, the deviation is negative or zero, and no correction is initiated or only a minor adjustment is made. If the comprehensive water quality parameters are greater than or equal to the preset safety threshold, a positive deviation occurs, and the magnitude of the deviation is equal to the comprehensive water quality parameters minus the preset safety threshold. The deviation is input into a preset proportional-integral-derivative controller algorithm, which outputs a correction coefficient in the range of 0 to 100%. This correction coefficient is superimposed on the reference valve opening corresponding to the minimum dilution ratio calculated in step S403 to obtain the final valve opening command. If the deviation persists and the integral term accumulates, the controller will gradually increase the correction amount until the deviation is eliminated. If the correction amount has reached the physical upper limit of the valve opening (fully open) and the deviation is still not eliminated, it is determined that the clean water source supply capacity is insufficient or the water quality is abnormal, triggering the safety interlock in step S600 or the re-optimization in step S500.

[0034] Step S402: Calculate the equivalent scaling ion concentration for the morphology-controlled reclaimed water and the equivalent scaling ion concentration for each clean water source. The equivalent scaling ion concentration is the concentration of scale-causing ions in the morphology-controlled reclaimed water after adjusting for scaling activity. To calculate the equivalent scaling ion concentration, firstly, the measured values ​​of calcium ion concentration, magnesium ion concentration, and sulfate ion concentration in the reclaimed water are obtained in real time using a water quality sensor array installed at the end of the main pipeline of the morphology-controlled reclaimed water. For the clean water sources, the same measured values ​​are obtained using water quality sensors installed individually on each branch. Then, based on the conversion factor table calibrated through numerous scaling experiments during the commissioning phase, a conversion factor is assigned to each ion. For example, calcium ions are used as the benchmark, and their conversion factor is set to 1. Magnesium ions, due to their higher solubility in magnesium sulfate and weaker scaling tendency compared to calcium ions, but because magnesium ions can interfere with calcium sulfate crystallization, have a conversion factor set to 0.3 to 0.5. The measured concentration of each scaling ion is multiplied by its corresponding conversion factor to obtain the equivalent scaling contribution value of that ion. Finally, the equivalent scaling contribution values ​​of all scaling ions are summed to obtain the total equivalent scaling ion concentration, expressed in milligrams per liter.

[0035] Step S403: Based on the material balance relationship, and with the constraint that the equivalent scaling ion concentration of the mixed water does not exceed a preset safe concentration, calculate the minimum dilution ratio required to satisfy this constraint. The minimum dilution ratio is the ratio between the minimum total amount of clean water introduced and the flow rate of the reclaimed water for state control. The upper limits of the sum of calcium and magnesium ions and the concentration of sulfate ions in the mixed water are preset. The material balance relationship is as follows: ; in, The current flow rate of recycled water is controlled by its shape. The equivalent scale ion concentration in reclaimed water is controlled by its morphology. It represents the total mass of equivalent scale ions carried into the makeup water header by the recycled water per unit time; The equivalent scale ion concentration of the i-th clean water source; This represents the inflow rate of the i-th clean water source; This represents the total equivalent mass of scale ions brought in by water source i per unit time. The preset safe concentration value is the equivalent scale ion concentration of the mixed water. This represents the current flow rate of the recycled water. Preset safe concentration value; This represents the total flow rate after mixing. The minimum total clean water intake is calculated based on the material balance relationship. The minimum dilution ratio required to achieve safe mixed water quality is calculated based on the minimum total amount of clean water introduced. The left side of the inequality represents the total equivalent scale ion mass input to the makeup water header, while the right side represents the maximum equivalent total scale ion mass allowed in the mixed water when the upper limit of the safe concentration is reached. The entire inequality indicates that the total scale mass input must be less than or equal to the total scale mass allowed under safe conditions.

[0036] The process of calculating the minimum total clean water intake based on material balance relationships includes assuming the total clean water intake is... , When introducing flow, the clean water source with the lowest equivalent scale ion concentration is preferentially used for dilution, and the clean water source is treated according to... Sort by size from smallest to largest. To determine the clean water source with the lowest equivalent scale ion concentration, we assume that the total intake of clean water comes entirely from the first water source with the best water quality. If multiple water sources have the same equivalent scale ion concentration, the source with the lowest unit cost coefficient or the highest supply reliability should be prioritized. After substituting the material balance relationship and performing inequality calculations, we obtain... The minimum total amount of clean water introduced. If the calculated numerator is negative, it means the recycled water itself meets the standards, and the minimum total clean water intake is 0. If the denominator is negative, it means the clean water quality is worse than the preset safety threshold, and the water source is determined not to be used for dilution. The next water source is then called. The final minimum total clean water intake is a flow rate value, which is then divided by the recycled water flow rate. This yields the minimum dilution ratio.

