Thermoelectric denitration precise ammonia injection zoning measurement ammonia injection frequency modulation cooperative control system

Abstract

The invention relates to the field of thermoelectric denitration, and discloses a thermoelectric denitration precise ammonia spraying zoning measurement ammonia spraying frequency modulation cooperative control system, which comprises an ammonia spraying amount optimization module used for establishing a model, predicting the denitration effect under different ammonia spraying amounts by using the model, researching the relationship between the ammonia spraying amount and the denitration efficiency, and verifying through actual operation data, determining the optimal ammonia spraying amount; and the ammonia spraying mode optimization module is used for contrastively analyzing the influence of different ammonia spraying modes on the denitration efficiency, researching ammonia distribution characteristics under different ammonia spraying modes through experiments, and optimizing the ammonia spraying modes. Through cooperative operation of all the modules, during denitration, the ammonia spraying frequency is controlled according to the concentration of a denitration inlet and a denitration outlet, through the improved SNCR technology, NOx concentration is pre-removed, meanwhile, ammonia-nitrogen wastewater is cooperatively treated, harmless resource utilization of the ammonia-nitrogen wastewater is achieved, and an in-situ multi-point synchronous direct measurement technology is adopted.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoelectric denitration, and in particular to a thermoelectric denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system. Background Art

[0002] Thermal power denitrification is a technology used to control and reduce nitrogen oxide (NOx) emissions. It is widely used in thermal power plants and industrial boilers. Thermal power denitrification uses ammonia (NH3) as a reducing agent. Under the action of a catalyst, nitrogen oxides are reduced to nitrogen (N2) and water (H2O), thereby effectively reducing air pollution and complying with environmental regulations.

[0003] As national environmental laws and regulations and emission standards become increasingly stringent, traditional single denitrification technology can no longer meet the country's requirements for denitrification emissions from thermal power plants. Excessive ammonia injection will lead to excessive consumption of urea or liquid ammonia, partial blockage of the catalyst, ash blockage in the air preheater, and increased plant power consumption. When the amount of ammonia injection is insufficient, the environmental protection indicators will fail to meet the standard due to excessive nitrogen oxides. Therefore, a precise ammonia injection zone measurement and ammonia injection frequency modulation coordinated control system for thermal power denitrification is proposed to solve the above problems. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a thermal power denitrification precise ammonia injection zone measurement and ammonia injection frequency modulation coordinated control system to solve the problems that the traditional single denitrification technology can no longer meet the national requirements for denitrification emissions in thermal power plants, and excessive ammonia injection will lead to excessive consumption of urea or liquid ammonia, partial blockage of the catalyst, ash blockage in the air preheater, and increased plant power consumption. When the ammonia injection amount is insufficient, the environmental protection indicators will fail to meet the standards due to excessive nitrogen oxides.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a thermal power denitrification precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system, comprising:

[0006] Ammonia injection amount optimization module: used to establish a model and use the model to predict the denitrification effect under different ammonia injection amounts, study the relationship between ammonia injection amount and denitrification efficiency, and verify it through actual operation data to determine the optimal ammonia injection amount;

[0007] Ammonia injection mode optimization module: used to compare and analyze the effects of different ammonia injection modes on denitrification efficiency, and to study the ammonia distribution characteristics under different ammonia injection modes through experiments to optimize the ammonia injection mode;

[0008] Measurement location optimization module: used for zone monitoring and coordination with ammonia injection devices, layout of multi-point sampling probe positions and depths, and calculation of the average NOx concentration of the section;

[0009] Denitrification inlet and outlet measurement module: used to monitor the parameters of denitrification inlet and outlet in real time, and transmit the parameters to the ammonia injection optimization module;

[0010] Auxiliary module: used to generate vortex and accelerate the mixing of original flue gas and ammonia.

