Internal and external desulfurization control optimization method and device for circulating fluidized bed boiler, computer equipment, readable storage medium and program product

Abstract

The invention relates to a circulating fluidized bed boiler internal and external desulfurization control optimization method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: selecting a plurality of load working condition points from a load range; screening first target historical operation data which are matched with each load working condition point and meet a steady-state working condition; determining a target out-of-furnace operation mode; screening out second target historical operation data which are matched with the target load working condition point and meet a load rising and falling rate condition; determining a pure flue gas sulfur dioxide actual value corresponding to each target load working condition point; optimizing each target load working condition point according to the difference between each pure flue gas sulfur dioxide actual value and each corresponding pure flue gas sulfur dioxide set value; and with the minimum desulfurization cost inside and outside the furnace as the target, the calcium-sulfur ratio set value and each target number are optimized. By adopting the method, the operation cost can be reduced on the basis of ensuring that the concentration of sulfur dioxide in the flue gas reaches the standard.

Description

Technical Field

[0001] This application relates to the field of circulating fluidized bed control technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for optimizing internal and external desulfurization control of a circulating fluidized bed boiler. Background Technology

[0002] Circulating fluidized bed (CFB) boilers are an important component of my country's clean coal technology. In the construction of new power systems, their role is shifting from being a primary power source to undertaking grid peak-shaving tasks, requiring them to frequently operate under rapid load changes.

[0003] With the implementation of national ultra-low emission standards, CFB units generally adopt a two-stage desulfurization system, both inside and outside the furnace, to ensure that the concentration of sulfur dioxide (SO2) in flue gas meets the emission standards. Under traditional operation, the unit often operates at a high load, while the slurry circulation pump of the external desulfurization system runs continuously, and the limestone feed rate inside the furnace is manually adjusted to match the actual desulfurization demand.

[0004] However, as the unit frequently participates in deep peak shaving and operates under rapid load changes for extended periods, frequent starting and stopping of the slurry circulation pump in response to load changes can easily lead to instantaneous SO2 emissions exceeding the standard. But if the slurry circulation pump is kept running to ensure compliance, it will result in a significant increase in operating costs. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, device, computer equipment, computer-readable storage medium, and computer program product for optimizing internal and external desulfurization control of circulating fluidized bed boilers, which can reduce operating costs while ensuring that the sulfur dioxide concentration in flue gas meets the standards.

[0006] In a first aspect, this application provides an optimization method for internal and external desulfurization control in a circulating fluidized bed boiler. The circulating fluidized bed boiler is equipped with an in-furnace desulfurization system and an external desulfurization system, the external desulfurization system including multiple slurry circulation pumps; the method includes:

[0007] Select multiple load conditions from the preset load range;

[0008] Acquire historical operating data, and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions from the historical operating data;

[0009] Based on the historical operating data of each first target, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset steady-state desulfurization efficiency model in the furnace, and the preset desulfurization efficiency model outside the furnace, the target outside furnace operating mode is determined. The target outside furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0010] Select a second target historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions from the historical operating data;

[0011] Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of net flue gas sulfur dioxide corresponding to each target load condition point is determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0012] Based on the difference between the actual sulfur dioxide value of each clean flue gas and its corresponding preset sulfur dioxide value, the operating point of each target load is optimized.

[0013] With the goal of minimizing the cost of desulfurization both inside and outside the furnace, the preset calcium-sulfur ratio setting and the quantity of each target were optimized.

[0014] Secondly, this application also provides an optimization device for internal and external desulfurization control of a circulating fluidized bed boiler. The circulating fluidized bed boiler is equipped with an in-furnace desulfurization system and an external desulfurization system. The external desulfurization system includes multiple slurry circulation pumps; including:

[0015] The selection module is used to select multiple load conditions from a preset load range;

[0016] The first filtering module is used to acquire historical operating data and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions.

[0017] The first determining module is used to determine the target external desulfurization mode based on the historical operating data of each first target, the preset set value of sulfur dioxide in the flue gas, the preset set value of calcium-sulfur ratio, the preset in-furnace steady-state desulfurization efficiency model and the preset external desulfurization efficiency model. The target external desulfurization mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0018] The second filtering module is used to filter out the second target historical operating data from the historical operating data that matches the target load condition point and meets the preset load increase / decrease rate conditions.

[0019] The second determining module is used to determine the actual value of sulfur dioxide in the net flue gas corresponding to each target load condition point when the external desulfurization system operates according to the target external desulfurization mode, based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset external desulfurization efficiency model.

[0020] The first optimization module is used to optimize each target load operating point based on the difference between the actual value of sulfur dioxide in each clean flue gas and the preset sulfur dioxide setting value in the clean flue gas.

[0021] The second optimization module is used to optimize the preset calcium-sulfur ratio and the quantity of each target, with the goal of minimizing the desulfurization cost inside and outside the furnace.

[0022] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0023] Select multiple load conditions from the preset load range;

[0024] Acquire historical operating data, and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions from the historical operating data;

[0025] Based on the historical operating data of each first target, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset steady-state desulfurization efficiency model in the furnace, and the preset desulfurization efficiency model outside the furnace, the target outside furnace operating mode is determined. The target outside furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0026] Select a second target historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions from the historical operating data;

[0027] Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of net flue gas sulfur dioxide corresponding to each target load condition point is determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0028] Based on the difference between the actual sulfur dioxide value of each clean flue gas and its corresponding preset sulfur dioxide value, the operating point of each target load is optimized.

[0029] With the goal of minimizing the cost of desulfurization both inside and outside the furnace, the preset calcium-sulfur ratio setting and the quantity of each target were optimized.

[0030] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0031] Select multiple load conditions from the preset load range;

[0032] Acquire historical operating data, and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions from the historical operating data;

[0033] Based on the historical operating data of each first target, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset steady-state desulfurization efficiency model in the furnace, and the preset desulfurization efficiency model outside the furnace, the target outside furnace operating mode is determined. The target outside furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0034] Select a second target historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions from the historical operating data;

[0035] Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of net flue gas sulfur dioxide corresponding to each target load condition point is determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0036] Based on the difference between the actual sulfur dioxide value of each clean flue gas and its corresponding preset sulfur dioxide value, the operating point of each target load is optimized.

[0037] With the goal of minimizing the cost of desulfurization both inside and outside the furnace, the preset calcium-sulfur ratio setting and the quantity of each target were optimized.

[0038] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0039] Select multiple load conditions from the preset load range;

[0040] Acquire historical operating data, and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions from the historical operating data;

[0041] Based on the historical operating data of each first target, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset steady-state desulfurization efficiency model in the furnace, and the preset desulfurization efficiency model outside the furnace, the target outside furnace operating mode is determined. The target outside furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0042] Select a second target historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions from the historical operating data;

[0043] Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of net flue gas sulfur dioxide corresponding to each target load condition point is determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0044] Based on the difference between the actual sulfur dioxide value of each clean flue gas and its corresponding preset sulfur dioxide value, the operating point of each target load is optimized.

[0045] With the goal of minimizing the cost of desulfurization both inside and outside the furnace, the preset calcium-sulfur ratio setting and the quantity of each target were optimized.

