Ammonia spraying control method based on NOX partition synchronous measurement

Abstract

The invention relates to the technical field of flue gas purification of thermal power plants, and discloses an ammonia injection control method based on NOx partition synchronous measurement, a plurality of partitions of a denitration outlet flue of a thermal power generating unit are respectively provided with a flue gas sampling probe, and flue gas samples collected by each flue gas sampling probe are sent to a flue gas analyzer in turn; the method comprises the steps that flue gas samples of a plurality of partitions on a denitration outlet flue of a thermal power generating unit are synchronously latched, NOx concentration field distribution of the section of the denitration outlet flue at the same moment is obtained, and the NOx concentration field distribution represents nitrogen oxide concentration space distribution of each partition of the section of the denitration outlet flue; based on the NOx concentration field distribution, an optimization control instruction of the ammonia spraying valve corresponding to each partition is generated; and adjusting the opening degree of the ammonia spraying valve of the corresponding subarea according to the optimization control instruction to realize accurate ammonia spraying of the subarea. Partitioned precise ammonia spraying is carried out through synchronously obtained NOx concentration field distribution at the same moment, the distribution uniformity of the NOx concentration at an SCR outlet is effectively improved, and therefore local ammonia escape is remarkably reduced.

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 method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. x The method can improve the uniformity of the NOx concentration field distribution, effectively improve the precision of the ammonia injection in each of the plurality of sub-regions, and effectively improve the uniformity of the NOx concentration field distribution at the outlet of the SCR, thereby significantly reducing the local ammonia slip. x The method can improve the uniformity of the NOx concentration field distribution, effectively improve the precision of the ammonia injection in each of the plurality of sub-regions, and effectively improve the uniformity of the NOx concentration field distribution at the outlet of the SCR, thereby significantly reducing the local ammonia slip.

[0007] To solve the above technical problems, a first aspect of an embodiment of the present application provides a method for synchronously measuring and controlling ammonia injection based on NOx concentration field distribution. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions.

[0008] Further, the method for synchronously measuring and controlling ammonia injection based on NOx concentration field distribution comprises the following steps. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. x The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions.

[0009] Further, the method for synchronously measuring and controlling ammonia injection based on NOx concentration field distribution comprises the following steps. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions. The method comprises the following steps: synchronously measuring the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions of the flue gas of the denitration outlet flue of the thermal power generating unit; and adjusting the opening degree of the ammonia injection valve of each of the plurality of sub-regions according to the NOx concentration field distribution of the flue gas in each of the plurality of sub-regions.

[0010] Further, after obtaining the preset intensity coefficient and the action amplitude value of each partition ammonia injection valve, the method further comprises: According to the average value of the partition wheel of all partitions, the NOx concentration of the denitration outlet flue cross section is calculated x Concentration distribution unevenness; According to the numerical change of the unevenness, the action amplitude is dynamically adjusted, 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 continues for several rounds below the preset threshold, the action amplitude value is restored to the initial preset value.

[0011] Further, after obtaining the preset intensity coefficient and the action amplitude value of each partition ammonia injection valve, the method further comprises: Obtain the concentration deviation of each partition in the current and historical adjustment rounds, and calculate the variance of the concentration deviation as the concentration stability index of the partition; Calculate the average value of the concentration stability index of all partitions as the reference stability level; Identify the concentration deviation sign of each partition in the continuous adjustment rounds to determine the consistent deviation direction; Compare the concentration stability index of each partition with the reference stability level, when the concentration stability index of the partition is higher than the reference stability level and there is a consistent deviation direction, 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 deviation direction, the intensity coefficient of the partition is decreased in the same proportion; When the concentration stability index of all partitions is lower than the reference stability level for continuous multiple adjustment rounds and there is no obvious consistent deviation direction, the intensity coefficient of all partitions is restored to the initial preset value.

[0012] Further, the method of generating the optimization control instruction for adjusting the opening of the corresponding partition ammonia injection valve based on the preset intensity coefficient and the action amplitude value, combined with the concentration deviation, comprises: The concentration deviation is processed by partition, and different intensity coefficients and action amplitude values are used for different size of concentration deviation interval; For the concentration deviation within the preset normal fluctuation range, standard intensity coefficient and standard action amplitude value are used for processing; For large concentration deviation exceeding the preset normal fluctuation range, the combination strategy of enhanced intensity coefficient and limited action amplitude value is used to ensure the adjustment strength while preventing over-adjustment.

[0013] Further, the method further comprises: x Before the concentration measurement, the method further comprises: Calculating the NOx concentration of the current round of the corresponding denitration outlet flue section of each partition; x The rate of change between the non-uniformity of the concentration distribution and the non-uniformity of the previous round; Comparing 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 fast optimization state, and the number of adjustment rounds is reduced; Comparing the absolute value of the rate of change 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 it is tending to be stable, and the number of adjustment rounds is increased.

[0014] Further, the denitration outlet flue of the thermal power generating unit comprises: a first flue and a second flue, and the ammonia injection control method further comprises: Respectively calculating a first overall round average value of all partitions corresponding to the first flue and a second overall round average value of all partitions corresponding to the second flue; Calculating a deviation value between the first overall round average value and the second overall round average value; Based on the deviation value, synchronously adjusting the total ammonia injection flow rate allocated to the first flue and the second flue respectively, so that the first overall round average value and the second overall round average value tend to be consistent.

[0015] Further, the synchronous adjustment of the total ammonia injection flow rate allocated to the first flue and the second flue respectively based on the deviation value comprises: Obtaining a real-time load value of the thermal power generating unit, and determining a preset load working condition interval to which it belongs according to the real-time load value; According to the preset load working condition interval, selecting a corresponding flue balance adjustment coefficient from a predefined mapping relationship; Based on the deviation value and the flue balance adjustment coefficient, calculating a reference adjustment amount of the total ammonia injection flow rate; Synchronously superimposing the reference adjustment amount on the total ammonia injection flow rate set value of the first flue and the second flue respectively, and implementing reverse symmetric adjustment on the first flue and the second flue.

