Ammonia spraying control device and control system for flue gas SCR (Selective Catalytic Reduction) denitration

Abstract

The utility model relates to the technical field of flue gas SCR denitration, in particular to an ammonia spraying control device and control system for flue gas SCR denitration, the device comprises an ammonia spraying header pipe, one side of the ammonia spraying header pipe is provided with a subarea ammonia spraying component, the outer surface of a branch header pipe is provided with a shunt pipe A in a penetrating mode, and the shunt pipe A is provided with an air inlet. And shunting pipes B are mounted on the outer surface of the branch header pipe and on one side of the shunting pipe A in a penetrating manner, and transverse connecting pipes are fixedly mounted in the multiple groups of shunting pipes B and shunting pipes A. Ammonia gas is uniformly distributed in the reactor, so that the ammonia-nitrogen molar ratio in the reactor is uniform, and the SCR denitration efficiency is improved; the rotating shafts in one group drive the rotating shafts in other groups to rotate; according to the system, a basic ammonia injection dynamic zoning optimization control model is built, and zoning regulating valve control and online closed-loop control of a main valve of zoning dynamic ammonia injection of the denitration system are achieved.

Description

Technical Field

[0001] This utility model relates to the field of flue gas SCR denitrification technology, specifically to an ammonia injection control device and control system for flue gas SCR denitrification. Background Technology

[0002] SCR (Selective Catalytic Reduction) denitrification technology in thermal power units is a method used to reduce nitrogen oxides (NOx). X Mature and efficient environmental protection technologies for nitrogen oxide emissions are crucial. As major energy producers, thermal power plants often emit large amounts of nitrogen oxides, which not only pollute the atmosphere but may also contribute to acid rain formation. Therefore, the application of SCR (Selective Catalytic Reduction) denitrification technology in thermal power units is extremely important.

[0003] Existing ammonia injectors are typically installed in the upper-middle part of the reaction tower (SCR reactor), at a certain height above the catalyst bed, to ensure that ammonia gas can react uniformly with NO in the flue gas. X While thorough mixing is important, during long-term use, the nozzles of the ammonia injector may become clogged by dust, ash, or catalyst particles in the flue gas. This can lead to uneven ammonia injection or insufficient injection volume, resulting in excessively high or low ammonia concentrations in some areas. This can affect the denitrification effect and cause inaccurate control of the ammonia injection volume, thus impacting the denitrification efficiency of the flue gas.

[0004] Based on this, we found that current environmental standards have relatively low emission limits, while emission monitoring is becoming increasingly stringent. Excessive ammonia injection not only increases operating costs but also adversely affects downstream equipment such as preheaters. Conversely, insufficient ammonia injection leads to excessive emissions. Therefore, a stable supply of NOx at the export level is crucial. X An automatic control system for emission data is also essential. Utility Model Content

[0005] The purpose of this invention is to provide an ammonia injection control device and control system for flue gas SCR denitrification, in order to solve the problem mentioned in the background art that the nozzle of the ammonia injector will be blocked, resulting in uneven ammonia injection or insufficient injection volume, and at the same time establish an automatic control system to stably maintain emission values.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an ammonia injection control device for flue gas SCR denitrification, comprising an ammonia injection main pipe, wherein a partitioned ammonia injection component is installed on one side of the ammonia injection main pipe, and multiple sets of partitioned ammonia injection components are provided, wherein a cleaning component is installed on one side of each set of partitioned ammonia injection components.

[0007] The zoned ammonia spraying component includes an inverted L-shaped branch pipe and a secondary branch main pipe that runs through one end of the inverted L-shaped branch pipe. A branch pipe A runs through the outer surface of the secondary branch main pipe, and a branch pipe B runs through the outer surface of the secondary branch main pipe and on one side of the branch pipe A. Horizontal connecting pipes are fixedly installed inside the multiple branch pipes B and A, and multiple sets of horizontal connecting pipes are provided. Spray holes are opened at the top of the multiple branch pipes B and A, and the spray holes are located at the intersection of the horizontal connecting pipes with the branch pipes B and A.

