A Coordinated Control Method and System for Desulfurization of CFB Units Based on Economic Optimization

Abstract

This invention relates to the field of automatic control technology, and in particular provides a method and system for coordinated desulfurization control of CFB units based on economic optimization. The method includes obtaining baseline emission values ​​and constructing a global economic optimization model; performing offline optimization and function fitting at an offline optimization layer based on the global economic optimization model; calculating online dynamic setpoints from the online control layer based on offline optimization and function fitting; comparing the dynamic setpoints with the measured SO2 concentration at the furnace outlet using a GPC controller and dynamically calculating the output signal; and optimizing the control of external desulfurization based on the output signal. This method provides adaptive feedforward coordinated control of in-furnace desulfurization and WFGD systems in CFB units, simultaneously solving problems related to pollutant emission control, economic operation, and system response delay.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology, and in particular to a coordinated control method and system for desulfurization of CFB units based on economic optimization. Background Technology

[0002] Currently, most circulating fluidized bed (CFB) power plants treat in-furnace calcium injection desulfurization and external wet flue gas desulfurization as two independent units in actual operation. In-furnace desulfurization typically employs a simple single-loop proportional-integral-derivative (PID) control system, with the setpoint (SO2 concentration) manually set by operators based on experience, usually a fixed value or a value with a very small range of variation. External wet flue gas desulfurization (WFGD) systems, on the other hand, rely primarily on feedback control based on the measured inlet SO2 concentration, adjusting the number of operating slurry circulation pumps and the slurry pH value to ensure that final emissions meet standards. This traditional control strategy has the following inherent drawbacks: 1. Systemic Deficiencies: The two systems operate independently, lacking information exchange and coordination, and cannot function as a whole to cope with disturbances from changes in coal quality and unit load. When the sulfur content of the coal entering the furnace increases or the load changes rapidly, the SO2 concentration at the furnace outlet will fluctuate drastically, easily exceeding the maximum desulfurization capacity design limit of the WFGD system, leading to instantaneous emissions exceeding standards. 2. Low Economic Efficiency: The control targets set by operators are usually conservative, prioritizing safe emissions, making it impossible to achieve optimal economic efficiency across multiple objectives such as limestone consumption, plant power consumption, and environmental protection material consumption. For example, to avoid exceeding standards, excessive slurry circulation pumps may be operated for extended periods, resulting in wasted energy; or the in-furnace desulfurization may be underutilized, leading to low limestone utilization. 3. Inherent Response Lag: The WFGD system itself is a process with significant inertia and delay. From the time SO2 enters the absorption tower to the completion of the slurry chemical reaction, and then to the measurement instruments reflecting changes in outlet concentration, there is a delay of several minutes to tens of minutes. Feedback control based on outlet concentration is always delayed, causing the control system to exhibit a continuous oscillation process of first exceeding the limit and then overcompensating. This not only increases the risk of exceeding the limit but also wastes material and energy. Summary of the Invention

[0003] In view of this, the present invention provides a CFB unit desulfurization coordinated control method and system based on economic optimization, which is used to perform adaptive feedforward coordinated control of in-furnace desulfurization and WFGD system of CFB unit, and at the same time solve the problems of pollutant emission control, economic operation and system response delay.

[0004] In a first aspect, the present invention provides a CFB unit desulfurization coordinated control method based on economic optimization, the method comprising: Step 1: Obtain baseline emission values ​​and construct a global economic optimization model; Step 2: Based on the global economic optimization model, perform offline optimization and function fitting in the offline optimization layer; Step 3: Based on offline optimization and function fitting, calculate the online dynamic setpoint from the online control layer; Step 4: Use a GPC controller to compare the dynamic setpoint with the measured SO2 concentration at the furnace outlet and dynamically calculate the output signal; Step 5: Optimize the control of external desulfurization based on the output signal.

[0005] Optionally, obtaining the baseline emission value in step 1 includes: Baseline emission value P max Through field tests, it was found that under the condition of the unit being at rated load and ensuring that the in-furnace desulfurization system is completely shut down, after boiler combustion and pollutant emissions, the SO2 concentration at the furnace outlet was continuously measured within a preset time, and the average value was taken and determined as the baseline emission value P under the load condition. max It is used to reflect the maximum sulfur release potential of the coal currently being burned.