[0016] Further, the synchronous adjustment of the total ammonia injection flow rate allocated to the first flue and the second flue respectively comprises: Respectively calculating the dynamic change rate of the overall round average value of the first flue and the second flue in continuous multiple adjustment rounds; calculating a ratio of the first flue dynamic change rate and the second flue dynamic change rate as a flue response rate ratio; based on the flue response rate ratio, calculating a dynamic allocation weight, wherein the flue with a slower dynamic change rate is given a higher allocation weight; differentially allocating the reference adjustment amount according to the dynamic allocation weight, and superimposing it on the total ammonia injection flow set value of the corresponding flue.

[0017] Correspondingly, the second aspect of the embodiment of the present application provides a NO x The partition synchronous measurement ammonia injection control system is characterized in that: a plurality of partitions of the flue of the thermal power generating unit denitration outlet are respectively provided with flue gas sampling probes, flue gas samples collected by each flue gas sampling probe are sent to a flue gas analyzer in turn, and the ammonia injection control system comprises: a data acquisition module, configured to synchronously latch flue gas samples of a plurality of partitions of the flue of the thermal power generating unit denitration outlet, and obtain NO x concentration field distribution of a cross section of the denitration outlet flue at the same time; x The NO x concentration field distribution represents the spatial distribution of nitrogen oxide concentration of each partition of the cross section of the denitration outlet flue. an instruction generation module, configured to generate an optimized control instruction of an ammonia injection valve of each partition based on the NO x concentration field distribution; a partition control module, configured to adjust the opening of the ammonia injection valve of the corresponding partition according to the optimized control instruction, and realize partition precise ammonia injection.

[0018] Correspondingly, the third aspect of the embodiment of the present application provides an electronic device, comprising: at least one processor; and a memory connected with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above-mentioned NO x partition synchronous measurement ammonia injection control method.

[0019] Correspondingly, the fourth aspect of the embodiment of the present application provides a computer readable storage medium, which stores computer instructions, and the instructions are executed by a processor to implement the above-mentioned NO x partition synchronous measurement ammonia injection control method.

[0020] The above technical solutions of the embodiment of the present application have the following beneficial technical effects: 1. By using the synchronous latching and measurement technology, the NO xThe accurate acquisition of the concentration field distribution overcomes the inherent defects of poor representativeness of traditional single-point measurement; on this basis, a closed-loop control loop from the concentration field to the partition valve instruction is constructed, which can accurately locate and eliminate the area with uneven concentration distribution, dynamically match the ammonia injection amount and the distribution of nitrogen oxides, significantly improve the denitration efficiency, and effectively solve the problem of high local ammonia slip caused by uneven distribution from the root cause; 2. By calculating the unevenness of the concentration distribution, the stability of the partition concentration and other indicators in real time, dynamically adjusting the key parameters such as control round, action amplitude and intensity coefficient, the accurate matching of the control strategy and the current running state of the system is realized; whether facing frequent load changes or responding to the dynamic response difference of different partitions, the control intensity and response speed can be automatically adjusted to achieve the best balance between rapid correction and stable operation, thereby maintaining excellent control quality in the whole working condition range; 3. By means of dilution air lower limit protection, valve lower limit protection and other measures, the operation risk of the equipment itself is prevented; by means of fault diagnosis and automatic rejection mechanism of the measuring device, it is ensured that the control system can still operate reliably when some measuring points are abnormal; in addition, the linkage of the double flue leveling logic and the load condition avoids the blockage of the downstream equipment caused by uneven ammonia injection, reduces the dependence of the system on manual intervention, and ensures the continuous, stable and safe operation of the system in the industrial field. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the NO x The flow chart of the ammonia injection control method based on NO Figure 2 is the structure schematic diagram of the denitration system of the thermal power generating unit provided by the embodiment of the present application; Figure 3 is the schematic diagram of the flue partition flue gas sample collection provided by the embodiment of the present application; Figure 4 is the NO x The module block diagram of the ammonia injection control system based on NO

[0022] REFERENCE NUMERALS: 1, data acquisition module, 2, instruction generation module, 3, partition control module. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present application clearer and more explicit, the present application is further described in detail below in combination with specific embodiments and with reference to the drawings. It should be understood that these descriptions are only exemplary and do not limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0024] The synchronous measurement device adopted by the present application is composed of a plurality of flue gas sampling probes and a central flue gas analyzer, and a one-to-many connection mode is adopted in specific implementation. The sampling probe has special design of high temperature resistance, high dust resistance and high corrosion resistance, and can adapt to the harsh flue gas environment of the denitration outlet of the thermal power plant. The synchronous latching of the sample gas is realized through a multi-channel switching valve group, and the key components include a sample chamber and an electromagnetic valve array, which together ensure that the flue gas state of the same time slice of the flue cross section can be fixed; a complete heat tracing and heat preservation system and a back purge device are also provided, which effectively prevent the sampling pipeline from being blocked and the sample from being distorted, and ensure the reliability of long-term operation.

[0025] Please refer to Figure 1 , Figure 2 and Figure 3 The first aspect of the embodiment of the present application provides a kind of based on NO x Partition synchronous measurement of ammonia injection control method, the flue of several partitions of the denitration outlet of thermal power unit is provided with flue gas sampling probe, and the flue gas sample collected by each flue gas sampling probe is sent to flue gas analyzer in turn, and the ammonia injection control method includes the following steps: Step S100, the flue gas sample of several partitions on the flue of the denitration outlet of thermal power unit is synchronously latched, and the NO x Concentration field distribution of the same time slice of the flue cross section of the denitration outlet is obtained. x Concentration field distribution represents the spatial distribution of nitrogen oxide concentration of each partition of the flue cross section of the denitration outlet.

[0026] In the operation scene of thermal power unit participating in grid peak shaving, due to frequent load changes, the flow field characteristics and NO x Concentration distribution of the outlet flue of selective catalytic reduction SCR (Selective Catalytic Reduction) denitration system are in continuous dynamic change. In order to accurately master the real concentration distribution of the flue cross section at this time, the sampling probe arranged in each partition of the denitration outlet horizontal flue simultaneously extracts flue gas sample, and the multi-channel switching valve group with high temperature resistance and anti-clogging characteristics is used to realize the synchronous latching of sample gas. In this process, the electromagnetic valves on all sampling paths act synchronously according to the preset time sequence, temporarily save the flue gas samples at different spatial positions in the sample chamber with specific volume, so as to fix the state of the flowing flue gas at a certain time slice. This latching mechanism effectively solves the concentration field distortion problem caused by different measurement time of traditional time-sharing wheel measurement mode, and provides original data with strict time and space consistency for subsequent analysis.