[0008] Preferably, a pneumatic regulating valve and an ultrasonic flow meter are installed at the middle end of the inverted L-shaped diverter, and the pneumatic regulating valve is located on one side of the ultrasonic flow meter.

[0009] Preferably, a dustproof mesh is installed inside the nozzle, and a rotating hole is opened on the outer surface of the diverter pipe A, with the rotating hole located on one side of the nozzle.

[0010] Preferably, the cleaning component includes an outer protective frame installed on one side of the outer surface of the diversion pipe A. The outer protective frame is provided with a rotating shaft and a gear. The gear is installed on the outer surface of the rotating shaft, and one end of the rotating shaft is inserted into the rotating hole. One end of the rotating shaft passes through the interior of the horizontal pipe. The number of rotating shafts, motors and horizontal pipes is the same. One end of one set of the rotating shafts is equipped with a motor, which is located inside the outer protective frame. Chains are connected to the outer surfaces of multiple sets of gears.

[0011] Preferably, an outer fixed block is installed on the outer surface of the rotating shaft, and an inverted T-shaped groove is opened inside the top of the outer fixed block. A compression spring is installed at the bottom of the inverted T-shaped groove, and a movable block is installed on the inner side of the inverted T-shaped groove.

[0012] Preferably, the movable block includes a connecting strip and a bottom sliding plate installed at the bottom end of the connecting strip, a semi-circular plate is installed at the top end of the connecting strip, and a brush layer is installed on the outer surface of the semi-circular plate.

[0013] A control system for an ammonia injection control device for flue gas SCR denitrification, as described above, includes an optimization zoning module, a zoning measurement module, and a zoning control module.

[0014] The optimized zoning module includes multiple reactors, each reactor inlet is set up with five zones, and each zone is equipped with a pneumatic regulating valve and a flow meter for adjusting and monitoring the precise ammonia injection in each zone.

[0015] The partition measurement module includes an analyzer installed at the outlet of each reactor. The analyzer performs rotational measurements on the five partitions at the inlet of the reactor. Each partition's sampling tube is equipped with a measuring valve. The measuring valve switches the sampling tubes of each partition to the measuring pool through the partition control module, and the measurement is performed by the analyzer.

[0016] The zonal control module is used to carry the precision ammonia injection control software installed in the ICS, and to communicate with the DCS system to obtain data from the denitrification CEMS system and boiler operation data, so as to complete the zonal regulating valve control and the online closed-loop control of the main valve for dynamic ammonia injection in the denitrification system.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. The ammonia injection control device for flue gas SCR denitrification described in this utility model divides ammonia gas through multiple sets of inverted L-shaped diversion pipes, and further divides ammonia gas by multiple sets of diversion pipes B and horizontal pipes and diversion pipes A, so as to evenly distribute ammonia gas inside the reactor, promote the uniform ammonia-nitrogen molar ratio in the reactor, and improve the denitrification efficiency of SCR.

[0019] 2. The ammonia injection control device for flue gas SCR denitrification described in this utility model involves a motor driving a set of rotating shafts to rotate, which in turn drives other sets of rotating shafts to rotate. The brush layer cleans the dustproof net, removing impurities from the mesh of the dustproof net to facilitate the normal injection of ammonia.