[0006] Optionally, in step 1, a global economic optimization model is constructed, unifying operating costs and environmental benefits within a single mathematical framework. Its total cost function is: C total = C1 + C2 - C3; C1 represents the cost of in-furnace desulfurization, which includes the consumption cost of limestone powder and the power consumption cost of the limestone feeder. The consumption cost of limestone powder is directly proportional to the voltage signal of the limestone feeder. C2 represents the cost of out-of-furnace desulfurization. The first part of the out-of-furnace desulfurization cost includes the power consumption cost of the high-voltage motors of the slurry circulation pump and the oxidation blower, which is directly proportional to the number of slurry circulation pumps in operation and the operating time. The second part of the out-of-furnace desulfurization cost includes the consumption cost of limestone and process water in the out-of-furnace limestone slurry preparation process, as well as the cost of desulfurization wastewater treatment. C3 represents the by-product revenue, which includes the sales revenue of gypsum, a by-product of desulfurization, and is directly proportional to the gypsum production.

[0007] Optionally, step 2 includes: Step 21: Collect historical operating data of the unit and classify the historical operating data into operating conditions based on different load states; Step 22: Under multiple steady-state operating conditions, for each load point M, based on the proportion of in-furnace desulfurization... To optimize the variables, the particle swarm optimization algorithm (PSO) is used to optimize the total cost function C.total Perform optimization calculations to find the optimal solution that minimizes the total cost. For similar load sections Calculate by taking the average value; Step 23: Combine different load points M and their corresponding optimal load points. Curve fitting was performed to obtain the load-optimal ratio relationship curve, i.e. The curve is represented by an approximate functional relationship: This involves embedding approximate functions into the online control system.

[0008] Optionally, step 3 includes: It receives real-time commands from the power grid for Automatic Generation Control (AGC) load point M; it dynamically calculates the target value of SO2 concentration in the furnace and generates a dynamic setpoint, the expression of which is: ; Among them, M n This is the rated load of the unit; The above expression means the theoretical maximum emission value under the current load multiplied by the expected desulfurization ratio in the furnace, from which the following is derived: It is the optimal setting value that changes dynamically with the load command.

[0009] Optionally, step 4 includes: a. The controlled object is the SO2 concentration at the furnace outlet of the CFB boiler desulfurization process, i.e., the limestone feeding process to the furnace outlet. b. The controller adopts a generalized predictive controller (GPC); it is based on a predictive model, rolling optimization and feedback correction, and is used to handle the setpoint tracking problem. c. The control process is to dynamically generate As the setpoint of the GPC controller; the GPC controller compares the dynamic setpoint with the measured value of SO2 concentration at the furnace outlet, dynamically calculates the output signal, and adjusts the speed of the limestone feeder to make the actual SO2 concentration track the dynamic optimal setpoint.

[0010] Optionally, step 5 includes: Step 51, Feedforward signal: The signal is sent to the WFGD control system as a feedforward signal to guide the external desulfurization system to act in advance. Step 52, Feedforward Calculation Model: The feedforward calculation model is embedded in the WFGD control system. The feedforward calculation model is based on the fitting of historical operating data. -Optimal Pump Combination- A lookup table of recommended pH settings, which is an empirical formula, defines the most economical and efficient equipment operation mode under different SO2 loads; Step 53, Control Action: Based on the received... The WFGD control system queries the feedforward calculation model and issues control commands: Step 531: For the slurry circulation pump: decide whether to start or stop the pump, and adjust the operating frequency of the variable frequency pump; Step 532, pH adjustment: Provide a preset pH value and adjust the pH value of the absorber slurry tank to the target range.

