A NO-based X Ammonia injection control method with zoned synchronous measurement

Abstract

This invention relates to the field of flue gas purification technology for thermal power plants, and discloses a method based on NO x A method for synchronous ammonia injection control with zoned measurements involves installing flue gas sampling probes in several zones of the denitrification outlet flue of a thermal power unit. Flue gas samples collected by each probe are sequentially sent to a flue gas analyzer. The method includes: synchronously latching flue gas samples from several zones of the denitrification outlet flue of the thermal power unit to obtain the NO concentration at the cross-section of the denitrification outlet flue at the same time. x Concentration field distribution, NO x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration in each section of the denitrification outlet flue gas duct; based on NO x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone; based on these optimized control commands, the opening degree of the ammonia injection valves in the corresponding zones is adjusted to achieve precise ammonia injection within each zone. This is achieved by synchronously acquiring NO levels at the same time. x Precise ammonia injection in zoned areas effectively improves NO concentration distribution at SCR outlets. x The uniformity of concentration distribution significantly reduces local ammonia escape.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification technology for thermal power plants, and particularly to a method based on NO. x Ammonia injection control method with zoned synchronous measurement. Background Technology

[0002] With the transformation of the energy structure, coal-fired power units are increasingly participating in grid peak shaving, and their load conditions change frequently, leading to changes in the flue gas flow characteristics and NO2 of the SCR denitrification system. x The concentration distribution characteristics also change rapidly. Under this dynamic operating environment, traditional ammonia injection control technology reveals many limitations.

[0003] First, traditional continuous flue gas monitoring systems typically employ single-point sampling, and the representativeness of the measurement location is limited by the complexity and variability of the flow field at the denitrification outlet, making it difficult to accurately reflect the true NO content across the entire flue gas cross-section. x Concentration distribution. Meanwhile, the cost of a single CEMS device is high, making it economically difficult to implement multi-point sampling measurements with sufficient representativeness. Furthermore, when the single-point measurement device is under maintenance or malfunctions, the NO₂ at the outlet of the entire denitrification system... x The concentration will lose its effective reference value, affecting the continuous and stable operation of the system.

[0004] Secondly, existing technologies have shortcomings in control strategies. Some power plants use rudimentary ammonia injection optimization systems, or their regulating valves are manually controlled. This configuration can only make rough adjustments for a specific stable load condition and cannot adapt to the frequently changing operating conditions during peak shaving, leading to increased NO levels in the SCR outlet horizontal flue. x Uneven concentration distribution. This unevenness directly leads to higher ammonia slip in local areas, and long-term ammonia slip can cause a series of chain problems such as ammonium bisulfate clogging the air preheater and aggravating catalyst loss.

[0005] Furthermore, in some systems employing a two-sided leveling strategy, control relies on existing single-point CEMS instruments. Due to the inherent limitations of single-point sampling, this leveling strategy frequently fails, leading to a long-term imbalance in ammonia injection on both sides of the flue, and consequently, high NO₂ levels at both outlets. x Significant concentration deviations ultimately led to severe blockage of one side of the air preheater. Simultaneously, a "reverse phenomenon"—a large discrepancy between CEMS measurements at the denitrification outlet and the chimney outlet—occurred frequently, further increasing the overall NO₂ levels. x The difficulty of precise control. Summary of the Invention

[0006] The purpose of this invention is to provide a NO-based xThe ammonia injection control method based on synchronous measurement in zones uses NO data acquired at the same time to achieve this. x Precise ammonia injection in zoned areas effectively improves NO concentration distribution at SCR outlets. x The uniformity of concentration distribution significantly reduces local ammonia escape.

[0007] To address the aforementioned technical problems, a first aspect of the present invention provides a NO-based... x A method for controlling ammonia injection with synchronous measurement in different zones: Several zones of the denitrification outlet flue gas duct of a thermal power unit are equipped with flue gas sampling probes. Flue gas samples collected by each sampling probe are sent to a flue gas analyzer in turn. The ammonia injection control method includes the following steps:

[0008] Simultaneously latch flue gas samples from several zones on the denitrification outlet flue of a thermal power unit to obtain the NO content of the cross-section of the denitrification outlet flue at the same time. x Concentration field distribution, the NO x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration in each section of the denitrification outlet flue gas duct cross-section;

[0009] Based on the NO x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone.

[0010] The opening degree of the ammonia injection valve in the corresponding zone is adjusted according to the optimized control command to achieve precise ammonia injection in the zone.

[0011] Furthermore, the statement based on the NO x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone, including:

[0012] Get multiple NOs for each partition across several adjustment rounds. x The concentration measurement values ​​are obtained, and the average value of the zone round measurement for each zone is calculated. Each adjustment round represents the completion of one round of concentration measurement for all zones.

[0013] Based on the average value of the zone-by-zone measurements of all the aforementioned zones, the overall average value of the denitrification outlet flue section is calculated.

[0014] Calculate the concentration deviation between the average value of the rotational measurements for each zone and the overall average value of the rotational measurements, and generate the optimized control command for adjusting the opening of the ammonia injection valve for the corresponding zone based on the concentration deviation.

[0015] Furthermore, after calculating the concentration deviation between the average value of each zone's round-robin measurements and the overall average value of round-robin measurements, the method further includes:

[0016] Obtain the preset strength coefficient and actuation amplitude value of the ammonia injection valve in each zone;

[0017] Based on the preset intensity coefficient and the action amplitude value, and combined with the concentration deviation, the optimized control command is generated to adjust the opening degree of the ammonia injection valve in the corresponding zone.

[0018] Furthermore, after obtaining the preset strength coefficient and actuation amplitude value of the ammonia injection valve for each zone, the method further includes:

[0019] Based on the average value of all zone measurements, calculate the NO content at the denitrification outlet flue section. x Concentration distribution non-uniformity;

[0020] The amplitude of the movement is dynamically adjusted based on the change in the value of the unevenness. When the value of the unevenness increases, the amplitude of the movement increases proportionally, and when the value of the unevenness decreases, the amplitude of the movement decreases proportionally.

[0021] When the unevenness remains below a preset threshold for several rounds, the motion amplitude value is restored to the initial preset value.

[0022] Furthermore, after obtaining the preset strength coefficient and actuation amplitude value of the ammonia injection valve for each zone, the method further includes:

[0023] Obtain the concentration deviation of each partition in the current and historical adjustment rounds, and calculate the variance of its concentration deviation as the concentration stability index of the partition.

[0024] Calculate the average concentration stability index for all zones as the baseline stability level;

[0025] Identify the concentration deviation sign of each zone in consecutive adjustment rounds and determine its continuous deviation direction;

[0026] The concentration stability index of each zone is compared with the baseline stability level. When the concentration stability index of a zone is higher than the baseline stability level and there is a consistent and continuous deviation direction, the intensity coefficient of the zone is increased proportionally.

[0027] When the concentration stability index of the partition is lower than the baseline stability level, or when the concentration stability index of the partition is higher than the baseline stability level but there is no consistent and continuous deviation direction, the intensity coefficient of the partition is reduced proportionally.

[0028] When the concentration stability index of all zones is lower than the baseline stability level for multiple consecutive adjustment rounds and there is no obvious and continuous deviation in direction, the intensity coefficient of all zones will be restored to the initial preset value.

[0029] Furthermore, the optimized control command for adjusting the opening of the corresponding zone ammonia injection valve, based on the preset intensity coefficient and the action amplitude value, combined with the concentration deviation, includes:

[0030] The concentration deviation is divided into segments, and different combinations of intensity coefficients and action amplitude values ​​are used for concentration deviation segments of different sizes.

[0031] For concentration deviations within the preset normal fluctuation range, standard intensity coefficients and standard action amplitude values ​​are used for processing;

[0032] For large concentration deviations that exceed the preset normal fluctuation range, a combination strategy of enhancing the intensity coefficient and limiting the action amplitude value is adopted to ensure the adjustment strength while preventing over-adjustment.

[0033] Furthermore, the step of obtaining multiple NOs for each partition within several adjustment rounds... x Before the concentration measurement, it also includes:

[0034] Calculate the NO of the denitrification outlet flue section corresponding to the current cycle. x Concentration distribution non-uniformity, the rate of change between the non-uniformity of the previous round;

[0035] The rate of change is compared with a preset negative rate of change threshold: if the rate of change is less than the preset negative rate of change threshold, it is determined that the system is in a rapid optimization state, and the number of adjustment rounds is reduced.

[0036] The absolute value of the rate of change is compared with a preset stable state threshold: if the absolute value of the rate of change is less than the stable state threshold, it is determined that the system is approaching stability, and the number of adjustment rounds is increased.

[0037] Furthermore, the denitrification outlet flue of the thermal power unit includes: a first flue and a second flue, and the ammonia injection control method further includes:

[0038] Calculate the first overall average value of all zones corresponding to the first flue and the second overall average value of all zones corresponding to the second flue.

[0039] Calculate the deviation between the first overall round measurement average value and the second overall round measurement average value;

[0040] Based on the deviation value, the total ammonia injection flow rate allocated to the first flue and the second flue is adjusted synchronously to make the first overall average value and the second overall average value tend to be consistent.

[0041] Further, the step of synchronously adjusting the total ammonia injection flow rate allocated to the first flue and the second flue respectively based on the deviation value includes:

[0042] The real-time load value of the thermal power unit is obtained, and the preset load condition range to which it belongs is determined based on the real-time load value;

[0043] Based on the preset load condition range, the corresponding flue balance adjustment coefficient is selected from a predefined mapping relationship;

[0044] Based on the deviation value and the flue gas balance adjustment coefficient, the baseline adjustment amount of the total ammonia injection flow rate is calculated;

[0045] The baseline adjustment amount is synchronously superimposed on the total ammonia injection flow rate set values ​​of the first and second flues, and the first and second flues are adjusted in opposite directions symmetrically.