[0011] Preferably, the ammonia injection amount optimization module includes a modeling unit, a prediction unit, and an optimization unit. The modeling unit is used to establish a corresponding model, and the model includes a kinetic model of denitrification reaction, a dynamic prediction model of NOx emissions from coal-fired power plants, and an adaptive algorithm model. The prediction unit is used to predict the denitrification effect under different ammonia injection amounts according to the corresponding model, and to study the relationship between the ammonia injection amount and the denitrification efficiency. The optimization unit is used to verify through actual operation data, and adjust the ammonia injection frequency according to real-time concentration data to determine the optimal ammonia injection amount.

[0012] Preferably, the optimization unit includes a self-learning optimization subunit, a data fusion subunit, a human-computer interaction subunit, and an early warning subunit. The self-learning optimization subunit is used to adaptively adjust the ammonia injection amount and frequency based on historical data. The data fusion subunit is used to fuse data from the measurement and ammonia injection control modules to generate comprehensive decision-making information. The human-computer interaction subunit is used to provide an interactive interface between the operator and the system, monitor and adjust system parameters, and the early warning subunit is used to monitor the system operation status in real time, determine whether it exceeds the set range, and trigger an alarm when an abnormality is detected.

[0013] Preferably, the ammonia spraying mode optimization module includes a measuring unit and a testing unit. The measuring unit is used to measure and analyze the effects of different ammonia spraying modes on the denitrification efficiency. The ammonia spraying modes include atomized ammonia spraying, aerosol ammonia spraying, and grid ammonia spraying. The testing unit is used to adjust the ammonia spraying mode according to the ammonia distribution characteristics under different ammonia spraying modes.

[0014] Preferably, the measurement position optimization module includes a partition unit, a monitoring unit, and an ammonia injection device. The partition unit is used to arrange the position and depth of the multi-point sampling probe according to the uniform layout of the ammonia spray gun above the denitrification reactor, the distribution of multi-point sampling at the outlet of the denitrification reactor, and the distribution of the flue gas concentration field under 30%-100% load. The monitoring unit is used to perform real-time ammonia amount monitoring on each partition and calculate the average concentration of NOx in the section to achieve the goal of accurate measurement. The ammonia injection device includes an ammonia injection grid, and an electric regulating valve is provided on one side of the ammonia injection grid.

[0015] Preferably, the denitrification inlet and outlet measurement module includes an inlet measurement unit and an outlet measurement unit. The inlet measurement unit is used to set three in-situ direct measurement devices on each side of the denitrification inlet A / B, and form multi-point in-situ synchronous direct measurement by adding calibration and purge pipelines and procedures. In addition, the number of inlet meters arranged is reduced with the cooperation of the flue gas mixer, so as to quickly measure NOx at the inlet. The outlet measurement unit is used to set four in-situ direct measurement devices on each side of the denitrification outlet A / B, so as to construct the O2 and NOx concentration fields at the denitrification inlet and outlet in real time and quickly. The in-situ direct measurement device is a dual-cell thick-film zirconium oxide nitrogen oxide sensor.

[0016] The present invention provides a thermal power denitrification precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system. It has the following beneficial effects:

[0017] 1. The present invention controls the frequency of ammonia injection according to the concentration of the denitrification inlet and outlet during denitrification through the coordinated operation of various modules, and simultaneously pre-removes the NOx concentration through the improved SNCR technology, and coordinates the treatment of ammonia nitrogen wastewater, thereby realizing the harmless resource utilization of ammonia nitrogen wastewater. In addition, the present invention realizes the rapid and synchronous construction of the denitrification concentration field through the in-situ multi-point synchronous direct measurement technology, which greatly reduces the delay of denitrification control and provides technical support for the zoning leveling of denitrification under flexible operating conditions.