[0046] The aforementioned optimization method, device, computer equipment, computer-readable storage medium, and computer program product for internal and external desulfurization control of circulating fluidized bed boilers first selects multiple load operating points from a preset load range and filters out the first target historical operating data that matches each load operating point and meets preset steady-state operating conditions from historical operating data. Then, using preset in-furnace steady-state desulfurization efficiency models and preset external desulfurization efficiency models, combined with preset net flue gas sulfur dioxide setpoints and preset calcium-sulfur ratio setpoints, the target external operating mode that meets steady-state operation requirements is determined, clarifying the target load operating points that require the slurry circulation pumps to be started, and the target number of slurry circulation pumps required to be started at each target load operating point. Next, the second target historical operating data that matches the target load operating points and meets preset load increase / decrease rate conditions is filtered out, and the preset... A dynamic desulfurization efficiency model for the furnace and a preset desulfurization efficiency model for the outside furnace are established to determine the actual values ​​of sulfur dioxide in the net flue gas at each target load point under the target outside furnace operation mode. By comparing the difference between the actual values ​​of sulfur dioxide in the net flue gas and the set values, the target load points that require the start and stop of the slurry circulation pumps are dynamically corrected and optimized, thereby effectively preventing the risk of exceeding emission standards due to response delays and reduced desulfurization efficiency during load changes. Finally, with the minimum cost of desulfurization inside and outside the furnace as the ultimate optimization objective, the fixed calcium-sulfur ratio set value in the previous steps and the target number of slurry circulation pumps to be started at each target load point determined under steady state are optimized collaboratively. By comprehensively considering the cost factors inside and outside the furnace, such as limestone consumption and pump power consumption, the system's operational economy is maximized while ensuring stable SO2 concentration compliance. In this way, by scientifically determining the start and stop timing and number of slurry circulation pumps, this application reduces the risk of exceeding emission standards caused by frequent start and stop, while also reducing energy waste caused by excessive pump operation to ensure compliance, achieving the dual goals of environmental protection and economy. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating the optimization method for internal and external desulfurization control of a circulating fluidized bed boiler in one embodiment of this application.

[0049] Figure 2 This is a flowchart illustrating the data time alignment steps in one embodiment of this application;

[0050] Figure 3This is a flowchart illustrating the configuration steps of the desulfurization system in one embodiment of this application;

[0051] Figure 4 This is a structural block diagram of the internal and external desulfurization control optimization device for a circulating fluidized bed boiler in one embodiment of this application;

[0052] Figure 5 This is an internal structural diagram of a computer device in one embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] As a highly efficient and clean combustion technology, the installed capacity of circulating fluidized bed (CFB) boilers in my country has been continuously increasing, and they are at the international leading level in terms of steam parameters, single unit capacity, operating performance, and pollutant emission control. Under the "dual carbon" goal, coal-fired power generation plays a "ballast" role in building a new power system. Thermal power units have gradually transformed from the main power source to a basic guarantee and system regulation power source that provides reliable capacity, peak shaving, frequency regulation, and other ancillary services. In the future, CFB units will undertake more grid peak shaving tasks and operate under rapid load changes for a long time.

[0055] With the implementation of national ultra-low emission standards, most CFB (Chemical Flue Gas) units have adopted a two-stage desulfurization system—in-furnace desulfurization and external desulfurization—to achieve ultra-low SO2 emissions. In-furnace desulfurization is achieved by directly introducing limestone into the furnace, while external desulfurization typically employs wet flue gas desulfurization. In traditional power systems, CFB units often operate under high or stable load conditions, and the two-stage desulfurization system operates according to design values. The external desulfurization slurry circulation pump is rarely started or stopped, resulting in high overall system economics. However, in new power systems, CFB units operate under rapid load changes for extended periods, leading to frequent fluctuations in in-furnace and external desulfurization efficiencies. The economic efficiency of the previous operating methods has significantly decreased. Furthermore, to further reduce the plant power consumption of the CFB unit's low-load desulfurization system, frequent start-ups and shutdowns of the external desulfurization slurry circulation pump are often necessary. The start-ups and shutdowns of the external desulfurization slurry circulation pump have a significant impact on external desulfurization efficiency, easily leading to SO2 emissions exceeding standards and affecting both in-furnace and external desulfurization costs.

[0056] Therefore, how to reduce overall costs by optimizing the coordinated operation of in-furnace and external desulfurization while ensuring ultra-low SO2 emissions has become a key issue that urgently needs to be addressed in the context of flexible peak shaving for CFB units.

[0057] In one exemplary embodiment, such as Figure 1As shown, an optimization method for internal and external desulfurization control in a circulating fluidized bed boiler is provided. This embodiment illustrates the application of this method to a terminal, where the terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. Portable wearable devices can be smartwatches, smart bracelets, head-mounted devices, etc. Head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. It is understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps S10-S70. Wherein:

[0058] Step S10: Select multiple load conditions from the preset load range.

[0059] CFB boilers, as a type of efficient and clean coal-fired boiler, inevitably produce SO2 during operation. Direct SO2 emissions would cause serious environmental pollution, thus requiring a highly efficient desulfurization system. The unique 850-950℃ bed temperature and abundant circulating material conditions of CFB boilers create an ideal environment for direct limestone addition for desulfurization, enabling the removal of most SO2 during the combustion stage at a relatively low cost. However, with the full implementation of national ultra-low emission standards, relying solely on in-furnace desulfurization is no longer sufficient to consistently achieve SO2 emission standards. Simply increasing the amount of limestone added to forcibly pursue higher desulfurization efficiency would not only lead to a sharp increase in limestone consumption and a significant increase in operating costs, but also result in resource waste due to diminishing marginal returns on reaction efficiency.

[0060] Against this backdrop, wet flue gas desulfurization (FGD), as a mature and reliable end-of-pipe treatment technology, has become a necessary guarantee for ensuring the stable compliance of CFB units' final emissions due to its extremely high desulfurization efficiency. However, the slurry circulation pump, the core equipment of the FGD system, is one of the main sources of plant power consumption. If it is kept running at full load continuously to ensure emissions, although environmental protection requirements can be met, it will lead to high operating costs and affect the economic efficiency of the unit's peak-shaving operation.

[0061] The load operating point refers to the specific state point at which the output power of a circulating fluidized bed boiler is during operation. For example, for a CFB boiler with a rated load of 300MW, its 50% load operating point refers to the operating state with an output power of 150MW.

[0062] For example, firstly, the load operating range input by the user is obtained. Then, within this load operating range, multiple discrete load condition points are selected at certain intervals or according to operating characteristics to form a set of load condition points that can comprehensively cover and characterize the entire load operating range, which serves as the specific object for subsequent data analysis and optimization.

[0063] As an example, the load operating range can be the load range covered by the deep peak shaving of the CFB unit. Users can set it themselves according to the deep peak shaving requirements of the unit. For example, the load operating range can be defined as 30% to 100% of the rated load.

[0064] As an example, the load operating range can be divided into 10% rated load intervals to obtain the load operating points. For instance, within the load operating range of 30% to 100% rated load, eight load operating points can be selected: 30% rated load, 40% rated load, 50% rated load, 60% rated load, 70% rated load, 80% rated load, 90% rated load, and 100% rated load.

[0065] As another example, different intervals can be set for different load operating ranges. For instance, in low-load peak-shaving ranges, such as the 30%-60% rated load range, where the unit's desulfurization characteristics change more drastically, a smaller interval can be used to select the load operating point; while in high-load peak-shaving ranges, such as the 60%-100% rated load range, where operation is relatively stable, a larger interval can be used to select the load operating point. This allows for more refined operating data and control strategies in critical load areas, improving the accuracy of desulfurization control under low-load peak-shaving conditions, while avoiding data redundancy and wasted computing resources caused by excessive subdivision in stable regions, making the entire optimization method more closely aligned with the actual operating characteristics of CFB units.