[0046] Furthermore, the synchronous adjustment of the total ammonia injection flow rate allocated to the first flue and the second flue respectively includes:

[0047] Calculate the dynamic rate of change of the overall average value of the first and second flues in multiple consecutive adjustment cycles;

[0048] Calculate the ratio of the dynamic change rate of the first flue to the dynamic change rate of the second flue, and use it as the flue response rate ratio.

[0049] Based on the flue response rate ratio, a dynamic allocation weight is calculated, wherein flues with a slower dynamic change rate are assigned a higher allocation weight.

[0050] The baseline adjustment amount is differentiated according to the dynamic allocation weight and superimposed on the total ammonia injection flow rate setting value of the corresponding flue.

[0051] Accordingly, a second aspect of the present invention provides a NO-based x A zoned synchronous measurement ammonia injection control system is provided, wherein several zones of the denitrification outlet flue gas duct of the thermal power unit are respectively equipped with flue gas sampling probes, and the flue gas samples collected by each of the flue gas sampling probes are sent to the flue gas analyzer in turn. The ammonia injection control system includes:

[0052] The data acquisition module is used to synchronously latch flue gas samples from several zones on the denitrification outlet flue of the thermal power unit, and obtain the NO content of the cross-section of the denitrification outlet flue at the same time. x Concentration field distribution, the NO x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration in each section of the denitrification outlet flue gas duct cross-section;

[0053] Instruction generation module, used for generating instructions based on the NO xThe concentration field distribution generates optimized control commands for the ammonia injection valves in each zone.

[0054] The zone control module is used to adjust the opening degree of the ammonia injection valve of the corresponding zone according to the optimized control command, so as to achieve precise ammonia injection in the zone.

[0055] Accordingly, a third aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the above-described NO-based... x Ammonia injection control method with zoned synchronous measurement.

[0056] Accordingly, a fourth aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described NO-based... x Ammonia injection control method with zoned synchronous measurement.

[0057] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0058] 1. Through synchronous latching and measurement technology, it was the first time that the NO at the same moment across the entire flue section at the SCR outlet was measured. x The accurate acquisition of the concentration field distribution overcomes the inherent defect of poor representativeness of traditional single-point measurement. On this basis, a closed-loop control loop from the concentration field to the zone valve command is constructed, which can accurately locate and eliminate areas with uneven concentration distribution, so that the ammonia injection rate and nitrogen oxide distribution can be dynamically matched. This not only significantly improves the denitrification efficiency, but also improves the uniformity of the outlet concentration from the root, effectively solving the problem of local ammonia escape caused by uneven distribution.

[0059] 2. By calculating indicators such as concentration distribution non-uniformity and zone concentration stability in real time, the system dynamically adjusts key parameters such as control rounds, action amplitude, and intensity coefficient, achieving precise matching between the control strategy and the current operating state of the system. Whether facing frequent load changes or dealing with dynamic response differences in different zones, the system can automatically adjust the control intensity and response speed, achieving the best balance between rapid correction and stable operation, thereby maintaining excellent control quality across the entire operating range.

[0060] 3. By implementing measures such as dilution air lower limit protection and valve lower limit protection, operational risks inherent in the equipment are prevented. Through fault diagnosis and automatic rejection mechanisms for measuring devices, the control system can still operate reliably even when some measuring points are abnormal. In addition, the linkage between the dual flue leveling logic and load conditions avoids downstream equipment blockage caused by uneven ammonia injection, reduces the system's reliance on manual intervention, and ensures its ability to operate continuously, stably, and safely in industrial settings. Attached Figure Description

[0061] Figure 1 This is based on NO provided in the embodiments of the present invention. x Flowchart of ammonia injection control method for zoned synchronous measurement;

[0062] Figure 2 This is a schematic diagram of the denitrification system for thermal power units provided in an embodiment of the present invention;

[0063] Figure 3 This is a schematic diagram of flue gas sample collection in a flue section provided in an embodiment of the present invention;

[0064] Figure 4 This is based on NO provided in the embodiments of the present invention. x Block diagram of the ammonia injection control system module for zoned synchronous measurement.

[0065] Figure label:

[0066] 1. Data acquisition module; 2. Instruction generation module; 3. Partition control module. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0068] The synchronous measurement device used in this invention consists of multiple flue gas sampling probes and a central flue gas analyzer, specifically implemented using a one-to-many connection mode. The sampling probes feature a special design resistant to high temperatures, high dust levels, and high corrosion, enabling them to adapt to the harsh flue gas environment at the denitrification outlet of thermal power plants. Synchronous sample gas latching is achieved through a multi-path switching valve group, with key components including a sample chamber and a solenoid valve array. These components together ensure that the flue gas state of the flue gas cross-section is fixed at the same time. A complete heat tracing and insulation system and a backflush device are also provided to effectively prevent sampling pipeline blockage and sample distortion, ensuring long-term operational reliability.

[0069] Please refer to Figure 1 , Figure 2 and Figure 3 The first aspect of the present invention provides a NO-based x The ammonia injection control method with zoned synchronous measurement involves installing flue gas sampling probes in several zones of the denitrification outlet flue gas duct of a thermal power unit. Flue gas samples collected by each sampling probe are sent to a flue gas analyzer in turn. The ammonia injection control method includes the following steps:

[0070] Step S100: Simultaneously latch flue gas samples from several zones on the denitrification outlet flue of the thermal power unit to obtain the NO content of the denitrification outlet flue section at the same time. x Concentration field distribution, NO x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration in each section of the denitrification outlet flue section.

[0071] In scenarios where thermal power units participate in grid peak shaving, frequent load fluctuations affect the flow field characteristics and NO levels in the outlet flue gas duct of the Selective Catalytic Reduction (SCR) denitrification system. x The concentration distribution is constantly changing dynamically. To accurately determine the true concentration distribution across the flue gas cross-section, sampling probes placed in each section of the horizontal flue gas duct at the denitrification outlet simultaneously extract flue gas samples. A multi-path switching valve assembly, resistant to high temperatures and blockages, is used to synchronously latch the sample gas. During this process, the solenoid valves on all sampling paths operate synchronously according to a preset time sequence, temporarily storing flue gas samples from different spatial locations within a sample chamber of a specific volume, thus fixing the state of the flowing flue gas at a given instant. This latching mechanism effectively solves the concentration field distortion problem caused by asynchronous measurement times in traditional time-sharing measurement methods, providing raw data with strict spatiotemporal consistency for subsequent analysis.

[0072] In typical coal-fired boiler denitrification systems, the latched sample gas is sequentially sent to a central flue gas analyzer for concentration detection according to a preset program. The analyzer uses standard methods such as ultraviolet differential absorption spectroscopy to measure NO. x The concentration values ​​were recorded, and the measurement results for each zone were recorded through a data acquisition system. Because the flue gas from the power plant's denitrification outlet is characterized by high temperature, high dust levels, and strong corrosiveness, the sampling system is also equipped with comprehensive heating, filtration, and backflushing devices to ensure the accuracy of the measurement data and the long-term reliability of the system. Since all sample gases represent the flue gas state at the same moment, the final NO concentration obtained is... x The concentration field distribution can accurately reflect the spatial differences in concentration in each zone at the denitrification outlet section, providing a reliable input basis for subsequent precise zone control.

[0073] Step S200, based on NO x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone.

[0074] To obtain NO at the current moment x After analyzing the concentration field distribution, to address the significant differences in the regulation characteristics of each branch of the Ammonia Injection Grid (AIG) during actual power plant operation, a multi-round statistical analysis of the concentration data for each zone was first conducted. Specifically, the concentration measurements for each zone were recorded over several consecutive adjustment rounds, and the average value of each zone's measurements was calculated. Furthermore, the overall average value for the entire flue gas duct section was calculated. By comparing the average values ​​of each zone with the overall average value, the concentration deviation for each zone was accurately calculated. This deviation objectively reflects the degree of matching between the ammonia injection rate and the actual denitrification requirements in that area, providing a quantitative basis for subsequent precise regulation.

[0075] Based on the calculated concentration deviation, the control algorithm, combined with preset intensity coefficients and action amplitude parameters, generates optimized control commands for the ammonia injection valves in each zone. The intensity coefficient adjusts the control system's response sensitivity to concentration deviations, while the action amplitude limits the maximum allowable range of change for a single adjustment. In practical power plant applications, the algorithm appropriately increases the adjustment intensity for zones with larger concentration deviations, while maintaining a smaller adjustment amplitude for zones with more ideal concentration distributions. Simultaneously, a dynamic parameter adjustment mechanism based on load conditions is introduced to ensure stable and accurate optimized control under different operating conditions.

[0076] In step S300, the opening degree of the ammonia injection valve in the corresponding zone is adjusted according to the optimized control command to achieve precise ammonia injection in the zone.

[0077] During the nitrogen injection execution phase, the generated optimized control commands are output to the pneumatic or electric regulating valve actuators on each nitrogen injection branch via the power plant's DCS control system. During control, the valve control status is monitored in real time. When the valve is in automatic control mode, the optimized commands directly act on the valve positioner, and by setting a valve command change rate limit, the system ensures that the command output change rate does not exceed a preset threshold, preventing sudden valve opening changes and precisely adjusting the valve opening position. When unit load fluctuations cause valve control mode switching, the system employs a seamless switching strategy to ensure that the valve position does not change abruptly during the transition between automatic and manual modes, maintaining system stability. This characteristic is particularly important when the unit participates in AGC frequency regulation.