[0027] In typical application of coal-fired boiler denitration system, the latched sample gas is sent to the central flue gas analyzer in turn according to the preset program for concentration detection. The analyzer measures NO xThe concentration values are recorded by the data acquisition system. Due to the high temperature, high dust, and strong corrosion of the flue gas at the denitration outlet of the power plant, the sampling system is equipped with perfect heat tracing, filtering, and back flushing devices to ensure the accuracy of the measurement data and the reliability of the long-term operation of the system. Since all sample gases represent the state of the flue gas at the same time, the final obtained NO x The concentration field distribution can truly reflect the spatial difference characteristics of the concentration of each partition at the denitration outlet cross section, providing reliable input basis for subsequent partition precise control.

[0028] In step S200, the NO x The concentration field distribution is used to generate the optimization control instructions of the ammonia injection valve of each partition.

[0029] After obtaining the NO x After obtaining the NO

[0030] Based on the calculated concentration deviation, the control algorithm generates optimization control instructions for the ammonia injection valve of each partition in combination with the preset intensity coefficient and action amplitude parameters. The intensity coefficient is used to adjust the response sensitivity of the control system to the concentration deviation, and the action amplitude limits the maximum allowed variation range of single adjustment. In actual application in the power plant, for the partitions with larger concentration deviation, the algorithm appropriately enhances the adjustment intensity; for the partitions with ideal concentration distribution, a smaller adjustment amplitude is maintained. Meanwhile, a dynamic parameter adjustment mechanism based on load conditions is introduced to ensure stable and precise optimization control under different operating conditions.

[0031] In step S300, the opening of the ammonia injection valve of the corresponding partition is adjusted according to the optimization control instructions, realizing partition precise ammonia injection.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The data reflecting the concentration distribution of the flue cross-section is obtained by synchronous latching sampling technology, and accurate partition control instructions are generated based on multi-round statistical analysis. Combined with intelligent execution and protection mechanism, the denitration system realizes efficient and stable operation in all working conditions, significantly improves the uniformity of NO x concentration distribution, effectively controls the ammonia escape level, and enhances the adaptability and reliability of the system, providing technical support for environmental protection standard of thermal power units under deep peak shaving conditions.

[0036] Further, in step S200, based on the NO x concentration field distribution, the optimization control instructions of the ammonia injection valve corresponding to each partition are generated, including: Step S210, obtaining a plurality of NO x concentration measurement values of each partition in several adjustment rounds, and calculating the partition round measurement average value of each partition, each adjustment round indicating that a round of concentration measurement is completed for all partitions.

[0037] In the actual operation of thermal power units, especially in the working condition of participating in deep peak shaving of power grid, the NO x concentration at the outlet of SCR denitration will change instantaneously due to combustion fluctuations. In order to eliminate the interference of such random fluctuations on the control system, a multi-round measurement data processing method is adopted. In specific implementation, several complete flue cross-section scanning measurements are continuously performed, and the flue gas samples of all partitions are sequentially collected and the corresponding NO x concentration values are obtained in each round of measurement. For example, for a flue divided into 8 partitions, 5-10 rounds of such complete scanning are continuously completed, and the concentration data of each partition in the corresponding round is recorded. Then, the arithmetic mean of the concentration values obtained in all rounds for each partition is calculated to obtain the stable and reliable partition round measurement average value of each partition. This multi-point average method based on time series effectively filters the instantaneous pulsation component of flue gas concentration, and provides basic data with statistical significance for subsequent control decision.

[0038] Step S220, based on the partition round measurement average values of all partitions, calculating the overall round measurement average value of the flue cross-section at the outlet of denitration.

[0039] After obtaining the reliable average value of each partition, the overall benchmark for evaluating the denitration effect of the entire flue cross-section needs to be established. In this step, the round measurement average values of all partitions are again subjected to arithmetic average operation, and the overall round measurement average value of the NO xThe overall round measurement average of the concentration level. This value reflects the overall performance of the denitration system under the current operating condition, and is an important reference benchmark for evaluating the uniformity of the concentration distribution in each subzone. In practical applications, this overall average is not only used for subzone regulation and control, but also serves as a monitoring indicator for the system operating state. When the unit load changes, operating personnel can observe the trend of the overall average to judge the overall response characteristics of the denitration system, providing a basis for operation optimization. At the same time, this value is also an important input parameter for determining whether two-side flue leveling control is needed.

[0040] Step S230, calculate the concentration deviation between the subzone round measurement average and the overall round measurement average of each subzone, and generate an optimized control instruction for adjusting the opening degree of the corresponding subzone ammonia injection valve based on the concentration deviation.

[0041] After obtaining the overall benchmark value, the algebraic difference between the round measurement average of each subzone and the overall round measurement average is calculated in sequence to obtain the concentration deviation value of each subzone. This deviation value accurately quantifies the deviation of each subzone from the overall average level, a positive value indicating that the subzone concentration is too high and the ammonia injection amount needs to be increased; a negative value indicates that the concentration is too low and the ammonia injection amount should be reduced. When generating specific valve control instructions, the concentration deviation is used as the basic input and combined with the pre-set control parameters for calculation. For example, for subzones with large concentration deviations, larger valve opening adjustment instructions are generated; while for subzones with small deviations, subtle adjustments are made. This subzone control strategy based on accurate quantification of deviation can effectively correct the concentration distribution unevenness on the flue cross section and ensure that the ammonia injection amount in each region accurately matches the actual denitration demand.

[0042] By averaging multiple rounds of measurements, stable subzone concentration data is obtained, a scientific overall concentration benchmark is established, and subzone control instructions are generated based on accurate calculation of concentration deviation, effectively improving the accuracy and adaptability of ammonia injection control, significantly improving the concentration distribution uniformity of the denitration system outlet cross section, and providing reliable technical support for the unit to achieve efficient and stable denitration performance under complex operating conditions.

