An ammonia metering and ammonia injection optimization adjustment system for SCR denitration

Abstract

This invention discloses an ammonia metering and optimized ammonia injection control system for SCR denitrification, comprising a flue gas zoning module; an inlet parameter measurement module including multiple inlet NOx concentration measurement probes; an outlet parameter measurement module including multiple outlet NOx concentration measurement probes and multiple ammonia slip measurement probes; and an ammonia precise metering and distribution module including an ammonia main pipe, an ammonia mass flow meter installed on the ammonia main pipe, multiple ammonia injection branch pipes connected to the ammonia main pipe, and an electrically controlled regulating valve and a branch pipe flow meter installed on each ammonia injection branch pipe. This invention ensures that the flue gas load carried by each measurement and control zone is basically consistent through equal flow rate zoning based on fluid dynamics simulation or measured flow velocity data, laying an accurate and reliable physical foundation for subsequent refined ammonia injection control and avoiding the representativeness error caused by traditional equal cross-section zoning.

Description

Technical Field

[0001] This invention relates to the field of flue gas denitrification technology, specifically to an ammonia metering and ammonia injection optimization and adjustment system for SCR denitrification. Background Technology

[0002] Selective catalytic reduction (SCR) denitrification technology is currently the mainstream flue gas denitrification method in coal-fired power plants, industrial boilers and other fields. Its principle is that, under the action of a catalyst, the injected ammonia (NH3) reacts with the nitrogen oxides (NOx) in the flue gas to generate harmless nitrogen and water.

[0003] In practical applications, due to frequent boiler load changes, large fluctuations in coal quality, and complex flue structure, the flue gas flow field and NOx concentration distribution at the SCR reactor inlet are often extremely uneven. Traditional ammonia injection regulation methods mostly adopt global PID control based on feedback of total inlet NOx and outlet NOx. This "extensive" regulation cannot match the concentration differences across the flue section, resulting in insufficient ammonia injection (NOx emissions exceeding standards) or excessive ammonia injection in local areas.

[0004] Excessive ammonia injection not only wastes reducing agent, but more seriously, the escaped ammonia reacts with SO3 in the flue gas to form ammonium bisulfate, clogging the downstream air preheater and severely affecting the safe and stable operation of the unit. To address this issue, existing technologies have developed zoned ammonia injection control techniques, such as the scheme proposed in CN121386944A that uses an outlet NOx distribution cloud map for ammonia injection leveling. However, such schemes typically focus on optimizing the control logic, paying little attention to the physical zoning basis of the ammonia injection system itself, the accurate metering of ammonia flow, and material balance verification. This can lead to issues in practical applications, such as uneven flow rates in different zones, inaccurate metering, or fluctuations in ammonia supply, affecting the control effectiveness.

[0005] Another technology, CN115779678A, discloses a method to control ammonia escape by synergistically regulating the amount of ammonia injected and the flue gas temperature. However, its control is still based on the total global amount and cannot solve the problem of local over-injection caused by uneven NOx distribution within the flue section.

[0006] Therefore, how to construct an optimized ammonia injection system that integrates physical zoning, precise metering, material balance verification, and hierarchical progressive control to achieve truly refined and adaptive ammonia injection remains a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] To address this issue, the present invention provides an ammonia metering and optimized ammonia injection control system for SCR denitrification, which solves the problem that excessive ammonia injection in the prior art not only wastes reducing agent and increases operating costs, but more seriously, unreacted ammonia (ammonia escape) reacts with SO3 in the flue gas to form ammonium bisulfate, a highly viscous substance that can clog the heat exchange elements of the downstream air preheater, leading to increased equipment resistance, decreased heat exchange efficiency, and even fan stall, seriously affecting the safe and stable operation of the unit.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An ammonia metering and ammonia injection optimization control system for SCR denitrification includes:

[0010] The flue partitioning module is used to divide the cross-sections of the SCR reactor inlet flue and outlet flue into multiple corresponding measurement zones and ammonia injection zones, respectively.

[0011] The inlet parameter measurement module includes multiple inlet NOx concentration measurement probes, which are installed one-to-one in each measurement zone of the inlet flue to collect inlet NOx concentration data of each zone in real time.