[0037] The preset safe concentration value is the maximum upper limit of the equivalent scale ion concentration that the mixed water is allowed to reach, which is preset and stored in the controller. By conducting long-term pipeline slab tests and differential pressure monitoring tests with mixed water of different equivalent scale ion concentrations, the maximum equivalent scale ion concentration that just does not cause obvious scaling on the pipe wall (such as the pressure difference growth rate per unit pipe length being lower than the warning value) is found, and this value is determined as the preset safe concentration value.

[0038] Step S404: Pre-adjust the opening of the regulating valves of each clean water source branch according to the minimum dilution ratio, ensuring that the actual ratio of the total clean water inflow to the reclaimed water flow rate under morphological control is not lower than the minimum dilution ratio. When calculating the regulating valve opening of each clean water source branch based on the minimum dilution ratio, the minimum total clean water inflow is obtained based on step S403. Flow rates are allocated sequentially from high to low according to the comprehensive priority score of each water source until the total inflow requirement is met. Finally, based on the target flow rate value allocated to each water source and the flow characteristic curve of the regulating valve for that branch, the required valve opening is calculated. The flow characteristic curve of the regulating valve records the measured flow rate values ​​corresponding to valve openings of 0%, 10%, 20%...100%. Using linear interpolation, the corresponding valve opening percentage is retrieved from the target flow rate. Finally, a 4-20 mA control current signal is sent to the servo motor of the electric regulating valve to rotate the valve to that opening.

[0039] In this embodiment, the implementation steps of pre-adjusting the opening of the regulating valves of each clean water source branch according to the minimum dilution ratio include: Characteristic data records are established for each clean water source, including water source type, equivalent scale ion concentration, unit cost coefficient, supply capacity limit, and supply reliability rating. Water source types include fresh water, circulating water discharge, reverse osmosis concentrate, and other wastewater. Supply reliability ratings are divided into levels 1 to 3, with level 1 indicating continuous availability and level 3 indicating limited supply. The unit cost coefficient is obtained from unit water cost data provided by the power plant's finance or operations department. The cost of fresh water includes water fees, water intake electricity consumption, and pretreatment reagent costs; the cost of circulating water discharge is usually lower, including only booster power consumption; the cost of reverse osmosis concentrate can be considered negative (if charged as concentrate discharge) or close to zero. The supply capacity limit is determined based on the physical supply constraints of the water source; for example, fresh water is limited by the municipal water supply contract flow or the plant's water tank capacity; circulating water discharge is limited by the circulating water system's discharge cycle and the rated flow of the discharge pump; and reverse osmosis concentrate is limited by the difference between the reverse osmosis unit's permeate rate and permeate volume. The supply reliability rating is set based on the historical availability rate of the water source in actual operation. Level 1 indicates continuous availability, that is, the availability time of the water source in the past statistical period (such as 30 days) is greater than 99%, and it is not affected by external condition fluctuations (such as the plant's fresh water system); Level 2 indicates intermittent availability, with the availability time between 90% and 99%, and there are planned shutdowns or the impact of upstream processes (such as the reduced discharge of circulating water wastewater when the unit is under low load); Level 3 indicates limited supply, with the availability time being less than 90%, or it can only be used under specific conditions (such as rainwater collection tanks).

[0040] The comprehensive priority score of each clean water source is calculated in real time based on feature data. The comprehensive priority score is negatively correlated with the unit cost coefficient, equivalent scale ion concentration and supply reliability rating. ;in, This represents the overall priority score of the i-th clean water source; the higher the score, the higher the priority for its use. This indicates the reference cost of fresh water; This represents the statistical upper limit of the equivalent scale ion concentration in reclaimed water; Let be the unit cost coefficient of the i-th clean water source; The equivalent scale ion concentration of the i-th clean water source; This represents the concentration influence weighting coefficient, used to adjust the importance of water quality factors in the overall impact score. It is typically set between 0.5 and 2. The larger the value, the greater the impact of water quality factors on the overall priority score; This indicates the supply reliability rating. The higher the supply reliability rating, the more likely it is to be included in the flow allocation portfolio. The lower the cost, the better the water quality, and the higher the reliability of the water source, the higher its overall priority score.

