Prediction control method, system and equipment for nitric oxide in flue gas and storage medium

Abstract

The invention discloses a predictive control method, system and device for nitric oxide in flue gas and a storage medium, and relates to the technical field of thermal power plant environmental protection control, and the method comprises the steps: drawing an NH3 flow function based on the active power of a generator set and the SCR inlet NOx instantaneous flow, and carrying out the correction according to a total outlet NOx set value; calculating NH3 flow correction according to the corrected function and the outlet NOx instantaneous value; the SCR outlet NOx change trend is predicted according to the SCR inlet and outlet NOx real-time monitoring values; adjusting an ammonia gas control instruction according to the running condition of the coal mill; the NOx set value is automatically adjusted according to the NOx real-time values of the total outlet and the SCR outlet; controlling the opening degree of the NH3 flow regulating valve based on the parameters; the method can effectively cope with the load and working condition changes of the generator set, stabilizes the NOx emission value of a total outlet in a set range, reduces the emission of nitrogen oxides, has a good environmental protection effect, and is high in practicability and popularization value.

Description

Technical Field

[0001] This invention relates to the field of environmental control technology for thermal power plants, and in particular to a predictive control method, system, equipment, and storage medium for nitrogen oxides in flue gas. Background Technology

[0002] As an important site for energy production, thermal power plants emit nitrogen oxides (NOx) in their flue gas. x Controlling nitrogen oxides (NOx) is crucial. Effective automatic control of NOx can not only reduce the environmental pollution caused by thermal power plants, but also determine whether they can achieve sustainable development.

[0003] Currently, automatic control of denitrification in thermal power plants, specifically NO in flue gas emissions... X Automatic control generally employs two methods: either implementation within the unit's DCS (Distributed Control System) or integration of a third-party controller into the unit's DCS. The control strategy estimates the NO content in the flue gas based on the flow rate of the flue gas entering the SCR (Selective Catalytic Reduction) reactor. X The method of calculating the set value of NH3 or product gas flow rate based on the content of NH3 or product gas (hereinafter collectively referred to as NH3) to control the opening of the NH3 or product gas flow regulating valve has the following problems: the existing flue gas flow measurement method produces large errors and cannot truly reflect the actual flow rate; it has poor adaptability to unit load changes, and the control system responds slowly when the load changes; NO X The measurement and chemical reaction processes both exhibit significant delays, resulting in a lag in the action of the control system; the control system experiences large-amplitude oscillations; and NO is present at the outlet during the start-up and shutdown of the coal mill. X Significant fluctuations and a high risk of exceeding limits; third-party plug-in controller programs are opaque, making it difficult for maintenance personnel to handle problems. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by this invention is: how to overcome the problems in existing automatic denitrification control systems for thermal power plants, such as large errors in flue gas flow measurement, poor adaptability to unit load changes, measurement and response delays, oscillations in the regulation system, and NO emissions during coal mill start-up and shutdown. x Addressing the issues of large fluctuations and opaque third-party controller programs, this study aims to achieve more accurate, efficient, stable, and easy-to-maintain monitoring of NO in flue gas emissions. x Automatic control.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for predicting and controlling nitrogen oxides in flue gas, comprising:

[0008] Based on generator set active power and SCR inlet NO x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected;

[0009] Based on the corrected NH3 flow function and outlet NO x The instantaneous value is used to calculate the correction amount for the NH3 flow rate;

[0010] NO based on SCR inlet and outlet x Real-time monitoring values, predicting SCR export NO x The changing trend;

[0011] Based on SCR export NO x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands.

[0012] According to total exports and SCR exports NO x Real-time value automatic adjustment NO x Setting value;

[0013] Based on the correction amount for NH3 flow rate, ammonia control command, and adjusted NO x The set value controls the opening degree of the NH3 flow regulating valve.

[0014] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0015] The data is based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The settings are corrected as follows:

[0016] The active power of the generator set is used to simulate and correct the flue gas flow rate. The functional relationship between the active power of the generator set and the flue gas flow rate is determined through experiments and big data analysis.

[0017] The corrected flue gas flow rate and SCR inlet NO x By combining instantaneous flow rates, the NO content in flue gas can be calculated. x The total amount;

[0018] Based on the equilibrium theory of chemical reaction equations and combined with the big data collected from experiments, the required NH3 flow function of the system was plotted.