[0043] Further, after calculating the concentration deviation between the subzone round measurement average and the overall round measurement average of each subzone in step S230, it further includes: Step S240, obtaining the pre-set intensity coefficient and action amplitude value of each subzone ammonia injection valve.

[0044] In the actual operation of thermal power units, due to the differences in the length and resistance characteristics of each branch of the ammonia injection grid, and the different flow field conditions of different partitions, it is difficult to achieve precise regulation by directly using uniform control parameters. Therefore, a dedicated intensity coefficient and action amplitude value are preset for each partition's ammonia injection valve. The intensity coefficient is mainly set according to the actual adjustment characteristics of each branch, and is used to adjust the response sensitivity of the control system to the concentration deviation. For example, a larger intensity coefficient can be set for a partition with a slower response to enhance the adjustment strength. The action amplitude value is set according to the valve characteristics and safety operation requirements, and is used to limit the maximum change range of the valve opening during a single adjustment process to prevent system oscillation caused by excessive adjustment. These parameters are determined through field tests at the beginning of system operation, and can be optimized and adjusted according to the actual effect during operation to adapt to the specific operating conditions of different units.

[0045] In step S250, based on the preset intensity coefficient and action amplitude value, an optimized control instruction for adjusting the opening of the ammonia injection valve of the corresponding partition is generated in combination with the concentration deviation.

[0046] After obtaining the concentration deviation and control parameters, the final valve adjustment instruction is generated through a specific control algorithm. In specific implementation, the concentration deviation value is multiplied by the corresponding intensity coefficient to obtain the basic adjustment amount, and then the action amplitude value is combined for amplitude limiting processing to ensure that the single adjustment amount is within a reasonable range. For example, when a larger positive deviation occurs in a partition, an instruction to increase the ammonia injection amount is generated, but through the limitation of the action amplitude value, the sudden change of the valve opening can be avoided to prevent excessive ammonia injection. This control strategy not only ensures a quick response to the concentration deviation, but also maintains the stability of the adjustment process. In actual application, the algorithm also considers valve nonlinearity compensation to ensure accurate control within the full opening range, thereby effectively improving the uniformity of the concentration distribution at the outlet cross-section of the denitrification system.

[0047] By configuring differentiated control parameters for each partition and using a scientific control algorithm to generate optimized instructions, precise matching of the ammonia injection amount and denitrification demand is achieved, effectively improving the accuracy and stability of the adjustment, significantly improving the denitrification efficiency and ammonia escape control level, and providing reliable protection for the unit to meet environmental standards under complex operating conditions.

[0048] In addition, considering the individual characteristic differences of the ammonia injection valves in each partition, a valve characteristic compensation mechanism is introduced. For valves with slower response speed, the lead adjustment component of the control instruction is appropriately increased. For valves with dead zone characteristics, a control algorithm with dead zone compensation is used. A valve characteristic database is also established to record the historical adjustment performance data of each valve. Machine learning algorithms can be used to continuously optimize the control parameters for each valve to ensure that all partition valves achieve the best adjustment effect.

[0049] 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: 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The dynamic adjustment of the action amplitude considers the balance between the adjustment effect and the operation stability. While increasing the action amplitude to accelerate the adjustment, the upper limit of the single adjustment amount of each partition valve is still maintained to avoid system oscillation caused by excessive adjustment. When the concentration distribution tends to be uniform and the non-uniformity value decreases, the action amplitude is correspondingly reduced, and the fine adjustment mode is entered, and the stable operation of the system is maintained through small amplitude adjustment. The control strategy of adaptive adjustment according to the distribution state can maintain excellent control performance of the system in the whole working condition range, and effectively improves the adaptability of the denitration system to complex operating conditions.

[0055] By calculating the concentration distribution non-uniformity in real time and dynamically adjusting the control parameters based on the change thereof, the adaptive ability of the control system to the operating conditions is realized, the control performance of the system under complex conditions such as load fluctuation is significantly improved, the concentration distribution uniformity of the outlet section of the denitration system is effectively improved, and the stability of the adjustment process is ensured, thereby providing reliable technical support for the environmental protection standard of the unit in the whole working condition range.

[0056] In step S2413, when the non-uniformity continues for several rounds below the preset threshold value, the action amplitude value is restored to the initial preset value.

[0057] When the concentration distribution non-uniformity remains below the preset excellent threshold value for a plurality of adjustment rounds, it indicates that the NOx concentration distribution of the flue gas section has reached an ideal state and remains stable. At this time, the system automatically restores the action amplitude value to the initial preset value to reserve the adjustment capacity for subsequent possible changes in operating conditions. This reset mechanism ensures that the control system always has sufficient adjustment margin, avoiding weakening the response ability of the system to sudden operating conditions due to long-term small amplitude adjustment.

[0058] In actual application, the judgment of the reset timing needs to consider the matching degree of the distribution stability and the operating condition. Usually, 3-5 consecutive adjustment rounds are set as the observation window, and the non-uniformity is required to be continuously below the threshold value and the load condition is relatively stable during this period. The reset process adopts gradual adjustment, which is restored to the initial value in 2-3 rounds, avoiding the impact on the system caused by parameter mutation. This intelligent reset strategy ensures the economic operation of the system under stable conditions and ensures the rapid response when the operating condition changes, realizing the best balance between control performance and operation stability.

[0059] Further, after obtaining the preset intensity coefficient and the action amplitude value of each partition ammonia injection valve in step S240, the method further includes: In step S2421, the concentration deviation of each partition in the current and historical adjustment rounds is obtained, and the variance of the concentration deviation is calculated as the concentration stability index of the partition.

[0060] In the actual operation of thermal power units, especially in the process of participating in deep load regulation of power grid, due to the instability of combustion conditions, the NOx concentration in each sub-zone of the denitration system is not stable x The concentration deviation values will show different fluctuation characteristics. In order to accurately evaluate the stability of the concentration in each sub-zone, the concentration deviation data sequences of each sub-zone in the current and historical multiple adjustment rounds are collected, and the quantitative sub-zone concentration stability index is obtained by calculating the statistical variance of these deviation values. This variance calculation based on time series can effectively reflect the fluctuation amplitude of the concentration deviation in each sub-zone, and the larger the variance value is, the more unstable the concentration control in the sub-zone is, and there may be problems such as uneven flow field or poor response of ammonia injection regulation. In actual application, this index provides a basis for stability evaluation at the sub-zone level for the operating personnel, which helps to identify specific areas with poor control effect.