[0041] If the actual concentration of equivalent scale ions in the mixed water exceeds the preset safe concentration value, feedback correction is performed. Then, the flow rate of the clean water source branch is finely adjusted first according to the comprehensive priority score from high to low. If the adjustment amount of a single clean water source branch reaches the upper limit of the water supply capacity of that water source and still cannot eliminate the scale, the clean water source branches are called in turn according to the economic order until the total supply capacity of the called clean water sources meets the minimum total amount of clean water introduced.

[0042] When the total regulation of clean water sources has reached the economically feasible upper limit, and further increasing the proportion of clean water sources will lead to a significant increase in operating costs or insufficient supply of clean water sources, the regulation signal will be sent to step S500 for the next decision.

[0043] When the characteristic data of a clean water source changes, the system performs autonomous priority calculation; when the measured equivalent scale ion concentration of a clean water source exceeds the standard for a predetermined number of times, the system automatically downgrades the supply reliability rating and correspondingly reduces its comprehensive priority score; when the measured equivalent scale ion concentration of a clean water source is lower than the historical average and reaches a threshold, the system automatically upgrades the supply reliability rating and correspondingly increases its comprehensive priority score; when two water sources with similar water quality have different costs, they are re-ranked according to the new unit cost coefficient value.

[0044] The water source activation order and composition determined after this active priority sorting will be automatically loaded into step S403 as the basis for the next round of calculation.

[0045] In this embodiment, the implementation steps for periodically optimizing the dosage of the morphology control agent and the introduction ratio of each clean water source include: Step S501: Obtain the cost of the form control agent and the cost of each clean water source per unit time. The optimization objective is to minimize the sum of the form control agent cost and the cost of each clean water source per unit time, i.e., minimize the total operating cost. Constraints are set, including mixed water constraints, differential pressure constraints in the reuse main pipeline, form control agent dosage constraints, and clean water source inlet flow rate constraints. The objective function is: ; in, Indicates total operating cost; This is the unit cost coefficient for the morphology control agent; This refers to the dosage of the form control agent; This refers to the instantaneous flow rate of recycled water. To optimize cycle duration, such as T being 4 hours, the setting can be adjusted according to actual operation. Let be the unit cost coefficient of the i-th clean water source; The flow rate of the i-th clean water source; Among the constraints, the mixed water constraint is that the equivalent scale ion concentration of the mixed water at the end of the makeup water header is less than or equal to the preset safe concentration value; the pressure difference constraint of the reuse main pipeline is that the pressure difference per unit length of the reuse main pipeline is less than or equal to the scale warning value; the form control agent dosage constraint is that the form control agent dosage is above the minimum effective dosage and below the maximum economic dosage; and the clean water source inlet flow constraint is that the clean water source inlet flow is greater than or equal to zero and less than or equal to the upper limit of the water source supply capacity.

[0046] The total operating cost is calculated by summing the consumption cost of the form control agent and the consumption cost of all clean water sources within an optimization cycle. The cost of the form control agent is calculated by multiplying the dosage by its unit cost coefficient within the optimization cycle. The cost of each clean water source is then calculated by multiplying its volume by its unit cost coefficient. These costs are then summed to obtain the total operating cost. By solving the optimization objective, an optimal combination of decision variables is found that minimizes the total operating cost J. This allows the system to automatically switch to the most economical operating mode based on real-time water quality and cost data.

[0047] Step S502: Divide the working space that meets all constraints into a morphology control agent-dominated area and a clean water source-dominated area. In the area dominated by the form control agent, the total scale load is at a medium to low level. Increasing the dosage of the form control agent is more economical than increasing the flow rate of the clean water source. Moreover, the pressure difference per unit length of the reuse main pipeline is within a safe range. Therefore, the dosage of the form control agent should be increased first. In areas dominated by clean water sources, the total scale load is at a high level or the dosage of form control agent is close to the upper limit, but the pressure difference per unit length of the reuse main pipeline is on the rise. If the dosage of form control agent is further increased, it will lead to an increase in economic costs. Therefore, the proportion of clean water source introduction should be increased first. When the total scale load continues to rise and adjusting the dosage of the form control agent alone can no longer simultaneously meet the water quality constraints of the mixed water and the pipeline pressure difference constraints, the dosage of the form control agent should be increased to its economic limit and the proportion of clean water source introduction should be increased so that both can work together to meet all constraints.