[0011] Secondly, the present invention provides a CFB unit desulfurization coordinated control system based on economic optimization, the system comprising: an economic optimization module, a dynamic setpoint generation module, and a furnace internal and external desulfurization coordinated control module. The economic optimization module is used to obtain baseline emission values ​​and construct a global economic optimization model; based on the global economic optimization model, offline optimization and function fitting are performed in the offline optimization layer. The dynamic setpoint generation module is used to calculate online dynamic setpoints from the online control layer based on offline optimization and function fitting. The furnace-external desulfurization coordination control module is used to compare the dynamic setpoint with the measured value of SO2 concentration at the furnace outlet using a GPC controller, dynamically calculate the output signal, and optimize the control of external desulfurization based on the output signal.

[0012] Thirdly, embodiments of the present invention provide a computer-readable storage medium comprising a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the CFB unit desulfurization coordinated control method based on economic optimization in the first aspect or any possible implementation thereof.

[0013] Fourthly, embodiments of the present invention provide an electronic device, comprising: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the CFB unit desulfurization coordinated control method based on economic optimization in the first aspect or any possible implementation of the first aspect.

[0014] The technical solution provided by this invention includes a method that involves obtaining baseline emission values ​​and constructing a global economic optimization model; performing offline optimization and function fitting at an offline optimization layer based on the global economic optimization model; calculating online dynamic setpoints from an online control layer based on the offline optimization and function fitting; comparing the dynamic setpoints with the measured SO2 concentration at the furnace outlet using a GPC controller and dynamically calculating the output signal; and optimizing the control of external desulfurization based on the output signal. This method provides adaptive feedforward coordinated control for the in-furnace desulfurization and WFGD systems of CFB units, while simultaneously addressing the issues of pollutant emission control, economic operation, and system response delay. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart of a CFB unit desulfurization coordinated control method based on economic optimization provided in an embodiment of the present invention; Figure 2 A flowchart of another CFB unit desulfurization coordinated control method based on economic optimization provided in an embodiment of the present invention; Figure 3 A schematic diagram of a CFB unit desulfurization coordinated control system based on economic optimization provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0018] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0020] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0021] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0022] Figure 1 A flowchart of the CFB unit desulfurization coordinated control method based on economic optimization provided in the embodiments of the present invention is shown below. Figure 1 As shown, the method includes: Step 1: Obtain baseline emission values ​​and construct a global economic optimization model.

[0023] In this embodiment of the invention, obtaining the baseline emission value in step 1 includes: Baseline emission value P max Through field tests, it was determined that, under the condition that the unit is at rated load (or one or more typical load points, such as 75% load), and the in-furnace desulfurization system (limestone feeder) is completely shut down, after boiler combustion and pollutant emissions, the SO2 concentration at the furnace outlet is continuously measured within a preset time, and the average value is taken and determined as the baseline emission value P under the load condition. max It is used to reflect the maximum sulfur release potential of the coal currently being burned.

[0024] In this embodiment of the invention, step 1 constructs a global economic optimization model, unifying operating costs and environmental benefits within a single mathematical framework. Its total cost function is: C total = C1 + C2 - C3; C1 represents the cost of in-furnace desulfurization, which includes the consumption cost of limestone powder and the power consumption cost of the limestone feeder. The consumption cost of limestone powder is directly proportional to the voltage signal of the limestone feeder. C2 represents the cost of out-of-furnace desulfurization. The first part of the out-of-furnace desulfurization cost includes the power consumption cost of the high-voltage motors of the slurry circulation pump and the oxidation blower, which is directly proportional to the number of slurry circulation pumps in operation and the operating time. Each start-up of the slurry circulation pump also causes a large amount of economic loss. The second part of the out-of-furnace desulfurization cost includes the consumption cost of limestone and process water in the limestone slurry preparation process outside the furnace, as well as the cost of desulfurization wastewater treatment. C3 represents the by-product revenue, which includes the sales revenue of gypsum, a by-product of desulfurization, and is directly proportional to the gypsum production.

[0025] Step 2: Based on the global economic optimization model, perform offline optimization and function fitting in the offline optimization layer.