[0020] 3. The ammonia injection control system for flue gas SCR denitrification described in this utility model combines a basic dynamic zoning optimization control model for ammonia injection. Through advanced artificial intelligence algorithms, it can realize the zoning regulating valve control and the online closed-loop control of the main valve for dynamic ammonia injection in the denitrification system. The system is reasonably designed, the method is simple, the control is accurate and reliable, the response speed is fast, it can meet multiple adjustments and has high adaptability and adjustment range, and has very good promotion value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0022] Figure 2 This is a three-dimensional structural diagram of the partitioned ammonia spraying component of this utility model;

[0023] Figure 3 For the present utility model Figure 1 Enlarged view of point A in the middle;

[0024] Figure 4 This is a three-dimensional structural diagram of the outer fixed block and the movable block of this utility model;

[0025] Figure 5 This is a schematic diagram of the overall modular structure of the ammonia injection system of this utility model;

[0026] In the diagram: 1. Ammonia injection main pipe; 2. Zoned ammonia injection component; 21. Inverted L-shaped branch pipe; 22. Pneumatic regulating valve; 23. Ultrasonic flow meter; 24. Sub-branch main pipe; 25. Branch pipe A; 26. Branch pipe B; 27. Spray hole; 271. Dustproof net; 28. Horizontal pipe; 29. ​​Rotary hole; 3. Cleaning component; 31. Outer protective frame; 32. Motor; 33. Rotating shaft; 34. Gear; 35. Chain; 36. Outer fixed block; 361. Inverted T-shaped slide groove; 362. Compression spring; 37. Movable block; 371. Connecting strip; 372. Bottom slide plate; 373. Semicircular plate; 374. Brush layer. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Example 1: Please refer to Figure 1 and Figure 2 A flue gas SCR denitrification ammonia injection control device includes an ammonia injection main pipe 1, a partitioned ammonia injection component 2 installed on one side of the ammonia injection main pipe 1, the partitioned ammonia injection component 2 being provided in multiple sets, and a cleaning component 3 installed on one side of each of the multiple sets of partitioned ammonia injection components 2.

[0029] The ammonia injection component 2 includes an inverted L-shaped diversion pipe 21 and a secondary diversion main pipe 24 that runs through one end of the inverted L-shaped diversion pipe 21. A diversion pipe A25 is installed through the outer surface of the secondary diversion main pipe 24, and a diversion pipe B26 is installed through the outer surface of the secondary diversion main pipe 24 and on one side of the diversion pipe A25. A horizontal pipe 28 is fixedly installed inside the multiple diversion pipes B26 and A25, and multiple sets of horizontal pipes 28 are provided. The top ends of the multiple diversion pipes B26 and A25 are all provided with spray holes 27, and the spray holes 27 are located at the intersection of the horizontal pipe 28 with the diversion pipes B26 and A25. The grid-like component composed of the diversion pipes A25, B26 and 28 can uniformly divert ammonia gas.

[0030] A pneumatic regulating valve 22 and an ultrasonic flow meter 23 are installed at the middle end of the inverted L-shaped diversion pipe 21. The pneumatic regulating valve 22 is located on one side of the ultrasonic flow meter 23. The pneumatic regulating valve 22 controls the amount of ammonia entering the re-diversion main pipe 24. The ultrasonic flow meter 23 detects the amount of ammonia. The pneumatic regulating valve 22 is a VCD-250 model. It controls the position of the valve core or valve seat through a pneumatic actuator, thereby regulating the flow rate of ammonia. The ultrasonic flow meter 23 is a FS230 model. It transmits ultrasonic signals and receives the difference in signal propagation time to determine the flow rate of ammonia. By measuring the ultrasonic propagation time difference between two points, the flow rate is calculated and the flow rate is further calculated.

[0031] A dustproof net 271 is installed inside the nozzle 27. A rotating hole 29 is opened on the outer surface of the diverter pipe A25, and the rotating hole 29 is opened on one side of the nozzle 27. The dustproof net 271 blocks dust in the flue gas. The rotating hole 29 and the center of the nozzle 27 are on the same horizontal plane.