[0066] Step S20: Obtain historical operating data, and select the first target historical operating data from the historical operating data that matches each load condition point and meets the preset steady-state operating conditions.

[0067] Among them, the preset steady-state operating conditions can refer to a series of preset standards used to determine whether the boiler is in a stable operating state.

[0068] As an example, the preset steady-state operating conditions can be set such that, over a continuous period of time, the unit's load fluctuation is less than a preset load fluctuation threshold, and the main steam pressure fluctuation is less than a preset pressure fluctuation threshold.

[0069] As another example, the preset steady-state operating conditions can be expressed as:

[0070] and

[0071] In the formula: X 1,max X represents the maximum load value from a continuous series of historical operating data. 1,min X represents the minimum load value across a continuous series of historical operating data. 1,a X is the average load from a continuous series of historical operating data; 2,max X represents the maximum coal feed rate from a continuous series of historical operating data. 2,min X represents the minimum coal feed rate across a continuous series of historical operating data. 2,a It is the average coal feed rate over a continuous series of historical operating data.

[0072] Historical operating data refers to a set of parameter records reflecting the operating status of a circulating fluidized bed boiler unit, automatically collected and stored by a distributed control system or monitoring information system during its past operation. This includes, but is not limited to, time-series data on load, coal feed rate, limestone feed rate in the furnace, raw flue gas SO2 concentration, clean flue gas SO2 concentration, slurry circulation pump operating status, and related process parameters. Historical operating data can originate from actual power plant operating records, typically covering operating cycles of several months or years, providing a real and reliable analytical basis for desulfurization system optimization. As the data foundation of this method, historical operating data is used to screen operating segments that meet specific operating conditions, thereby supporting the formulation and optimization of coordinated desulfurization control strategies both inside and outside the furnace.

[0073] In some feasible implementations, the historical operating data of the first target covers a time range greater than 900 seconds to ensure that the selected data segment can fully reflect the operating characteristics of the unit under steady-state conditions and eliminate the impact of short-term fluctuations and transient disturbances on the desulfurization efficiency calculation. This time length conforms to the power industry's criteria for determining steady-state operating conditions, is sufficient to allow the boiler combustion system and desulfurization system to reach a state of thermal equilibrium, and can also acquire a sufficient number of data points for statistical analysis, thereby improving the reliability and accuracy of subsequent model calculations and optimization results.

[0074] For example, historical operating data can be obtained from the unit's distributed control system or historical database. Then, for each preset load condition point, based on the set load deviation range and steady-state operating conditions, the operating segment data that meets the requirements is retrieved and filtered from the historical operating data. For each load condition point, multiple data segments that meet the above conditions can be identified.

[0075] The load deviation range can be ±1% of the rated load, ±2% of the rated load, etc., and can be determined according to the actual situation and test results. This embodiment does not impose any restrictions on this.

[0076] Step S30: Based on the historical operating data of each first target, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset in-furnace steady-state desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, determine the target out-of-furnace operating mode. The target out-of-furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0077] The calcium-sulfur ratio refers to the molar ratio of calcium to sulfur in the added calcium-based desulfurizer during the in-furnace desulfurization process. For example, if the calcium-sulfur ratio is set to 3, it means that 3 mol of calcium are needed for the desulfurization reaction for every 1 mol of sulfur.

[0078] The preset calcium-sulfur ratio setting can be determined based on engineering experience and equipment operating limits. Usually, a value that is high enough to ensure that the desulfurization in the furnace can perform most of its functions under most operating conditions is selected.

[0079] In determining the target furnace operation mode, a preset calcium-to-sulfur ratio setting is used as a fixed input condition to simulate the operation of the furnace desulfurization limestone feed upper limit.

[0080] During the global optimization process, the preset calcium-sulfur ratio setting can be used as a hard constraint to ensure that the final optimized calcium-sulfur ratio will not exceed this upper limit, thereby avoiding operational problems such as increased bed material sintering and blockage risk caused by excessive feeding in the furnace, and ensuring the engineering applicability of the optimization results.

[0081] In some feasible implementations, the preset calcium-sulfur ratio setting value can be between 2 and 5.

[0082] The setpoint for sulfur dioxide in clean flue gas refers to the upper limit of the permissible concentration of sulfur dioxide in flue gas after treatment by a desulfurization system. The setpoint for sulfur dioxide in clean flue gas can be determined according to national standards, or set by the user to a value that is more stringent than the national standards.

[0083] The in-furnace steady-state desulfurization efficiency model can refer to a nonlinear mathematical model or neural network model that describes the relationship between the desulfurization efficiency and relevant parameters of the in-furnace desulfurization system under steady-state operating conditions.

[0084] The preset in-furnace dynamic desulfurization efficiency model can refer to a nonlinear mathematical model or neural network model that describes the relationship between the desulfurization efficiency and related parameters of the in-furnace desulfurization system under dynamic operating conditions of load changes.

[0085] In some feasible implementations, both the in-furnace steady-state desulfurization efficiency model and the in-furnace dynamic desulfurization efficiency model take the load condition point and calcium-sulfur ratio as inputs, and output the in-furnace desulfurization efficiency. The in-furnace steady-state desulfurization efficiency model is obtained by fitting or training historical operating data under steady-state conditions; therefore, it can accurately calculate or predict the in-furnace desulfurization efficiency under steady-state conditions based on the load condition point and calcium-sulfur ratio. Similarly, the in-furnace dynamic desulfurization efficiency model is obtained by fitting or training historical operating data under dynamic conditions; therefore, it can accurately calculate or predict the in-furnace desulfurization efficiency under dynamic conditions based on the load condition point and calcium-sulfur ratio.

[0086] The external desulfurization efficiency model can refer to a nonlinear mathematical model or neural network model that describes the relationship between the desulfurization efficiency of the external desulfurization system and related parameters.

[0087] In some feasible implementations, the input to the external desulfurization efficiency model is the load condition point, calcium-sulfur ratio, and external operating mode, and the output is the external desulfurization efficiency. Since the external desulfurization efficiency is less affected by load fluctuations, it can be obtained by fitting or training historical operating data under any one or more operating conditions.

[0088] In some feasible implementations, the in-furnace steady-state desulfurization efficiency model, the out-of-furnace desulfurization efficiency model, and the preset in-furnace dynamic desulfurization efficiency model can all employ a BP (back propagation) neural network. The BP neural network can adopt a three-layer network structure, using the RELU (Rectified Linear Unit) activation function and the MSE (Mean Squared Error) loss function to optimize the model parameters.

[0089] The target external operating mode refers to a guiding scheme for the operation of slurry circulation pumps in the external desulfurization system, determined based on historical operating data under steady-state conditions. The target external operating mode defines the start-up and shutdown strategies for slurry circulation pumps under different load conditions, including the specific load thresholds at which the slurry circulation pumps need to be started and the exact number of pumps required to be started at each load threshold. For example, the target external operating mode could explicitly indicate: no slurry circulation pumps should be started below 40% load; one pump should be started between 40% and 70% load; and two pumps should be started above 70% load. This mode serves as the basic framework for subsequent variable load analysis and economic optimization, providing an initial operating strategy for the coordinated control of the internal and external desulfurization systems.