[0078] During the command execution phase, multiple safety protection mechanisms are implemented simultaneously to ensure operational safety. These include: setting a lower limit protection for dilution air, real-time monitoring of the dilution fan flow rate, and automatic intervention of valve commands when the flow rate falls below a safe threshold to prevent excessive ammonia-air ratio from forming an explosive mixture; setting a lower limit protection for valve opening to prevent blockage of the ammonia injection pipeline; and a robust state-switching non-disruptive tracking mechanism to ensure smooth transition of command output when switching between automatic and manual modes, effectively preventing command jumps during state transitions. Precise adjustment of ammonia injection volume in each zone allows for more thorough mixing and reaction of ammonia with nitrogen oxides in the flue gas cross-section, ultimately promoting NO reduction at the denitrification outlet. x The concentration distribution tends to be uniform. This precise control method is particularly suitable for solving the long-standing problem of uneven ammonia injection on both sides of dual-flue units, effectively reducing the risk of local ammonia escape and extending the service life of downstream air preheaters and catalysts.

[0079] The NOx concentration at each monitoring point is monitored in real time and compared with the overall average NOx concentration of the region. When the current concentration at a certain monitoring point is significantly lower or significantly higher than the average value of all measurements (e.g., satisfying C≤0.2X or C≥2), the NOx concentration is considered lower. X ,in C This is the current test concentration. X NO for the whole partition x When the average concentration is reached, a fault diagnosis and automatic rejection mechanism is activated, and a self-diagnosis timer is started. If the abnormal state continues for a preset time (e.g., 4 hours) under automatic zone activation, an abnormal alarm is output, and the data of that measuring point is automatically rejected, preventing it from participating in the zone system calculation. Even if some measuring points malfunction, other zones can still spray ammonia normally, ensuring the NO concentration in the area remains stable. x Concentration uniformity and reliable operation of the control system.

[0080] By acquiring data that accurately reflects the concentration distribution across the flue gas duct cross-section using synchronous latching sampling technology, and generating precise zone control commands based on multi-round statistical analysis, combined with intelligent execution and protection mechanisms, the denitrification system achieves efficient and stable operation under all operating conditions, significantly improving NO reduction. x The uniformity of concentration distribution effectively controls ammonia slip levels, while enhancing the system's adaptability and reliability, providing technical support for thermal power units to meet environmental protection standards under deep peak shaving conditions.

[0081] Furthermore, in step S200, based on NO... x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone, including:

[0082] Step S210: Obtain multiple NOs for each partition within several adjustment rounds. xThe concentration measurement values ​​are obtained, and the average value of the zone measurements for each zone is calculated. Each adjustment round represents the completion of one round of concentration measurement for all zones.

[0083] In actual operation of thermal power units, especially under conditions of participating in deep peak shaving of the power grid, the NO at the SCR denitrification outlet... x The concentration can fluctuate instantaneously due to combustion fluctuations. To eliminate the interference of such random fluctuations on the control system, a multi-round measurement data processing method is adopted. In practice, several rounds of complete flue gas cross-section scanning measurements are performed continuously. In each round of measurement, flue gas samples from all zones are collected sequentially, and the corresponding NO is obtained. x Concentration values. For example, for a flue divided into 8 zones, complete 5-10 rounds of such full scans are performed, recording the concentration data for each zone in the corresponding round. Subsequently, the arithmetic mean of the concentration values ​​obtained for each zone across all rounds is calculated individually, yielding a stable and reliable average value for each zone. This multi-point averaging method based on time series effectively filters out the instantaneous fluctuations in flue gas concentration, providing statistically significant basic data for subsequent control decisions.

[0084] Step S220: Calculate the overall average value of the denitrification outlet flue section based on the average value of the zone-by-zone measurements for all zones.

[0085] After obtaining reliable average values ​​for each zone, it is necessary to establish an overall benchmark for evaluating the denitrification effect of the entire flue gas duct cross-section. This step involves performing an arithmetic mean calculation on the average values ​​of all zones to determine the NO₂ value representing the entire denitrification outlet flue gas duct cross-section. x The overall average concentration level is measured in rounds. This value reflects the overall performance of the denitrification system under current operating conditions and serves as an important reference benchmark for assessing the uniformity of concentration distribution in each zone. In practical applications, this overall average value is not only used for zone control but also as a monitoring indicator of system operating status. When the unit load changes, operators can observe the trend of the overall average value to determine the overall response characteristics of the denitrification system, providing a basis for operational optimization. Simultaneously, this value is also an important input parameter for determining whether leveling control of the flue gas ducts on both sides is necessary.

[0086] Step S230: Calculate the concentration deviation between the average value of each zone's rotational measurements and the overall average value of rotational measurements, and generate optimized control commands based on the concentration deviation to adjust the opening of the ammonia injection valve in the corresponding zone.

[0087] After obtaining the overall baseline value, the algebraic difference between the average value of each zone's round-robin measurements and the overall average value is calculated sequentially to obtain the concentration deviation value for each zone. This deviation value accurately quantifies the degree of deviation of each zone from the overall average level. A positive value indicates that the concentration in that zone is too high, requiring an increase in ammonia injection; a negative value indicates that the concentration is too low, requiring a decrease in ammonia injection. When generating specific valve control commands, the concentration deviation is used as the basic input, combined with preset control parameters for calculation. For example, for zones with large concentration deviations, a larger valve opening adjustment command is generated; while for zones with smaller deviations, fine adjustments are made. This zone control strategy based on precise deviation quantification can effectively correct the problem of uneven concentration distribution on the flue gas duct cross-section, ensuring that the ammonia injection rate in each area is precisely matched with the actual denitrification requirements.

[0088] By obtaining stable zonal concentration data through multiple rounds of measurement averaging, a scientific overall concentration benchmark is established, and zonal control commands are generated based on the accurately calculated concentration deviation. This effectively improves the accuracy and adaptability of ammonia injection control, significantly improves the uniformity of concentration distribution at the outlet section of the denitrification system, and provides a reliable technical guarantee for the unit to achieve efficient and stable denitrification performance under complex operating conditions.

[0089] Furthermore, after calculating the concentration deviation between the average value of each zone's round-robin measurements and the overall average value in step S230, the method further includes:

[0090] Step S240: Obtain the preset strength coefficient and actuation amplitude value of the ammonia injection valve for each zone.

[0091] In actual operation of thermal power units, due to differences in the length and resistance characteristics of each branch of the ammonia injection grid, and the varying flue gas flow conditions in different zones, it is difficult to achieve precise adjustment by directly using uniform control parameters. Therefore, dedicated intensity coefficients and actuation amplitude values ​​are preset for the ammonia injection valves of each zone. The intensity coefficient is mainly set based on the actual adjustment characteristics of each branch, used to adjust the control system's response sensitivity to concentration deviations. For example, a larger intensity coefficient is set for zones with slower responses to enhance the adjustment force. The actuation amplitude value is set according to valve characteristics and safe operation requirements, used to limit the maximum range of valve opening change during a single adjustment, preventing system oscillations caused by over-adjustment. These parameters are determined through on-site testing during the initial system commissioning and can be optimized and adjusted based on actual results during operation to adapt to the specific operating conditions of different units.

[0092] Step S250: Based on the preset intensity coefficient and action amplitude value, and combined with the concentration deviation, generate an optimized control command to adjust the opening degree of the corresponding zone ammonia injection valve.

[0093] After obtaining the concentration deviation and control parameters, a specific control algorithm generates the final valve adjustment command. In practice, the concentration deviation value is multiplied by the corresponding intensity coefficient to obtain the basic adjustment amount, which is then combined with the action amplitude value for limiting, ensuring that the single adjustment amount is within a reasonable range. For example, when a large positive deviation occurs in a certain zone, an instruction to increase the ammonia injection rate is generated, but by limiting the action amplitude value, excessive ammonia injection caused by sudden valve opening changes can be avoided. This control strategy ensures both rapid response to concentration deviations and maintains the stability of the adjustment process. In practical applications, the algorithm also considers valve nonlinearity compensation to ensure precise control across the full opening range, thereby effectively improving the uniformity of concentration distribution at the denitrification system outlet.

[0094] By configuring differentiated control parameters for each zone and using scientific control algorithms to generate optimized instructions, the precise matching of ammonia injection volume and denitrification requirements was achieved, effectively improving the accuracy and stability of regulation, significantly improving denitrification efficiency and ammonia escape control level, and providing a reliable guarantee for the unit to meet environmental protection standards under complex operating conditions.

[0095] Furthermore, considering the individual characteristics of ammonia injection valves in each zone, a valve characteristic compensation mechanism was introduced. For valves with slow response speeds, the lead adjustment component of the control command was appropriately increased; for valves with dead-zone characteristics, a control algorithm with dead-zone compensation was adopted; a valve characteristic database was also established to record the historical regulation performance data of each valve, and the control parameters for each valve can be continuously optimized through machine learning algorithms to ensure that all zone valves achieve the best regulation effect.

[0096] Furthermore, after obtaining the preset strength coefficient and actuation amplitude value of the ammonia injection valve in each zone in step S240, the process also includes:

[0097] Step S2411: Calculate the NO content of the denitrification outlet flue section based on the average value of all zone measurements. x Concentration distribution unevenness.

[0098] During the actual operation of thermal power units, especially when participating in deep peak shaving of the power grid, the NO at the outlet section of the SCR denitrification system increases due to frequent changes in boiler combustion conditions. x Concentration distribution uniformity fluctuates continuously. To quantitatively assess the degree of this non-uniformity, the concentration distribution non-uniformity is calculated based on the average values ​​of measurements from each zone. This index characterizes the dispersion of measurements from each zone relative to the overall average. Its calculation process comprehensively considers concentration data from all zones, objectively reflecting the concentration distribution across the entire flue cross-section. In practical applications, this index provides operators with an intuitive basis for evaluating distribution uniformity, helping to promptly identify distribution deterioration problems caused by changes in the flow field or uneven ammonia injection.