[0012] The outlet parameter measurement module includes multiple outlet NOx concentration measurement probes and multiple ammonia slip measurement probes. The outlet NOx concentration measurement probes and ammonia slip measurement probes are set one-to-one in each measurement zone of the outlet flue, and are used to collect outlet NOx concentration data and ammonia slip rate data of each zone in real time.

[0013] The ammonia gas precise metering and distribution module includes an ammonia gas main pipe, an ammonia gas mass flow meter installed on the ammonia gas main pipe, multiple ammonia injection branch pipes connected to the ammonia gas main pipe, and an electrically controlled regulating valve and a branch pipe flow meter installed on each ammonia injection branch pipe. The outlet of each ammonia injection branch pipe corresponds to one of the ammonia injection zones.

[0014] The intelligent control module is electrically connected to the inlet parameter measurement module, the outlet parameter measurement module, and the ammonia precise metering and distribution module, respectively. The intelligent control module receives the inlet NOx concentration data, the outlet NOx concentration data, and the ammonia slip rate data, and calculates the target ammonia injection amount required for each ammonia injection zone according to the preset optimized control strategy. Then, it generates control commands to adjust the opening degree of each of the electrically controlled regulating valves. At the same time, based on the feedback data from the ammonia mass flow meter and the branch pipe flow meter, it performs closed-loop correction on the total ammonia injection amount and the zone flow.

[0015] Preferably, in the flue partitioning module, the partitioning of the inlet flue and the outlet flue is based on the results of fluid dynamics simulation or on-site measured velocity distribution data, so that the flue gas flow rate of each partition is equal within the same flue cross-section.

[0016] Preferably, the optimized control strategy built into the intelligent control module includes: first, calculating the basic ammonia injection demand for each zone based on the inlet NOx concentration and the preset target outlet NOx concentration; second, performing a first-level PID feedback correction on the basic ammonia injection demand by combining the deviation between the measured value and the target value of the outlet NOx concentration of the corresponding zone; and finally, introducing the measured value of the ammonia slip rate of the corresponding zone, and if the ammonia slip rate exceeds the preset safety threshold, performing a second-level forced reduction correction on the ammonia injection amount of the zone until the ammonia slip rate falls back to within the safety threshold.

[0017] Preferably, the intelligent control module is also used to calculate the sum of the basic ammonia injection demand of all zones and compare it with the total ammonia injection quantity measured by the ammonia mass flow meter; when the deviation between the two exceeds the allowable range, the intelligent control module determines that there is a measurement abnormality or fluctuation in ammonia preparation and supply in the system, and issues an early warning signal. At the same time, it uses the measured value of the ammonia mass flow meter as a benchmark and dynamically adjusts the target ammonia injection quantity sent to each zone proportionally.

[0018] Preferably, the ammonia escape measurement probe in the outlet parameter measurement module is a laser spectral analysis sensor, which is used to measure the trace ammonia concentration in the flue gas at the outlet of each zone in real time and accurately, providing a direct basis for determining excessive ammonia injection.

[0019] Preferably, the ammonia precise metering and distribution module further includes a pressure regulating valve and a temperature compensation unit installed on the ammonia main pipe. The temperature compensation unit is used to compensate the measured value of the ammonia mass flow meter according to the temperature change of the ammonia to ensure the accuracy of the total ammonia injection measurement under all operating conditions. The branch pipe flow meter adopts a thermal gas mass flow meter to directly monitor the ammonia mass flow supplied to the corresponding ammonia injection zone by each ammonia injection branch pipe, and forms a cascade control loop with the electronically controlled regulating valve to improve the response speed and accuracy of the zone flow control.

[0020] Preferably, the intelligent control module is also connected to the upstream unit's distributed control system (DCS) to read the unit's load and flue gas volume operating parameters in real time. The intelligent control module uses these parameters, combined with the changing trend of the inlet NOx concentration, to construct a feedforward control model. When the unit load changes, it adjusts the total ammonia injection in advance to overcome the inherent reaction lag of the SCR system and achieve dynamic advance adjustment of the ammonia injection volume.