[0018] 2. The present invention is based on the precise control technology of ammonia injection based on operating condition prediction and machine self-learning. Through the total amount prediction + machine self-learning ammonia injection main valve and sub-valve collaborative control algorithm, automatic leveling of the NOx concentration field at the denitrification outlet is achieved; and through the "one-key leveling" semi-automatic rapid control strategy, this strategy can achieve rapid leveling of the NOx concentration field after combining the operating condition judgment, and the adjustment process is visual and controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a system architecture diagram of the thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system proposed by the present invention;

[0020] Figure 2 This is a schematic diagram of the ammonia injection amount optimization module architecture of the thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system proposed by the present invention;

[0021] Figure 3 This is an optimized unit architecture diagram of the thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system proposed by the present invention;

[0022] Figure 4 This is a module architecture diagram for optimizing the ammonia injection mode of the thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system proposed by the present invention;

[0023] Figure 5This is a measurement position optimization module architecture diagram of the thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system proposed by the present invention;

[0024] Figure 6 This is the architecture diagram of the denitrification import and export measurement module of the thermal power denitrification precise ammonia injection zone measurement and ammonia injection frequency modulation coordinated control system proposed in the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example:

[0027] Please refer to the attached Figure 1 The embodiment of the present invention provides a thermal power denitration precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system, including:

[0028] Ammonia injection amount optimization module: used to establish a model and use the model to predict the denitrification effect under different ammonia injection amounts, study the relationship between ammonia injection amount and denitrification efficiency, and verify it through actual operation data to determine the optimal ammonia injection amount;

[0029] Ammonia injection mode optimization module: used to compare and analyze the effects of different ammonia injection modes on denitrification efficiency, and to study the ammonia distribution characteristics under different ammonia injection modes through experiments to optimize the ammonia injection mode;

[0030] Measurement location optimization module: used for zone monitoring and coordination with ammonia injection devices, layout of multi-point sampling probe positions and depths, and calculation of the average NOx concentration of the section;

[0031] Denitrification inlet and outlet measurement module: used to monitor the denitrification inlet and outlet parameters in real time, and transmit the parameters to the ammonia injection optimization module;

[0032] Auxiliary module: used to generate vortex and accelerate the mixing of original flue gas and ammonia.

[0033] Specifically, by establishing a model, a corresponding basis is provided for subsequent prediction and optimization, and the model is used to predict the denitrification effect under different ammonia injection amounts, and the relationship between the ammonia injection amount and the denitrification efficiency is studied, so as to provide a reference for practical application, and verified by actual operation data, the optimal ammonia injection amount is determined, so as to achieve efficient denitrification; by comparing and analyzing the effects of different ammonia injection methods on the denitrification efficiency, a basis is provided for selecting the optimal ammonia injection method, and through experimental research on the ammonia distribution characteristics under different ammonia injection methods, the ammonia injection method is optimized to improve the denitrification efficiency; through zoning monitoring and coordinating with the ammonia injection device, the position and depth of the multi-point sampling probe are arranged to ensure the representativeness of the sample, and the section is calculated The average concentration of NOx can be measured accurately; the parameters of the denitrification inlet and outlet can be monitored in real time to provide accurate data support for the coordinated control optimization of ammonia injection; the mixing of the original flue gas and ammonia can be accelerated by generating vortices, thereby accelerating the mixing of the original flue gas and ammonia and improving the reaction efficiency; therefore, when denitrification is carried out, the frequency of ammonia injection is controlled according to the concentration of the denitrification inlet and outlet, thereby solving the problem that the traditional single denitrification technology can no longer meet the national requirements for denitrification emissions from thermal power plants, and excessive ammonia injection will lead to excessive consumption of urea or liquid ammonia, partial blockage of the catalyst, ash blockage in the air preheater, and increased power consumption of the plant. When the amount of ammonia injection is insufficient, the environmental protection indicators will fail to meet the standards due to excessive nitrogen oxides.