[0032] The cleaning component 3 includes an outer protective frame 31 installed on one side of the outer surface of the diversion pipe A25. Inside the outer protective frame 31 are a rotating shaft 33 and a gear 34. The gear 34 is installed on the outer surface of the rotating shaft 33, and one end of the rotating shaft 33 is inserted into the rotating hole 29. One end of the rotating shaft 33 passes through the interior of the horizontal connecting pipe 28. The number of rotating shafts 33, motors 32, and horizontal connecting pipes 28 is the same. One end of each set of rotating shafts 33 is equipped with a motor 32, which is located inside the outer protective frame 31. Chains 35 are connected to the outer surfaces of multiple sets of gears 34. The motor 32 drives one set of rotating shafts 33 and gears 34 to rotate, and the chain 35 drives the remaining sets of rotating shafts 33 and gears 34 to rotate.

[0033] In this embodiment: the ammonia injection main pipe 1 transports ammonia gas, which is then diverted through multiple sets of inverted L-shaped diversion pipes 21. An ultrasonic flow meter 23 monitors the amount of ammonia gas entering the inverted L-shaped diversion pipes 21. The ammonia gas entering the re-diversion main pipe 24 is further diverted through diversion pipes A25 and B26. A horizontal pipe 28 is installed between the multiple diversion pipes B26 and A25, allowing for further diversion of the ammonia gas. A nozzle 27 is provided at the intersection of the horizontal pipe 28 and the diversion pipes B26 and A25, through which ammonia gas is injected, distributing it evenly within the reactor. This promotes a uniform ammonia-nitrogen molar ratio within the reactor, improving the denitrification efficiency of the SCR. Rotating the ultrasonic flow meter 23 adjusts the amount of ammonia gas entering the re-diversion main pipe 24, effectively controlling the amount of ammonia gas used.

[0034] Example 2: This example is an improvement upon Example 1. For details, please refer to [link / reference]. Figure 3 and Figure 4 An outer fixing block 36 is installed on the outer surface of the rotating shaft 33. An inverted T-shaped groove 361 is opened inside the top of the outer fixing block 36. A compression spring 362 is installed at the bottom of the inverted T-shaped groove 361. A movable block 37 is installed on the inner side of the inverted T-shaped groove 361. The outer fixing block 36 is positioned below the dustproof net 271.

[0035] The movable block 37 includes a connecting strip 371 and a bottom slide plate 372 installed at the bottom of the connecting strip 371. A semi-circular plate 373 is installed at the top of the connecting strip 371. A brush layer 374 is installed on the outer surface of the semi-circular plate 373. The dustproof net 271 can be cleaned by using the movable brush layer 374.

[0036] In this embodiment: When the partitioned ammonia injection component 2 is used inside the reactor, dust in the flue gas will fall into the dustproof net 271 inside the injection hole 27. With the continuous use of the reactor, the dust will clog the holes of the dustproof net 271. The motor 32 operates by driving a set of rotating shafts 33 to rotate. Since gears 34 are installed on the outer surface of the rotating shafts 33, and chains 35 are connected to the outer surfaces of multiple sets of gears 34, the rotating shafts 33 can drive other sets of rotating shafts 33 to rotate, so that the outer fixed block 36 and the movable block 37 rotate below the dustproof net 271. The movable block 37 rotates from the horizontal direction to the vertical direction. The brush layer 374 set on the outer surface of the semi-circular plate 373 cleans the dustproof net 271 and removes the impurities in the holes of the dustproof net 271, so as to facilitate the normal injection of ammonia and perform SCR denitrification treatment on the flue gas in the thermal power unit.

[0037] Working principle: Ammonia gas is diverted through multiple sets of inverted L-shaped diversion pipes 21, and then further diverted through multiple sets of diversion pipes B26 and horizontal pipes 28 and diversion pipes A25, so that the ammonia gas is evenly distributed inside the reactor, promoting uniform ammonia-nitrogen molar ratio in different zones within the reactor, thereby improving the denitrification efficiency of SCR. The motor 32 drives a set of rotating shafts 33 to rotate, and the rotating shafts 33 drive other sets of rotating shafts 33 to rotate. The brush layer 374 cleans the dust screen 271, removing impurities from the mesh of the dust screen 271 to facilitate the normal injection of ammonia gas.