[0019] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0020] The data is based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The setting correction also includes:

[0021] According to total exports NO x The setpoint corrects the plotted NH3 flow function, specifically by setting the value relative to the total outlet NO. x A correction function that is inversely proportional to the setpoint is used to correct the NH3 flow rate function, resulting in the corrected NH3 flow rate setpoint function.

[0022] The beneficial effects of this preferred technical solution are: based on total exports NO x Adjusting the NH3 flow function with setpoints allows for more flexible NH3 flow rate settings that better adapt to actual emission requirements. Setting an inversely proportional correction function can be adapted to different total outlet NO levels. x The dynamic adjustment of NH3 flow rate by setting the value improves the accuracy and effectiveness of nitrogen oxide control, which helps to achieve stricter emission targets.

[0023] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0024] The modified NH3 flow function and outlet NO x The instantaneous value, the correction amount for calculating the NH3 flow rate includes:

[0025] A closed-loop control method is adopted to monitor and analyze the NO at the outlet in real time. x Instantaneous value;

[0026] Calculate the correction value for the NH3 flow setpoint and limit the output range of the correction value to a certain range;

[0027] Based on the corrected NH3 flow function and the resulting correction value, the NH3 flow setpoint with the correction amount is obtained.

[0028] The beneficial effects of this preferred technical solution are: real-time monitoring and analysis of outlet NO using a closed-loop control method. x Instantaneous values ​​provide timely feedback on actual emissions, enabling dynamic adjustment of NH3 flow. Limiting the output range of the correction value within a certain interval avoids system instability caused by excessively large or small corrections, thus improving control stability and reliability. Combining the corrected NH3 flow function and the correction value yields an NH3 flow setpoint with the correction amount, making NH3 flow control more precise and better adaptable to changes in operating conditions.

[0029] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0030] The NO based on SCR inlet and outlet x Real-time monitoring values, predicting SCR export NO x The changing trends include:

[0031] Calculate the NO at the SCR inlet and outlet respectively. x The difference between the current value and the value at a specific time point is used to obtain the rate of change per unit time.

[0032] The rate of change is further processed using differential and arithmetic methods. Based on the processing results, the NO at the SCR inlet and outlet is predicted. x The changing trend.

[0033] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0034] The SCR-based export NO x Based on the changing trend and the operating conditions of the coal mill, the ammonia control commands are adjusted as follows:

[0035] Calculate the number of coal mills in operation and analyze the NO at the SCR outlet before and after the coal mills start and stop. x The rate of change;

[0036] According to SCR export NO x The changing trend, combined with the number of coal mills in operation and NO x The rate of change is used to adjust the ammonia control commands.

[0037] As a preferred method for predictive control of nitrogen oxides in flue gas, wherein:

[0038] The data is based on total exports and SCR exports NO. x Real-time value automatic adjustment NO x The settings include:

[0039] NO to total exports x Real-time monitoring values ​​and SCR outlet NO x Real-time monitoring values ​​are compared and analyzed at fixed time periods;

[0040] Based on the comparative analysis results, if total exports NO x NO higher than SCR outlet NO within a fixed time period x The system automatically reduces NO x Set value; if total outlet NO x NO below SCR outlet within a fixed time period x The system automatically increases NO. x Setting value;

[0041] Limited NO xThe adjustment range of the set value is within a certain range.

[0042] The beneficial effects of this preferred technical solution are: It reduces total exports and SCR exports by NO. x By performing comparative analysis of real-time values ​​at fixed time periods, the relationship between the two can be dynamically grasped, providing a basis for automatic adjustment of NO. x The set value provides a basis. NO is automatically adjusted based on the comparison results. x The setpoints are designed to better reflect actual emissions, improving the flexibility and adaptability of nitrogen oxide control. Limiting the adjustment range prevents excessive adjustments to the setpoints, ensuring system stability and reliability.

[0043] Secondly, the present invention provides a predictive control system for nitrogen oxides in flue gas, comprising:

[0044] The NH3 flow function construction and correction module is used to construct and correct the flow function based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected;

[0045] The NH3 flow correction calculation module is used to calculate the corrected NH3 flow rate based on the corrected NH3 flow function and the outlet NO. x The instantaneous value is used to calculate the correction amount for the NH3 flow rate;

[0046] SCR Export NO x Trend prediction module for NO based on SCR inlet and outlet x Real-time monitoring values, predicting SCR export NO x The changing trend;

[0047] Ammonia control command adjustment module, used to adjust the NO based on SCR outlet x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands.