[0090] For example, before actual optimization, the preset in-furnace steady-state desulfurization efficiency model and the preset external desulfurization efficiency model can be optimized or reconstructed based on the historical operating data corresponding to the first target at each load condition point. This results in preset in-furnace desulfurization efficiency prediction models and preset external desulfurization efficiency models that better fit the actual operating characteristics of the CFB boiler. This process involves correlation analysis between the load value, actual calcium-sulfur ratio, and corresponding measured in-furnace desulfurization efficiency in the historical operating data. The least squares method or machine learning algorithm is used to fit a more accurate functional relationship, thereby correcting the deviation of the original model and improving the accuracy of the net flue gas SO2 concentration prediction in subsequent steps. This lays a data foundation for determining a scientific and reasonable slurry circulation pump start-up and shutdown strategy, avoiding the risk of excessive desulfurization or emission exceeding standards due to model inaccuracies.

[0091] Furthermore, for each load condition, the corresponding historical operating data of the first target is first used, combined with the preset calcium-sulfur ratio setting, and the optimized preset in-furnace steady-state desulfurization efficiency model and preset out-of-furnace desulfurization efficiency model are used to calculate the net flue gas SO2 concentration under different numbers of slurry circulation pumps operating. Based on the calculation results, a decision is made: if the predicted net flue gas SO2 concentration is still lower than or equal to the preset net flue gas sulfur dioxide setting when the slurry circulation pump is not running, then it is determined that the load condition does not require the slurry circulation pump to be started and is not included in the target load condition category; if the predicted net flue gas SO2 concentration can only meet the preset net flue gas sulfur dioxide setting when at least one slurry circulation pump is running, then the load condition is determined as the target load condition. For the determined target load condition, with the net flue gas SO2 concentration not exceeding the preset net flue gas sulfur dioxide setting as a hard constraint, the minimum number of slurry circulation pumps operating that meets this constraint is selected as the target number for the target load condition. Through the above process, the corresponding number of slurry circulation pumps are allocated to all target load operating points, ultimately forming a complete target furnace operation mode.

[0092] Step S40: Select second target historical operating data from the historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions.

[0093] Among them, the preset load increase / decrease rate condition can refer to the standard used to screen historical operating data of boilers under load change conditions.

[0094] Load change rate conditions refer to the limiting conditions for the rate of change of unit load, used to filter historical operating data under variable load conditions. For example, the preset load change rate condition can be set to a load change rate greater than or equal to 1% of rated load per minute.

[0095] For example, for each target load condition point, the first target historical operating data can be selected, and a data time period that meets the preset load increase / decrease rate condition can be found within a certain time range nearby. The historical operating data within this data time period is then determined as the second target historical operating data.

[0096] Step S50: Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, determine the actual value of sulfur dioxide in the net flue gas corresponding to each target load condition point when the out-of-furnace desulfurization system operates according to the target out-of-furnace operating mode.

[0097] Among them, the actual value of sulfur dioxide in clean flue gas can refer to the specific value of SO2 concentration in flue gas at the inlet or outlet of the chimney after complete desulfurization treatment.

[0098] For example, before actual optimization, the preset in-furnace dynamic desulfurization efficiency model can be optimized or reconstructed based on the historical operating data of the second target corresponding to each target load condition point, so as to obtain a preset in-furnace dynamic desulfurization efficiency model that is more in line with the actual operating characteristics of the CFB boiler.

[0099] Furthermore, for each target load operating point, the target load operating point and the second target historical operating data are input into the preset in-furnace dynamic desulfurization efficiency measurement model to infer the desulfurization efficiency in the furnace during the variable load process; then, combined with the preset external desulfurization efficiency model and the target external operating mode, the actual value of sulfur dioxide in the clean flue gas when the unit dynamically passes through each target load point is calculated when the external desulfurization system is running according to the target external operating mode.

[0100] Step S60: Optimize each target load operating point based on the difference between the actual value of sulfur dioxide in each clean flue gas and the corresponding preset sulfur dioxide setting value in each clean flue gas.

[0101] For example, the target load operating point is adjusted by comparing the inferred actual value of sulfur dioxide in the flue gas with the preset sulfur dioxide setting value for environmental protection requirements. If the actual value of sulfur dioxide in the flue gas is less than or equal to the preset sulfur dioxide setting value, it means that the current target load operating point and the corresponding pump operation strategy can meet the emission requirements and can remain unchanged; if the actual value of sulfur dioxide in the flue gas is greater than the preset sulfur dioxide setting value, it means that emissions may exceed the standard during the load change process, and the slurry circulation pump needs to be started in advance, that is, the load operating point where the pump needs to be started is adjusted to the low load direction to ensure that emissions meet the standards during the load change process.

[0102] Step S70: Optimize the preset calcium-sulfur ratio setting and the quantity of each target with the goal of minimizing the desulfurization cost inside and outside the furnace.

[0103] The cost of desulfurization inside and outside the furnace can refer to the total amount of resources required to operate the desulfurization system inside and outside the furnace, and may include at least one of the following: material consumption, energy consumption, carbon emission expenditure, gypsum revenue, etc.

[0104] For example, economic optimization can be performed while meeting emission requirements. Using the minimum cost of desulfurization both inside and outside the furnace as the objective function, an optimization algorithm adjusts the preset calcium-to-sulfur ratio and the target number of slurry circulation pumps required for each load condition. The optimization results will provide the most economically efficient combination of desulfurization parameters for each load condition, achieving a balance between economic efficiency and environmental protection.

[0105] In some feasible implementations, optimizing the preset calcium-sulfur ratio and the quantities of each target value with the goal of minimizing the cost of desulfurization both inside and outside the furnace can include:

[0106] First, construct a cost function with the objective of minimizing the total cost of desulfurization inside and outside the furnace at the i-th target load point, f(x). i It consists of the following parts:

[0107] Material consumption expenditure C i,物 This includes, but is not limited to, the cost of limestone consumed in in-furnace desulfurization and external desulfurization. Material consumption expenditure multiplied by the preset calcium-to-sulfur ratio setting x i,1 Directly related.

[0108] Energy expenditure C i,能 This includes, but is not limited to, the electricity cost consumed by the slurry circulation pumps in the external desulfurization system. Energy expenditure is calculated as the target number of slurry circulation pumps multiplied by... i,2 Directly related.

[0109] Carbon emission expenditure C i,碳 This is the innovation cost item for introducing the carbon trading mechanism, which can be expressed as:

[0110]

[0111] Among them, P 碳 For carbon trading prices; E 碳 E represents the carbon emissions after optimizing the ratio of internal and external desulfurization in the furnace. 基 The desulfurization carbon emissions are calculated based on the design values ​​of the desulfurization ratio inside and outside the furnace.

[0112] This formula means that additional expenditures are only incurred when actual carbon emissions exceed the baseline.

[0113] Gypsum revenue W i,石 Gypsum, a byproduct of the external desulfurization reaction, can be sold as a commodity. This is a negative cost, i.e. a revenue, used to offset part of the total cost.

[0114] Therefore, the objective function can be expressed as:

[0115]

[0116] In some exemplary embodiments, the optimized preset calcium-sulfur ratio setting is greater than zero and less than or equal to the original preset calcium-sulfur ratio setting.

[0117] The number of targets after optimization is greater than or equal to the number of targets before optimization;

[0118] When the in-furnace desulfurization system is configured according to the optimized preset calcium-sulfur ratio setting value, and the external desulfurization system is configured according to the optimized target external operating mode, the actual value of sulfur dioxide in the clean flue gas corresponding to each target load operating point is less than or equal to the corresponding preset value of sulfur dioxide in the clean flue gas.

[0119] To ensure the feasibility, safety, and environmental compliance of the optimization results, constraints can be set, which can be expressed as follows:

[0120]

[0121] Among them, at any target load operating point, the optimized preset calcium-sulfur ratio setpoint x i,1 Less than or equal to the preset calcium-sulfur ratio setting value x before optimization i,1 By using calcium-sulfur ratio boundary constraints, we can prevent the optimization of excessively high feed rates that are either infeasible or detrimental to boiler operation.