[0038] like Figure 5 As shown, the ammonia injection control system of this utility model includes an optimization zoning module, a zoning measurement module, and a zoning control module.

[0039] Specifically, the optimized zoning module employs SCR zoning mixing and dynamic leveling technology, using a zoning dynamic precision ammonia injection design to ensure an ammonia escape rate of no more than 2.5 ppm and an SO2 / SO3 conversion rate of less than 1%. Based on thorough optimization of the flue gas velocity field, various mixing / guiding measures are implemented in the SCR inlet flue to achieve full-section flue gas premixing of nitrogen oxides. After the ammonia injection grid, the "anti-clogging ash-filled large-basin AIG + static mixer" technology is used for zoning mixing, controlling the number of zoning zones in each flue to five. Simultaneously, NO2 in each outlet zone is controlled... X Conduct round-robin monitoring and automatically adjust the ammonia injection rate in each section of the ammonia injection grid to ensure the NO at the SCR outlet. X The ammonia distribution is dynamically uniform, resulting in the lowest ammonia slip level. The ammonia / flue gas mixing system is designed based on the cross-section and length of the flue gas duct and the structural form of the SCR reactor body. This ensures that the ammonia injected into the flue gas is fully mixed with the flue gas before entering the SCR reactor body, allowing the catalyst to exert its effect uniformly. The ammonia injection system has both lateral and longitudinal adjustment capabilities. Backflow mixers, large-nozzle AIGs, and static mixers are installed before the reactor to uniformly mix the flue gas, ensuring that the velocity deviation at each point before the ammonia injection grid is less than 10%.

[0040] The overall structural design of the reactor should fully consider the deviation of the inlet flue gas velocity, the inlet flue gas direction, the inlet flue gas temperature, and the NH3 / NO ratio at the first catalyst layer. X The absolute deviation of the molar ratio, etc., ultimately meet the following requirements: the flow velocity deviation above the catalyst inlet is <10%, the ammonia-nitrogen molar ratio CV deviation is <2.5%, the flue gas temperature deviation is <25℃, and the maximum incident angle is <10°, to ensure that the flue gas enters the reactor in a uniform state for full reaction and to ensure that the corresponding catalytic efficiency is achieved.

[0041] 1) Inlet flue gas velocity deviation: <10% (root mean square deviation rate);

[0042] 2) Maximum angle of flue gas flow direction at the inlet: ±10°;

[0043] 3) Inlet flue gas temperature deviation: <±25℃;

[0044] 4) NH3 / NO X Molar ratio deviation: <2.5% (root mean square deviation rate);

[0045] To ensure the above technical requirements are met, computational fluid dynamics (CFD) numerical analysis and flow field digital model experiments were conducted on the SCR unit (from the economizer outlet to the air preheater inlet flue gas system, including the reducing agent injection device). This was done to prevent NO from entering the SCR inlet. X Uneven distribution leads to significant flue gas deviation. This project employs zoned dynamic ammonia injection regulation, with each reactor having 5 zones, as follows: Figure 1As shown, each zone has 6 branch pipes. A flue gas mixer is used before the zone. The mixing, diversion, guiding, and rectifying devices in the zone flue are made of wear-resistant materials. Each zone has a pneumatic regulating valve for remote control and automatic adjustment. A flow meter is installed after the regulating valve to measure the ammonia injection rate of each zone.

[0046] The described zone measurement module includes five U-shaped reactor inlets, each with an outlet corresponding to one of five zones. Each zone uses a multi-point sampling probe with multiple sampling holes leading to the outside of the reactor. These holes are then collected by a pneumatic valve and led to the air preheater outlet. The pressure difference between the reactor outlet and the air preheater outlet draws flue gas from the probes in each zone. A measurement pool is installed on the main collection pipe, and a NO3- meter is installed on the measurement pool. X The sampling probe, by switching the valve on the probe rod, leads the flue gas in each zone to the measurement pool, where it is measured by the analyzer. The control system obtains the measurement value of each zone based on the switched zone and the measurement results of the analyzer.