[0061] The calculation of the concentration stability index adopts the standard variance statistical method, and through processing the concentration deviation data in continuous multiple control periods, a quantitative evaluation result reflecting the control quality of each sub-zone is obtained. In the working conditions of rapid load change of the unit or large fluctuation of coal quality, the concentration stability index of some sub-zones will increase significantly, accurately reflecting the control difficulty of these areas in variable working conditions. By continuously monitoring the changes of the stability index of each sub-zone, an important basis is provided for the subsequent optimization of control parameters, so that the control system can implement differentiated optimization strategies according to the actual control conditions of different sub-zones.

[0062] In step S2422, the average value of the concentration stability indexes of all sub-zones is calculated as the system reference stability level.

[0063] After obtaining the concentration stability index of each sub-zone, it is necessary to establish a reference for evaluating the overall control stability of the system. The stability indexes of all sub-zones are calculated by arithmetic mean to obtain a reference stability level representing the overall control stability of the denitration system. This reference value reflects the average stability degree of the control of each sub-zone under the current operating conditions, providing a comparison reference for evaluating the relative stability of each sub-zone. In the normal operation process of the unit, this reference stability level will remain relatively stable, and when the operating conditions of the unit change significantly, the reference stability level can timely reflect the fluctuation of the overall control stability of the system.

[0064] The establishment of the reference stability level provides a scientific basis for the relative evaluation of the control performance of each sub-zone. In actual operation, when the overall control stability is good, the stability indexes of each sub-zone are usually close to the reference stability level; when there is an abnormal control in an individual sub-zone, the stability index of the sub-zone will deviate significantly from the reference value. The operating personnel can monitor the difference between the stability index of each sub-zone and the reference stability level to timely find the sub-zone with abnormal control and take corresponding treatment measures. At the same time, this reference stability level is also a key reference for the parameter self-optimization of the control system.

[0065] Step S2423, identify the concentration deviation sign of each partition in the continuous adjustment round, determine its sustained deviation direction.

[0066] In the evaluation of the control stability of each partition, only relying on the variance index cannot distinguish between random fluctuations and systematic deviations. Therefore, it is necessary to analyze the concentration deviation sign sequence of each partition in the continuous adjustment round, and identify the sustained deviation mode by counting the number of rounds of continuous same direction deviation. When a partition has continuous same direction deviation for multiple rounds (sustained positive deviation or sustained negative deviation), it indicates that there is a systematic control problem in this area, rather than random fluctuations. The identification of this sustained deviation direction provides an important basis for the accurate adjustment of the intensity coefficient in the subsequent.

[0067] In practical application, the judgment of sustained deviation direction needs to set a clear round threshold. Usually, it is required that the same direction deviation occurs for 3 or more adjustment rounds to be recognized as a sustained deviation direction. For each partition, the system will record the deviation sign sequence of the last 10 rounds, and identify the sustained deviation mode through sliding window analysis. This analysis process is carried out synchronously with the calculation of the stability index, and together constitutes a complete evaluation system of the control status of the partition.

[0068] Step S2424, compare the concentration stability index of each partition with the system benchmark stability level, when the concentration stability index of the partition is higher than the benchmark stability level and there is a consistent sustained deviation direction, increase the intensity coefficient of the partition by the same proportion.

[0069] After obtaining the system benchmark stability level and the stability index of each partition, a comprehensive judgment is made in combination with the identification result of the sustained deviation direction. For the partition with significantly higher stability index than the benchmark stability level and consistent sustained deviation direction, it indicates that this area not only has poor control effect, but also has systematic control deviation, and the control effort needs to be strengthened. At this time, according to the degree of the stability index of the partition being higher than the benchmark stability level, the intensity coefficient of the partition is increased by the pre-set proportional relationship. This dual judgment mechanism based on stability evaluation and deviation direction identification can accurately identify the partition that really needs to be strengthened, and avoid over-adjustment of the random fluctuation area.

[0070] In the adjustment process of the intensity coefficient, a progressive optimization strategy is adopted. When the stability index of a certain partition continuously exceeds the benchmark stability level and there is a consistent deviation direction, the intensity coefficient of the partition is gradually increased until the control stability of the partition is significantly improved. At the same time, an upper limit of the intensity coefficient is set to prevent system oscillation caused by excessive parameter adjustment. In practical applications, this parameter self-adaptive adjustment mechanism based on double judgment enables the control system to accurately identify problem areas and implement targeted optimization, effectively improving the control adaptability and stability of the system in the full operating range.

[0071] Step S2425, when the concentration stability index of a partition is lower than the benchmark stability level, or the concentration stability index of a partition is higher than the benchmark stability level but there is no consistent sustained deviation direction, then the intensity coefficient of the partition is reduced proportionally.

[0072] For partitions with good control effect, the control intensity needs to be reduced in time to avoid over-regulation. When the concentration stability index of a certain partition is lower than the benchmark stability level, it indicates that the control effect of this region is better than the average level of the system, at which time the intensity coefficient should be reduced proportionally and the fine adjustment mode should be entered. Similarly, when the stability index of a partition is higher than the benchmark stability level but there is no consistent sustained deviation direction, it indicates that the fluctuation of this region is of random nature rather than systematic deviation, and the intensity coefficient should also be reduced to avoid overreaction to random fluctuations.

[0073] The reduction process of the intensity coefficient also adopts a progressive strategy to ensure smooth transition of the control system. The adjustment amplitude is proportional to the degree of deviation of the stability index from the benchmark stability level, but a lower limit is set to prevent the intensity coefficient from being too small and causing insufficient control. This two-way adjustment mechanism ensures that the control intensity of each partition always matches the actual control demand, ensuring control effect and improving system operation economy.

[0074] Step S2426, when the concentration stability index of all partitions is lower than the benchmark stability level for a plurality of consecutive adjustment rounds and there is no obvious sustained deviation direction, the intensity coefficient of all partitions is restored to the initial preset value.