[0122] At any target load condition, the optimized target quantity x i,2 Greater than or equal to the target number x before optimization i,2 By constraining the number of slurry circulation pumps, we ensure that the emission safety margin remains adequate during the dynamic process, even after cost optimization.

[0123] At any target load point, the actual value of net flue gas sulfur dioxide C i,SO2 Less than or equal to their respective preset net flue gas sulfur dioxide setpoint C i,SO2设 This is an environmental red line that cannot be crossed in the entire optimization process.

[0124] After determining the objective function and constraints, the particle swarm optimization algorithm can be used as the optimization algorithm. This algorithm initializes a swarm of "particles" in the solution space and simulates swarm intelligence to perform iterative search, eventually converging to the optimal solution that satisfies all the above constraints and minimizes the objective function.

[0125] In the aforementioned optimization method for internal and external desulfurization control of circulating fluidized bed boilers, firstly, multiple load operating points are selected from a preset load range, and first target historical operating data matching each load operating point and meeting preset steady-state operating conditions are screened from historical operating data. Then, using preset in-furnace steady-state desulfurization efficiency models and preset external desulfurization efficiency models, combined with preset net flue gas sulfur dioxide setpoints and preset calcium-sulfur ratio setpoints, the target external operating mode that meets the steady-state operation requirements is determined, the target load operating points that require the slurry circulation pump to be started are identified, and the target number of slurry circulation pumps to be started for each target load operating point is determined. Next, second target historical operating data matching the target load operating points and meeting preset load increase / decrease rate conditions are screened, and the preset in-furnace dynamic desulfurization efficiency model and preset external desulfurization efficiency models are used to determine the target external operating mode that meets the steady-state operation requirements. An external desulfurization efficiency model was established to determine the actual values ​​of sulfur dioxide in the net flue gas at each target load point under the target external operating mode. By comparing the difference between the actual values ​​of sulfur dioxide in the net flue gas and the set values, the target load points that require the start and stop of the slurry circulation pumps were dynamically corrected and optimized, thereby effectively preventing the risk of exceeding emission standards due to response delays and reduced desulfurization efficiency in the furnace during load changes. Finally, with the minimum cost of desulfurization inside and outside the furnace as the ultimate optimization objective, the fixed calcium-sulfur ratio set value in the previous steps and the target number of slurry circulation pumps required to be started at each target load point under steady state were optimized collaboratively. By comprehensively considering the cost factors inside and outside the furnace, such as limestone consumption and pump power consumption, the system's operational economy was maximized while ensuring that the SO2 concentration remained stable and met the standards. In this way, by scientifically determining the start and stop timing and number of slurry circulation pumps, this application reduced the risk of exceeding emission standards caused by frequent start and stop, while also reducing energy waste caused by excessive operation of pump sets to ensure compliance or material waste caused by excessive calcium-sulfur ratio in the furnace desulfurization, thus achieving the dual goals of environmental protection and economy.

[0126] In an exemplary embodiment, based on historical operating data of each first target, preset setpoints for sulfur dioxide in clean flue gas, preset setpoints for calcium-sulfur ratio, preset in-furnace steady-state desulfurization efficiency models, and preset out-of-furnace desulfurization efficiency models, a target out-of-furnace operating mode is determined, including:

[0127] Based on the historical operating data of each primary target, the preset sulfur dioxide setpoint in the flue gas, the preset steady-state desulfurization efficiency model in the furnace, and the preset desulfurization efficiency model outside the furnace, the target external desulfurization mode that minimizes the total power consumption of the external desulfurization system is determined when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setpoint.

[0128] It should be noted that under traditional operating conditions, the internal and external desulfurization systems of CFB units lack coordination during load changes. To ensure emissions meet standards, operators often adopt conservative strategies, such as continuously running the slurry circulation pumps of the external desulfurization system or starting them prematurely, or operating the internal desulfurization system at a fixed high calcium-to-sulfur ratio. While this "one-size-fits-all" approach can mitigate environmental risks, it leads to persistently high plant power consumption or high limestone consumption, resulting in poor overall system economics.

[0129] For example, for each load condition point, firstly, using its corresponding first target historical operating data, combined with a preset calcium-to-sulfur ratio setting, and through a jointly optimized preset in-furnace steady-state desulfurization efficiency model and a preset external desulfurization efficiency model, the net flue gas SO2 concentration under different numbers of operating slurry circulation pumps is calculated. Based on the calculation results, a decision is made: if the predicted net flue gas SO2 concentration is still lower than or equal to the preset net flue gas sulfur dioxide setting when the slurry circulation pump is not running, then it is determined that the load condition point does not need to start the slurry circulation pump and is not included in the target load condition point category; if the predicted net flue gas SO2 concentration can only meet the preset net flue gas sulfur dioxide setting when at least one slurry circulation pump is running, then the load condition point is determined as the target load condition point. For the determined target load condition point, with the net flue gas SO2 concentration not exceeding the preset net flue gas sulfur dioxide setting as a hard constraint, the number of operations that satisfies this constraint and minimizes the total power consumption of the external desulfurization system is selected as the target number for the target load condition point. Through the above process, the corresponding number of slurry circulation pumps are allocated to all target load operating points, ultimately forming a complete target furnace operation mode.

[0130] Based on the historical operating data of each secondary target, the preset calcium-to-sulfur ratio setpoint, the preset in-furnace dynamic desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, the actual net flue gas sulfur dioxide values ​​corresponding to each target load operating point are determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operating mode, including:

[0131] Based on the historical operating data of each secondary target, the preset in-furnace dynamic desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, the actual values ​​of sulfur dioxide in the net flue gas corresponding to each target load condition point are determined when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setting value and the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0132] For example, for each target load operating point, the target load operating point and the second target historical operating data are input into the preset in-furnace dynamic desulfurization efficiency model to calculate the desulfurization efficiency in the furnace during the variable load process when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setting value. Then, combined with the preset external desulfurization efficiency model and the target external operating mode, the actual value of sulfur dioxide in the clean flue gas when the unit dynamically passes through each target load point is calculated when the external desulfurization system is running according to the target external operating mode.

[0133] In this embodiment, based on steady-state historical data and a desulfurization efficiency model, the optimal number of slurry circulation pumps operating at different load points was scientifically determined with the goal of minimizing the total power consumption of the external desulfurization system. This avoids the energy waste caused by excessive pump operation to ensure compliance, as is common in traditional methods. Furthermore, considering the dynamic process of variable load, the actual value of sulfur dioxide in the flue gas was accurately predicted using an in-furnace dynamic desulfurization efficiency model. This provides a basis for subsequent optimization and adjustment, preventing the risk of emissions exceeding standards due to untimely pump start-up and shutdown. Thus, even with frequent load changes during deep peak shaving, the CFB boiler can ensure stable compliance with flue gas SO2 emissions while significantly reducing the energy consumption of the desulfurization system, achieving the dual goals of environmental protection and economy.

[0134] In one exemplary embodiment, such as Figure 2 As shown, the historical operating data includes a sequence of flue gas sulfur dioxide concentration values, and the first target historical operating data includes a sequence of target concentration values. The first target historical operating data, which matches each load condition and meets the preset steady-state operating conditions, is selected from the historical operating data, including steps S21 to S23, wherein:

[0135] Step S21: Select an initial concentration value sequence from the flue gas sulfur dioxide concentration value sequence that matches each load condition point and meets the preset steady-state condition conditions, and determine the initial time range corresponding to the initial concentration value sequence.