[0034] Please refer to the attached Figure 2 , Attachment Figure 3 The ammonia injection optimization module includes a modeling unit, a prediction unit, and an optimization unit. The modeling unit is used to establish a corresponding model, which includes a kinetic model of denitrification reaction, a dynamic prediction model of NOx emissions from coal-fired power plants, and an adaptive algorithm model. The prediction unit is used to predict the denitrification effect under different ammonia injection amounts according to the corresponding model, and study the relationship between the ammonia injection amount and the denitrification efficiency. The optimization unit is used to verify through actual operation data, and adjust the ammonia injection frequency according to real-time concentration data to determine the optimal ammonia injection amount; the optimization unit includes a self-learning optimization subunit, a data fusion subunit, a human-computer interaction subunit, and an early warning subunit. The self-learning optimization subunit is used to adaptively adjust the ammonia injection amount and frequency based on historical data. The data fusion subunit is used to fuse data from the measurement and ammonia injection control modules to generate comprehensive decision-making information. The human-computer interaction subunit is used to provide an interactive interface between the operator and the system, monitor and adjust system parameters, and the early warning subunit is used to monitor the system operation status in real time, determine whether it exceeds the set range, and trigger an alarm when an abnormality is detected.

[0035] Specifically, a kinetic model of the denitrification reaction, a dynamic prediction model for NOx emissions, and an adaptive algorithm model are established to provide a theoretical basis for subsequent prediction and optimization. By predicting the denitrification effect under different ammonia injection amounts based on the model, the relationship between the ammonia injection amount and the denitrification efficiency is studied to provide a reference for practical applications. The model is verified through actual operation data, the ammonia injection frequency is adjusted in real time, and the optimal ammonia injection amount is determined to achieve efficient denitrification.

[0036] Please refer to the attached Figure 4 The ammonia injection mode optimization module includes a measuring unit and a test unit. The measuring unit is used to measure and analyze the influence of different ammonia injection modes on the denitrification efficiency. The ammonia injection modes include atomized ammonia injection, aerosol ammonia injection, and grid ammonia injection. The test unit is used to adjust the ammonia injection mode according to the ammonia distribution characteristics under different ammonia injection modes.

[0037] Please refer to the attached Figure 5 The measurement position optimization module includes a partition unit, a monitoring unit, and an ammonia injection device. The partition unit is used to arrange the position and depth of the multi-point sampling probe according to the uniform layout of the ammonia spray gun above the denitrification reactor, the distribution of multi-point sampling at the outlet of the denitrification reactor, and the distribution of the flue gas concentration field under 30%-100% load. The monitoring unit is used to monitor the ammonia amount in each partition in real time and calculate the average concentration of NOx in the section to achieve the goal of accurate measurement. The ammonia injection device includes an ammonia injection grid, and an electric regulating valve is arranged on one side of the ammonia injection grid.

[0038] Specifically, the partition monitoring and the ammonia spraying device will greatly improve the accuracy of ammonia spraying control and a series of benefits for improving working conditions. Therefore, the partition division is critical. According to the uniform layout of the ammonia spray gun above the denitrification reactor and the distribution of multi-point sampling at the outlet of the denitrification reactor, the best solution is to measure the distribution of the flue gas concentration field under 30% to 100% load, and layout the position and depth of the multi-point sampling probe according to this concentration field. In general, it is difficult for enterprises to give a relatively accurate distribution of the concentration field. All our multi-point probes are basically arranged and evenly divided according to the geometric dimensions of the cross-section of the flue at the installation position. According to the size of the flue cross-sectional area, the partition area covered by each multi-point sampling probe is also different. According to the requirements of the enterprise, the single-side flue is planned to be measured in multiple partitions.

[0039] And through real-time monitoring of partitions, it can not only help control the upstream ammonia amount, but also calculate the average concentration of NOx in the section to achieve the goal of accurate measurement. Each partition is an independent monitoring unit, and each partition monitors complementary interference in real time. Compared with the extraction analysis system, it responds extremely quickly, and there is no risk of blockage and loss of measured materials due to extraction.

[0040] Please refer to the attached Figure 6The denitrification inlet and outlet measurement modules include an inlet measurement unit and an outlet measurement unit. The inlet measurement unit is used to set up three in-situ direct measurement devices on the A / B side of the denitrification inlet. By adding calibration and purge pipelines and procedures, multi-point in-situ synchronous direct measurement is formed. In cooperation with the flue gas mixer, the number of inlet meters is reduced to quickly measure NOx at the inlet. The outlet measurement unit is used to set up four in-situ direct measurement devices on the A / B side of the denitrification outlet. The O2 and NOx concentration fields of the denitrification inlet and outlet are constructed in real time and quickly. The in-situ direct measurement device is a double-cell thick-film zirconium oxide nitrogen oxide sensor.