[0021] Preferably, the intelligent control module further includes a human-machine interface for real-time display of inlet NOx concentration distribution cloud maps, outlet NOx concentration distribution cloud maps, ammonia slip rate distribution cloud maps, and instantaneous flow rate and valve opening status of each ammonia injection branch; at the same time, the human-machine interface allows operators to manually set the target outlet NOx concentration value and ammonia slip rate safety threshold, and can switch between automatic control mode and manual control mode.

[0022] The present invention has the following advantages:

[0023] Precise physical zoning basis: By using equal flow rate zoning based on fluid dynamics simulation or measured flow velocity data, it is ensured that the flue gas load carried by each measurement and control zone is basically consistent, laying an accurate and reliable physical foundation for subsequent refined ammonia injection control and avoiding the representativeness error caused by traditional equal cross-section zoning.

[0024] High-precision metering and material balance self-calibration: By installing a high-precision mass flow meter in the ammonia main pipe and combining it with the flow meters in each branch pipe, a two-level precise metering system of "main-branch" is constructed. The intelligent control module compares the sum of the demand in each zone with the actual measured total in the main pipe in real time, which can effectively identify measurement anomalies or fluctuations in ammonia supply, and dynamically redistribute the supply based on the actual measured value in the main pipe, greatly enhancing the system's fault tolerance and operational stability.

[0025] Rapid-response zone flow control: The cascade control loop consisting of a "branch flow meter and electronically controlled regulating valve" on each ammonia injection branch can quickly overcome downstream pressure disturbances, ensuring that the actual ammonia injection volume in the zone strictly and rapidly follows the command value changes, significantly improving the dynamic response quality and control accuracy of zone flow control.

[0026] A scientifically progressive multi-level optimization control strategy: This strategy employs a three-level progressive control approach: inlet feedforward calculation of basic quantities → outlet NOx feedback PID fine correction → mandatory protection against ammonia slip exceeding limits. This strategy is logically clear and hierarchically distinct, ensuring both denitrification efficiency and strictly controlling ammonia slip within a safe threshold. It prevents air preheater blockage risks caused by localized over-spraying from the source, achieving the dual goals of compliant emissions and equipment protection.

[0027] Significant economic and environmental benefits: Through the above-mentioned comprehensive and precise metering and optimization, this invention can significantly improve the uniformity of NOx distribution at the SCR outlet. While ensuring compliance with emission standards, it minimizes the total ammonia injection and ammonia slip rate, thereby effectively extending catalyst life, preventing downstream equipment blockage, and reducing denitrification operating costs, achieving a high degree of unity between environmental and economic benefits. Attached Figure Description

[0028] To more intuitively illustrate the prior art and this application, exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0029] Figure 1 This is a block diagram of an ammonia metering and ammonia injection optimization and control system for SCR denitrification provided in an embodiment of this application. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these embodiments are merely for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Technical engineers in the field can make some non-essential improvements and adjustments to the present invention based on the above-described content. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1 A system for ammonia metering and optimized ammonia injection control in SCR denitrification includes:

[0032] The flue partitioning module is used to divide the cross-sections of the SCR reactor inlet flue and outlet flue into multiple corresponding measurement zones and ammonia injection zones, respectively.

[0033] The inlet parameter measurement module includes multiple inlet NOx concentration measurement probes, which are installed one-to-one in each measurement zone of the inlet flue to collect inlet NOx concentration data of each zone in real time.

[0034] The outlet parameter measurement module includes multiple outlet NOx concentration measurement probes and multiple ammonia slip measurement probes. The outlet NOx concentration measurement probes and ammonia slip measurement probes are set one-to-one in each measurement zone of the outlet flue, and are used to collect outlet NOx concentration data and ammonia slip rate data of each zone in real time.

[0035] The ammonia gas precise metering and distribution module includes an ammonia gas main pipe, an ammonia gas mass flow meter installed on the ammonia gas main pipe, multiple ammonia injection branch pipes connected to the ammonia gas main pipe, and an electrically controlled regulating valve and a branch pipe flow meter installed on each ammonia injection branch pipe. The outlet of each ammonia injection branch pipe corresponds to one of the ammonia injection zones.