[0048] NO x The setpoint automatic adjustment module is used to adjust the setpoint based on the total outlet and SCR outlet NO. x Real-time value automatic adjustment NO x Setting value;

[0049] The NH3 flow regulating valve control module is used to adjust the NO flow rate based on the correction amount of NH3 flow, ammonia control commands, and the adjusted NO flow. x The set value controls the opening degree of the NH3 flow regulating valve.

[0050] Thirdly, the present invention provides an electronic device, comprising:

[0051] Memory and processor;

[0052] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the one or more programs are executed by the one or more processors, the one or more processors implement the predictive control method for nitrogen oxides in flue gas as described in this invention.

[0053] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the aforementioned predictive control method for nitrogen oxides in flue gas.

[0054] The beneficial effects of this invention: This invention corrects the NO content in flue gas by adjusting the unit load. x The content avoids the impact of flue gas flow measurement errors. The active power of the generator set has a functional relationship with the flue gas flow rate; the active power is used to calculate the flue gas flow rate, and then combined with the SCR inlet NO content... x The instantaneous flow rate is calculated to determine the total amount, making the calculation results more accurate and providing a reliable basis for subsequent control. This solves the problem of estimating NO using flue gas flow rate in existing technologies. x The content is prone to large errors and cannot truly reflect the actual situation; therefore, predicting the SCR inlet / outlet NO content is used. x The system can detect changes in the NO₂ concentration trend in advance and enable the control system to respond accordingly. When significant disturbances occur in the boiler combustion conditions, such as load changes, the system can quickly adjust to ensure the total outlet NO₂ is maintained. x The numerical values ​​do not fluctuate significantly, effectively overcoming the problem of large delays and improving the timeliness and stability of control. The original regulating system's actuator switching action was prone to large-amplitude oscillations; this invention makes the actuator switching action smoother, reducing equipment wear and control instability caused by violent actions, extending the lifespan of the actuator, and also improving the reliability of the entire control system. It can automatically predict NO levels during the start-up and shutdown of the coal mill. x Based on the changing trends and magnitudes, adjustments can be made in advance. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is an overall flowchart of the predictive control method for nitrogen oxides in flue gas provided by the present invention. Detailed Implementation

[0057] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0058] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a method for predictive control of nitrogen oxides in flue gas, comprising:

[0059] S1: Based on generator set active power and SCR inlet NO x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected;

[0060] S2: Based on the modified NH3 flow function and outlet NO x The instantaneous value is used to calculate the correction amount for the NH3 flow rate;

[0061] S3: NO based on SCR inlet and outlet x Real-time monitoring values, predicting SCR export NO x The changing trend;

[0062] S4: Based on SCR export NO x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands.

[0063] S5: Based on total exports and SCR export NO x Real-time value automatic adjustment NO x Setting value;

[0064] S6: Correction based on NH3 flow rate, ammonia control command, adjusted NO x The set value controls the opening degree of the NH3 flow regulating valve.

[0065] It should be noted that, through S1-S6, the process involves constructing and correcting the NH3 flow function, calculating the NH3 flow correction, and predicting NO. x Trends in change, adjustments to ammonia control instructions and NO x The set value ultimately achieves precise control over the opening of the NH3 flow regulating valve. This effectively addresses changes in load and operating conditions during generator unit operation, ensuring the total outlet NO... x The emission values ​​are kept stable within the set range, thereby significantly reducing the emission of nitrogen oxides in flue gas, achieving good environmental protection results, and having high practicality and promotion value.

[0066] Example 2, refer to Figure 1 As one embodiment of the present invention, based on the previous embodiment, a predictive control method for nitrogen oxides in flue gas is provided, comprising:

[0067] In this embodiment, step S1 above is based on the generator set's active power and the SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The settings are corrected as follows:

[0068] The active power of the generator set is used to simulate and correct the flue gas flow rate;

[0069] It should be noted that there is a certain functional relationship between the active power of the generator set and the flue gas flow rate, which was determined through experiments and big data analysis.

[0070] The corrected flue gas flow rate and SCR inlet NO x By combining instantaneous flow rates, the NO content in the flue gas can be calculated. x The total amount;

[0071] Based on the equilibrium theory of chemical reaction equations and combined with the big data collected from experiments, the required NH3 flow function of the system was plotted.