[0041] The following is further introduced in conjunction with specific embodiments:

[0042] Embodiment 1:

[0043] On the basis of retaining the low-nitrogen burner, an ammonia injection branch pipe is installed at the flame deflection angle position on the top of the furnace or at the inlet flue of the economizer, and the waste water discharged from the urea hydrolyzer is sprayed directly into the flue. The waste heat of the flue gas is used for in-situ SNCR denitrification or pyrolysis to produce ammonia. When the NOx concentration at the inlet of the SCR denitrification is too high, urea solution can be sprayed at the flame deflection angle in advance to reduce the NOx concentration at the inlet of the SCR denitrification.

[0044] The vortex mixing (vortex forced mixer) technology is widely used in power plants under the State Power Corporation. Ammonia is directly sprayed on the baffle with an inclined angle to generate a vortex, and the original flue gas and ammonia are mixed. The pressure difference of 300MW and 600MW units in the deployed power plants is about 30-50Pa. There is no application record for 1000MW units, and the design pressure difference is less than 60Pa. According to the layout of the 600MW unit, 4-6 mixers can be arranged for ammonia spraying in a single SCR flue of the 1000MW unit, and an electric regulating valve can be installed on the ammonia spray pipe to realize zoned ammonia spraying. The double-cell thick-film zirconium oxide nitrogen oxide sensor can realize in-situ direct measurement of NOx. The oxygen concentration on both sides of the zirconium oxide is different at high temperature, and a potential difference will be generated at both ends. The oxygen concentration is fed back to the controller according to the potential difference to calculate the current nitrogen oxide NOx concentration. From sampling in the flue to analyzing the data, the response time is within 10s, which can effectively solve the long lag time of traditional denitrification sampling and analysis devices. It has been applied in Zhenhai Power Plant and Changxing Power Plant. During the investigation, Changxing Power Plant had been running stably for one month. This plan plans to set up multiple in-situ direct measurement devices at the denitrification inlet by region, and form a multi-point in-situ synchronous direct measurement system by adding calibration and purge pipelines and procedures. With the cooperation of the flue gas mixer, the denitrification inlet can achieve inter-layer stability of the concentration field, reduce the number of inlet meters, and realize rapid measurement of inlet NOx. Sampling grids are set up at the denitrification outlet by layer and zone to form a multi-point in-situ synchronous direct measurement system. The O2 and NOx concentration fields at the denitrification inlet and outlet are constructed in real time and quickly to provide a decision-making basis for zoned ammonia injection control.

[0045] The preliminary plan for zoning measurement is: the denitrification outlet is divided into four zones, the denitrification inlet is divided into three zones, and three in-situ direct measurement devices are set on the A / B side of the denitrification inlet, and four in-situ direct measurement devices are set on the A / B side of the denitrification outlet. The double-cell thick-film zirconium oxide nitrogen oxide flue gas analyzer is easy to move and can be arranged in different positions according to different plans during the test.

[0046] The precise control technology of ammonia injection based on operating condition prediction and machine self-learning has established a dynamic prediction model of NOx emissions from coal-fired power plants using big data modeling and particle swarm optimization algorithm, laying the foundation for further research on the precise control of ammonia injection. The SCR flue gas denitrification system was modeled using the recursive least squares method with a variable forgetting factor, and the application effect of the adaptive algorithm in the denitrification system was further studied. However, there have been no reports on the application of control algorithms for coordinated ammonia injection grids and ammonia injection main valves. Thanks to the low latency and synchronous construction of concentration fields of dual-cell thick-film zirconia in-situ partitioned measurement, this scheme adopts a coupling control strategy of automatic leveling and semi-automatic one-button leveling.