[0099] The calculation of concentration distribution non-uniformity employed standard statistical methods, quantifying distribution quality by analyzing the deviation of data from the overall average in each zone. Compared to simple comparisons of maximum and minimum values, this indicator provides a more comprehensive characterization of the distribution characteristics across the entire cross-section. The non-uniformity value increases significantly during rapid changes in unit load or fluctuations in coal quality, accurately reflecting the instability of the concentration distribution at these times. Continuous monitoring of this parameter's changing trend provides crucial information for subsequent adaptive adjustments to control parameters, ensuring the control system can intelligently adjust its control strategy based on actual operating conditions.

[0100] Step S2412: Based on the change in the value of non-uniformity, the motion amplitude is dynamically adjusted. When the value of non-uniformity increases, the motion amplitude value is increased proportionally; when the value of non-uniformity decreases, the motion amplitude value is decreased proportionally.

[0101] After obtaining the real-time concentration distribution non-uniformity, the control loop's action amplitude parameter is dynamically adjusted based on the changes in this parameter. When a significant increase in the non-uniformity value is detected, indicating a deterioration in the concentration distribution across the flue gas duct, the action amplitude value is increased accordingly according to a preset proportional relationship to enhance the adjustment force and accelerate the response to the non-uniformity problem. When the non-uniformity value continues to decrease, indicating an improvement in the distribution, the action amplitude value is decreased accordingly according to the same proportional relationship to avoid over-adjustment. This dynamic adjustment mechanism allows the control system to flexibly adjust the control intensity according to actual needs, adopting a more aggressive adjustment strategy when the distribution is severely non-uniform, ensuring a rapid restoration to a uniform distribution state.

[0102] During the dynamic adjustment of the actuation amplitude, a balance between adjustment effect and operational stability is considered simultaneously. While increasing the actuation amplitude to accelerate adjustment, the upper limit of the single adjustment amount of each zone valve is still maintained to avoid system oscillation caused by over-adjustment. When the concentration distribution tends to be uniform and the non-uniformity value decreases, the actuation amplitude is reduced accordingly, switching to fine adjustment mode to maintain stable system operation through small adjustments. This adaptive adjustment strategy based on the distribution condition enables the system to maintain excellent control performance across the entire operating range, effectively improving the denitrification system's adaptability to complex operating conditions.

[0103] By calculating the concentration distribution non-uniformity in real time and dynamically adjusting the control parameters based on its changes, the system's adaptive capability to operating conditions is realized, significantly improving the system's control performance under complex conditions such as load fluctuations. It effectively improves the concentration distribution uniformity at the outlet section of the denitrification system while ensuring the stability of the adjustment process, providing reliable technical support for the unit to meet environmental protection standards across the entire operating range.

[0104] Step S2413: When the unevenness remains below a preset threshold for several rounds, the motion amplitude value is restored to the initial preset value.

[0105] When the concentration non-uniformity remains below the preset excellent threshold for multiple consecutive adjustment cycles, it indicates that the NOx concentration distribution in the flue gas duct section has reached an ideal state and remains stable. At this point, the system automatically restores the action amplitude value to the initial preset value, reserving adjustment capacity to cope with possible subsequent changes in operating conditions. This reset mechanism ensures that the control system always has sufficient adjustment margin, avoiding weakening the system's response capability to sudden operating conditions due to prolonged small-amplitude adjustment.

[0106] In practical applications, determining the timing of the reset requires comprehensive consideration of the distribution stability and the degree of matching between operating conditions. Typically, a observation window of 3-5 consecutive adjustment cycles is set, during which the non-uniformity must remain below the threshold and the load conditions must be relatively stable. The reset process employs a gradual adjustment, restoring the system to its initial value in 2-3 cycles to avoid shocks caused by sudden parameter changes. This intelligent reset strategy ensures both economical operation under stable conditions and rapid response to changes in operating conditions, achieving an optimal balance between control performance and operational stability.

[0107] Furthermore, after obtaining the preset strength coefficient and actuation amplitude value of the ammonia injection valve in each zone in step S240, the process also includes:

[0108] Step S2421: Obtain the concentration deviation of each partition in the current and historical adjustment rounds, and calculate the variance of its concentration deviation as a concentration stability index for the partition.

[0109] In actual operation of thermal power units, especially when participating in deep peak shaving of the power grid, due to the instability of combustion conditions, NO in each zone... x Concentration deviations exhibit varying fluctuation characteristics. To accurately assess the stability of concentrations in each zone, concentration deviation data sequences for each zone are collected across current and historical adjustment cycles. By calculating the statistical variance of these deviations, a quantified zone concentration stability index is obtained. This time-series-based variance calculation effectively reflects the fluctuation range of concentration deviations in each zone. A larger variance value indicates less stable concentration control in that zone, potentially indicating problems such as uneven flow field or poor ammonia injection response. In practical applications, this index provides operators with a basis for zone-level stability assessment, helping to identify specific areas with poor control performance.

[0110] The concentration stability index was calculated using standard variance statistics. By processing concentration deviation data over multiple consecutive control cycles, a quantitative assessment of the control quality of each zone was obtained. Under conditions of rapid load changes or significant coal quality fluctuations, the concentration stability index of some zones will increase significantly, accurately reflecting the control difficulty in these areas under changing conditions. Continuous monitoring of the stability index changes in each zone provides an important basis for subsequent control parameter optimization, enabling the control system to implement differentiated optimization strategies based on the actual control conditions of different zones.

[0111] Step S2422: Calculate the average value of the concentration stability index for all partitions as the system baseline stability level.

[0112] After obtaining the concentration stability indices for each zone, a benchmark reference for evaluating the overall control stability of the system needs to be established. The stability indices of all zones are calculated using an arithmetic mean to obtain the benchmark stability level representing the overall control stability of the denitrification system. This benchmark value reflects the average stability of each zone's control under the current operating conditions, providing a comparative benchmark for assessing the relative stability of each zone. During normal unit operation, this benchmark stability level remains relatively stable, while when significant changes occur in the unit's operating conditions, the benchmark stability level can promptly reflect the fluctuations in the overall control stability of the system.

[0113] The establishment of a baseline stability level provides a scientific basis for the relative evaluation of the control performance of each zone. In actual operation, when the overall control stability is good, the stability indicators of each zone are usually close to the baseline stability level; however, when individual zones experience control anomalies, the stability indicators of these zones will deviate significantly from the baseline values. Operators can monitor the differences between the stability indicators of each zone and the baseline stability level to promptly identify zones with control anomalies and take appropriate measures. Furthermore, this baseline stability level is also a key reference for the control system's parameter self-optimization.

[0114] Step S2423: Identify the concentration deviation sign of each zone in the continuous adjustment rounds and determine its continuous deviation direction.

[0115] When assessing the control stability of each zone, variance alone cannot distinguish between random fluctuations and systematic deviations. Therefore, it is necessary to analyze the concentration deviation sign sequence of each zone in consecutive adjustment rounds, and identify persistent deviation patterns by statistically counting the number of rounds with consecutive positive deviations. When a zone shows consecutive positive or negative deviations in multiple rounds, it indicates a systematic control problem in that area, rather than random fluctuations. Identifying this persistent deviation direction provides crucial information for the precise adjustment of subsequent intensity coefficients.

[0116] In practical applications, determining a persistent deviation requires setting a clear round threshold. Typically, a persistent deviation is considered to exist only after three or more consecutive adjustment rounds showing a deviation in the same direction. For each zone, the system records the deviation sign sequence of the most recent 10 rounds and identifies persistent deviation patterns through sliding window analysis. This analysis process is performed simultaneously with the calculation of stability indicators, together forming a complete evaluation system for the zone control status.

[0117] Step S2424: Compare the concentration stability index of each zone with the system's baseline stability level. When the concentration stability index of a zone is higher than the baseline stability level and there is a consistent and continuous deviation direction, increase the intensity coefficient of the zone proportionally.

[0118] After obtaining the system's baseline stability level and the stability indices of each partition, a comprehensive judgment is made based on the identification results of persistent deviation directions. For partitions with stability indices significantly higher than the baseline stability level and exhibiting a consistent, persistent deviation direction, it indicates that this region not only has poor control performance but also exhibits systemic control bias, requiring enhanced control measures. In this case, the intensity coefficient of the partition is increased accordingly, based on the degree to which its stability index exceeds the baseline stability level, according to a preset proportional relationship. This dual judgment mechanism, based on stability assessment and deviation direction identification, can accurately identify partitions that truly require strengthened control, avoiding over-adjustment of regions with random fluctuations.

[0119] A gradual optimization strategy was adopted during the adjustment of the strength coefficient. When the stability index of a certain zone consistently exceeded the baseline stability level and showed a consistent deviation direction, the strength coefficient of that zone was gradually increased until the control stability of that zone was significantly improved. Simultaneously, an upper limit for the adjustment of the strength coefficient was set to prevent system oscillations caused by excessive parameter adjustment. In practical applications, this parameter adaptive adjustment mechanism based on dual judgment enables the control system to accurately identify problem areas and implement targeted optimizations, effectively improving the system's control adaptability and stability across the entire operating range.

[0120] Step S2425: When the concentration stability index of a zone is lower than the baseline stability level, or when the concentration stability index of a zone is higher than the baseline stability level but there is no consistent and continuous deviation direction, the intensity coefficient of the zone is reduced proportionally.

[0121] For zones with good control performance, the control intensity should be reduced in a timely manner to avoid over-adjustment. When the concentration stability index of a zone is lower than the baseline stability level, it indicates that the control performance in that area is better than the system average. In this case, the intensity coefficient should be reduced proportionally, and a fine-tuning mode should be entered. Similarly, when the stability index of a zone is higher than the baseline stability level but there is no consistent and continuous deviation direction, it indicates that the fluctuation in that area is random rather than a systematic deviation. The intensity coefficient should also be reduced to avoid overreacting to random fluctuations.

