Method, device and equipment for controlling flow of nitric oxide in flue gas of thermal power plant

Abstract

The invention discloses a method, device and equipment for controlling the flow of nitric oxide in flue gas of a thermal power plant, and relates to the field of automatic control of the thermal power plant. The method comprises the steps that in the operation process of the thermal power plant, the flue gas flow of a generator set, the oxygen content of the generator set and the instantaneous flow of nitric oxide at an inlet of a selective catalytic reduction reactor are collected in real time; calculating the ammonia flow at the inlet of the selective catalytic reduction reactor; correcting the ammonia gas flow at the inlet of the selective catalytic reduction reactor according to the nitrogen oxide set correction amount to obtain a preliminary ammonia gas injection amount; correcting the initial ammonia gas injection amount according to a set amplification coefficient and static deviation time to obtain a final ammonia gas injection amount; and adjusting the flow of the ammonia gas injected into the selective catalytic reduction reactor according to the final injection amount of the ammonia gas so as to control the flow of nitrogen oxides in the selective catalytic reduction reactor. The control precision and efficiency of the nitric oxide flow are improved.

Description

Technical Field

[0001] This application relates to the field of automatic control in thermal power plants, and in particular to a method, apparatus and equipment for controlling the flow of nitrogen oxides in flue gas of thermal power plants. Background Technology

[0002] Currently, automatic control of denitrification in thermal power plants (i.e., automatic control of NOx in flue gas emissions) is generally implemented in the unit's distributed control system (DCS) or by using a third-party controller (black box) connected to the unit's DCS. The control strategy estimates the NOx content in the flue gas based on the flow rate of the flue gas entering the selective catalytic reduction (SCR) reactor, calculates the setpoint for the flow rate of NH3 or product gas, and then controls the opening of the NH3 or product gas (hereinafter referred to as NH3) flow regulating valve. However, this method has the following problems: 1) Existing flue gas flow measurement methods produce large errors and cannot accurately reflect the actual flow rate; 2) Poor adaptability to unit load changes, and the control system responds slowly when the load changes; 3) There are significant delays in both NOx measurement and the chemical reaction process, resulting in a relatively lagging action of the regulating system; 4) The regulating system experiences large-amplitude oscillations; 5) The NOx at the outlet fluctuates greatly during the start-up and shutdown of the coal mill, posing a significant risk of exceeding the standard; 6) The third-party external controller program is not transparent, making it difficult for maintenance personnel to handle problems. Summary of the Invention

[0003] The purpose of this application is to provide a method, apparatus, and equipment for controlling the flow rate of nitrogen oxides in flue gas from thermal power plants, which can improve the control accuracy and efficiency of nitrogen oxide flow rate.

[0004] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a method for controlling the flow rate of nitrogen oxides in flue gas from a thermal power plant, comprising: During the operation of the thermal power plant, the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor are collected in real time. Calculate the ammonia flow rate at the inlet of the selective catalytic reduction reactor based on the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor. The ammonia flow rate at the inlet of the selective catalytic reduction reactor is corrected based on the nitrogen oxide setting correction amount to obtain the initial ammonia injection amount; The initial ammonia injection amount is corrected according to the set amplification factor and static deviation time to obtain the final ammonia injection amount. The flow rate of ammonia injected into the selective catalytic reduction reactor is adjusted according to the final ammonia injection amount in order to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0005] Secondly, this application provides a nitrogen oxide flow control device for flue gas in thermal power plants, comprising: The data acquisition module is used to collect the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor in real time during the operation of the thermal power plant. The ammonia flow calculation module is used to calculate the ammonia flow rate at the inlet of the selective catalytic reduction reactor based on the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor. The first ammonia correction module is used to correct the ammonia flow rate at the inlet of the selective catalytic reduction reactor according to the set correction amount of nitrogen oxides, so as to obtain the initial ammonia injection amount. The second ammonia correction module is used to correct the initial ammonia injection amount according to the set amplification factor and static deviation time to obtain the final ammonia injection amount. The flow regulation module is used to adjust the flow rate of ammonia injected into the selective catalytic reduction reactor according to the final ammonia injection amount, so as to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0006] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for controlling the flow of nitrogen oxides in flue gas from a thermal power plant.