[0136] It should be noted that during boiler operation, there are physical delays from limestone feeding to its effective action, and from flue gas flowing from the furnace to the sulfur dioxide concentration measuring point. Directly using unaligned operational data for analysis will incorrectly correlate operations and results at different times, leading to a distorted model and consequently causing deviations in the optimized control based on it, thus failing to accurately guide operation.

[0137] Historical operating data includes coal feed rate, limestone feed rate in the furnace, and sulfur dioxide concentration in flue gas. The sulfur dioxide concentration includes both the raw flue gas concentration and the net flue gas concentration. Due to the transmission delay in the desulfurization process, the flue gas generated by the coal feed rate and limestone feed rate collected at a certain moment will only be captured by the monitoring system after a certain time delay. If, during data analysis, the coal feed rate, limestone feed rate, and sulfur dioxide concentration data collected at the same moment are directly combined as the analysis sample, ignoring this crucial time delay characteristic, the established desulfurization efficiency model will deviate significantly from the actual dynamic characteristics of the system. Optimization control decisions based on such distorted models cannot accurately predict the desulfurization effect under varying load conditions, easily leading to operational deviations such as exceeding emission standards or excessive desulfurization during varying load processes, preventing the desulfurization system from achieving the optimal balance between environmental compliance and economic operation.

[0138] For example, firstly, the sequence of flue gas sulfur dioxide concentration values ​​recorded in the historical operation database is obtained, which includes timestamps and corresponding concentration values; for each preset load condition point, the set load deviation range is used as the matching condition; the historical data is traversed to filter out the time periods in which the unit load is within the corresponding interval of the load condition point; for each selected time period, it is checked whether it meets the preset steady-state operating conditions; the flue gas sulfur dioxide concentration values ​​corresponding to the time periods that meet the preset steady-state operating conditions are retained to form the initial concentration value sequence corresponding to the load condition point; at the same time, the start time and end time of the sequence are recorded to form the initial time range.

[0139] Step S22: Determine the target time range based on the preset delay duration and the initial time range.

[0140] The preset delay time can refer to the time interval required from operation adjustment to flue gas collection, which is preset based on the dynamic characteristics of the desulfurization system.

[0141] For example, for each initial time range, the start time of the initial time range can be delayed by a preset delay time, while the end time remains unchanged, to form a target time range.

[0142] Step S23: Extract the target concentration value sequence corresponding to the target time range from the initial concentration value sequence.

[0143] For example, for the initial concentration value sequence and its corresponding timestamp, according to the target time range, all data points of flue gas sulfur dioxide concentration values ​​whose timestamps fall within the target time range are selected; the flue gas sulfur dioxide concentration values ​​and their time order of these data points are retained to form the target concentration value sequence.

[0144] In some feasible implementations, since the flue gas sulfur dioxide concentration includes both the raw flue gas sulfur dioxide concentration and the net flue gas sulfur dioxide concentration, the preset delay times corresponding to the raw flue gas sulfur dioxide concentration and the net flue gas sulfur dioxide concentration may be different. In this case, their corresponding target concentration value sequences can be determined separately.

[0145] In some feasible implementations, when the historical operation data includes multiple types, the end times of various first target historical operation data can also be aligned. For example, for each initial time range, the start time of the initial time range can be delayed by a preset delay period, while the end time remains unchanged, forming an intermediate time range. Then, the shortest duration among the various intermediate time ranges corresponding to various historical operation data is determined as the target duration. By shifting the end time of each intermediate time range forward, the duration of each intermediate time range is made equal to the target duration, forming the target time range. For example, assuming the initial time range is 1-1000 time units, the preset delay time corresponding to the original flue gas sulfur dioxide concentration is 100 time units, and the preset delay time corresponding to the net flue gas sulfur dioxide concentration is 200 time units, then the intermediate time range corresponding to the original flue gas sulfur dioxide concentration can be 100-1000 time units, the intermediate time range corresponding to the net flue gas sulfur dioxide concentration can be 200-1000 time units, the intermediate time range corresponding to the coal feed rate can be 0-1000 time units, and the limestone feed rate in the furnace can also be... The corresponding intermediate time range can be 0-1000 time units, with a minimum duration of 800 time units. Based on this, further adjustments to the intermediate time range determine that the target time range corresponding to the original flue gas sulfur dioxide concentration is 100-900 time units, the target time range corresponding to the net flue gas sulfur dioxide concentration is 200-1000 time units, the target time range corresponding to the coal feed rate is 0-800 time units, and the target time range corresponding to the limestone feed rate in the furnace is 0-800 time units. This allows for time alignment of various primary target historical operating data.

[0146] In this embodiment, by correcting the delayed flue gas sulfur dioxide concentration sequence, the final output is high-quality data that has undergone rigorous screening and time correction. The desulfurization efficiency model built upon this data more accurately reflects the system's dynamic characteristics, making subsequent optimization control strategies more precise and effective, thus overcoming the model distortion and control deviation problems caused by data asynchrony.

[0147] In an exemplary embodiment, before determining the target time range based on a preset delay duration and an initial time range, the method further includes:

[0148] Obtain the distance between the sulfur dioxide concentration measuring point in the flue gas and the limestone feed inlet; determine the preset delay time based on the distance and the preset flue gas velocity.

[0149] The interval distance value can refer to the physical distance of the flue gas flow path between the flue gas sulfur dioxide concentration measuring point and the limestone feed port. It can be determined based on the design parameters or test results of the circulating fluidized bed boiler system, and this embodiment does not impose any restrictions on it.

[0150] The preset flue gas velocity can refer to the average flow velocity of the flue gas along the flow path between the flue gas sulfur dioxide concentration measuring point and the limestone feed port, which is predetermined based on boiler design parameters and typical operating conditions.

[0151] For example, for each target load condition, firstly, the interval distance value between the flue gas sulfur dioxide concentration measuring point and the limestone feed port, which is pre-stored or detected and determined, is obtained; then, the corresponding preset flue gas velocity value is retrieved from the preset load-flue gas velocity mapping table; then, the interval distance value is divided by the preset flue gas velocity to calculate the theoretical transmission time of the flue gas flowing from the limestone feed port to the measuring point, and this theoretical transmission time is determined as the preset delay duration.

[0152] In this embodiment, by accurately quantifying the inherent transmission delay of the system, the time relationship between different operating data can be effectively aligned, thereby ensuring that the established desulfurization efficiency model can truly reflect the dynamic characteristics of the system, providing an accurate and reliable basis for subsequent optimization control, and fundamentally solving the control deviation problem caused by data asynchrony.

[0153] In an exemplary embodiment, optimization is performed on each target load operating point based on the difference between the actual value of sulfur dioxide in each clean flue gas and the preset set value of sulfur dioxide in the clean flue gas, including:

[0154] For the target load condition point where the actual value of sulfur dioxide in the clean flue gas is greater than or equal to the preset sulfur dioxide setting value in the clean flue gas, the preset adjustment step value is reduced to obtain the optimized target load condition point. The preset adjustment step value is equal to the product of the preset rated load and the preset adjustment ratio.

[0155] It should be noted that during the load change process of the unit, due to the lag in the response of the desulfurization system, if the start and stop load points of the slurry circulation pump are determined only based on the steady-state operating conditions, the actual sulfur dioxide emission concentration may instantly exceed the standard when the load changes dynamically, which will fail to meet environmental protection requirements.

[0156] The preset adjustment step size value can refer to the basic incremental unit used for load condition point optimization adjustment, which is equal to the product of the preset rated load and the preset adjustment ratio.