[0036] The intelligent control module is electrically connected to the inlet parameter measurement module, the outlet parameter measurement module, and the ammonia precise metering and distribution module, respectively. The intelligent control module receives the inlet NOx concentration data, the outlet NOx concentration data, and the ammonia slip rate data, and calculates the target ammonia injection amount required for each ammonia injection zone according to the preset optimized control strategy. Then, it generates control commands to adjust the opening degree of each of the electrically controlled regulating valves. At the same time, based on the feedback data from the ammonia mass flow meter and the branch pipe flow meter, it performs closed-loop correction on the total ammonia injection amount and the zone flow.

[0037] By precisely dividing the inlet and outlet flue sections of the SCR system into zones and installing corresponding NOx concentration and ammonia slip measurement devices, refined sensing of key parameters within the reactor is achieved. Based on this, an ammonia mass flow meter is introduced to accurately measure the total ammonia injection rate. Combined with a zoned actuator, the core intelligent controller dynamically allocates the total ammonia injection rate to each ammonia injection zone according to a preset optimization algorithm, ensuring that the ammonia-nitrogen molar ratio in each zone approaches the ideal value.

[0038] In the flue duct zoning module, the inlet and outlet flues are divided based on fluid dynamics simulation results or on-site measured velocity distribution data, ensuring that the flue gas flow rate is equal in each zone within the same flue duct cross-section. Traditional equal-section zoning ignores the non-uniformity of velocity distribution within the flue duct, leading to measurement values ​​from zones with high flow rates that cannot represent the overall load. This solution introduces an equal-flow-rate zoning method based on fluid dynamics simulation or measured velocity to ensure that each zone carries a substantially similar flue gas load. This allows the data collected by each measuring probe to accurately reflect the total amount of pollutants in the corresponding area, providing an accurate data foundation for subsequent precise ammonia injection allocation.

[0039] To address the insufficient adaptability of single PID control under complex operating conditions, the following technical solution is implemented: The optimized control strategy built into the intelligent control module includes: First, calculating the basic ammonia injection demand for each zone based on the inlet NOx concentration and the preset target outlet NOx concentration; Second, performing a first-level PID feedback correction on the basic ammonia injection demand by combining the deviation between the measured value and the target value of the outlet NOx concentration of the corresponding zone; Finally, introducing the measured value of the ammonia slip rate of the corresponding zone, if the ammonia slip rate exceeds the preset safety threshold, performing a second-level forced reduction correction on the ammonia injection amount of that zone until the ammonia slip rate falls back to within the safety threshold. Through the above technical solution, the dual objectives of on-demand ammonia injection and over-injection prevention are achieved, ensuring compliance with emission standards while maximizing the protection of downstream equipment from the hazards of ammonium bisulfate blockage.

[0040] The intelligent control module is also used to calculate the sum of the basic ammonia injection demand of all zones and compare it with the total ammonia injection quantity measured by the ammonia mass flow meter. When the deviation between the two exceeds the allowable range, the intelligent control module determines that there is a measurement abnormality or fluctuation in ammonia preparation and supply in the system, and issues an early warning signal. At the same time, it uses the measured value of the ammonia mass flow meter as a benchmark and dynamically adjusts the target ammonia injection quantity sent to each zone proportionally. By comparing the cumulative value of the demand of each zone with the measured value of the main pipeline mass flow meter in real time, an early warning is issued once the deviation exceeds the standard, and the material is redistributed proportionally based on the measured value of the main pipeline, a closed-loop verification of material balance is realized, which enhances the fault tolerance of the system.

[0041] When this solution was implemented, it solved the problem of mismatch between the total calculated by the zones and the total measured by the main pipe, thus avoiding system loss of control due to probe measurement errors or fluctuations in ammonia supply.

[0042] The ammonia escape measurement probe in the outlet parameter measurement module is a laser spectral analysis sensor, which is used to measure the trace ammonia concentration in the flue gas at the outlet of each zone in real time and accurately, providing a direct basis for determining excessive ammonia injection.