[0007] According to the specific embodiments provided in this application, this application achieves the following technical effects: By calculating the basic ammonia volume through real-time acquisition of flue gas flow, oxygen content, and instantaneous nitrogen oxide flow at the denitrification inlet, the ammonia flow rate is precisely matched with the unit operating conditions, significantly improving the real-time performance and accuracy of nitrogen oxide removal. Furthermore, by combining nitrogen oxide set correction, amplification factor, and static deviation time for multi-level correction, system lag and operating condition disturbances can be accurately compensated, further improving the accuracy of nitrogen oxide flow control. The entire process adopts data-driven closed-loop control logic, requiring no complex hardware modifications. While optimizing nitrogen oxide emission reduction, it also reduces ammonia waste and lowers the operating costs of denitrification in thermal power plants. Attached Figure Description

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

[0009] Figure 1 This is a flowchart illustrating a method for controlling the flow rate of nitrogen oxides in flue gas from a thermal power plant, provided as an embodiment of this application.

[0010] Figure 2 This is a framework diagram of a method for controlling the flow rate of nitrogen oxides in flue gas from a thermal power plant, provided as an embodiment of this application.

[0011] Figure 3 This is a schematic diagram of the functional modules of a nitrogen oxide flow control device in flue gas of a thermal power plant, provided as an embodiment of this application. Detailed Implementation

[0012] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] In one exemplary embodiment, such as Figure 1 As shown, a method for controlling the flow rate of nitrogen oxides in flue gas of a thermal power plant is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. The method for controlling the flow rate of nitrogen oxides in flue gas of a thermal power plant includes the following steps 101 to 110.

[0015] Step 101: During the operation of the thermal power plant, the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor are collected in real time. Specifically, the flue gas flow rate and oxygen content of the generator set boiler are collected.

[0016] Step 102: Calculate the ammonia flow rate at the inlet of the selective catalytic reduction reactor based on the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor.

[0017] In a specific application example, step 102 includes steps 21 to 23.

[0018] Step 21, based on the oxygen content of the generator set, use formula O c =21 / (1-O Calculate the converted oxygen content. Wherein, O... c This is the converted value of oxygen content, where O represents the oxygen content of the generator set.

[0019] Step 22: Based on the oxygen content conversion value, the flue gas flow rate of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor, the NOx value is calculated using the formula... z =G O c Calculate the total nitrogen oxides at the inlet of the selective catalytic reduction reactor. Among them, NOx... z This represents the total amount of nitrogen oxides (NOx) at the inlet of the selective catalytic reduction reactor. f G represents the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor, and G represents the flue gas flow rate of the generator set.

[0020] Step 23: Based on the total amount of nitrogen oxides at the inlet of the selective catalytic reduction reactor, the ammonia flow rate at the inlet of the selective catalytic reduction reactor is determined using a pre-constructed relationship between the total amount of nitrogen oxides and the ammonia flow rate.

[0021] Specifically, through experiments, a large amount of total nitrogen oxide emissions and ammonia flow rate were collected. Based on the equilibrium theory of chemical reaction equations, a relationship between the total nitrogen oxide emissions and ammonia flow rate was established, namely F... NH3流量 =f1(NOX z )=ARRAY{X 1,1 …X 1,10 ;Y 1,1 …Y 1,10}. Among them, F NH3流量 Let f1 be the ammonia flow rate, f1() be the function used to calculate the ammonia flow rate based on the total nitrogen oxides, and X be the ammonia flow rate. 1,1 ~X 1,10 Y represents the total amount of nitrogen oxides collected in the experiment. 1,1 ~Y 1,10 The flow rate of ammonia gas collected for the experiment.

[0022] Step 103: Correct the ammonia flow rate at the inlet of the selective catalytic reduction reactor according to the nitrogen oxide setting correction amount to obtain the preliminary ammonia injection amount, so as to make the control more precise.

[0023] In a specific application example, the nitrogen oxide setpoint correction is converted into an ammonia setpoint correction. The ammonia setpoint correction is then summed (or multiplied) with the ammonia flow rate at the inlet of the selective catalytic reduction reactor to obtain the initial ammonia injection rate.