[0075] When the system as a whole enters a highly stable state, the control parameters need to be restored to the initial setting in time to reserve adjustment capacity for subsequent operating condition changes. When the stability index of all partitions is lower than the benchmark stability level for a plurality of rounds (usually 5-7 rounds) and no obvious sustained deviation direction is detected in each partition, it indicates that the system has reached an ideal stable state. At this time, the intensity coefficient of all partitions is uniformly restored to the initial preset value to ensure that the system maintains the best regulation margin.

[0076] The reset process adopts a step-by-step progressive way, and the parameter recovery is gradually completed in 2-3 adjustment rounds. This progressive reset avoids the impact of parameter mutation on the system, while allowing the system to continuously monitor stability changes during the reset process. After the reset is completed, the system enters a new cycle of monitoring-evaluation-adjustment to ensure continuous optimal control performance. This intelligent reset mechanism is an important embodiment of the adaptive ability of the control system, effectively balancing the relationship between control accuracy and system stability.

[0077] By establishing a partition concentration stability evaluation system, based on the difference between the stability of each partition and the reference stability level, the adaptive adjustment of the intensity coefficient is implemented, realizing the intelligent optimization of the control parameters, significantly improving the adaptability of the system to the control characteristics of each partition, effectively improving the stability and uniformity of the concentration control, and providing reliable technical support for the unit to maintain excellent denitration performance under complex operating conditions.

[0078] Further, in step S250, based on the preset intensity coefficient and the action amplitude value, an optimized control instruction for adjusting the opening of the corresponding partition ammonia injection valve is generated in combination with the concentration deviation, which includes: In step S2501, the concentration deviation is processed in sections, and different combination strategies of intensity coefficient and action amplitude value are adopted for different size of concentration deviation interval.

[0079] In the actual operation of thermal power units participating in deep peak regulation of the power grid, the concentration deviation of each partition of the SCR denitration system is significantly nonlinear due to the influence of multiple factors such as boiler combustion fluctuations and flue gas flow field changes. To cope with this complex condition, the control system divides the concentration deviation into three typical intervals based on long-term operation data accumulation and flow field characteristics under different loads: small deviation interval (within ±5 mg / Nm³), medium deviation interval (±5-15 mg / Nm³), and large deviation interval (above ±15 mg / Nm³). Each interval is strictly tested and parameter set on site, and is configured with a specially optimized combination of intensity coefficient and action amplitude to ensure accurate matching of control parameters and deviation characteristics.

[0080] In the specific implementation process, the value and trend of the concentration deviation in each partition are monitored in real time to dynamically determine the interval range to which the current deviation belongs. For the small deviation interval, a mild adjustment strategy is adopted to mainly eliminate the influence of random fluctuations; for the medium deviation interval, a moderate adjustment intensity is adopted to speed up the adjustment speed while ensuring stability; for the large deviation interval, a strengthened adjustment mode is started to focus on solving the significant uneven distribution problem caused by flow field mutation or abnormal ammonia injection system. This section-by-section processing method enables the control system to flexibly adjust the control intensity according to actual needs, avoiding equipment wear caused by frequent adjustment, and ensuring the rapid response capability to various deviations.

[0081] The parameter combination of each deviation interval is set in full consideration of the balance between adjustment effect and system stability. In actual operation process, the interval threshold and control parameters can also be fine-tuned by the operation personnel according to the specific characteristics of the unit, so as to adapt to the individualized needs of different units. At the same time, a parameter self-adaptive mechanism is established, which can automatically optimize the interval parameter settings according to the long-term operation effect, so as to ensure that the control system always maintains excellent control performance in the full working condition range. This fine segmentation control strategy significantly improves the adaptability of the denitration system to complex operating conditions, and provides reliable guarantee for environmental protection standard during deep peak shaving of the unit.

[0082] In step S2502, for the concentration deviation within the preset normal fluctuation range, a standard intensity coefficient and a standard action amplitude value are used for processing.

[0083] When the concentration deviation of each subzone of the denitration system is within the preset normal fluctuation range, it indicates that the ammonia injection amount of the subzone and the denitration demand are basically matched, and the system is in good running state. At this time, the control system uses the standard intensity coefficient and the standard action amplitude value verified by a large amount of practice for processing. This parameter combination can maintain moderate adjustment strength, which can not only eliminate small amplitude concentration deviation caused by slight fluctuation of combustion in time, but also effectively avoid frequent action of valve and system oscillation caused by excessive adjustment. This control strategy is particularly suitable for long-term continuous operation condition of the unit under stable load, and through maintaining the stable adjustment of the ammonia injection valve of each subzone, it ensures that the denitration system operates in the best working condition interval.

[0084] In actual engineering application, the determination of the normal fluctuation range uses a statistical analysis method based on historical operation data. By collecting the concentration data of each subzone of the unit during stable operation at different load sections, the standard deviation and distribution characteristics are calculated, so as to scientifically set the normal fluctuation threshold corresponding to each load section. For example, under the stable operation condition of the unit at 75% load, the normal fluctuation range can be set to ±3 mg / Nm³, and at 50% load, it can be adjusted to ±4 mg / Nm³. This differentiated setting based on load condition ensures that the control system can achieve fine and stable control in the full working condition range, which not only ensures the control sensitivity, but also maintains the long-term running stability of the system.

[0085] In step S2503, for large concentration deviation exceeding the preset normal fluctuation range, a combination strategy of enhanced intensity coefficient and limited action amplitude value is used to ensure the adjustment strength while preventing excessive adjustment.

[0086] When the SCR denitration system detects a large concentration deviation beyond the normal fluctuation range in a certain partition, the enhanced control mode is immediately started. This large deviation usually occurs under conditions such as rapid load change of the unit, sudden change of coal quality, or abnormal flow field distribution, etc. At this time, the intensity coefficient is increased to 1.5-2.0 times of the standard value, significantly enhancing the adjustment sensitivity, while the action amplitude value is limited within 50%-70% of the standard range, ensuring that the single adjustment amount has sufficient adjustment strength and will not cause system instability due to excessive amplitude. This parameter combination has been verified through strict field tests, which can effectively avoid concentration oscillation caused by valve action overshoot while ensuring the adjustment effect.