[0047] The aforementioned zone control module is used to achieve precise ammonia injection control.

[0048] Its control process is as follows: First, based on the inlet NO... X The resulting process flow was analyzed, and its causal relationship with the fuel quantity, air volume, and various combustion conditions input into the boiler was examined. Neural network technology was used to establish an SCR inlet NO... X The concentration prediction model was used to conduct big data analysis across multiple power generation load segments. Covariance, correlation coefficient, Pearson correlation, and significance tests were employed to predict NO concentration. X Using the value as the dependent variable and key parameters such as unit load, damper opening, coal mill combination, flue gas flow rate, and temperature as independent variables, linear / nonlinear regression analysis was performed. Based on historical operating data of the SCR system (unit load, damper opening, coal mill combination, flue gas flow rate and temperature, NO...),... X (Important parameters such as inlet concentration distribution and ammonia injection rate) Establish the inlet NO of the SCR reactor. X The concentration prediction model adopts a relatively generalizable multiple linear regression model to predict concentrations, thereby improving the prediction of ammonia injection and inlet NO. X The following behavior. After configuration comparison, it was found that the fitted curve after mathematical simulation calculation showed that the action took precedence over NO. X Actual measurement curves, based on calculations, indicate an advance response time of approximately 60 seconds, which allows for some advance control and reduces ammonia injection consumption. Secondly, regarding the inlet NO... X The fitting of the measurement results for soft measurement is long-term and requires verification and correction of hard measurement results from continuous 24-hour cyclic sampling over a long period of time in order to recursively derive a more accurate and timely soft measurement result.

[0049] Meanwhile, the control system possesses big data modeling capabilities, enabling the establishment of corresponding denitrification operation control models based on historical data, and continuous updating and iteration of these models based on collected relevant data and control results. A modeling method for SCR denitrification in coal-fired power plant boilers, based on a selectively integrated model library, is employed. By establishing a model library of parameter values ​​at the SCR reactor inlet and outlet, the method overcomes the problem of inaccurate ammonia injection control due to model failure, enabling the prediction of nitrogen oxides at the outlet under varying operating conditions. This allows for the adjustment of ammonia injection rates, preventing excessive NOx emissions and ammonia slip. The actual process includes the following steps: (a) Collect parameter values ​​at the inlet and outlet of the SCR reactor over multiple days, divide them into training and test sets, select a learner, and train multiple models using the training set data to form a model library; (b) Use the models in the model library to predict the predicted value at each time of day; (c) t=t+1, return to step (b), after completing the prediction for all times of the day, update the model library, use the updated model library as the current model library, return to step (b), until the model library for the last day in the test set is updated, thus obtaining the final required model library, i.e., completing the modeling of SCR denitrification. This constructed model library uses a selective real-time error weighting method improved for the short-term correlation of SCR operating data, and is equipped with a suitable model library update strategy. This effectively solves the model failure problem caused by changes in coal quality and system characteristics during the long-term operation of the boiler SCR system, and achieves the prediction of NO at the reactor outlet. X Long-term stable prediction of concentration; the selective model library not only ensures the long-term effectiveness of the model, but also greatly reduces the data screening and parameter tuning problems caused by model updates, reduces manual intervention, and enhances the level of intelligence. In addition, based on the model library, rolling optimization of ammonia injection flow / valve opening is achieved, improving the accuracy, response speed, and stability of SCR ammonia injection control.