[0026] In embodiments of the present invention, such as Figure 2 As shown, step 2 includes: Step 21: Collect historical operating data of the unit and classify the historical operating data into operating conditions based on different load states; Step 22: Under multiple steady-state operating conditions, for each load point M, based on the proportion of in-furnace desulfurization... To optimize the variables, Particle Swarm Optimization (PSO) is used to optimize the total cost function C. total Perform optimization calculations to find the optimal solution that minimizes the total cost. For similar load sections Calculate by taking the average value; In this embodiment of the invention, The optimal in-furnace desulfurization ratio is represented as a percentage, indicating the proportion of desulfurization tasks that the in-furnace desulfurization system should undertake to achieve the lowest total cost under the current load. Besides Particle Swarm Optimization (PSO), other intelligent optimization algorithms such as Genetic Algorithm (GA), Simulated Annealing (SA), or Differential Evolution (DE) can also be used for economic optimization.

[0027] Step 23: Combine different load points M and their corresponding optimal load points. Curve fitting was performed to obtain the load-optimal ratio relationship curve, i.e. The curve is represented by an approximate functional relationship: This involves embedding approximate functions into the online control system.

[0028] Step 3: Calculate the online dynamic setpoint from the online control layer based on offline optimization and function fitting.

[0029] In this embodiment of the invention, step 3 includes: It receives real-time commands from the power grid for Automatic Generation Control (AGC) load point M; dynamically calculates the target value of SO2 concentration in the furnace, and generates a dynamic setpoint, the expression of which is: ; Among them, M n This is the rated load of the unit; The above expression means the theoretical maximum emission value under the current load multiplied by the expected desulfurization ratio in the furnace, from which the following is derived: It is the optimal setting value that changes dynamically with the load command.

[0030] Step 4: Use a GPC controller to compare the dynamic setpoint with the measured SO2 concentration at the furnace outlet and dynamically calculate the output signal.

[0031] In this embodiment of the invention, step 4 includes: a. The controlled object is the SO2 concentration at the furnace outlet of the CFB boiler desulfurization process, i.e., the limestone feeding process to the furnace outlet. b. The controller adopts a generalized predictive control (GPC); GPC is an advanced control algorithm that is particularly suitable for processes with large inertia and large delay characteristics, such as CFB units. It is based on predictive models, rolling optimization and feedback correction, and is used to deal with setpoint tracking problems. In this embodiment of the invention, in addition to generalized predictive control (GPC), the advanced controller for the in-furnace desulfurization process can also employ other algorithms with good setpoint tracking performance and anti-interference capabilities, such as fuzzy PID control, adaptive PID control, expert control, and MPC control.

[0032] c. The control process is to dynamically generate As the setpoint of the GPC controller; the GPC controller compares the dynamic setpoint with the measured value of SO2 concentration at the furnace outlet, dynamically calculates the output signal, and adjusts the speed (feed rate) of the limestone feeder to make the actual SO2 concentration track the dynamic optimal setpoint, so that the original flue gas SO2 emission accurately tracks the setpoint.

[0033] Step 5: Optimize the control of external desulfurization based on the output signal.

[0034] In this embodiment of the invention, step 5 includes: Step 51, Feedforward signal: The signal is sent to the WFGD control system as a feedforward signal to guide the external desulfurization system to act in advance. Step 52, Feedforward Calculation Model: The feedforward calculation model is embedded in the WFGD control system. The feedforward calculation model is based on the fitting of historical operating data. -Optimal Pump Combination- A lookup table of recommended pH settings, which is an empirical formula, defines the most economical and efficient equipment operation mode under different SO2 loads; In this embodiment of the invention, in addition to lookup tables, the WFGD feedforward computation model can also employ a real-time computation model trained based on machine learning such as neural networks (NN) or support vector machines (SVM), or a computation model based on mechanistic formulas.

[0035] Step 53, Control Action: Based on the received... The WFGD control system queries the feedforward calculation model and issues control commands: Step 531, For the slurry circulation pump: Decide whether to start or stop the pump, and adjust the operating frequency of the variable frequency pump; for example, when When the value is high, an additional pump is started in advance; when the value is low, one pump is stopped in advance. This avoids frequent pump start-ups and shutdowns, achieving energy conservation and consumption reduction.

[0036] Step 532, pH adjustment: A preset pH value is given, and the pH value of the absorber slurry pool is adjusted to the target range. This prepares the conditions for efficient desulfurization chemical reaction and overcomes the lag of pH adjustment.