[0087] In actual operation, this control strategy pays special attention to the smoothness of the dynamic adjustment process. By monitoring the deviation trend in real time, the specific combination of the enhancement coefficient and the amplitude limit value is dynamically adjusted. When the deviation is monitored to start converging, the enhancement coefficient is gradually reduced to smoothly transition to the standard control mode. This intelligent transition mechanism ensures smooth and stable adjustment during large deviation adjustment, ensuring rapid response capability and maintaining long-term operation reliability of the system, providing an important guarantee for the unit to meet environmental protection indicators under complex working conditions.

[0088] By segmenting the concentration deviation and using differentiated control parameter combinations, the control strategy is precisely matched with the deviation level, ensuring smooth adjustment of small deviations and 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 optimal operation of the denitration system under all operating conditions.

[0089] Further, the multiple NOx concentration values of each partition in a plurality of adjustment rounds in step S210 are obtained by a plurality of NOx concentration measuring devices arranged in the SCR denitration system. x The concentration measurement value further includes: In step S201, the NOx concentration of the SCR denitration outlet flue cross-section corresponding to the current round is calculated. x The concentration distribution uniformity, and the change rate between the uniformity of the previous round.

[0090] The concentration distribution uniformity of the denitration system outlet cross-section in actual operation will dynamically fluctuate with the load change. To accurately grasp the change trend of the concentration distribution, the change rate of the uniformity between the current round and the previous round is calculated in real time after each measurement round is completed. This change rate is obtained by comparing the numerical difference of the uniformity of the adjacent two rounds with the time interval, which can quantitatively represent the improvement or deterioration speed of the concentration distribution uniformity. When the unit load changes rapidly, this change rate 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.

[0091] Step S202, compare the rate of change with the preset negative rate threshold: if the rate of change is less than the preset negative rate threshold, it is determined that it is in the fast optimization state, and the number of adjustment rounds is reduced.

[0092] When the system detects that the rate of change of the concentration distribution non-uniformity is continuously below the preset negative threshold through real-time monitoring, this quantitative indicator clearly shows that the ammonia injection adjustment in each partition is producing significant effects, and the concentration field distribution is rapidly tending to be uniform. At this time, the control system automatically enters the fast optimization mode, and improves the system response performance by dynamically adjusting the data acquisition strategy. In specific implementation, the number of adjustment rounds for calculating the average value of the partition rounds is gradually reduced from the baseline of 8 rounds to 4-5 rounds. This adjustment is based on in-depth analysis of the dynamic characteristics of the system, and ensures that the update frequency of the control command is significantly improved while maintaining data effectiveness.

[0093] In the dynamic load change stage of the unit, this adaptive round adjustment mechanism shows significant advantages. When the unit load rises or falls at a rate of 1-2% per minute, reducing the adjustment rounds can make the control system complete the command update 2-3 control periods in advance, ensuring that the ammonia injection adjustment timely tracks the load change. In actual application, by monitoring the duration and amplitude of the rate of change of non-uniformity, the appropriate timing and adjustment amplitude of round adjustment are intelligently judged, avoiding control command fluctuations caused by excessive reduction of rounds. This fine adjustment strategy not only ensures the timeliness of control, but also maintains the stability of the system.

[0094] The dynamic round adjustment mechanism has been verified through practice in multiple power plants, significantly improving the system response speed while ensuring control accuracy. Boundary protection for round adjustment is also provided to ensure that the number of rounds always remains above the minimum number of rounds required for effective statistics. Through this intelligent round management, the control system achieves the best balance between fast response and stable operation during unit peak shaving, providing reliable technical support for responding to rapid changes in grid load instructions.

[0095] Step S203, compare the absolute value of the rate of change with the 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 tends to be stable, and the number of adjustment rounds is increased.

[0096] When it is detected that the absolute value of the rate of change of the concentration distribution non-uniformity is continuously below the stable state threshold, it indicates that the concentration field in each partition has entered a relatively stable stage, and the overall control effect of the system has reached an optimal level. At this time, the control system automatically switches to the fine control mode, and gradually increases the adjustment rounds for calculating the average value of the partition rounds from the baseline of 8 rounds to 12 rounds. This adjustment strategy improves the reliability of data statistics by increasing the number of samples, and uses more round measurement data to eliminate the interference of random fluctuations on control decisions, laying a foundation for generating more accurate control commands.

[0097] In actual operation, this round increase mechanism is particularly suitable for long-term operation of the unit with stable load. By using the sliding average algorithm to process the concentration data of 12 rounds, the measurement noise and instantaneous fluctuations can be effectively filtered out, and the obtained round average value is more representative. At the same time, a dynamic management mechanism of the number of rounds is established, which intelligently adjusts the number of rounds according to the duration of stable state and fluctuation characteristics, so as to ensure that the control accuracy is maintained while avoiding excessive extension of response time. This intelligent round management strategy enables the control system to maintain higher control accuracy in stable conditions, effectively reduces unnecessary frequent action of the valve, and improves the economy and service life of the system operation.

[0098] In one specific embodiment of the embodiment of the present application, the denitration outlet flue of the thermal power generating unit comprises: a first flue and a second flue. Correspondingly, the ammonia injection control method further comprises: Step S410, respectively calculating a first overall round average value of all partitions corresponding to the first flue and a second overall round average value of all partitions corresponding to the second flue.

[0099] In the actual operation of the thermal power generating unit with a double-flue structure, due to factors such as boiler combustion characteristics, flue arrangement differences, and the like, the flow field distribution and NO x concentration characteristics often have inherent differences. In order to accurately grasp the overall denitration effect of each flue, independent data processing is performed on all partitions contained in the first flue and the second flue. By performing weighted average calculation on the round average values of each partition in each flue, the first overall round average value and the second overall round average value representing the overall concentration level of each flue are obtained. This partition statistical method can eliminate the influence of abnormal data of a single partition on overall evaluation, and ensure that the obtained overall concentration value of the flue is fully representative.