[0024] Specifically, firstly, under the premise of meeting environmental assessment indicators, a setpoint is artificially set for the current NOx flow rate. Then, based on a pre-constructed relationship between the setpoint and the correction amount, the setpoint is converted into a setpoint correction amount for nitrogen oxides. The larger the setpoint, the smaller the correction amount; conversely, the smaller the setpoint, the larger the correction amount, and theoretically, the greater the amount of ammonia required.

[0025] The relationship between the setpoint and the correction amount was obtained by fitting a large number of setpoints and nitrogen oxide setpoint correction amounts through experiments, i.e., SV. 修正量 =f2(SV)=ARRAY{X 2,1 …X 2,10 ;Y 2,1 …Y 2,10}. Among them, SV 修正量 Set a correction amount for nitrogen oxides, where SV is the set value, f2() is the function to calculate the nitrogen oxide setting correction amount based on the set value, and X 2,1 ~X 2,10 Y1~Y10 are the set values ​​for the experimental collection, and Y1~Y10 are the set correction values ​​for the nitrogen oxides collected in the experiment.

[0026] Step 104: Correct the initial ammonia injection amount according to the set amplification factor and static deviation time to obtain the final ammonia injection amount, thereby improving the control accuracy.

[0027] Specifically, based on the set amplification factor and static deviation time, formula A is used. c =K P (1+1 / T S Calculate the ammonia correction amount. Where A c K is the correction amount for ammonia. p T is the magnification factor. S The static deviation time is used. The final ammonia injection amount is obtained by summing (or multiplying) the ammonia correction amount and the initial ammonia injection amount.

[0028] Step 105: Adjust the ammonia flow rate injected into the selective catalytic reduction reactor according to the final ammonia injection amount, so as to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0029] Step 106: Calculate the rate of change of nitrogen oxides at the inlet of the selective catalytic reduction reactor based on the instantaneous flow rate of nitrogen oxides at the current time and the previous time.

[0030] Specifically, the formula (NOX) is used. T2,in -NOX T1,in e ST) / e STCalculate the rate of change of nitrogen oxides at the inlet of the selective catalytic reduction reactor.

[0031] Step 107: Based on the rate of change of nitrogen oxides at the inlet of the selective catalytic reduction reactor, predict the trend of nitrogen oxide flow at the inlet of the selective catalytic reduction reactor, and obtain the inlet trend.

[0032] Step 108: Real-time acquisition of the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor, and calculation of the rate of change of nitrogen oxides at the outlet of the selective catalytic reduction reactor based on the instantaneous flow rate of nitrogen oxides at the current time and the previous time.

[0033] Specifically, the formula (NOX) is used. T2,out -NOX T1,out e ST / e ST Calculate the rate of change of nitrogen oxides at the outlet of the selective catalytic reduction reactor.

[0034] Where T2 is the current time, T1 is the previous time, ST is the scan time, and NOX is the current time. T2,in The instantaneous flow rate of nitrogen oxides (NOx) at the inlet of the selective catalytic reduction reactor at the current moment. T1,in The instantaneous flow rate of nitrogen oxides (NOx) at the inlet of the selective catalytic reduction reactor at the previous moment. T2,out The instantaneous flow rate of nitrogen oxides (NOx) at the outlet of the selective catalytic reduction reactor at the current moment. T1,out This represents the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor at the previous moment.

[0035] Step 109: Based on the rate of change of nitrogen oxides at the outlet of the selective catalytic reduction reactor, predict the trend of change of nitrogen oxide flow rate at the outlet of the selective catalytic reduction reactor, and obtain the outlet change trend.

[0036] Step 110: Adjust the ammonia flow rate injected into the selective catalytic reduction reactor according to the inlet change trend and the outlet change trend, so as to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0037] In a specific application example, if the inlet or outlet change trend exceeds a set threshold for a continuous period of time, the opening of the controller is increased until both the inlet and outlet change trends are less than the set threshold, at which point the opening of the controller is decreased. The controller is used to regulate the ammonia flow rate injected into the selective catalytic reduction reactor.

[0038] Specifically, the future trend of nitrogen oxide (NOx) changes is determined based on the magnitude of the rate of change. When the rate of change of NOx continuously exceeds a certain range and persists for a certain period of time (generally 10 seconds depending on the actual operating conditions of the unit), it is judged as a sustained large-scale change. When a sustained large-scale change (increase or decrease) is judged to occur, the regulation system responds promptly to ensure a stable change in NOx at the total outlet.