[0037] The above is flow-based rather than concentration-based control. Before the flue gas even reaches the WFGD inlet, the system is already prepared based on the predicted SO2 load, thus completely eliminating the response delay of the WFGD system. In this embodiment of the invention, the entire system can be fully integrated into the power plant's existing DCS system, or it can be deployed on an independent industrial optimization server that communicates with the DCS system.

[0038] This invention provides a CFB unit desulfurization coordinated control system based on economic optimization, such as... Figure 3 As shown, the system includes: an economic optimization module, a dynamic setpoint generation module, and a coordinated control module for desulfurization inside and outside the furnace; The economic optimization module is used to obtain baseline emission values ​​and construct a global economic optimization model; based on the global economic optimization model, offline optimization and function fitting are performed in the offline optimization layer; the dynamic setpoint generation module is used to calculate online dynamic setpoints from the online control layer based on offline optimization and function fitting; the furnace internal and external desulfurization coordinated control module is used to compare the dynamic setpoints with the measured values ​​of SO2 concentration at the furnace outlet using a GPC controller, dynamically calculate the output signal; and optimize the control of furnace external desulfurization based on the output signal.

[0039] This invention proposes global economic optimization as the core control objective of the CFB desulfurization system, and establishes a corresponding comprehensive cost model (C1+C2-C3) and offline optimization and online function mapping based on PSO. Method; This invention relates to a dynamic feedforward setpoint generation algorithm based on AGC instructions. This invention directly transforms grid dispatch commands into optimized control objectives for in-furnace desulfurization; it constructs a coordinated control architecture for the CFB unit desulfurization system: based on... To unify the bridge, one path is used for precise tracking of in-furnace GPC, and the other for advanced pre-control of external WFGD, achieving full-process coordination and delay compensation. This invention generates dynamic optimization targets based on a model-based economic decision-making layer, achieves advanced precise control based on a dual-feedforward coordinated execution layer, and ensures long-term optimization effects based on a data-driven adaptive layer. This invention establishes a system and method for adaptive feedforward coordinated control of in-furnace desulfurization and external wet desulfurization (WFGD) systems in CFB units by establishing a global economic optimization model, dynamically allocating desulfurization tasks inside and outside the furnace, and utilizing AGC commands and coal feed signals to form a dual-feedforward mechanism. The aim is to simultaneously solve three core problems: pollutant emission control, economic operation, and system response delay.

[0040] This invention solves the problem of isolated control systems: it breaks down the control barriers between the in-furnace and external desulfurization systems, establishing an integrated control architecture with information exchange and coordinated action, avoiding the loss of control over clean flue gas due to sudden changes in the SO2 concentration of the original flue gas; it solves the problem of lag in large inertial systems: it designs an advanced feedforward control mechanism to fundamentally compensate for the huge delay of the WFGD system, eliminating instantaneous exceedances and periodic oscillations in SO2 emissions, and achieving stable and precise control; it solves the problem of optimizing operational economy: it transcends traditional, conservative control modes, establishing an economic model aimed at minimizing the overall operating cost of the entire process, and optimizing it with artificial intelligence algorithms to obtain the optimal desulfurization setpoint, significantly reducing desulfurization costs.

[0041] Compared with the prior art, the present invention has the following advantages: (1) This invention achieves the optimal operation of the global desulfurization system: by establishing a comprehensive cost model and using intelligent algorithms to find the best balance between limestone consumption, power consumption, material consumption and environmental benefits, it fundamentally changes the extensive mode set by experience. It can automatically find the best balance between limestone consumption, power consumption, material consumption and environmental benefits, significantly reducing the desulfurization operation cost of power plants. The economic benefits are huge and directly quantifiable.

[0042] (2) This invention improves control quality by utilizing the proactive nature of AGC commands, thus mitigating disturbances at the source and providing sufficient preparation time for the WFGD system, enabling it to shift from passive response to active preparation and fundamentally overcoming the control challenges of large-delay systems. Ultimately, this results in a stable SO2 emission curve, eliminating the risk of instantaneous exceedances and demonstrating extremely high environmental reliability.