[0048] When partitioning the operating space, the following parameters are first obtained: current total scale load, recycled water flow rate, current dosage of form control agent and its real-time unit cost, current inflow rate of each clean water source and its real-time unit cost, and the current measured pressure difference per unit length of the recycled main pipeline. Then, an efficiency partitioning map based on debugging and historical operating data is pre-established within the controller. The efficiency partitioning map uses total scale load as the horizontal axis and pressure difference per unit length of the recycled main pipeline as the vertical axis, dividing the plane into three regions: the lower left corner is the form control agent-dominated region (total scale load is moderate to low, pressure difference is safe, and the marginal cost of increasing the agent is lower than increasing the clean water source); the lower right corner is the clean water source-dominated region (total scale load is high or the agent has reached its economic limit, and the marginal cost of increasing the clean water source is lower than continuing to increase the agent); and the upper right corner is the coordinated adjustment region (both require increases). Finally, the current data points are mapped onto the efficiency partitioning map to determine their region. Through partitioning adjustments, the convergence speed and effectiveness of rolling optimization are significantly improved.

[0049] Step S503: Adjust the preset safety threshold and preset safety concentration value in dynamic regulation based on the results of periodic rolling optimization. The process of adjusting the preset safety threshold in dynamic regulation based on the results of periodic rolling optimization includes: first, completing a rolling optimization calculation for one optimization cycle (e.g., 4 hours) to obtain the optimal dosage of the form control agent and the optimal inflow rate of each clean water source within that cycle; then, during the execution of the next optimization cycle, the system performs open-loop settings according to the optimal dosage of the form control agent and the optimal inflow rate of each clean water source, and records the average and maximum deviations between the comprehensive water quality parameters and the current preset safety threshold in the feedback control of step S401 in the next cycle. If, over multiple consecutive optimization cycles (e.g., three cycles), the average equivalent scaling ion concentration of the actual mixed water is observed to be significantly lower than the current preset safe concentration value (e.g., lower than 80% of the preset safe concentration value), it indicates that the current preset safe concentration value is set too conservatively, allowing the mixed water to have a higher ion concentration without causing scaling. In this case, the preset safe concentration value is automatically increased by a preset step size (e.g., 2% of the threshold) to reduce reliance on clean water sources and further reduce costs. Conversely, if in multiple consecutive optimization cycles, the feedback control requires frequent and significant increases in the amount of clean water introduced to bring the water quality below the preset safety threshold, and sometimes even fails to bring it below the preset safety threshold, it indicates that the current preset safety threshold setting is too lenient, causing the water to remain close to the scaling edge even after a large dilution. In this case, the system automatically lowers the preset safety threshold by a preset step size to enhance safety redundancy. The final adjusted new preset safety concentration value will be immediately applied to the feedback deviation calculation in step S401 and the material balance solution in step S403.

[0050] The dosage of the form control agent obtained through periodic rolling optimization is used to update the set flow rate of the form control agent injection pump in step S200, serving as the execution benchmark value for continuous injection in the next optimization cycle. The proportion of each clean water source introduced through rolling optimization is used to update the benchmark opening of each electric regulating valve in step S404, serving as the target set value for feedforward control in the next optimization cycle. Step S400 is a short-cycle, fast-response feedback correction based on real-time deviation, with the goal of achieving water quality standards at this moment, on a time scale of seconds to minutes. The rolling optimization in step S500 is a long-cycle, slow-response economic optimization based on cumulative cost, with the goal of minimizing total cost over a future period, on a time scale of hours. Rolling optimization provides a benchmark value for dynamic adjustment. Dynamic adjustment fine-tunes and corrects real-time disturbances around this benchmark value, ensuring that the system operates on an economically optimal macroscopic trajectory and that the system does not deviate from safety constraints at microscopic moments.

[0051] In this embodiment, the steps for automatically executing safety interlock protection when an abnormal operating condition is detected include: The pressure difference before and after the morphological control zone is continuously monitored. When the pressure difference exceeds the warning pressure difference threshold, it is determined that there is a risk of blockage in the pipeline. The introduction of desulfurization wastewater is automatically stopped, and the clean water source bypass is opened to flush the reuse main pipeline. After flushing, the introduction of desulfurization wastewater is resumed. The warning pressure difference threshold is set based on the measured benchmark pressure difference of the pipeline in a scale-free state and the pipeline's scaling risk tolerance and safety margin. Generally, it is dynamically calculated by multiplying the benchmark pressure difference of the pipeline in a scale-free state by a safety factor. The safety factor is between 1.5 and 2.5, that is, 1.5 to 2.5 times the benchmark pressure difference of the pipeline. When the pressure difference exceeds this ratio, it is determined that there is a risk of blockage in the pipeline.