[0157] The preset rated load can refer to the maximum continuous output value specified in the design of the CFB unit or marked on the nameplate.

[0158] The preset adjustment ratio can refer to the proportional coefficient used to calculate the load adjustment step size. It can be determined in advance based on the actual situation or test results, etc. This embodiment does not limit it.

[0159] For example, for each target load operating point, after determining its corresponding actual value of net flue gas sulfur dioxide, the actual value of net flue gas sulfur dioxide can be compared with the preset net flue gas sulfur dioxide setting value. For target load operating points where the actual value of net flue gas sulfur dioxide is greater than or equal to the preset net flue gas sulfur dioxide setting value, it is determined that there is a risk of exceeding the emission standard or being close to exceeding the standard. Therefore, the value of the value of net flue gas sulfur dioxide is reduced by an amount equal to the preset adjustment step value, thereby optimizing the target load operating point and obtaining the optimized target load operating point. For target load operating points where the actual value of net flue gas sulfur dioxide is less than the preset net flue gas sulfur dioxide setting value, it is determined that the risk of exceeding the emission standard or being close to exceeding the standard is low. Therefore, no adjustment is required.

[0160] In this embodiment, a simple and effective load point shifting mechanism significantly reduces the risk of dynamic emission exceedances caused by system response lag. This allows the slurry circulation pump to start operating earlier during load increases, reserving buffer time for the desulfurization system to establish sufficient processing capacity. This ensures stable compliance with environmental emission requirements even under variable load conditions, greatly improving the reliability of the control system.

[0161] In one exemplary embodiment, such as Figure 3 As shown, after optimizing the preset calcium-sulfur ratio and the quantities of each target with the goal of minimizing the desulfurization cost inside and outside the furnace, the method further includes steps S80 to S90, wherein:

[0162] Step S80: Determine the limestone feed rate of the in-furnace desulfurization system under different load conditions based on the optimized preset calcium-sulfur ratio setting value.

[0163] It should be noted that the traditional desulfurization system control method of CFB unit is relatively crude. The limestone feed rate of desulfurization in the furnace and the operation mode of the desulfurization slurry circulation pump outside the furnace are often fixed values ​​or manually adjusted by the experience of the operators. It is difficult to achieve precise coordination between the desulfurization system inside and outside the furnace during rapid load changes, resulting in either unstable emission control or high operating costs.

[0164] For example, for each target load condition, the precise limestone feed rate required to achieve that calcium-sulfur ratio is calculated using stoichiometry based on its corresponding optimized preset calcium-sulfur ratio. As an example, the coal consumption at the target load condition can be obtained from historical unit operating data or a real-time monitoring system, and the sulfur content of the coal can be obtained from a coal quality analysis report or online monitoring equipment. Combined with the optimized preset calcium-sulfur ratio, the limestone feed rate can be calculated. For variable load processes, a functional relationship between load and limestone feed rate can be constructed, for example, using a piecewise linear function. The feed rate at intermediate load points is interpolated using the optimized target load conditions as nodes, ultimately forming a complete load-limestone feed rate correspondence table.

[0165] Step S90: Configure the in-furnace desulfurization system according to the amount of limestone fed, and configure the external desulfurization system according to the optimized target load conditions and the optimized target quantities.

[0166] For example, a load-limestone feed rate correspondence table can be used as a feedforward setpoint and sent to the limestone feeder control system of the in-furnace desulfurization system, so that it operates according to this benchmark value. On the other hand, the optimized target load operating points and their corresponding target quantities can be used as logical judgment conditions and written into the sequential control logic of the external desulfurization system. When the actual load of the unit reaches a certain optimized target load operating point, the external desulfurization system can automatically start and stop the corresponding slurry circulation pumps according to the optimized target quantities.

[0167] In this embodiment, by translating the complete optimization results into specific system configurations and control commands, the automatic, precise, and coordinated operation of in-furnace desulfurization and external desulfurization across the entire load range is achieved. This ensures that the unit can maintain a more economical operating state while meeting ultra-low emission requirements, thus achieving a balance between environmental protection and economy.

[0168] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0169] Based on the same inventive concept, this application also provides a circulating fluidized bed boiler internal and external desulfurization control optimization device for implementing the aforementioned circulating fluidized bed boiler internal and external desulfurization control optimization method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more circulating fluidized bed boiler internal and external desulfurization control optimization device embodiments provided below can be found in the limitations of the circulating fluidized bed boiler internal and external desulfurization control optimization method described above, and will not be repeated here.

[0170] In one exemplary embodiment, such as Figure 4 As shown, a circulating fluidized bed boiler internal and external desulfurization control optimization device is provided. The circulating fluidized bed boiler is equipped with an in-furnace desulfurization system and an external desulfurization system. The external desulfurization system includes multiple slurry circulation pumps. The device includes: a selection module 402, a first screening module 404, a first determination module 406, a second screening module 408, a second determination module 410, a first optimization module 412, and a second optimization module 414, wherein:

[0171] The selection module 402 is used to select multiple load condition points from a preset load range;

[0172] The first filtering module 404 is used to acquire historical operating data and filter out the first target historical operating data that matches each load condition point and meets the preset steady-state operating conditions from the historical operating data.

[0173] The first determining module 406 is used to determine the target external desulfurization mode based on the historical operating data of each first target, the preset set value of sulfur dioxide in the flue gas, the preset set value of calcium-sulfur ratio, the preset in-furnace steady-state desulfurization efficiency model and the preset external desulfurization efficiency model. The target external desulfurization mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point.

[0174] The second filtering module 408 is used to filter out the second target historical operating data from the historical operating data that matches the target load condition point and meets the preset load rise and fall rate conditions.

[0175] The second determining module 410 is used to determine the actual value of sulfur dioxide in the flue gas corresponding to each target load condition point when the external desulfurization system operates according to the target external desulfurization mode, based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset external desulfurization efficiency model.

[0176] The first optimization module 412 is used to optimize each target load operating point based on the difference between the actual value of sulfur dioxide in each clean flue gas and the preset sulfur dioxide setting value in the clean flue gas.

[0177] The second optimization module 414 is used to optimize the preset calcium-sulfur ratio setting and the quantity of each target with the goal of minimizing the desulfurization cost inside and outside the furnace.

[0178] In an exemplary embodiment, the first determining module 406 is further configured to:

[0179] Based on the historical operating data of each first target, the preset sulfur dioxide setpoint in the flue gas, the preset steady-state desulfurization efficiency model in the furnace and the preset desulfurization efficiency model outside the furnace, the target outside furnace operation mode that minimizes the total power consumption of the outside furnace desulfurization system is determined when the calcium-sulfur ratio of the inside furnace desulfurization system is equal to the preset calcium-sulfur ratio setpoint.

[0180] The second determining module 410 is also used for:

[0181] Based on the historical operating data of each secondary target, the preset in-furnace dynamic desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, the actual values ​​of sulfur dioxide in the net flue gas corresponding to each target load condition point are determined when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setting value and the out-of-furnace desulfurization system operates according to the target out-of-furnace operation mode.

[0182] In an exemplary embodiment, the historical operating data includes a sequence of flue gas sulfur dioxide concentration values, and the first target historical operating data includes a target concentration value sequence; the first screening module 404 is further configured to:

[0183] From the flue gas sulfur dioxide concentration value sequence, an initial concentration value sequence that matches each load condition and meets the preset steady-state condition is selected, and the initial time range corresponding to the initial concentration value sequence is determined.

[0184] Determine the target time range based on the preset delay duration and initial time range;

[0185] Extract the target concentration value sequence corresponding to the target time range from the initial concentration value sequence.