[0050] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flue gas SCR denitrification ammonia injection control device, comprising an ammonia injection main pipe (1), characterized in that: A partitioned ammonia injection component (2) is installed on one side of the main ammonia injection pipe (1). The partitioned ammonia injection component (2) is provided in multiple sets, and a cleaning component (3) is installed on one side of each set of partitioned ammonia injection components (2). The partitioned ammonia spraying component (2) includes an inverted L-shaped diversion pipe (21) and a sub-diversion main pipe (24) that is installed through one end of the inverted L-shaped diversion pipe (21). A diversion pipe A (25) is installed through the outer surface of the sub-diversion main pipe (24). A diversion pipe B (26) is installed through the outer surface of the sub-diversion main pipe (24) and on one side of the diversion pipe A (25). A horizontal pipe (28) is fixedly installed inside the multiple diversion pipes B (26) and the diversion pipe A (25). The horizontal pipe (28) is provided with multiple sets. The top ends of the multiple diversion pipes B (26) and the diversion pipe A (25) are all provided with spray holes (27). The spray holes (27) are located at the intersection of the horizontal pipe (28) and the diversion pipes B (26) and A (25).

2. The ammonia injection control device for flue gas SCR denitrification according to claim 1, characterized in that: The inverted L-shaped diverter (21) is equipped with a pneumatic regulating valve (22) and an ultrasonic flow meter (23) at its middle end, and the pneumatic regulating valve (22) is located on one side of the ultrasonic flow meter (23).

3. The ammonia injection control device for flue gas SCR denitrification according to claim 1, characterized in that: The nozzle (27) is equipped with a dustproof net (271), and the outer surface of the diversion pipe A (25) is provided with a rotating hole (29), which is located on one side of the nozzle (27).

4. The ammonia injection control device for flue gas SCR denitrification according to claim 1, characterized in that: The cleaning component (3) includes an outer protective frame (31) installed on one side of the outer surface of the diversion pipe A (25). The outer protective frame (31) is provided with a rotating shaft (33) and a gear (34). The gear (34) is installed on the outer surface of the rotating shaft (33), and one end of the rotating shaft (33) is inserted into the rotating hole (29). One end of the rotating shaft (33) passes through the interior of the horizontal pipe (28). The number of rotating shafts (33), motors (32) and horizontal pipes (28) is the same. One end of one set of the rotating shafts (33) is equipped with a motor (32). The motor (32) is located inside the outer protective frame (31). The outer surfaces of multiple sets of gears (34) are connected with chains (35).

5. The ammonia injection control device for flue gas SCR denitrification according to claim 4, characterized in that: An outer fixed block (36) is installed on the outer surface of the rotating shaft (33). An inverted T-shaped groove (361) is opened inside the top of the outer fixed block (36). A compression spring (362) is installed at the bottom of the inverted T-shaped groove (361). A movable block (37) is installed on the inner side of the inverted T-shaped groove (361).

6. The ammonia injection control device for flue gas SCR denitrification according to claim 5, characterized in that: The movable block (37) includes a connecting strip (371) and a bottom plate (372) installed at the bottom of the connecting strip (371). A semi-circular plate (373) is installed at the top of the connecting strip (371), and a brush layer (374) is installed on the outer surface of the semi-circular plate (373).

7. A control system for an ammonia injection control device for flue gas SCR denitrification according to any one of claims 1-6, characterized in that, The control system includes an optimization zoning module, a zoning measurement module, and a zoning control module; The optimized zoning module includes multiple reactors, each reactor inlet is set up with five zones, and each zone is equipped with a pneumatic regulating valve and a flow meter for adjusting and monitoring the precise ammonia injection in each zone. The partition measurement module includes an analyzer installed at the outlet of each reactor. The analyzer performs rotational measurements on the five partitions at the inlet of the reactor. Each partition's sampling tube is equipped with a measuring valve. The measuring valve switches the sampling tubes of each partition to the measuring pool through the partition control module, and the measurement is performed by the analyzer. The zonal control module is used to carry the precision ammonia injection control software installed in the ICS, and to communicate with the DCS system to obtain data from the denitrification CEMS system and boiler operation data, so as to complete the zonal regulating valve control and the online closed-loop control of the main valve for dynamic ammonia injection in the denitrification system.

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