[0043] (3) The invention is highly feasible and has low modification costs: mainly based on the innovation of software algorithms and system architecture, the core control logic can be implemented in the existing distributed control system by adding an optimized control station, or deployed on an independent optimized server to communicate with the DCS. There is no need to carry out large-scale modification of the existing hardware equipment, which is highly feasible and has a short investment return period.

[0044] The technical solution provided by this invention includes a method that involves obtaining baseline emission values ​​and constructing a global economic optimization model; performing offline optimization and function fitting at an offline optimization layer based on the global economic optimization model; calculating online dynamic setpoints from an online control layer based on the offline optimization and function fitting; comparing the dynamic setpoints with the measured SO2 concentration at the furnace outlet using a GPC controller and dynamically calculating the output signal; and optimizing the control of external desulfurization based on the output signal. This method provides adaptive feedforward coordinated control for the in-furnace desulfurization and WFGD systems of CFB units, while simultaneously addressing the issues of pollutant emission control, economic operation, and system response delay.

[0045] The various steps in the embodiments of the present invention can be performed by an electronic device. This electronic device includes, but is not limited to, tablet computers, portable PCs, and desktop computers.

[0046] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is running, it controls the electronic device containing the computer-readable storage medium to execute the above-described embodiment of the CFB unit desulfurization coordinated control method based on economic optimization.

[0047] Figure 4 A schematic diagram of an electronic device provided in an embodiment of the present invention, such as... Figure 4 As shown, the electronic device 21 includes a processor 211, a memory 212, and a computer program 213 stored in the memory 212 and executable on the processor 211. When the computer program 213 is executed by the processor 211, it implements the CFB unit desulfurization coordinated control method based on economic optimization in the embodiment. To avoid repetition, it will not be described in detail here.

[0048] Electronic device 21 includes, but is not limited to, processor 211 and memory 212. Those skilled in the art will understand that... Figure 4This is merely an example of electronic device 21 and does not constitute a limitation on electronic device 21. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device may also include input / output devices, network access devices, buses, etc.

[0049] The processor 211 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0050] The memory 212 can be an internal storage unit of the electronic device 21, such as a hard disk or RAM of the electronic device 21. The memory 212 can also be an external storage device of the electronic device 21, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or FlashCard equipped on the electronic device 21. Furthermore, the memory 212 can include both internal and external storage units of the electronic device 21. The memory 212 is used to store computer programs and other programs and data required by network devices. The memory 212 can also be used to temporarily store data that has been output or will be output.

[0051] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A desulfurization coordinated control method for CFB units based on economic optimization, characterized in that, The method includes: Step 1: Obtain baseline emission values ​​and construct a global economic optimization model; Step 2: Based on the global economic optimization model, perform offline optimization and function fitting in the offline optimization layer; Step 3: Based on offline optimization and function fitting, calculate the online dynamic setpoint from the online control layer; Step 4: Use a GPC controller to compare the dynamic setpoint with the measured SO2 concentration at the furnace outlet and dynamically calculate the output signal; Step 5: Optimize the control of external desulfurization based on the output signal.

2. The method according to claim 1, characterized in that, Obtaining the baseline emission value in step 1 includes: Baseline emission value P max Through field tests, it was found that under the condition of the unit being at rated load and ensuring that the in-furnace desulfurization system is completely shut down, after boiler combustion and pollutant emissions, the SO2 concentration at the furnace outlet was continuously measured within a preset time, and the average value was taken and determined as the baseline emission value P under the load condition. max It is used to reflect the maximum sulfur release potential of the coal currently being burned.

3. The method according to claim 2, characterized in that, In step 1, a global economic optimization model is constructed, unifying operating costs and environmental benefits within a single mathematical framework. Its total cost function is: C total = C1 + C2 - C3; C1 represents the cost of in-furnace desulfurization, which includes the consumption cost of limestone powder and the power consumption cost of the limestone feeder. The consumption cost of limestone powder is directly proportional to the voltage signal of the limestone feeder. C2 represents the cost of out-of-furnace desulfurization. The first part of the out-of-furnace desulfurization cost includes the power consumption cost of the high-voltage motors of the slurry circulation pump and the oxidation blower, which is directly proportional to the number of slurry circulation pumps in operation and the operating time. The second part of the out-of-furnace desulfurization cost includes the consumption cost of limestone and process water in the out-of-furnace limestone slurry preparation process, as well as the cost of desulfurization wastewater treatment. C3 represents the by-product revenue, which includes the sales revenue of gypsum, a by-product of desulfurization, and is directly proportional to the gypsum production.