[0186] In an exemplary embodiment, the first filtering module 404 is further configured to:

[0187] Obtain the distance between the sulfur dioxide concentration measuring point in the flue gas and the limestone feed inlet;

[0188] The preset delay time is determined based on the interval distance value and the preset flue gas velocity.

[0189] In an exemplary embodiment, the first optimization module 412 is further configured to:

[0190] For the target load condition point where the actual value of sulfur dioxide in the clean flue gas is greater than or equal to the preset sulfur dioxide setting value in the clean flue gas, the preset adjustment step value is reduced to obtain the optimized target load condition point. The preset adjustment step value is equal to the product of the preset rated load and the preset adjustment ratio.

[0191] In an exemplary embodiment, the circulating fluidized bed boiler internal and external desulfurization control optimization device further includes a configuration module; after optimizing the preset calcium-sulfur ratio setpoint and each target quantity with the goal of minimizing the cost of internal and external desulfurization, the configuration module is used to:

[0192] Based on the optimized preset calcium-sulfur ratio setting, determine the limestone feed rate of the in-furnace desulfurization system under different load conditions;

[0193] Configure the in-furnace desulfurization system according to the amount of limestone fed, and configure the external desulfurization system according to the optimized target load conditions and the optimized target quantities.

[0194] In one exemplary embodiment, the optimized preset calcium-sulfur ratio setting is greater than zero and less than or equal to the original preset calcium-sulfur ratio setting.

[0195] The number of targets after optimization is greater than or equal to the number of targets before optimization;

[0196] When the in-furnace desulfurization system is configured according to the optimized preset calcium-sulfur ratio setting value, and the external desulfurization system is configured according to the optimized target external operating mode, the actual value of sulfur dioxide in the clean flue gas corresponding to each target load operating point is less than or equal to the corresponding preset value of sulfur dioxide in the clean flue gas.

[0197] Each module in the aforementioned circulating fluidized bed boiler internal and external desulfurization control optimization device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0198] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements an optimization method for internal and external desulfurization control of a circulating fluidized bed boiler. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0199] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0200] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0201] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0202] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0203] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0204] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0205] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0206] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An optimization method for internal and external desulfurization control in a circulating fluidized bed boiler, characterized in that, The circulating fluidized bed boiler is equipped with an in-furnace desulfurization system and an external desulfurization system, the external desulfurization system including multiple slurry circulation pumps; the method includes: Select multiple load conditions from the preset load range; Acquire historical operating data, and filter out the first target historical operating data that matches each of the load conditions and meets the preset steady-state operating conditions from the historical operating data; Based on the historical operating data of each of the first targets, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for calcium-sulfur ratio, the preset in-furnace steady-state desulfurization efficiency model, and the preset out-of-furnace desulfurization efficiency model, the target out-of-furnace operating mode is determined. The target out-of-furnace operating mode includes at least the target load condition point that requires the slurry circulation pump to be started and the target number of slurry circulation pumps that need to be started at each target load condition point. Select a second target historical operating data that matches the target load condition and meets the preset load increase / decrease rate conditions from the historical operating data; Based on the historical operating data of each second target, the preset calcium-sulfur ratio setting value, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of net flue gas sulfur dioxide corresponding to each target load condition point is determined when the out-of-furnace desulfurization system operates according to the target out-of-furnace operating mode. Based on the difference between the actual value of sulfur dioxide in each of the above-mentioned clean flue gas and the corresponding preset value of sulfur dioxide in each of the above-mentioned clean flue gas, the target load operating point is optimized. With the goal of minimizing the cost of desulfurization both inside and outside the furnace, the preset calcium-sulfur ratio setting and the quantity of each target are optimized.

2. The method according to claim 1, characterized in that, The step of determining the target external desulfurization mode based on the historical operating data of each of the first targets, the preset setpoint for sulfur dioxide in clean flue gas, the preset setpoint for the calcium-sulfur ratio, the preset in-furnace steady-state desulfurization efficiency model, and the preset external desulfurization efficiency model includes: Based on the historical operating data of each of the first targets, the preset sulfur dioxide setpoint in the flue gas, the preset in-furnace steady-state desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the target out-of-furnace operation mode that minimizes the total power consumption of the out-of-furnace desulfurization system when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setpoint is determined. The step of determining the actual net flue gas sulfur dioxide value corresponding to each of the target load conditions under the condition that the external desulfurization system operates according to the target external operating mode, based on the historical operating data of each of the second targets, the preset calcium-sulfur ratio setpoint, the preset in-furnace dynamic desulfurization efficiency model, and the preset external desulfurization efficiency model, includes: Based on the historical operating data of each of the second targets, the preset in-furnace dynamic desulfurization efficiency model and the preset out-of-furnace desulfurization efficiency model, the actual value of sulfur dioxide in the net flue gas corresponding to each of the target load conditions is determined when the calcium-sulfur ratio of the in-furnace desulfurization system is equal to the preset calcium-sulfur ratio setting value and the out-of-furnace desulfurization system is operating according to the target out-of-furnace operating mode.

3. The method according to claim 1, characterized in that, The historical operating data includes a sequence of flue gas sulfur dioxide concentration values, and the first target historical operating data includes a sequence of target concentration values; the step of selecting the first target historical operating data that matches each of the load conditions and meets the preset steady-state operating conditions from the historical operating data includes: From the flue gas sulfur dioxide concentration value sequence, an initial concentration value sequence that matches each of the load conditions and meets the preset steady-state conditions is selected, and the initial time range corresponding to the initial concentration value sequence is determined. The target time range is determined based on the preset delay duration and the initial time range; Extract the target concentration value sequence corresponding to the target time range from the initial concentration value sequence.

4. The method according to claim 3, characterized in that, Before determining the target time range based on the preset delay duration and the initial time range, the method further includes: Obtain the distance between the sulfur dioxide concentration measuring point in the flue gas and the limestone feed inlet; The preset delay time is determined based on the interval distance value and the preset flue gas velocity.

5. The method according to claim 1, characterized in that, The optimization of each target load operating point based on the difference between the actual value of sulfur dioxide in each of the clean flue gas and the preset value of sulfur dioxide in the clean flue gas includes: For the target load condition point where the actual value of sulfur dioxide in the clean flue gas is greater than or equal to the preset sulfur dioxide setting value in the clean flue gas, the preset adjustment step value is reduced to obtain the optimized target load condition point. The preset adjustment step value is equal to the product of the preset rated load and the preset adjustment ratio.

6. The method according to any one of claims 1 to 5, characterized in that, After optimizing the preset calcium-sulfur ratio and the target quantities with the goal of minimizing desulfurization costs inside and outside the furnace, the method further includes: Based on the optimized preset calcium-sulfur ratio setting, the limestone feed rate of the in-furnace desulfurization system under different load conditions is determined; The in-furnace desulfurization system is configured according to the limestone feed rate, and the external desulfurization system is configured according to the optimized target load conditions and the optimized target quantities.

7. The method according to any one of claims 1 to 5, characterized in that, The optimized preset calcium-sulfur ratio setting is greater than zero and less than or equal to the original preset calcium-sulfur ratio setting. The number of targets after optimization is greater than or equal to the number of targets before optimization; When the in-furnace desulfurization system is configured according to the optimized preset calcium-sulfur ratio setting value, and the external desulfurization system is configured according to the optimized target external operating mode, the actual value of sulfur dioxide in the clean flue gas corresponding to each target load operating point is less than or equal to the corresponding preset value of sulfur dioxide in the clean flue gas.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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