[0039] For special operating conditions in thermal power plants, such as the start-up and shutdown of coal mills and the fact that the total amount of nitrogen oxides at the outlet is higher than the nitrogen oxide flow rate at the SCR outlet for a long time, the adjustment and control are carried out through steps 106 to 110.

[0040] Specifically, during the start-up and shutdown of the coal mill, the increase or decrease in primary air volume causes a large instantaneous change in the oxygen content in the flue gas. The calculated NOx at the SCR inlet / outlet changes significantly. The regulating system predicts the trend and magnitude of NOx changes before and after the process, and quickly increases or decreases the regulator opening to adjust the NH3 supply in advance to adapt to the changes in the system.

[0041] After the coal mill starts, if the rate of change of nitrogen oxides exceeds +0.1%, the regulator command increases; conversely, when the coal mill stops, if the rate of change of nitrogen oxides is less than -0.1%, the regulator output command decreases. When the total outlet NOx is higher than the SCR outlet NOx for an extended period, the control system automatically decreases the setpoint; conversely, it automatically increases the setpoint.

[0042] like Figure 2 As shown, the NH3 setting correction is performed based on the instantaneous NOx flow rate at the SCR outlet and the NOx setpoint at the outlet, and the ammonia setting correction amount is determined; the instantaneous NOx flow rate is calculated based on the NOx flow rate at the SCR inlet, the flue gas flow rate of the generator set, and the oxygen content; the NOx trend is predicted at the SCR inlet based on the NOx flow rate at the SCR inlet; the NOx trend is predicted at the SCR outlet based on the NOx flow rate at the SCR outlet; based on the above data, the NH3 flow rate injected into the SCR reactor is adjusted by controlling the actuator through the drive unit.

[0043] This application improves the response capability of the control system when the load changes by predicting the change trend of NOx at the SCR inlet / outlet, overcomes the large delay in NOx measurement and chemical reaction process, and provides targeted control for the working conditions of large changes in outlet NOx during the start-up and shutdown of the coal mill. The regulating system will act in advance to ensure that NOx does not deviate from the set value during the process, which is convenient for maintenance personnel.

[0044] Specifically, this application demonstrates a strong ability to respond to changes in load and operating conditions. When significant disturbances occur in the boiler combustion conditions, it can ensure that the total outlet NOx value remains within 40±5%. When the load is stable, the outlet NOx value remains within 40±3. The regulating system automatically predicts the trend and magnitude of NOx changes during the start-up and shutdown of the coal mill, and takes adjustment actions in advance to prevent NOx values ​​from exceeding the standard or becoming too low. By predicting the trend of NOx changes at the SCR inlet / outlet, the regulating system takes adjustment actions in advance to overcome disturbances in the boiler combustion system and the large hysteresis of NOx.

[0045] Based on the same inventive concept, this application also provides an apparatus for implementing the method described above. The solution provided by this apparatus is similar to the solution described in the above method; therefore, specific limitations in one or more apparatus embodiments provided below can be found in the limitations of the method described above, and will not be repeated here.

[0046] In one exemplary embodiment, such as Figure 3 As shown, a nitrogen oxide flow control device for flue gas in thermal power plants is provided, comprising the following functional modules.

[0047] The data acquisition module 301 is used to collect the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor in real time during the operation of the thermal power plant.

[0048] The ammonia flow calculation module 302 is used to calculate the ammonia flow at the inlet of the selective catalytic reduction reactor based on the flue gas flow of the generator set, the oxygen content of the generator set, and the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor.

[0049] The first ammonia correction module 303 is used to correct the ammonia flow rate at the inlet of the selective catalytic reduction reactor according to the set correction amount of nitrogen oxides, so as to obtain the initial ammonia injection amount.

[0050] The second ammonia correction module 304 is used to correct the initial ammonia injection amount according to the set amplification factor and static deviation time to obtain the final ammonia injection amount.

[0051] The flow regulation module 305 is used to adjust the flow rate of ammonia injected into the selective catalytic reduction reactor according to the final ammonia injection amount, so as to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0052] The inlet rate determination module 306 is used to calculate the rate of change of nitrogen oxides at the inlet of the selective catalytic reduction reactor based on the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor at the current time and the previous time.