[0122] The reduction of the intensity coefficient also employs a gradual strategy to ensure a smooth transition of the control system. The magnitude of each adjustment is proportional to the degree to which the stability index deviates from the baseline stability level, but a lower limit protection is set to prevent insufficient control due to an excessively small intensity coefficient. This two-way adjustment mechanism ensures that the control intensity of each zone always matches the actual control requirements, guaranteeing both control effectiveness and improved system operational economy.

[0123] Step S2426: When the concentration stability index of all zones is lower than the baseline stability level for multiple consecutive adjustment rounds and there is no obvious and continuous deviation in direction, restore the intensity coefficient of all zones to the initial preset value.

[0124] When the system as a whole enters a highly stable state, the control parameters need to be restored to their initial settings in a timely manner to reserve adjustment capacity for subsequent changes in operating conditions. When the stability indicators of all zones are lower than the baseline stability level for several consecutive cycles (usually 5-7 cycles), and no obvious continuous deviation direction is detected in any zone, it indicates that the system has reached an ideal stable state. At this time, the strength coefficients of all zones should be uniformly restored to their initial preset values ​​to ensure that the system maintains optimal adjustment margin.

[0125] The reset process employs a step-by-step, gradual approach, progressively restoring parameters over 2-3 adjustment cycles. This gradual reset avoids the impact of sudden parameter changes on the system, while allowing continuous monitoring of stability changes during the reset process. After reset, the system enters a new monitoring-evaluation-adjustment cycle to ensure optimal control performance is maintained. This intelligent reset mechanism is a key manifestation of the control system's adaptive capability, effectively balancing control accuracy and system stability.

[0126] By establishing a zoned concentration stability assessment system, and implementing adaptive adjustment of the intensity coefficient based on the difference between the stability of each zone and the baseline stability level, intelligent optimization of control parameters was achieved. This significantly improved the system's adaptability to the control characteristics of each zone, effectively improved the stability and uniformity of concentration control, and provided reliable technical support for the unit to maintain excellent denitrification performance under complex operating conditions.

[0127] Furthermore, in step S250, based on a preset intensity coefficient and action amplitude value, and combined with the concentration deviation, an optimized control command is generated to adjust the opening degree of the corresponding zone ammonia injection valve, including:

[0128] Step S2501: The concentration deviation is divided into segments, and different combinations of intensity coefficients and action amplitude values ​​are used for concentration deviation intervals of different sizes.

[0129] In the actual operation of thermal power units participating in deep peak shaving of the power grid, the concentration deviation of each zone of the SCR denitrification system exhibits obvious nonlinear characteristics due to multiple factors such as boiler combustion fluctuations and changes in flue gas flow field. To cope with this complex operating condition, the control system, based on long-term operating data accumulation and flow field characteristics under different loads, divides the concentration deviation into three typical ranges: small deviation range (within ±5mg / Nm³), medium deviation range (±5-15mg / Nm³), and large deviation range (above ±15mg / Nm³). Each range has undergone rigorous field testing and parameter tuning, and is configured with a specially optimized combination of intensity coefficient and action amplitude to ensure precise matching between control parameters and deviation characteristics.

[0130] In practice, the magnitude and trend of concentration deviations in each zone are monitored in real time to dynamically determine the current deviation range. For small deviation ranges, a mild adjustment strategy is adopted to primarily eliminate the impact of random fluctuations; for medium deviation ranges, a moderate adjustment intensity is applied to accelerate the adjustment speed while ensuring stability; for large deviation ranges, an enhanced adjustment mode is activated to address significant uneven distribution caused by sudden changes in the flow field or abnormalities in the ammonia injection system. This segmented approach allows the control system to flexibly adjust the control intensity according to actual needs, avoiding equipment wear caused by frequent adjustments while ensuring rapid response to various deviations.

[0131] The parameter combinations for each deviation interval fully consider the balance between regulation effect and system stability. During actual operation, operators can fine-tune the interval thresholds and control parameters according to the specific characteristics of the unit to adapt to the individual needs of different units. Simultaneously, a parameter adaptive mechanism has been established, which can automatically optimize the parameter settings for each interval based on long-term operating results, ensuring that the control system maintains excellent control performance throughout the entire operating range. This refined segmented control strategy significantly improves the denitrification system's adaptability to complex operating conditions, providing a reliable guarantee for environmental compliance during deep peak shaving periods.

[0132] Step S2502: For concentration deviations within the preset normal fluctuation range, standard intensity coefficient and standard action amplitude value are used for processing.

[0133] When the concentration deviation of each zone in the denitrification system is within the preset normal fluctuation range, it indicates that the ammonia injection rate of that zone is basically matched with the denitrification demand, and the system is operating well. At this time, the control system uses a standard intensity coefficient and standard action amplitude value that have been verified through extensive practice. This parameter combination maintains a moderate adjustment level, effectively eliminating small concentration deviations caused by slight combustion fluctuations while also preventing frequent valve operations and system oscillations due to over-adjustment. This control strategy is particularly suitable for long-term continuous operation of the unit under stable load conditions, ensuring the denitrification system operates within its optimal operating range by maintaining stable adjustment of the ammonia injection valves in each zone.

[0134] In practical engineering applications, the determination of the normal fluctuation range employs a statistical analysis method based on historical operating data. By collecting concentration data for each zone during stable operation of the unit at different load segments, the standard deviation and distribution characteristics are calculated, thereby scientifically setting the normal fluctuation threshold corresponding to each load segment. For example, under stable operation at 75% load, the normal fluctuation range might be set to ±3 mg / Nm³, while at 50% load, it might be adjusted to ±4 mg / Nm³. This differentiated setting based on load conditions ensures that the control system can achieve refined and stable control across the entire operating range, guaranteeing both control sensitivity and maintaining the long-term operational stability of the system.

[0135] Step S2503: For large concentration deviations that exceed the preset normal fluctuation range, a combination strategy of enhancing the intensity coefficient and limiting the action amplitude value is adopted to ensure the adjustment strength while preventing over-adjustment.

[0136] When the SCR denitrification system detects a large concentration deviation exceeding the normal fluctuation range in a certain zone, the enhanced control mode is immediately activated. This large deviation typically occurs under conditions such as rapid load changes in the unit, sudden changes in coal quality, or abnormal flow field distribution. In such cases, the intensity coefficient is increased to 1.5-2.0 times the standard value, significantly enhancing the adjustment sensitivity. Simultaneously, the action amplitude is limited to 50%-70% of the standard range, ensuring that each adjustment has sufficient force without causing system instability due to excessive amplitude. This parameter combination has been rigorously verified through field testing and can effectively prevent concentration oscillations caused by valve overshoot while ensuring the adjustment effect.

[0137] In actual operation, this control strategy places particular emphasis on the smoothness of the dynamic adjustment process. By monitoring the trend of deviation changes in real time, the specific combination of the enhancement coefficient and the limit value is dynamically adjusted. When the deviation begins to converge, the enhancement coefficient is gradually reduced, smoothly transitioning to the standard control mode. This intelligent transition mechanism ensures smooth stability during large deviation adjustments, guaranteeing both rapid response capability and maintaining the long-term operational reliability of the system, providing an important guarantee for the unit to meet environmental protection standards under complex operating conditions.

[0138] By segmenting the concentration deviation and using differentiated control parameter combinations, a precise match between the control strategy and the degree of deviation is achieved. This ensures smooth adjustment of small deviations while enhancing the rapid response capability to large deviations, significantly improving the control adaptability and stability under different operating conditions, and providing a reliable guarantee for the optimized operation of the denitrification system under all operating conditions.

[0139] Furthermore, in step S210, multiple NOs for each partition are obtained within several adjustment rounds. x Before the concentration measurement, it also includes:

[0140] Step S201: Calculate the NO of the corresponding denitrification outlet flue section for the current cycle. x Concentration distribution non-uniformity, the rate of change between the non-uniformity of the previous round and that of the previous round.

[0141] In actual operation, the uniformity of concentration distribution at the outlet section of a denitrification system fluctuates dynamically with changes in load. To accurately grasp the trend of concentration distribution changes, the rate of change of non-uniformity between the current and previous measurements is calculated in real time after each measurement cycle. This rate of change is obtained by comparing the ratio of the difference in non-uniformity values ​​between two adjacent cycles to the time interval, and can quantitatively characterize the rate of improvement or deterioration of concentration distribution uniformity. When the unit load changes rapidly, this rate of change can effectively reflect the adjustment effect of the control system on the concentration distribution, providing an important basis for the optimization of subsequent control parameters.

[0142] Step S202: Compare the rate of change with a preset negative rate of change threshold: If the rate of change is less than the preset negative rate of change threshold, it is determined that it is in a rapid optimization state and the number of adjustment rounds is reduced.

[0143] When the system detects through real-time monitoring that the rate of change of concentration distribution non-uniformity is consistently below a preset negative threshold, this quantitative indicator clearly shows that the ammonia injection regulation in each zone is producing a significant effect, and the concentration field distribution is rapidly becoming more uniform. At this point, the control system automatically enters a rapid optimization mode, improving system response performance by dynamically adjusting the data acquisition strategy. In specific implementation, the number of adjustment rounds used to calculate the average value of zone measurements is gradually reduced from the baseline of 8 rounds to 4-5 rounds. This adjustment is based on in-depth analysis of the system's dynamic characteristics, ensuring a significant increase in the update frequency of control commands while maintaining data validity.