[0047] The automatic leveling strategy adopts the total amount prediction + machine self-learning ammonia injection main valve and sub-valve collaborative control algorithm, which can predict the NOx mass flow rate at the denitrification inlet according to load, coal consumption, air volume and other data, and guide the adjustment of the main valve and sub-valve; and the ammonia injection main valve and sub-valve collaborative control algorithm is used to coordinate the total amount adjustment and zone leveling to truly achieve the consistency of denitrification control, and the non-uniformity of the NOx concentration field at the denitrification outlet (relative standard deviation, the same below) is ≤15%. In order to achieve rapid leveling, this solution also sets up a "one-button leveling" semi-automatic control strategy. The operator can perform one-button leveling based on the working condition judgment and set the expected average NOx concentration; after the work starts, the system matches the working condition, proposes the preset valve opening from the self-learning database, and levels the NOx concentration field at the denitrification outlet through cyclic adjustment, with a non-uniformity of ≤5%; the system can be exited at any time.

[0048] The denitrification optimization control process route of the present invention is improved SNCR pre-removal technology + flue gas premixing technology + in-situ multi-point synchronous direct measurement technology + precise ammonia injection control technology based on working condition prediction and machine self-learning. Through the pre-removal of NOx, the removal pressure of the denitrification reactor is reduced, the ammonia injection pressure is reduced, and the harmless resource utilization of ammonia nitrogen wastewater in the whole plant is realized. Through flue gas premixing + strong mixing after ammonia injection + rectification, the mixing of ammonia and flue gas is improved to avoid biased flow. Through the in-situ multi-point synchronous direct measurement technology, the rapid synchronous construction of the denitrification inlet and outlet concentration fields is realized, and the denitrification ammonia injection control capability is improved. The self-learning main valve and sub-valve collaborative control system is used to achieve precise leveling of the denitrification outlet concentration field; by setting the "one-key leveling" function, the rapid response of the denitrification leveling work is achieved.

[0049] By improving the pre-removal technology of SNCR, it is expected to reduce the NOx concentration at the denitrification inlet to more than 50mg / m3 (standard dry basis, 6% O2, the same below). By improving the pre-removal technology of SNCR, the concentration of ammonia nitrogen wastewater is concentrated and used as a supplementary reducing agent to achieve harmless resource utilization of ammonia nitrogen wastewater (especially urea hydrolysis fixed discharge wastewater). A single unit is expected to treat 10-15t / h of ammonia nitrogen wastewater. Through the flue gas premixing technology, the unevenness between the denitrification flue gas layers is improved, and the uniform distribution of the denitrification inlet flow field is achieved, with an unevenness within 10%; the uniform distribution of the concentration between the denitrification inlet layers is achieved, with an unevenness within 5%. Through the in-situ multi-point synchronous direct measurement technology, the concentration field is quickly and synchronously constructed, reducing the response time to less than 20s. Based on the operating condition prediction and machine self-learning, the precise control technology of ammonia spraying can achieve the adaptability of the operating conditions of denitrification ammonia spraying, and improve the stability and rapid response of ammonia spraying control through prediction. Through this process package, the non-uniformity of NOx concentration field at the denitrification outlet can be within 15% and ammonia slip can be less than 3ppm under load fluctuation conditions (load change rate ≥ 2.0%); under stable load conditions (load change ≤ ± 1.0%), the non-uniformity of NOx concentration field at the denitrification outlet can be within 10% and ammonia slip can be less than 2ppm. Through this process package, the consumption of denitrification ammonia can be reduced by about 5%-20%, and the air preheater differential pressure rise rate can be reduced by more than 50%.

[0050] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Thermoelectric denitrification precise ammonia injection zone measurement ammonia injection frequency modulation coordinated control system is characterized by: include: Ammonia injection amount optimization module: used to establish a model and use the model to predict the denitrification effect under different ammonia injection amounts, study the relationship between ammonia injection amount and denitrification efficiency, and verify it through actual operation data to determine the optimal ammonia injection amount; Ammonia injection mode optimization module: used to compare and analyze the effects of different ammonia injection modes on denitrification efficiency, and to study the ammonia distribution characteristics under different ammonia injection modes through experiments to optimize the ammonia injection mode; Measurement location optimization module: used for zone monitoring and coordination with ammonia injection devices, layout of multi-point sampling probe positions and depths, and calculation of the average NOx concentration of the section; Denitrification inlet and outlet measurement module: used to monitor the denitrification inlet and outlet parameters in real time, and transmit the parameters to the ammonia injection optimization module.