[0053] The inlet trend prediction module 307 is used to predict the trend of nitrogen oxide flow at the inlet of the selective catalytic reduction reactor based on the rate of change of nitrogen oxides at the inlet of the reactor, and thus obtain the inlet trend.

[0054] The outlet rate determination module 308 is used to collect the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor in real time, and calculate the rate of change of nitrogen oxides at the outlet of the selective catalytic reduction reactor based on the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor at the current time and the previous time.

[0055] The export trend prediction module 309 is used to predict the change trend of nitrogen oxide flow rate at the outlet of the selective catalytic reduction reactor based on the rate of change of nitrogen oxides at the outlet of the reactor, and thus obtain the export change trend.

[0056] The ammonia regulating module 310 is used to adjust the ammonia flow rate injected into the selective catalytic reduction reactor according to the inlet change trend and the outlet change trend, so as to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

[0057] In one exemplary embodiment, a computer device is 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-described method embodiments.

[0058] In this application, all actions to acquire signals, information, or data are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with the authorization granted by the owner of the relevant device.

[0059] Those skilled in the art will understand that all or part of the processes in 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. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0060] 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 specification.

[0061] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that, The method comprises: During the operation of the thermal power plant, the flue gas flow of the generator set, the oxygen content of the generator set, and the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor are collected in real time; According to the flue gas flow of the generator set, the oxygen content of the generator set, and the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor, the ammonia flow at the inlet of the selective catalytic reduction reactor is calculated; According to the nitrogen oxide setting correction amount, the ammonia flow at the inlet of the selective catalytic reduction reactor is corrected to obtain a preliminary ammonia injection amount; According to the set amplification coefficient and static deviation time, the preliminary ammonia injection amount is corrected to obtain a final ammonia injection amount; According to the final ammonia injection amount, the ammonia flow injected into the selective catalytic reduction reactor is adjusted to control the flow of nitrogen oxides in the selective catalytic reduction reactor.

2. The method of claim 1, wherein the method is a method of controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that, According to the flue gas flow of the generator set, the oxygen content of the generator set, and the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor, the ammonia flow at the inlet of the selective catalytic reduction reactor is calculated, comprising: According to the oxygen content of the generator set, the formula O c =21 / (1-O is used to calculate the oxygen content conversion value; wherein O c is the oxygen content conversion value, and O is the oxygen content of the generator set. According to the oxygen conversion value, the flue gas flow of the generator set and the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor, a formula NOX z =G O c The total amount of nitrogen oxides at the inlet of the selective catalytic reduction reactor is calculated; wherein NOX z is the total amount of nitrogen oxides at the inlet of the selective catalytic reduction reactor, NOX f is the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor, and G is the flue gas flow of the generator set. According to the total amount of nitrogen oxides at the inlet of the selective catalytic reduction reactor, a pre-constructed relationship between the total amount of nitrogen oxides and the ammonia flow is used to determine the ammonia flow at the inlet of the selective catalytic reduction reactor.

3. The method of claim 1, wherein the method is a method of controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that, According to the nitrogen oxide setting correction amount, the ammonia flow at the inlet of the selective catalytic reduction reactor is corrected to obtain a preliminary ammonia injection amount, comprising: The nitrogen oxide setting correction amount is converted into an ammonia setting correction amount; The ammonia setting correction amount and the ammonia flow at the inlet of the selective catalytic reduction reactor are summed to obtain a preliminary ammonia injection amount.

4. The method of claim 1, wherein the method is a method of controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that, According to the set amplification coefficient and static deviation time, the preliminary ammonia injection amount is corrected to obtain a final ammonia injection amount, comprising: According to the set amplification coefficient and static deviation time, ammonia correction amount is calculated by formula A c =K P (1+1 / T S ) ; wherein, A c is ammonia correction amount, K p is amplification coefficient, and T S is static deviation time. The ammonia correction amount and the preliminary ammonia injection amount are summed to obtain a final ammonia injection amount.