[0072] For example, during the operation of a thermal power plant, the real-time active power of the generator unit is 600MW, and the SCR inlet NO... x Instantaneous flow rate is 120 mg / m³ 3 Based on big data, the corrected flue gas flow rate corresponding to this power is determined, and then the NO is calculated. x Calculate the total amount, and then plot the corresponding NH3 flow function.

[0073] Based on total exports NO x The NH3 flow function obtained in the first step of setting value correction;

[0074] Specifically, according to total exports NO x The set value is used to set a correction function, which outputs the value and NO. x The setpoint (ranging from 45 to 20) is inversely proportional. This correction function is used to correct the obtained NH3 flow rate function, resulting in the corrected NH3 flow rate setpoint function.

[0075] For example, if the NH3 flow function obtained in the first step is f1(NH3), the total outlet NO x The set value is 25mg / m 3 Through the inverse proportional correction function f 修正 The corrected function f2(NH3) = f 修正 (25)*f1(NH3).

[0076] In another possible implementation, when plotting the NH3 flow function, regression analysis methods from machine learning, such as support vector regression (SVR), can be used to establish the generator set's active power and SCR inlet NO. x Regression model between instantaneous flow rate and NH3 flow rate.

[0077] Using historical data as the training set, the SVR model is trained, and the model parameters are adjusted to achieve the best fit, thereby obtaining the initial NH3 flow function.

[0078] In this embodiment, step S2 above is based on the modified NH3 flow function and the outlet NO x The instantaneous value, the correction amount for calculating the NH3 flow rate includes:

[0079] A closed-loop control method is adopted, based on the export NO x The correction amount for NH3 flow rate is calculated based on the instantaneous value.

[0080] Specifically, a closed-loop control method is used to monitor the NO at the outlet in real time. x Instantaneous values ​​are monitored and analyzed. Through a series of calculations, a correction value for the NH3 flow setpoint is obtained, with the output range limited to +200 to -160. The final NH3 flow setpoint with the correction is then obtained.

[0081] For example, the corrected NH3 flow setpoint function is known to be f2(NH3), and the current outlet NO x The instantaneous value was 22 mg / m³ 3 The correction value is calculated to be -30 by the closed-loop control algorithm. Therefore, the NH3 flow setpoint with the correction is f2(NH3)-30.

[0082] In this embodiment, the NO in step S3 above is based on the SCR inlet and outlet. x Real-time monitoring values, predicting SCR export NO x The changing trends include:

[0083] NO for SCR inlet and outlet respectively x The data is used to calculate the difference between the current value and the value 60 seconds ago, thus obtaining the rate of change per unit time. Then, differential and arithmetic operations are used to further process the rate of change, thereby predicting the SCR inlet / outlet NO. x The changing trend.

[0084] For example, for SCR export NO x The current monitoring value is 70 mg / m³. 3 60 seconds ago, the concentration was 65 mg / m³. 3Calculate the rate of change (70-65) / 60, and then combine it with differential and arithmetic operations to determine the SCR outlet NO. x It is on the rise.

[0085] In this embodiment, in step S4 above, the SCR outlet NO is used as the basis for... x Based on the changing trend and the operating conditions of the coal mill, the ammonia control commands are adjusted as follows:

[0086] Calculate the number of coal mills in operation, and analyze the NO at the SCR outlet before and after the coal mills start and stop. x The rate of change. Based on the SCR outlet NO... x Based on the changing trend, adjust the ammonia control instructions in a timely manner.

[0087] For example, when the number of coal mills operating increased from 3 to 4, NO at the SCR outlet was monitored. x As the rate of change accelerates, and in conjunction with the predicted upward trend, the control system adjusts the ammonia control commands in advance, increasing the ammonia supply.

[0088] In another possible implementation, quantitative indicators of the coal mill's operating status can be defined, such as the number of operating coal mills and the load rate. Different operating modes can be established based on the coal mill's operating status, such as "high load with multiple coal mills operating" or "low load with fewer coal mills operating."

[0089] In another possible implementation, different operating modes and SCR outlet NO can be targeted. x Based on the changing trends, formulate corresponding ammonia control command adjustment strategies. For example, in situations where "multiple coal mills are operating at high load" and SCR outlet NO... x When the trend is upward, appropriately increase the ammonia supply; when "low load and few coal mills are operating" and the SCR outlet NO... x When the trend is downward, reduce the supply of ammonia.