[0052] The system continuously monitors the comprehensive water quality parameters of the mixed water. When the equivalent scale ion concentration of the mixed water continues to exceed the preset safe concentration value, it automatically reduces the proportion of form control reclaimed water and increases the proportion of clean water source. If the mixed water quality still exceeds the standard after the form control reclaimed water is completely shut off, an alarm for abnormal clean water source quality will be issued. When a morphology control agent supply interruption or a seed crystal replenishment device malfunction is detected, the desulfurization wastewater inlet volume is automatically reduced and the clean water inlet volume is increased, while an alarm signal is issued.

[0053] In this embodiment, the method further includes correcting the output of the morphological control model based on the measured data from the differential pressure sensor installed on the main reuse pipeline and the water quality comparison analysis results of the sections before and after the morphological control zone. The correction steps include: Water quality samples are collected in real time from upstream and downstream of the morphology control zone to calculate the morphology conversion efficiency of scale ions in the control zone. The upstream scale ion concentration and the downstream equivalent scale ion concentration are obtained from the upstream and downstream water quality samples, respectively. The morphology conversion efficiency is obtained by subtracting the downstream equivalent scale ion concentration from the upstream scale ion concentration and then dividing by the upstream scale ion concentration. A higher morphology conversion efficiency indicates a greater proportion of scale ions converted into suspended crystals. After calculating the morphology conversion efficiency, it is compared with a preset efficiency target value (e.g., 85%). If the morphology conversion efficiency is lower than the efficiency target value, and the pressure difference per unit length of the main pipeline shows a continuous upward trend, the current morphology control treatment intensity is considered insufficient, and the model correction process is initiated. If the morphology conversion efficiency is lower than the target value but the pressure difference is stable, it may indicate insufficient seed concentration or uneven reagent mixing; the seed replenishment system should be checked first.

[0054] Monitor the changing trend of pressure difference per unit length of the reuse main pipeline; when the pressure difference per unit length is stable for a long period of time and there is no continuous upward trend, it is determined that the current morphology control treatment intensity is sufficient to control the scaling risk; when the pressure difference per unit length shows a continuous increase, it indicates that a scale layer has begun to form on the pipe wall, and it is determined that the current morphology control treatment intensity is insufficient. The safety factor of the dosage of morphology control agent in step S202 is gradually increased according to the preset step size, and the increased dosage, along with the scaling tendency index and total scale load under this operating condition, are used as new empirical data points to correct the mapping relationship between input and output in the morphology control model. After increasing the dosage, continue monitoring for a verification period (e.g., 24 hours) to observe whether the upward trend of the pressure difference per unit pipe length slows down and eventually stabilizes, and whether the morphological transformation efficiency recovers to above the target value. If the pressure difference stabilizes and the efficiency recovers, it is confirmed that the new dosage is the effective minimum dosage for the current working conditions. This set of new empirical data points is used as the basis for correction to update the output values ​​of the corresponding grid points in the two-dimensional interpolation table of the morphological control model. The new values ​​and the old values ​​are used for smoothing the update. If there is no data, new data points are directly inserted, and the interpolation table is re-interpolated in two dimensions to fill the adjacent unknown areas.

[0055] If the adjustment is ineffective, it continues to be adjusted until the economic dosage limit of the morphology control agent (determined by cost accounting) is reached. If the limit is still ineffective, the model is no longer corrected, but step S500 optimization is triggered, forcibly requiring an increase in the proportion of clean water. This correction process enables online adaptive self-learning of the morphology control model, automatically identifying that the current model's minimum dosage is insufficient to suppress scaling, and proactively adjusting the safety factor. The corrected effective dosage is then backfilled into the model, allowing the morphology control model to continuously approximate real dynamic characteristics. This avoids control failure after long-term operation due to model solidification, greatly enhancing the system's robustness and long-term reliability against uncertainties such as coal type changes and water quality drift.