2. According to claim 1, the precise ammonia injection zone measurement and ammonia injection frequency modulation coordinated control system for thermal power denitration is characterized by: The ammonia injection amount optimization module includes a modeling unit, a prediction unit, and an optimization unit. The modeling unit is used to establish a corresponding model, and the model includes a kinetic model of denitrification reaction, a dynamic prediction model of NOx emissions from a coal-fired power plant, and an adaptive algorithm model. The prediction unit is used to predict the denitrification effect under different ammonia injection amounts according to the corresponding model, and to study the relationship between the ammonia injection amount and the denitrification efficiency. The optimization unit is used to verify through actual operation data, and adjust the ammonia injection frequency according to real-time concentration data to determine the optimal ammonia injection amount.

3. The precise ammonia injection and frequency modulation coordinated control system for thermal power denitration according to claim 2 is characterized by: The optimization unit includes a self-learning optimization subunit, a data fusion subunit, a human-computer interaction subunit, and an early warning subunit. The self-learning optimization subunit is used to adaptively adjust the ammonia injection amount and frequency based on historical data. The data fusion subunit is used to fuse data from the measurement and ammonia injection control modules to generate comprehensive decision-making information. The human-computer interaction subunit is used to provide an interactive interface between the operator and the system, monitor and adjust system parameters, and the early warning subunit is used to monitor the system operation status in real time, determine whether it exceeds the set range, and trigger an alarm when an abnormality is detected.

4. The precise ammonia injection and frequency modulation coordinated control system for thermal power denitration according to claim 1 is characterized by: The ammonia spraying mode optimization module includes a measuring unit and a testing unit. The measuring unit is used to measure and analyze the influence of different ammonia spraying modes on the denitrification efficiency. The ammonia spraying modes include atomized ammonia spraying, aerosol ammonia spraying, and grid ammonia spraying. The testing unit is used to adjust the ammonia spraying mode according to the ammonia distribution characteristics under different ammonia spraying modes.

5. According to claim 1, the precise ammonia injection zone measurement and ammonia injection frequency modulation coordinated control system for thermal power denitrification is characterized by: The measurement position optimization module includes a partition unit, a monitoring unit, and an ammonia injection device. The partition unit is used to arrange the position and depth of the multi-point sampling probe according to the uniform layout of the ammonia spray gun above the denitrification reactor, the distribution of multi-point sampling at the outlet of the denitrification reactor, and the distribution of the flue gas concentration field under 30%-100% load. The monitoring unit is used to perform real-time ammonia amount monitoring on each partition and calculate the average concentration of NOx in the section to achieve the goal of accurate measurement. The ammonia injection device includes an ammonia injection grid, and an electric regulating valve is arranged on one side of the ammonia injection grid.

6. The precise ammonia injection and frequency modulation coordinated control system for thermal power denitration according to claim 1 is characterized by: The denitrification inlet and outlet measurement module includes an inlet measurement unit and an outlet measurement unit. The inlet measurement unit is used to set three in-situ direct measurement devices on each side of the denitrification inlet A / B. By adding calibration and purge pipelines and procedures, multi-point in-situ synchronous direct measurement is formed, and with the cooperation of the flue gas mixer, the number of inlet meters arranged is reduced to quickly measure NOx at the inlet. The outlet measurement unit is used to set four in-situ direct measurement devices on each side of the denitrification outlet A / B to construct the denitrification inlet and outlet O2 and NOx concentration fields in real time and quickly. The in-situ direct measurement device is a dual-cell thick-film zirconium oxide nitrogen oxide sensor.

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