5. The method of claim 1, wherein the method is a method of controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that, The method further comprises: According to the instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor at the current time and the previous time, the change rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor is calculated; According to the change rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor, the change trend of the nitrogen oxide flow at the inlet of the selective catalytic reduction reactor is predicted to obtain an inlet change trend; The instantaneous flow of nitrogen oxides at the outlet of the selective catalytic reduction reactor is collected in real time, and according to the instantaneous flow of nitrogen oxides at the outlet of the selective catalytic reduction reactor at the current time and the previous time, the change rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor is calculated; According to the change rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor, the change trend of the nitrogen oxide flow at the outlet of the selective catalytic reduction reactor is predicted to obtain an outlet change trend; According to the inlet change trend and the outlet change trend, the ammonia flow injected into the selective catalytic reduction reactor is adjusted to control the flow of nitrogen oxides in the selective catalytic reduction reactor.

6. The method of claim 5, wherein the flow rate of the NOx in the flue gas of the thermal power plant is controlled by adjusting the flow rate of the ammonia in the aqueous solution of ammonia. The rate of change of nitrogen oxides at the inlet of the selective catalytic reduction reactor is calculated using the formula (NOX T2,in -NOX T1,in e ST) / e ST ) NOx T2,out -NOx T1,out ) / (T2- e ST / e ST ) to calculate the rate of change of nitrogen oxides at the outlet of the selective catalytic reduction reactor; NOX (T2) = NOX (T1) + ST * (NOX (T2) - NOX (T1)) / T1 T2,in instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor at the current time, NOX T1,in instantaneous flow of nitrogen oxides at the inlet of the selective catalytic reduction reactor at the previous time, NOX T2,out instantaneous flow of nitrogen oxides at the outlet of the selective catalytic reduction reactor at the current time, NOX T1,out instantaneous flow of nitrogen oxides at the outlet of the selective catalytic reduction reactor at the previous time.

7. The method of claim 5, wherein the flow rate of the NOx is controlled by adjusting the flow rate of the ammonia. According to the inlet change trend and the outlet change trend, the ammonia flow injected into the selective catalytic reduction reactor is adjusted, comprising: If the inlet variation trend or the outlet variation trend exceeds a set threshold for a certain time, the opening of the regulator is increased until the inlet variation trend and the outlet variation trend are both less than the set threshold, and then the opening of the regulator is decreased; the regulator is used to adjust the ammonia flow rate injected into the selective catalytic reduction reactor.

8. A device for controlling the flow of nitrogen oxides in the flue gas of a thermal power plant, characterized in that it comprises: The device executes the method for controlling the flow rate of nitrogen oxides in flue gas of a thermal power plant according to any one of claims 1-7, and the device comprises: a data acquisition module, configured to acquire, in real time during operation of the thermal power plant, the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor; an ammonia flow rate calculation module, configured to calculate the ammonia flow rate at the inlet of the selective catalytic reduction reactor according to the flue gas flow rate of the generator set, the oxygen content of the generator set, and the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor; a first ammonia correction module, configured to correct the ammonia flow rate at the inlet of the selective catalytic reduction reactor according to a set correction amount of nitrogen oxides, to obtain a preliminary ammonia injection amount; a second ammonia correction module, configured to correct the preliminary ammonia injection amount according to a set amplification coefficient and a static deviation time, to obtain a final ammonia injection amount; a flow rate adjustment module, configured to adjust the ammonia flow rate injected into the selective catalytic reduction reactor according to the final ammonia injection amount, to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

9. The device according to claim 8, characterized in that, The device further comprises: an inlet rate determination module, configured to calculate the variation rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor according to the instantaneous flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor at a current time and a previous time; an inlet trend prediction module, configured to predict the variation trend of the flow rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor according to the variation rate of nitrogen oxides at the inlet of the selective catalytic reduction reactor, to obtain an inlet variation trend; an outlet rate determination module, configured to acquire, in real time, the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor, and calculate the variation rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor according to the instantaneous flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor at a current time and a previous time; an outlet trend prediction module, configured to predict the variation trend of the flow rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor according to the variation rate of nitrogen oxides at the outlet of the selective catalytic reduction reactor, to obtain an outlet variation trend; an ammonia adjustment module, configured to adjust the ammonia flow rate injected into the selective catalytic reduction reactor according to the inlet variation trend and the outlet variation trend, to control the flow rate of nitrogen oxides in the selective catalytic reduction reactor.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for controlling the flow rate of nitrogen oxides in flue gas of a thermal power plant according to any one of claims 1-7.

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