[0144] During periods of dynamic load change in the generating unit, this adaptive cycle adjustment mechanism demonstrates significant advantages. When the unit load increases or decreases at a rate of 1-2% per minute, reducing the number of adjustment cycles allows the control system to update commands 2-3 control cycles earlier, ensuring that ammonia injection regulation tracks load changes in a timely manner. In practical applications, by monitoring the duration and magnitude of the non-uniformity rate of change, the appropriate timing and magnitude of cycle adjustments are intelligently determined, avoiding control command fluctuations caused by excessive reduction in cycles. This refined adjustment strategy ensures both timely control and system stability.

[0145] This dynamic rotation adjustment mechanism has been validated in practice at multiple power plants, significantly improving system response speed while ensuring control accuracy. It also incorporates boundary protection for rotation adjustments, ensuring the number of rotations is always maintained above the minimum required for effective statistics. Through this intelligent rotation management, the control system achieves an optimal balance between rapid response and stable operation during unit peak shaving, providing reliable technical support for responding to rapid changes in grid load commands.

[0146] Step S203: Compare the absolute value of the rate of change with the preset steady-state threshold: If the absolute value of the rate of change is less than the steady-state threshold, the system is determined to be stable, and the number of adjustment rounds is increased.

[0147] When the absolute value of the rate of change of concentration distribution non-uniformity is consistently below the steady-state threshold, it indicates that the concentration fields of each zone have entered a relatively stable stage, and the overall control effect of the system has reached a relatively optimal level. At this time, the control system automatically switches to fine-tuning mode, gradually increasing the number of adjustment rounds used to calculate the average value of zone measurements from the baseline of 8 rounds to 12 rounds. This adjustment strategy improves the reliability of data statistics by increasing the number of samples, utilizes measurement data from more rounds to eliminate the interference of random fluctuations on control decisions, and lays the foundation for generating more accurate control commands.

[0148] In actual operation, this cycle-increasing mechanism is particularly suitable for long-term operation of the unit under stable load. By using a moving average algorithm to process the concentration data from 12 cycles, measurement noise and instantaneous fluctuations can be effectively filtered out, making the obtained average value more representative. Simultaneously, a dynamic management mechanism for the number of cycles is established, intelligently adjusting the number of cycles based on the duration of the stable state and fluctuation characteristics, ensuring that control accuracy is maintained while avoiding excessively prolonged response time. This intelligent cycle management strategy enables the control system to maintain higher control accuracy under stable operating conditions, effectively reducing unnecessary frequent valve movements, improving system operation economy and equipment lifespan.

[0149] In one specific embodiment of the present invention, the denitrification outlet flue of a thermal power unit includes: a first flue and a second flue. Correspondingly, the ammonia injection control method further includes:

[0150] Step S410: Calculate the first overall average value of all zones corresponding to the first flue and the second overall average value of all zones corresponding to the second flue.

[0151] In the actual operation of thermal power units with a dual-flue structure, due to factors such as boiler combustion characteristics and differences in flue layout, the flow field distribution and NO in the two flues vary. x Concentration characteristics often exhibit inherent differences. To accurately assess the overall denitrification effect of each flue, independent data processing was performed on all zones within the first and second flues. A weighted average of the average values ​​measured in each zone within each flue was calculated to obtain the first and second overall average values ​​representing the overall concentration level of each flue. This zonal statistical method eliminates the impact of anomalies in individual zone data on the overall assessment, ensuring that the obtained overall flue concentration values ​​are sufficiently representative.

[0152] In practical applications, a sliding window averaging method is used to process the concentration data of each zone, ensuring the timeliness and accuracy of the calculation results. For a typical dual-flue structure with eight zones, the average concentration of four zones in each of the two flues is calculated separately, and the influence of abnormal measurements is eliminated through a data validity verification mechanism. This independent calculation method can accurately reflect the actual operating status of each flue, providing a reliable data foundation for subsequent flue leveling control, and is particularly suitable for solving long-term concentration deviation problems caused by flue structure asymmetry.

[0153] Step S420: Calculate the deviation between the average value of the first overall round measurement and the average value of the second overall round measurement.

[0154] After obtaining the overall average concentration of the two flues, the concentration deviation between them is calculated using algebraic operations. This deviation accurately quantifies the degree of concentration difference between the two flues; a positive value indicates that the concentration in the first flue is higher than that in the second, while a negative value indicates the opposite. During actual unit operation, this deviation may be caused by various factors such as uneven burner air distribution and unbalanced flue gas recirculation distribution. Accurate deviation calculation provides a clear basis for the direction and magnitude of subsequent leveling control.

[0155] When calculating the deviation value, the changing trend of historical deviation data is also considered. By comparing the difference between the current deviation and the historical average level, it is determined whether the deviation is a temporary fluctuation or a systematic deviation. For long-term systematic deviations, an enhanced balancing mode is activated, while a relatively mild adjustment strategy is adopted for random fluctuations. This intelligent deviation analysis mechanism ensures the accuracy and effectiveness of balancing control and can adapt to the balancing needs of the unit under various operating conditions.

[0156] Step S430: Based on the deviation value, synchronously adjust the total ammonia injection flow rate allocated to the first flue and the second flue respectively, so that the average value of the first overall rotation measurement and the average value of the second overall rotation measurement tend to be consistent.

[0157] Based on the calculated deviation, a specially designed balancing control algorithm generates coordinated adjustment commands for the total ammonia injection flow rate in the two flues. When the concentration in the first flue is detected to be higher than that in the second flue, the total ammonia injection flow rate in the second flue is increased simultaneously, while the ammonia injection flow rate in the first flue is decreased accordingly. This reverse symmetrical adjustment method can quickly eliminate the concentration difference between the two flues while maintaining the overall stability of the total ammonia level in the system. The balancing control adopts a gradual adjustment strategy, ensuring a smooth transition of the system to a balanced state through gradual adjustments over multiple control cycles.

[0158] During the leveling control process, the concentration change response of the two flues is monitored in real time, and the adjustment parameters are dynamically optimized. For flues with slower response, the adjustment intensity is appropriately increased; for flues with significant overshoot, a smaller adjustment step size is adopted. Simultaneously, a limit protection for the leveling amplitude is set to prevent concentration oscillations caused by excessive adjustment. This intelligent leveling control strategy has demonstrated excellent performance in practical applications at multiple power plants, effectively solving the long-standing concentration deviation problem in dual-flue units.

[0159] By calculating the overall concentration level of the two flues separately, the concentration deviation between the flues is accurately quantified, and intelligent coordination and leveling control is implemented based on the deviation value. This effectively eliminates the concentration difference between the two flues, significantly improves the uniformity and stability of the overall operation of the denitrification system, prevents the blockage of the air preheater on one side caused by uneven ammonia injection in the flue, and enhances the unit's environmental control capabilities under complex operating conditions.

[0160] Further, step S430, based on the deviation value, synchronously adjusts the total ammonia injection flow rate allocated to the first and second flues respectively, including:

[0161] Step S4311: Obtain the real-time load value of the thermal power unit and determine its preset load condition range based on the real-time load value.

[0162] When thermal power units participate in grid peak shaving, frequent changes in unit load significantly affect boiler combustion and flue gas flow characteristics, leading to dynamic changes in the concentration distribution between the two flue gas ducts. To adapt to these changes in operating conditions, the unit load signal is collected in real time, and the current load operating condition range is accurately determined according to a preset load range division standard. In practical applications, the load range is typically divided into three typical operating condition segments: low load range (below 50% of rated load), medium load range (50%-80% of rated load), and high load range (above 80% of rated load). Each operating condition segment corresponds to different flue gas flow characteristics and concentration distribution features.

[0163] The division of load condition ranges is based on statistical analysis of a large amount of historical operating data, comprehensively considering flue gas velocity, temperature distribution, and NO under different loads. x The changing patterns of generation characteristics are observed. Unit load data is acquired in real-time via the DCS interface, and a hysteresis comparison algorithm is employed to avoid frequent switching of operating conditions at interval boundaries, ensuring the accuracy and stability of load condition identification. This load-condition-based adaptive mechanism provides crucial information for subsequent balancing parameter selection, enabling the control system to intelligently adjust its control strategy according to changes in operating conditions.

[0164] Step S4312: Select the corresponding flue gas balance adjustment coefficient from a predefined mapping relationship according to the preset load condition range.

[0165] To address the differences in dynamic characteristics of a dual-flue system under varying load conditions, a mapping relationship between load conditions and flue balance adjustment coefficients was established. This mapping relationship, tuned based on extensive field test data, accurately reflects the optimal response characteristics of the balancing control system under each load condition. Under low load conditions, due to lower flue gas velocity and poorer mixing, a relatively small balance adjustment coefficient is selected to avoid system oscillation caused by over-adjustment. Under medium-to-high load conditions, a larger adjustment coefficient is used to ensure the speed and effectiveness of balancing control.

[0166] The preset mapping relationship of the balancing adjustment coefficients is stored in the system configuration file and can be optimized and adjusted online according to the actual operating effect of the unit. A coefficient smooth transition mechanism is also set up; when the load condition changes, the balancing adjustment coefficients will gradually transition to the target value at a preset rate, avoiding control disturbances caused by sudden coefficient changes. This refined coefficient management strategy ensures the adaptability and stability of the balancing control system across the entire load range, effectively improving the system's control quality.

[0167] Step S4313: Based on the deviation value and the flue gas balance adjustment coefficient, calculate the baseline adjustment amount of the total ammonia injection flow rate.

[0168] After obtaining the concentration deviation values ​​between flue gas ducts and the corresponding balance adjustment coefficients, the baseline adjustment amount for the total ammonia injection flow rate is calculated through multiplication. This calculation process fully considers the combined effects of the deviation magnitude and operating conditions to ensure that the adjustment amount accurately matches the actual leveling requirements. When the concentration deviation between flue gas ducts is large, a larger baseline adjustment amount is generated by combining an appropriate balance adjustment coefficient to accelerate the leveling process; for smaller concentration deviations, a relatively mild adjustment amount is generated to maintain the stable operation of the system.