[0090] In this embodiment, in step S5 above, the total outlet and SCR outlet NO are used as the basis for calculation. x Real-time value automatic adjustment NO x The settings include:

[0091] NO to total exports x Real-time monitoring values ​​and SCR outlet NO x The real-time monitoring values ​​were compared and analyzed over a long period of time. When the total export NO x NO levels exceeding SCR export levels for an extended period x When the total output NO is high, the system automatically decreases the set value; conversely, when the total output NO is high, the system automatically decreases the set value. x NO levels below SCR export levels for an extended period x When the system automatically increases the set value, the adjustment range of the set value is between ±6.

[0092] For example, if total exports NO x Maintaining at 38 mg / m 3 SCR export NO x 32mg / m 3 The system automatically reduced the set value by 4 mg / m³. 3 The adjusted setting is now 28 mg / m³ 3 .

[0093] In this embodiment, the correction amount based on the NH3 flow rate in step S6 above, the ammonia control command, and the adjusted NO x The setpoints controlling the opening of the NH3 flow regulating valve include:

[0094] The control system is based on the NH3 flow setpoint with correction, the adjusted ammonia control command, and the adjusted NO... x The set value precisely controls the opening of the NH3 flow regulating valve. By adjusting the valve opening, precise control of the NH3 supply is achieved, thereby ensuring the total outlet NO... x Emissions remained stable. Under varying load and operating conditions, total outlet NO... x Emission values ​​remain within ±9 of the set range; under stable load conditions, they remain within ±3 of the set range.

[0095] For example, based on the NH3 flow rate setpoint with correction, the adjusted ammonia control command, and the adjusted NO... x Set value 30mg / m 3 Control the opening of the NH3 flow regulating valve to ensure that the total outlet NO x Emissions remained stable at 27-33 mg / m³ 3 between.

[0096] In another possible implementation, a multivariate predictive control algorithm can be used to adjust the NH3 flow rate, ammonia control command, and adjusted NO. x The set value is used as the input variable, and the opening degree of the NH3 flow regulating valve is used as the output variable.

[0097] A predictive model is established to predict the future output response of the system, and the control strategy is optimized based on the prediction results to calculate the optimal opening degree of the NH3 flow regulating valve.

[0098] Example 3: The above is an illustrative scheme of the predictive control method for nitrogen oxides in flue gas according to this embodiment. It should be noted that the technical solution of the predictive control system for nitrogen oxides in flue gas and the technical solution of the predictive control method for nitrogen oxides in flue gas described above belong to the same concept. Details not described in detail in the technical solution of the predictive control system for nitrogen oxides in flue gas in this embodiment can be found in the description of the technical solution of the predictive control method for nitrogen oxides in flue gas described above.

[0099] This embodiment also provides a predictive control system for nitrogen oxides in flue gas, including:

[0100] The NH3 flow function construction and correction module is used to construct and correct the flow function based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected;

[0101] The NH3 flow correction calculation module is used to calculate the corrected NH3 flow rate based on the corrected NH3 flow function and the outlet NO. x The instantaneous value is used to calculate the correction amount for the NH3 flow rate;

[0102] SCR Export NO x Trend prediction module for NO based on SCR inlet and outlet x Real-time monitoring values, predicting SCR export NO x The changing trend;

[0103] Ammonia control command adjustment module, used to adjust the NO based on SCR outlet x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands.

[0104] NO x The setpoint automatic adjustment module is used to adjust the setpoint based on the total outlet and SCR outlet NO. x Real-time value automatic adjustment NO x Setting value;

[0105] The NH3 flow regulating valve control module is used to adjust the NO flow rate based on the correction amount of NH3 flow, ammonia control commands, and the adjusted NO flow. x The set value controls the opening degree of the NH3 flow regulating valve.

[0106] This embodiment also provides an electronic device applicable to predictive control methods for nitrogen oxides in flue gas, including:

[0107] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the predictive control method for nitrogen oxides in flue gas as described in the above embodiments.

[0108] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the predictive control method for nitrogen oxides in flue gas as proposed in the above embodiments.

[0109] The storage medium proposed in this embodiment and the predictive control method for nitrogen oxides in flue gas proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0110] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for predicting and controlling nitrogen oxides in flue gas, characterized in that, include: Based on generator set active power and SCR inlet NO x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected; Based on the corrected NH3 flow function and outlet NO x The instantaneous value is used to calculate the correction amount for the NH3 flow rate; NO based on SCR inlet and outlet x Real-time monitoring values ​​to predict SCR export NO x The changing trend; Based on SCR export NO x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands. According to total exports and SCR exports NO x Real-time value automatic adjustment NO x Setting value; Based on the correction amount for NH3 flow rate, ammonia control command, and adjusted NO x The set value controls the opening degree of the NH3 flow regulating valve.

2. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 1, characterized in that, The data is based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The settings are corrected as follows: The active power of the generator set is used to simulate and correct the flue gas flow rate. The functional relationship between the active power of the generator set and the flue gas flow rate is determined through experiments and big data analysis. The corrected flue gas flow rate and SCR inlet NO x By combining instantaneous flow rates, the NO content in flue gas can be calculated. x The total amount; Based on the equilibrium theory of chemical reaction equations and combined with the big data collected from experiments, the required NH3 flow function of the system was plotted.

3. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 2, characterized in that, The data is based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The setting correction also includes: According to total exports NO x The setpoint corrects the plotted NH3 flow function, specifically by setting the value relative to the total outlet NO. x A correction function that is inversely proportional to the setpoint is used to correct the NH3 flow rate function, resulting in the corrected NH3 flow rate setpoint function.

4. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 3, characterized in that, The modified NH3 flow function and outlet NO x The instantaneous value, the correction amount for calculating the NH3 flow rate includes: A closed-loop control method is adopted to monitor and analyze the outlet NO in real time. x Instantaneous value; Calculate the correction value for the NH3 flow setpoint and limit the output range of the correction value to a certain range; Based on the corrected NH3 flow function and the resulting correction value, the NH3 flow setpoint with the correction amount is obtained.

5. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 4, characterized in that, The NO based on SCR inlet and outlet x Real-time monitoring values ​​to predict SCR export NO x The changing trends include: Calculate the NO at the SCR inlet and outlet respectively. x The difference between the current value and the value at a specific time point is used to obtain the rate of change per unit time. The rate of change is further processed using differential and arithmetic methods. Based on the processing results, the NO at the SCR inlet and outlet is predicted. x The changing trend.

6. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 5, characterized in that, The SCR-based export NO x Based on the changing trend and the operating conditions of the coal mill, the ammonia control commands are adjusted as follows: Calculate the number of coal mills in operation and analyze the NO at the SCR outlet before and after the coal mills start and stop. x The rate of change; According to SCR export NO x The changing trend, combined with the number of coal mills in operation and NO x The rate of change is used to adjust the ammonia control commands.

7. The method for predicting and controlling nitrogen oxides in flue gas as described in claim 6, characterized in that, The data is based on total exports and SCR exports NO. x Real-time value automatic adjustment NO x The settings include: NO to total exports x Real-time monitoring values ​​and SCR outlet NO x Real-time monitoring values ​​are compared and analyzed at fixed time periods; Based on the comparative analysis results, if total exports NO x NO higher than SCR outlet NO within a fixed time period x The system automatically reduces NO x Set value; if total outlet NO x NO below SCR outlet within a fixed time period x The system automatically increases NO. x Setting value; Limited NO x The adjustment range of the set value is within a certain range.

8. A predictive control system for nitrogen oxides in flue gas, employing the method described in any one of claims 1 to 7, characterized in that, include: The NH3 flow function construction and correction module is used to construct and correct the flow function based on the generator set's active power and SCR inlet NO. x Plot the NH3 flow function based on instantaneous flow rate and the total outlet NO. x The set value was corrected; The NH3 flow correction calculation module is used to calculate the corrected NH3 flow rate based on the corrected NH3 flow function and the outlet NO. x The instantaneous value is used to calculate the correction amount for the NH3 flow rate; SCR Export NO x Trend prediction module for NO based on SCR inlet and outlet x Real-time monitoring values ​​to predict SCR export NO x The changing trend; Ammonia control command adjustment module, used to adjust the NO based on SCR outlet x Based on the changing trend and the operating conditions of the coal mill, adjust the ammonia control commands. NO x The setpoint automatic adjustment module is used to adjust the setpoint based on the total outlet and SCR outlet NO. x Real-time value automatic adjustment NO x Setting value; The NH3 flow regulating valve control module is used to adjust the NO flow rate based on the correction amount of NH3 flow, ammonia control commands, and the adjusted NO flow. x The set value controls the opening degree of the NH3 flow regulating valve.

9. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, It stores computer-executable instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.

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