[0043] The ammonia precise metering and distribution module also includes a pressure regulating valve and a temperature compensation unit installed on the ammonia main pipe. The pressure regulating valve is used to stabilize the main pipe pressure and suppress upstream fluctuations. The temperature compensation unit is used to compensate the measured value of the ammonia mass flow meter according to the temperature change of the ammonia to ensure the accuracy of the total ammonia injection measurement under all operating conditions. The branch pipe flow meter adopts a thermal gas mass flow meter to directly monitor the ammonia mass flow supplied to the corresponding ammonia injection zone by each ammonia injection branch pipe, and forms a cascade control loop with the electronically controlled regulating valve to improve the response speed and accuracy of the zone flow control. The cascade control can quickly overcome the pressure disturbance downstream of the branch pipe, so that the ammonia injection volume of the zone is strictly executed according to the command, which greatly improves the dynamic response quality and control stability of the system.

[0044] The intelligent control module is also connected to the upstream unit's distributed control system (DCS) to read the unit's load and flue gas volume operating parameters in real time. The intelligent control module uses these parameters, combined with the changing trend of the inlet NOx concentration, to construct a feedforward control model. When the unit load changes, it adjusts the total ammonia injection in advance to overcome the inherent reaction lag of the SCR system and achieve dynamic advance adjustment of the ammonia injection volume.

[0045] The intelligent control module also includes a human-machine interface for real-time display of inlet NOx concentration distribution cloud maps, outlet NOx concentration distribution cloud maps, ammonia slip rate distribution cloud maps, and instantaneous flow rate and valve opening status of each ammonia injection branch. At the same time, the human-machine interface allows operators to manually set the target outlet NOx concentration value and ammonia slip rate safety threshold, and can switch between automatic control mode and manual control mode.

[0046] During implementation, this system first divides the SCR reactor inlet and outlet flues into several corresponding zones based on the principle of equal flue gas flow rates using a flue gas zoning module. The inlet parameter measurement module collects the NOx concentration of each zone in real time as a feedforward signal; the outlet parameter measurement module simultaneously collects the outlet NOx concentration and ammonia slip rate of the corresponding zone as a feedback signal.

[0047] The intelligent control module receives all the above data. First, it calculates the basic ammonia injection demand based on the NOx load and target emission value at the inlet of each zone. Then, it performs the first-stage PID correction by combining the NOx deviation at the outlet of the corresponding zone to eliminate steady-state error. Finally, it introduces the ammonia slip rate as a mandatory constraint. If the ammonia slip of a certain zone exceeds the standard, the ammonia injection of that zone will be reduced immediately to ensure that over-injection does not occur.

[0048] After the above calculations, the intelligent control module determines the optimal target ammonia injection amount for each zone. The command is then sent to the ammonia precision metering and distribution module: the ammonia mass flow meter on the main pipe precisely measures the total amount, the electrically controlled regulating valves on each ammonia injection branch adjust their opening according to the command, and the branch flow meters provide real-time feedback on the actual flow, forming a cascade control to ensure that the ammonia amount allocated to each ammonia injection zone accurately executes the command.