[0056] like Figure 2 An automated control-based desulfurization wastewater reuse and treatment system for thermal power plants, the system comprising: The influent water quality monitoring module is used to continuously collect desulfurization wastewater quality parameters at the influent end of the desulfurization wastewater reuse main pipeline, and calculate the scaling tendency index and total scale load based on the desulfurization wastewater quality parameters. The morphology control module is used to obtain the initial dosage of the morphology control agent by taking the scaling tendency index and total scale load as input and combining them with a preset morphology control model; and to continuously inject the morphology control agent into the desulfurization wastewater according to the initial dosage to obtain morphology-controlled recycled water. A supplementary mixing module is used to independently introduce the morphology-controlled recycled water and multiple clean water sources into the water supply header to obtain mixed water. The automated control module is used to acquire the comprehensive water quality parameters of the mixed water in real time. The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal. The equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source are calculated as feedforward signals. The module dynamically adjusts the dosage of the form control agent and the introduction ratio of each clean water source to keep the comprehensive water quality parameters of the mixed water within the preset safety threshold. The module also acquires the cost of the form control agent and the cost of each clean water source per unit time. With the goal of minimizing the total operating cost, the module periodically and continuously optimizes the dosage of the form control agent and the introduction ratio of each clean water source. The safety interlock module is used to automatically execute safety interlock protection when abnormal operating conditions are detected.

[0057] In this embodiment, a morphology control zone is set up on the main pipeline for desulfurization wastewater reuse. By continuously injecting morphology control agents into the wastewater and pre-placing induced crystal seeds, the scaling ions in the wastewater are transformed into fine, smooth-surfaced micro-suspended crystals under the dual effects of molecular inhibition by the morphology control agents and heterogeneous nucleation on the crystal seed surface. These crystals remain stably suspended in the water in a harmless form, avoiding direct nucleation and deposition on the pipe wall surface. Unlike conventional softening methods that achieve scale prevention by removing a large number of scaling ions, this invention retains most of the scaling ions in the water and achieves scale prevention without removing scale by changing their crystal morphology. This is based on real-time calculations of the scaling tendency index and total scale load. The calculation results show that the minimum dosage of reagent to meet the anti-scaling requirements is determined by the morphological control model pre-installed in the controller, avoiding the economic waste of excessive dosing. At the same time, the introduction of induced crystal seeds causes the heterogeneous nucleation of scale ions to occur preferentially on the surface of the crystal seeds rather than on the pipe wall surface, reducing the frequency of pipe cleaning and equipment maintenance costs. The scale prevention problem is transformed into a crystal morphology control problem. In-situ treatment effectively reduces the footprint and is applicable to the treatment of desulfurization wastewater of different coal types and seasons. No large-scale equipment modification is required, saving costs and extending the service life of pipelines. While effectively solving the bottleneck of pipeline scaling, the reagent cost is optimized.

[0058] This invention employs a method of mixing morphology-controlled reclaimed water with multiple clean water sources in a main water supply pipe. The deviation of the mixed water's overall water quality parameters from a preset safety threshold serves as feedback, while the equivalent scale ion concentrations of the morphology-controlled reclaimed water and each clean water source serve as feedforward signals. A composite mode of feedforward pre-adjustment and feedback micro-correction dynamically adjusts the proportion of each water source introduced. Closed-loop correction of the mixing ratio is performed based on real-time water quality monitoring data, enabling automatic adaptation to significant fluctuations in desulfurization wastewater quality. Furthermore, with the optimization objective of minimizing the sum of the costs of morphology control agents and each clean water source per unit time, the minimum dilution ratio is obtained by calculating the relevant conditions for meeting the safety constraints of the mixed water quality. This achieves joint economic optimization of water and chemical consumption, compressing the consumption of clean water sources to the minimum required to meet safety constraints. While ensuring the safe operation of the desulfurization system, this reduces water resource consumption and the overall cost of wastewater reuse, achieving automated control of the entire wastewater reuse process.

[0059] This application also provides an electronic device. The electronic device may include one or more processors and one or more memories. The memories store computer-readable code that, when executed by the one or more processors, can perform the automated control-based desulfurization wastewater reuse treatment system and method for thermal power plants as described above.