[0169] The calculation of the benchmark adjustment also incorporates a limiting protection mechanism, ensuring that the adjustment range for each instance remains within a reasonable range by setting upper and lower limits. Simultaneously, the benchmark adjustment is dynamically corrected based on the deviation trend; when the deviation is detected to be continuously increasing, the adjustment intensity is appropriately increased; when the deviation shows a convergence trend, the adjustment intensity is correspondingly decreased. This intelligent adjustment calculation strategy ensures both the speed of leveling control and the stability of the adjustment process.

[0170] Step S4314: The baseline adjustment amount is synchronously superimposed onto the total ammonia injection flow rate set values ​​of the first and second flues, and the first and second flues are adjusted in opposite directions symmetrically.

[0171] After calculating the baseline adjustment amount, it is synchronously applied to the total ammonia injection flow control loop of both flues. In practice, for the flue with the higher concentration, the baseline adjustment amount is subtracted from its total ammonia injection flow setpoint; for the flue with the lower concentration, the same adjustment amount is added to the original setpoint. This reverse symmetrical adjustment method can quickly and effectively eliminate the concentration deviation between the two flues while maintaining the total ammonia injection flow rate of the system essentially unchanged, avoiding adverse effects on the overall denitrification efficiency of the system due to leveling operations.

[0172] During the execution of adjustment commands, the ammonia injection flow and concentration changes in both flues are monitored in real time, and the adjustment effect is dynamically optimized through a closed-loop feedback mechanism. When a slow response is detected in one flue, the adjustment component on that side is appropriately increased; when overshoot occurs, the adjustment intensity is promptly reduced. Simultaneously, an adjustment rate limit is set to ensure smooth changes in ammonia injection flow and prevent impact on downstream equipment. The successful application of this refined leveling control strategy in multiple power plants demonstrates its effectiveness in solving the long-standing problem of uneven concentration in dual-flue units.

[0173] By establishing a load-adaptive flue gas balancing adjustment mechanism, a benchmark adjustment amount is generated based on the accurately calculated concentration deviation and intelligently selected adjustment coefficient. A reverse symmetrical adjustment strategy is adopted to implement dual flue gas balancing control, which effectively eliminates the concentration difference between flues, significantly improves the uniformity and stability of the denitrification system, and enhances the adaptability to different operating conditions, providing a reliable guarantee for the unit to meet environmental protection standards across the entire load range.

[0174] Further, the synchronous adjustment in step S430, which allocates the total ammonia injection flow rate to both the first and second flues, includes:

[0175] Step S4321: Calculate the dynamic rate of change of the overall average value of the first flue and the second flue in multiple consecutive adjustment cycles.

[0176] In the actual operation of dual-flue thermal power units, the response characteristics of the two flues to ammonia injection regulation often differ significantly due to differences in flue structure, catalyst activity, or flow field resistance. To accurately grasp the dynamic response characteristics of each flue, the dynamic change rate of the first and second flues was calculated by analyzing the changing trend of the overall average value measured in multiple consecutive adjustment cycles. This change rate was obtained by processing the time series data using a linear regression method, which can quantitatively characterize the rate of change of the concentration value of each flue over time. When the unit load changes or the ammonia injection rate is adjusted, this dynamic monitoring can promptly reflect the inertial characteristics of each flue system, providing an important basis for subsequent intelligent leveling.

[0177] The dynamic change rate is calculated using a sliding time window technique, selecting data from the most recent 8-12 adjustment cycles for regression analysis to ensure the timeliness and accuracy of the calculation results. In practical applications, a data validity verification mechanism is also established to automatically remove invalid data points caused by measurement anomalies, ensuring the reliability of the change rate calculation. Continuous monitoring of the dynamic change rates of the two flues allows for accurate identification of flues with slow responses, providing data support for implementing differentiated leveling strategies and effectively solving the leveling difficulties caused by uneven flue characteristics.

[0178] Step S4322: Calculate the ratio of the dynamic change rate of the first flue to the dynamic change rate of the second flue, and use it as the flue response rate ratio.

[0179] After obtaining the dynamic change rates of the two flues, their ratio is calculated through division to obtain a standardized flue response rate ratio. This ratio eliminates the influence of the dimensions of the absolute rate values ​​and clearly reflects the difference in the relative response capabilities of the two flues. When the ratio is greater than 1, it indicates that the first flue responds faster than the second flue; a ratio less than 1 indicates that the second flue has a faster response characteristic. This relative comparison method allows for accurate determination of the differences in dynamic characteristics between the flues, providing a precise quantitative basis for subsequent weight allocation.

[0180] In actual operation, the response rate ratio is monitored and filtered in real time. A moving average algorithm is used to eliminate the impact of instantaneous fluctuations, ensuring the stability and reliability of the ratio. Simultaneously, a range protection mechanism for the ratio variation is implemented. When an abnormal speed ratio is detected, a backup strategy is automatically activated to prevent control errors caused by measurement anomalies. This refined processing mechanism ensures the stable operation of the leveling control system under various operating conditions, significantly improving the system's robustness and reliability.

[0181] Step S4323: Calculate the dynamic allocation weight based on the flue response rate ratio, where flues with slower dynamic change rates are assigned higher allocation weights.

[0182] Based on the calculated flue response rate ratio, a dynamic weight allocation is generated using a pre-defined weighting function. This function employs an inverse proportional relationship, assigning a larger weight to flues with slower response rates, thus providing them with more adjustment resources during the leveling process. For example, when the response rate of one flue is only half that of another, its weight may be 1.5-2 times that of the other. This weight allocation strategy effectively compensates for the differences in dynamic characteristics between flues, ensuring that both flues can reach the leveling target synchronously.

[0183] The calculation of dynamically allocated weights also considers the system's stability requirements, preventing overcompensation by setting upper and lower limits for the weights. A smooth transition algorithm is employed; when the response rate ratio changes, the allocated weights are gradually adjusted to the target value at a preset rate, avoiding control disturbances caused by sudden weight changes. Simultaneously, a weight self-learning mechanism is established to automatically optimize the weight calculation parameters based on historical leveling results, continuously improving the accuracy and adaptability of the leveling control.

[0184] Step S4324: The baseline adjustment amount is differentially allocated according to the dynamic allocation weight and superimposed on the total ammonia injection flow rate setting value of the corresponding flue.

[0185] After obtaining the dynamic allocation weights, the baseline adjustment amount is differentiated according to the weight ratio to generate specific adjustment instructions for each flue. Flues with slower response times receive more adjustment amounts due to their larger weights, thus accelerating their response. Conversely, flues with faster response times receive relatively less adjustment amounts to prevent overshoot. This differentiated allocation strategy effectively coordinates the adjustment progress of the two flues, ensuring they reach concentration equilibrium synchronously.

[0186] During the execution of adjustment commands, the concentration changes in each flue are monitored in real time, and the weight allocation is dynamically optimized. When the adjustment effect of a certain flue deviates from the expected value, its weight allocation is adjusted promptly to ensure the smooth progress of the leveling process. Simultaneously, rate and amplitude limits for the adjustment amount are set to prevent excessive impact on the flue system. The successful application of this intelligent leveling control strategy in multiple power plants demonstrates its effectiveness in solving the problem of asynchronous leveling caused by differences in the dynamic characteristics of flues.

[0187] By monitoring the dynamic response characteristics of the dual flues in real time, intelligently calculating and allocating weights based on the response rate ratio, and implementing differentiated allocation of the benchmark adjustment amount, the problem of asynchronous leveling caused by differences in flue characteristics is effectively solved. This significantly improves the accuracy and efficiency of dual flue concentration leveling, ensuring that the optimal leveling state can be reached quickly and smoothly under various operating conditions, providing a reliable guarantee for the safe and stable operation of the unit.

[0188] In addition to basic concentration control functions, a comprehensive operational status assessment system has been established. By continuously monitoring multiple indicators such as concentration change trends in each zone, valve adjustment frequency, and ammonia injection fluctuations, the system's operational status is comprehensively evaluated. When a zone experiences persistent concentration anomalies or frequent valve operations, the system automatically generates operational optimization suggestions to guide operators in making corresponding adjustments and maintenance. The system can also automatically identify potential problems such as decreased catalyst activity and clogged ammonia injection grids, providing crucial information for preventative equipment maintenance.

[0189] Accordingly, please refer to Figure 4 The second aspect of the present invention provides a NO-based x The ammonia injection control system with zoned synchronous measurement is equipped with flue gas sampling probes in several zones of the denitrification outlet flue gas duct of the thermal power unit. Flue gas samples collected by each sampling probe are sent to the flue gas analyzer in turn. The ammonia injection control system includes:

[0190] Data acquisition module 1 is used to synchronously latch flue gas samples from several zones on the denitrification outlet flue of thermal power units, obtaining the NO content of the denitrification outlet flue cross-section at the same time. x Concentration field distribution, NO xThe concentration field distribution represents the spatial distribution of nitrogen oxide concentration in each section of the denitrification outlet flue gas duct.

[0191] Instruction generation module 2, used for NO x The concentration field distribution generates optimized control commands for the ammonia injection valves in each zone.

[0192] The zone control module 3 is used to adjust the opening degree of the ammonia injection valve in the corresponding zone according to the optimized control command, so as to achieve precise ammonia injection in the zone.

[0193] Accordingly, a third aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the above-described NO-based... x Ammonia injection control method with zoned synchronous measurement.

[0194] Accordingly, a fourth aspect of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the above-described NO-based... x Ammonia injection control method with zoned synchronous measurement.