[0049] Furthermore, the system also constructs feedforward control by reading parameters such as load from the unit's DCS, adjusting in advance when operating conditions change to overcome SCR response lag. Ultimately, through this mode of zoned measurement, independent calculation, and precise allocation, the system dynamically adapts to the uneven distribution of NOx concentration in the flue, transforming ammonia injection control from the traditional "extensive overall adjustment" to "refined zoned adaptive adjustment," achieving compliance with emission standards while minimizing ammonia slip.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An ammonia metering and ammonia injection optimization control system for SCR denitrification, characterized in that, include: The flue partitioning module is used to divide the cross-sections of the SCR reactor inlet flue and outlet flue into multiple corresponding measurement zones and ammonia injection zones, respectively. The inlet parameter measurement module includes multiple inlet NOx concentration measurement probes, which are installed one-to-one in each measurement zone of the inlet flue to collect inlet NOx concentration data of each zone in real time. The outlet parameter measurement module includes multiple outlet NOx concentration measurement probes and multiple ammonia slip measurement probes. The outlet NOx concentration measurement probes and ammonia slip measurement probes are set one-to-one in each measurement zone of the outlet flue, and are used to collect outlet NOx concentration data and ammonia slip rate data of each zone in real time. The ammonia gas precise metering and distribution module includes an ammonia gas main pipe, an ammonia gas mass flow meter installed on the ammonia gas main pipe, multiple ammonia injection branch pipes connected to the ammonia gas main pipe, and an electrically controlled regulating valve and a branch pipe flow meter installed on each ammonia injection branch pipe. The outlet of each ammonia injection branch pipe corresponds to one of the ammonia injection zones. The intelligent control module is electrically connected to the inlet parameter measurement module, the outlet parameter measurement module, and the ammonia precise metering and distribution module, respectively. The intelligent control module receives the inlet NOx concentration data, the outlet NOx concentration data, and the ammonia slip rate data, and calculates the target ammonia injection amount required for each ammonia injection zone according to the preset optimized control strategy. Then, it generates control commands to adjust the opening degree of each of the electrically controlled regulating valves. At the same time, based on the feedback data from the ammonia mass flow meter and the branch pipe flow meter, it performs closed-loop correction on the total ammonia injection amount and the zone flow rate. In the flue partitioning module, the partitioning of the inlet flue and the outlet flue is based on the results of fluid dynamics simulation or the actual measured flow velocity distribution data on site, so that the flue gas flow rate of each partition is equal within the same flue cross-section. The intelligent control module has built-in optimization control strategies including: First, calculating the basic ammonia injection demand for each zone based on the inlet NOx concentration and the preset target outlet NOx concentration. Secondly, based on the deviation between the measured value and the target value of the NOx concentration at the outlet of the corresponding zone, the basic ammonia injection demand is corrected using the first-level PID feedback. Finally, the measured value of the ammonia slip rate of the corresponding zone is introduced. If the ammonia slip rate exceeds the preset safety threshold, the ammonia injection amount of the zone is corrected using the second-level forced reduction until the ammonia slip rate falls back to within the safety threshold. The intelligent control module is also used to calculate the sum of the basic ammonia injection demand of all zones and compare it with the total ammonia injection amount measured by the ammonia mass flow meter. When the deviation between the two exceeds the allowable range, the intelligent control module determines that there is a measurement abnormality or fluctuation in ammonia preparation and supply in the system, and issues an early warning signal. At the same time, it uses the measured value of the ammonia mass flow meter as a benchmark and dynamically adjusts the target ammonia injection amount sent to each zone proportionally.

2. The ammonia metering and ammonia injection optimization and control system for SCR denitrification according to claim 1, characterized in that, The ammonia escape measurement probe in the outlet parameter measurement module is a laser spectral analysis sensor, which is used to measure the trace ammonia concentration in the flue gas at the outlet of each zone in real time and accurately, providing a direct basis for determining excessive ammonia injection.

3. The ammonia metering and ammonia injection optimization and control system for SCR denitrification according to claim 1, characterized in that, The ammonia precise metering and distribution module also includes a pressure regulating valve and a temperature compensation unit installed on the ammonia main pipe. The temperature compensation unit is used to compensate the measured value of the ammonia mass flow meter according to the temperature change of the ammonia to ensure the accuracy of the total ammonia injection measurement under all operating conditions. The branch pipe flow meter adopts a thermal gas mass flow meter to directly monitor the ammonia mass flow supplied to the corresponding ammonia injection zone by each ammonia injection branch pipe, and forms a cascade control loop with the electronically controlled regulating valve to improve the response speed and accuracy of the zone flow control.

4. The ammonia metering and ammonia injection optimization and control system for SCR denitrification according to claim 3, characterized in that, The intelligent control module is also connected to the upstream unit's distributed control system (DCS) to read the unit's load and flue gas volume operating parameters in real time. The intelligent control module uses these parameters, combined with the changing trend of the inlet NOx concentration, to construct a feedforward control model. When the unit load changes, it adjusts the total ammonia injection in advance to overcome the inherent reaction lag of the SCR system and achieve dynamic advance adjustment of the ammonia injection volume.

5. The ammonia metering and ammonia injection optimization and control system for SCR denitrification according to claim 4, characterized in that, The intelligent control module also includes a human-machine interface for real-time display of inlet NOx concentration distribution cloud maps, outlet NOx concentration distribution cloud maps, ammonia slip rate distribution cloud maps, and instantaneous flow rate and valve opening status of each ammonia injection branch. At the same time, the human-machine interface allows operators to manually set the target outlet NOx concentration value and ammonia slip rate safety threshold, and can switch between automatic control mode and manual control mode.

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