[0060] The methods or systems according to the embodiments of this application can also be implemented using the architecture of the electronic device shown in this application. The electronic device may include a bus, one or more CPUs, ROM, RAM, a communication port connected to a network, input / output, a hard disk, etc. The storage device in the electronic device, such as a ROM or hard disk, may store the automated control-based desulfurization wastewater reuse treatment system and method for thermal power plants provided in this application. Furthermore, the electronic device may also include a user interface. Of course, the architecture shown in this application is merely exemplary; when implementing different devices, one or more components in the electronic device shown in this application may be omitted according to actual needs.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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 a reference structure" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for the reuse and treatment of desulfurization wastewater from thermal power plants based on automated control, characterized in that, The method includes: Water quality parameters of desulfurization wastewater are continuously collected at the inlet of the main pipeline for desulfurization wastewater reuse. Based on the water quality parameters of desulfurization wastewater, the scaling tendency index and total scale load are calculated. Using the scaling tendency index and total scale load as inputs, and combining them with a preset morphology control model, the initial dosage of the morphology control agent is obtained; the morphology control agent is continuously injected into the desulfurization wastewater according to the initial dosage to obtain morphology-controlled recycled water. The reclaimed water with the controlled morphology and the multiple clean water sources are introduced independently into the water supply header to obtain mixed water; The comprehensive water quality parameters of the mixed water are acquired in real time. The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal. The equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source are calculated as feedforward signals. The dosage of the form control agent and the introduction ratio of each clean water source are dynamically adjusted to keep the comprehensive water quality parameters of the mixed water within the preset safety threshold. The cost of the form control agent and the cost of each clean water source per unit time are obtained. With the goal of minimizing the total operating cost, the dosage of the form control agent and the introduction ratio of each clean water source are periodically and continuously optimized. When abnormal operating conditions are detected, safety interlock protection is automatically activated.

2. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The calculation of scaling tendency index and total scale load based on desulfurization wastewater quality parameters includes: The water quality parameters of the desulfurization wastewater include calcium ion concentration, magnesium ion concentration, sulfate ion concentration, pH value, conductivity, and temperature. The supersaturation ratio of each sparingly soluble salt component was calculated based on the water quality parameters of the desulfurization wastewater, and the supersaturation ratios were weighted and summed to obtain the scaling tendency index, which characterizes the overall scaling risk of the desulfurization wastewater. The instantaneous flow rate of the desulfurization wastewater is obtained, and the total amount of scale ions entering the reuse system per unit time is calculated in combination with the calcium ion concentration, which is taken as the total scale load.

3. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The construction process of the preset morphology control model includes: Multiple sets of desulfurization wastewater samples with different calcium ion concentrations, magnesium ion concentrations, sulfate ion concentrations, and pH values ​​were pre-configured; The particle size distribution of precipitated crystals and the scaling rate of pipe walls were measured for each desulfurization wastewater sample under different dosage conditions of different form control agents. Using the scaling tendency index and total scale load as input variables, and the minimum dosage when the scaling rate of the pipe wall is lower than the preset rate threshold and the crystal particle size does not exceed the upper limit of micrometers as the output variable, a mapping relationship between input and output is established, and the mapping relationship is used as a morphological control model in the form of a piecewise linear function or an interpolation table.

4. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The step of continuously injecting a speciation control agent into the desulfurization wastewater according to the initial dosage to obtain speciation control reclaimed water includes: Using the scaling tendency index and total scale load as query conditions, the morphological control model is invoked to obtain the minimum dosage. Then, the minimum dosage is multiplied by a preset safety factor to obtain the initial dosage. The morphology control agent is continuously injected into the desulfurization wastewater according to the initial dosage, so that the morphology control agent molecules are adsorbed on the surface of the newly formed crystal nuclei and simultaneously adsorbed on the inner wall of the pipe, inhibiting the direct nucleation of crystal nuclei on the pipe wall and distorting the normal growth direction of the crystals. A morphology control zone is divided inside the main reuse pipeline. Induced crystal seeds are introduced into the morphology control zone to transform scale ions in the desulfurization wastewater into fine suspended crystals under the combined action of the morphology control agent and the induced crystal seeds. The sludge discharge valve is opened periodically to discharge the settled oversized particles, thus obtaining morphology-controlled reused water.

5. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The dosage of the dynamically adjustable form control agent and the proportion of each clean water source introduced include: Calculate the equivalent scale ion concentration for the reclaimed water with morphological control and the equivalent scale ion concentration for each clean water source. With the constraint that the equivalent scale ion concentration of the mixed water does not exceed the preset safe concentration, the minimum dilution ratio required to satisfy this constraint is determined. The minimum dilution ratio is the ratio between the minimum total amount of clean water introduced and the flow rate of the reclaimed water controlled by the morphology. The opening of the regulating valves of each clean water source branch is pre-adjusted according to the minimum dilution ratio so that the actual ratio of the total amount of clean water introduced to the flow rate of the reclaimed water controlled by the morphology is not lower than the minimum dilution ratio.

6. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 5, characterized in that, The pre-adjustment of the opening of the regulating valves of each clean water source branch according to the minimum dilution ratio includes: Establish characteristic data records for each clean water source, including water source type, equivalent scale ion concentration, unit cost coefficient, supply capacity limit and supply reliability rating; The comprehensive priority score of each clean water source is calculated in real time based on feature data; According to the comprehensive priority score from high to low, each clean water source branch is called in turn until the total supply capacity of the called clean water sources meets the minimum total amount of clean water to be introduced.

7. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The periodic rolling optimization of the dosage of the morphology control agent and the introduction ratio of each clean water source include: Obtain the cost of the morphology control agent and the cost of each clean water source per unit time. The optimization objective is to minimize the sum of the costs of the morphology control agent and each clean water source per unit time, and constraints are set accordingly. The working space that meets all constraints is divided into a morphology control agent-dominated zone and a clean water source-dominated zone. In the morphology control agent-dominated zone, the dosage of morphology control agent is increased first. In the clean water source-dominated zone, the proportion of clean water source introduction is increased first. When the total scale load continues to rise and adjusting the dosage of the form control agent alone can no longer meet the constraints, the dosage of the form control agent is increased to its cost limit, and the proportion of clean water source is increased so that the two work together to meet all constraints. The preset safety threshold in the dynamic adjustment is adjusted based on the results of periodic rolling optimization.

8. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 7, characterized in that, The automatic execution of safety interlock protection upon detection of abnormal operating conditions includes: The pressure difference before and after the morphological control zone is continuously monitored. When the pressure difference exceeds the warning pressure difference threshold, it is determined that there is a risk of blockage in the pipeline. The introduction of desulfurization wastewater is automatically stopped and the clean water source bypass is opened to flush the reuse main pipeline. After flushing is completed, the introduction of desulfurization wastewater is resumed. The system continuously monitors the comprehensive water quality parameters of the mixed water. When the equivalent scale ion concentration of the mixed water continues to exceed the preset safe concentration value, it automatically reduces the proportion of form control reclaimed water and increases the proportion of clean water source. If the mixed water quality still exceeds the standard after the form control reclaimed water is completely shut off, an alarm for abnormal clean water source quality will be issued. When a failure to supply the morphology control agent is detected, the system automatically reduces the amount of desulfurization wastewater introduced and increases the amount of clean water introduced, while simultaneously issuing an alarm signal.

9. The method for treating desulfurization wastewater from thermal power plants based on automated control according to claim 1, characterized in that, The method further includes: Water quality samples were collected in real time from upstream and downstream of the morphology control zone, and the morphology conversion efficiency of the morphology control zone for scaling ions was calculated. Monitor the changing trend of pressure difference per unit length of the main pipeline for reuse. When the pressure difference per unit length continues to rise, it is determined that the current morphological control treatment intensity is insufficient. The safety factor of the dosage of morphological control agent is gradually increased according to the preset step size. The increased dosage, along with the scaling tendency index and total scale load under this condition, are used as new empirical data points to correct the mapping relationship between input and output in the morphological control model.

10. A wastewater reuse and treatment system for desulfurization in thermal power plants based on automated control, characterized in that: The system includes: The influent water quality monitoring module is used to continuously collect desulfurization wastewater quality parameters at the influent end of the desulfurization wastewater reuse main pipeline, and calculate the scaling tendency index and total scale load based on the desulfurization wastewater quality parameters. The morphology control module is used to obtain the initial dosage of the morphology control agent by taking the scaling tendency index and total scale load as inputs and combining them with a preset morphology control model, and then adding it to the desulfurization wastewater to obtain morphology control recycled water. A supplementary mixing module is used to independently introduce the morphology-controlled recycled water and multiple clean water sources into the water supply header to obtain mixed water. The automated control module is used to acquire the comprehensive water quality parameters of the mixed water in real time. The deviation between the comprehensive water quality parameters and the preset safety threshold is used as a feedback signal. The equivalent scale ion concentration of the reclaimed water and the equivalent scale ion concentration of each clean water source are calculated as feedforward signals. The dosage of the form control agent and the introduction ratio of each clean water source are dynamically adjusted. With the goal of minimizing the total operating cost, the dosage of the form control agent and the introduction ratio of each clean water source are periodically and continuously optimized. The safety interlock module is used to automatically execute safety interlock protection when abnormal operating conditions are detected.

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