[0195] The embodiments of the present invention aim to protect a NO-based x The ammonia injection control method based on zoned synchronous measurement has the following advantages:

[0196] 1. Through synchronous latching and measurement technology, it was the first time that the NO at the same moment across the entire flue section at the SCR outlet was measured. x The accurate acquisition of the concentration field distribution overcomes the inherent defect of poor representativeness of traditional single-point measurement. On this basis, a closed-loop control loop from the concentration field to the zone valve command is constructed, which can accurately locate and eliminate areas with uneven concentration distribution, so that the ammonia injection rate and nitrogen oxide distribution can be dynamically matched. This not only significantly improves the denitrification efficiency, but also improves the uniformity of the outlet concentration from the root, effectively solving the problem of local ammonia escape caused by uneven distribution.

[0197] 2. By calculating indicators such as concentration distribution non-uniformity and zone concentration stability in real time, the system dynamically adjusts key parameters such as control rounds, action amplitude, and intensity coefficient, achieving precise matching between the control strategy and the current operating state of the system. Whether facing frequent load changes or dealing with dynamic response differences in different zones, the system can automatically adjust the control intensity and response speed, achieving the best balance between rapid correction and stable operation, thereby maintaining excellent control quality across the entire operating range.

[0198] 3. By implementing measures such as dilution air lower limit protection and valve lower limit protection, operational risks inherent in the equipment are prevented. Through fault diagnosis and automatic rejection mechanisms for measuring devices, the control system can still operate reliably even when some measuring points are abnormal. In addition, the linkage between the dual flue leveling logic and load conditions avoids downstream equipment blockage caused by uneven ammonia injection, reduces the system's reliance on manual intervention, and ensures its ability to operate continuously, stably, and safely in industrial settings.

[0199] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0200] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0201] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0202] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0203] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method of controlling NOxemissions from a combustion process based on the measurement of NOx x ammonia injection control method based on the partitioned synchronization measurement, characterized by, A plurality of partitioned zones of a flue gas denitration outlet flue of a thermal power unit are respectively provided with flue gas sampling probes, flue gas samples collected by each of the flue gas sampling probes are sent to a flue gas analyzer in turn, and the ammonia injection control method comprises the following steps: synchronously lock the flue gas samples of several partitions of the denitration outlet flue of the thermal power unit to obtain the NO x concentration field distribution of the denitration outlet flue section of the thermal power unit x The NO x concentration field distribution represents the spatial distribution of nitrogen oxide concentration of each partition of the denitration outlet flue section. based on the NO x a concentration field distribution, generating an optimized control instruction of the ammonia injection valve corresponding to each partition; Adjusting the opening degree of the ammonia injection valve of the corresponding partition according to the optimization control instruction to realize precise ammonia injection in the partition; The NO x The concentration field distribution, generating the optimization control instruction of each partition corresponding to the ammonia injection valve, comprises: acquiring a plurality of NOx concentrations of each of the zones over a plurality of adjustment rounds, each of the adjustment rounds representing a round of concentration measurements for all of the zones x acquiring a plurality of NOx concentrations of each of the zones over a plurality of adjustment rounds, each of the adjustment rounds representing a round of concentration measurements for all of the zones Calculating the overall round-measuring average value of the denitration outlet flue section based on the round-measuring average values of all the partitions; Calculating the concentration deviation between the round-measuring average value of each partition and the overall round-measuring average value, and generating the optimization control instruction for adjusting the opening degree of the ammonia injection valve of the corresponding partition based on the concentration deviation; After the concentration deviation between the round-measuring average value of each partition and the overall round-measuring average value is calculated, the method further comprises the following steps: Obtaining a preset intensity coefficient and an action amplitude value of the ammonia injection valve of each partition; Generating the optimization control instruction for adjusting the opening degree of the ammonia injection valve of the corresponding partition based on the preset intensity coefficient and the action amplitude value in combination with the concentration deviation; After the preset intensity coefficient and the action amplitude value of the ammonia injection valve of each partition are obtained, the method further comprises the following steps: The NOx concentration at the outlet of the denitration section is calculated as the average of the values measured at the outlet of each of the sub-sections, according to the sub-section wheel. x Concentration distribution non-uniformity; According to the numerical change of the unevenness, the action amplitude is dynamically adjusted, and when the numerical value of the unevenness increases, the action amplitude value is increased in the same proportion, and when the numerical value of the unevenness decreases, the action amplitude value is decreased in the same proportion; When the unevenness continuously decreases below a preset threshold value for a plurality of rounds, the action amplitude value is restored to an initial preset value.

2. The NOx-based exhaust gas treatment system of claim 1, wherein the NOx-based exhaust gas treatment system is a selective catalytic reduction (SCR) system. x The method of claim 1, wherein the method is a method of partitioned synchronous measurement of ammonia injection control. After the preset intensity coefficient and the action amplitude value of the ammonia injection valve of each partition are obtained, the method further comprises the following steps: Obtaining the concentration deviation of each partition in the current and historical adjustment rounds, and calculating the variance of the concentration deviation as the concentration stability index of the partition; Calculating the average value of the concentration stability indexes of all the partitions as a reference stability level; Identifying the sign of the concentration deviation of each partition in the continuous adjustment rounds to determine the direction of the continuous deviation; Comparing the concentration stability index of each partition with the reference stability level, and when the concentration stability index of the partition is higher than the reference stability level and there is a consistent direction of the continuous deviation, the intensity coefficient of the partition is increased in the same proportion; When the concentration stability index of the partition is lower than the reference stability level, or the concentration stability index of the partition is higher than the reference stability level but there is no consistent direction of the continuous deviation, the intensity coefficient of the partition is decreased in the same proportion; When the concentration stability indexes of all the partitions are continuously lower than the reference stability level for a plurality of adjustment rounds and there is no obvious direction of the continuous deviation, the intensity coefficients of all the partitions are restored to the initial preset value.

3. The NOx-based exhaust gas treatment fluid of claim 1, wherein the NOx-based exhaust gas treatment fluid is a liquid. x The method for synchronizing the partitioned measurement of the ammonia injection control, characterized in that, The optimization control instruction for adjusting the opening degree of the ammonia injection valve of the corresponding partition based on the preset intensity coefficient and the action amplitude value in combination with the concentration deviation comprises: The concentration deviation is processed in sections, and different intensity coefficients and action amplitude values are adopted for different size of concentration deviation intervals; For the concentration deviation within a preset normal fluctuation range, a standard intensity coefficient and a standard action amplitude value are adopted for processing. For large concentration deviation beyond the preset normal fluctuation range, a combination strategy of enhanced intensity coefficient and limited action amplitude value is adopted to prevent over-regulation while ensuring the regulation strength.

4. The NOx-based exhaust gas treatment fluid of claim 1, wherein the NOx-based exhaust gas treatment fluid is a liquid. x The method of claim 1, wherein the method is a method of partitioned synchronous measurement. said obtaining a plurality of NO x before the concentration measurement, further comprising: calculating the NO concentration of the flue gas at the denitration outlet cross section corresponding to the current round x a rate of change between the concentration distribution unevenness and the unevenness of the previous round; The change rate is compared with a preset negative change rate threshold: if the change rate is less than the preset negative change rate threshold, it is determined that it is in a fast optimization state, and the number of adjustment rounds is reduced; The absolute value of the change rate is compared with a preset stable state threshold: if the absolute value of the change rate is less than the stable state threshold, it is determined that it is tending to be stable, and the number of adjustment rounds is increased.

5. The NO-based method according to any one of claims 1-4 x The ammonia injection control method based on zoned synchronous measurement is characterized by, The flue gas denitration outlet of the thermal power unit comprises a first flue and a second flue, and the ammonia injection control method further comprises: The first overall round average value of all partitions corresponding to the first flue is calculated respectively, and the second overall round average value of all partitions corresponding to the second flue is calculated respectively; The deviation value between the first overall round average value and the second overall round average value is calculated; Based on the deviation value, the total ammonia injection flow rate allocated to the first flue and the second flue is synchronously adjusted respectively to make the first overall round average value and the second overall round average value consistent.

6. The NOx-based system of claim 5, wherein the NOx-based system is a selective catalytic reduction (SCR) system. x The method for synchronizing the partitioned measurements of the ammonia injection control, characterized in that, The synchronous adjustment of the total ammonia injection flow rate allocated to the first flue and the second flue based on the deviation value comprises: Obtaining the real-time load value of the thermal power unit, and determining the preset load working condition interval to which it belongs according to the real-time load value; According to the preset load working condition interval, a corresponding flue balance adjustment coefficient is selected from a predefined mapping relationship; Based on the deviation value and the flue balance adjustment coefficient, a reference adjustment amount of the total ammonia injection flow rate is calculated; The reference adjustment amount is synchronously superimposed on the total ammonia injection flow rate set value of the first flue and the second flue respectively, and reverse symmetric adjustment is implemented for the first flue and the second flue.

7. The NOx-based system of claim 5, wherein the NOx-based system is a selective catalytic reduction (SCR) system. x The method for synchronizing the partitioned measurements of the ammonia injection control, characterized in that, The synchronous adjustment of the total ammonia injection flow rate allocated to the first flue and the second flue comprises: The dynamic change rate of the overall round average value of the first flue and the second flue in a plurality of continuous adjustment rounds is calculated respectively; The ratio of the dynamic change rate of the first flue to the dynamic change rate of the second flue is calculated as the flue response rate ratio; Based on the flue response rate ratio, a dynamic allocation weight is calculated, wherein the flue with slower dynamic change rate is given higher allocation weight; The reference adjustment amount is differentially allocated according to the dynamic allocation weight and superimposed on the total ammonia injection flow rate set value of the corresponding flue.

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