4. The method according to claim 3, characterized in that, Step 2 includes: Step 21: Collect historical operating data of the unit and classify the historical operating data into operating conditions based on different load states; Step 22: Under multiple steady-state operating conditions, for each load point M, based on the proportion of in-furnace desulfurization... To optimize the variables, the particle swarm optimization algorithm (PSO) is used to optimize the total cost function C. total Perform optimization calculations to find the optimal solution that minimizes the total cost. For similar load sections Calculate by taking the average value; Step 23: Combine different load points M and their corresponding optimal load points. Curve fitting was performed to obtain the load-optimal ratio relationship curve, i.e. The curve is represented by an approximate functional relationship: This involves embedding approximate functions into the online control system.

5. The method according to claim 4, characterized in that, Step 3 includes: It receives real-time commands from the power grid for Automatic Generation Control (AGC) load point M; it dynamically calculates the target value of SO2 concentration in the furnace and generates a dynamic setpoint, the expression of which is: ； Among them, M n This is the rated load of the unit; The above expression means the theoretical maximum emission value under the current load multiplied by the expected desulfurization ratio in the furnace, from which the following is derived: It is the optimal setting value that changes dynamically with the load command.

6. The method according to claim 5, characterized in that, Step 4 includes: a. The controlled object is the SO2 concentration at the furnace outlet of the CFB boiler desulfurization process, i.e., the limestone feeding process to the furnace outlet. b. The controller adopts a generalized predictive controller (GPC); it is based on a predictive model, rolling optimization and feedback correction, and is used to handle the setpoint tracking problem. c. The control process is to dynamically generate As the setpoint of the GPC controller; the GPC controller compares the dynamic setpoint with the measured value of SO2 concentration at the furnace outlet, dynamically calculates the output signal, and adjusts the speed of the limestone feeder to make the actual SO2 concentration track the dynamic optimal setpoint.

7. The method according to claim 6, characterized in that, Step 5 includes: Step 51, Feedforward signal: The signal is sent to the WFGD control system as a feedforward signal to guide the external desulfurization system to act in advance. Step 52, Feedforward Calculation Model: The feedforward calculation model is embedded in the WFGD control system. The feedforward calculation model is based on the fitting of historical operating data. -Optimal Pump Combination- A lookup table of recommended pH settings, which is an empirical formula, defines the most economical and efficient equipment operation mode under different SO2 loads; Step 53, Control Action: Based on the received... The WFGD control system queries the feedforward calculation model and issues control commands: Step 531: For the slurry circulation pump: decide whether to start or stop the pump, and adjust the operating frequency of the variable frequency pump; Step 532, pH adjustment: Provide a preset pH value and adjust the pH value of the absorber slurry tank to the target range.

8. A desulfurization coordinated control system for CFB units based on economic optimization, characterized in that, The system includes: an economic optimization module, a dynamic setpoint generation module, and a coordinated control module for desulfurization inside and outside the furnace; The economic optimization module is used to obtain baseline emission values ​​and construct a global economic optimization model; based on the global economic optimization model, offline optimization and function fitting are performed in the offline optimization layer. The dynamic setpoint generation module is used to calculate online dynamic setpoints from the online control layer based on offline optimization and function fitting. The furnace-external desulfurization coordination control module is used to compare the dynamic setpoint with the measured value of SO2 concentration at the furnace outlet using a GPC controller, dynamically calculate the output signal, and optimize the control of furnace-external desulfurization based on the output signal.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the CFB unit desulfurization coordinated control method based on economic optimization as described in any one of claims 1 to 7.

10. An electronic device, characterized in that, include: One or more processors; Memory; And one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the CFB unit desulfurization coordinated control method based on economic optimization as described in any one of claims 1 to 7.

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