[0100] In actual application, the sliding window average method is used to process the concentration data of each partition, ensuring the timeliness and accuracy of the calculation results. For a typical double-flue structure containing 8 partitions, the concentration average values of the 4 partitions of each flue are calculated, and the influence of abnormal measurement values is excluded through a data validity checking mechanism. This independent calculation method can accurately reflect the actual operation state of each flue, and provide a reliable data basis for subsequent flue-to-flue leveling control, and is particularly suitable for solving the long-term concentration deviation problem caused by asymmetric flue structure.

[0101] Step S420, calculating the deviation value between the first overall round average value and the second overall round average value.

[0102] After obtaining the overall round average values of the two flues, the concentration deviation value between the two flues is calculated by algebraic operation. The deviation value accurately quantifies the degree of concentration difference between the two flues, and a positive value indicates that the concentration of the first flue is higher than that of the second flue, and a negative value indicates the opposite. During the actual operation of the unit, this deviation may be caused by many factors such as uneven air distribution of the burner, unbalanced distribution of flue gas recirculation, etc. Accurate deviation calculation provides a clear adjustment direction and amplitude basis for subsequent leveling control.

[0103] When calculating the deviation value, the 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 deviation, the reinforced leveling mode is started, and for random fluctuations, a relatively mild adjustment strategy is adopted. This intelligent deviation analysis mechanism ensures the accuracy and effectiveness of the leveling control, and can adapt to the leveling needs of the unit under various operating conditions.

[0104] Step S430, based on the deviation value, synchronously adjusting the total ammonia injection flow rate allocated to each of the first flue and the second flue, so that the first overall round average value and the second overall round average value tend to be consistent.

[0105] According to the calculated deviation value, a specially designed leveling control algorithm is used to generate coordinated adjustment instructions for the total ammonia injection flow rate of the two flues. When it is monitored that the concentration of the first flue is higher than that of the second flue, the total ammonia injection flow rate of the second flue is increased and the ammonia injection amount of the first flue is correspondingly reduced. This reverse symmetric adjustment method can quickly eliminate the concentration difference between the two flues while maintaining the total ammonia amount of the system basically stable. The leveling control adopts a gradual adjustment strategy, which gradually adjusts through multiple control cycles to ensure smooth transition of the system to the equilibrium state.

[0106] 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 strength is appropriately increased; for flues with obvious overshoot, a smaller adjustment step is used. At the same time, a limit protection of the leveling amplitude is set to prevent concentration oscillation caused by excessive adjustment. This intelligent leveling control strategy has shown excellent performance in the actual application of multiple power plants, effectively solving the long-standing concentration deviation problem of double-flue units.

[0107] By calculating the overall concentration level of the double flues respectively, the concentration deviation between the flues is accurately quantified, and intelligent coordinated leveling control is implemented based on the deviation value, effectively eliminating the concentration difference between the double flues, significantly improving the uniformity and stability of the overall operation of the denitrification system, preventing the problem of single-sided air preheater blockage caused by uneven ammonia injection of the flue, and enhancing the environmental protection control ability of the unit under complex operating conditions.

[0108] Further, the step S430 of synchronously adjusting the total ammonia injection flow rate allocated to the first flue and the second flue based on the deviation value comprises: In step S4311, the real-time load value of the thermal power generating unit is obtained, and the preset load working condition interval to which the real-time load value belongs is determined.

[0109] When the thermal power generating unit participates in the peak shaving operation of the power grid, the frequent change of the unit load can significantly affect the boiler combustion condition and the flue gas flow characteristics, thereby causing the dynamic change of the concentration distribution relationship between the double flues. To adapt to such working condition change, the unit load signal is collected in real time, and the load working condition interval in which the current load belongs is accurately determined according to the preset load interval division standard. In actual application, the load range is usually divided into three typical working condition sections, i.e., a low load interval (below 50% rated load), a medium load interval (50%-80% rated load), and a high load interval (above 80% rated load), each of which corresponds to different flue flow characteristics and concentration distribution characteristics.

[0110] The division of the load working condition interval is based on the statistical analysis of a large amount of historical operation data, and comprehensively considers the flue gas flow rate, temperature distribution, and NO x The change law of the generation characteristics is generated. The unit load data is obtained in real time through the DCS interface, and the hysteresis comparison algorithm is used to avoid the frequent switching of the working condition judgment at the interval boundary, so as to ensure the accuracy and stability of the load working condition recognition. This adaptive mechanism based on the load working condition provides an important basis for the subsequent selection of the leveling parameters, so that the control system can intelligently adjust the control strategy according to the change of the working condition.

[0111] In step S4312, the corresponding flue balance adjustment coefficient is selected from a predefined mapping relationship according to the preset load working condition interval.

[0112] A mapping relationship between the load working condition and the flue balance adjustment coefficient is established according to the difference in the dynamic characteristics of the double flue system under different load working conditions. The mapping relationship is set based on a large amount of field test data, and accurately reflects the optimal response characteristics of the leveling control system under each load working condition. In the low load working condition, a relatively small balance adjustment coefficient is selected due to the low flue gas flow rate and poor mixing effect, so as to avoid system oscillation caused by excessive adjustment; in the medium and high load working conditions, a larger adjustment coefficient is used to ensure the rapidity and effectiveness of the leveling control.

[0113] The preset mapping relationship of the balance adjustment coefficient is stored in a system configuration file, and can be adjusted online according to the actual operation effect of the unit. A coefficient smoothing transition mechanism is also provided, so that when the load condition changes, the balance adjustment coefficient gradually transitions to the target value at a preset rate, avoiding control disturbance caused by sudden changes in the coefficient. This refined coefficient management strategy ensures the adaptability and stability of the leveling control system in the full load range, effectively improving the control quality of the system.

[0114] In step S4313, a reference adjustment amount of the total ammonia injection flow is calculated based on the deviation value and the flue balance adjustment coefficient.

[0115] After obtaining the flue deviation value and the corresponding balance adjustment coefficient, the reference adjustment amount of the total ammonia injection flow is calculated through product operation. This calculation process fully considers the comprehensive influence of the deviation size and the working condition characteristics, ensuring that the adjustment amount accurately matches the actual leveling demand. When the flue deviation is large, combined with appropriate balance adjustment coefficient, a larger reference adjustment amount is generated to speed up the leveling process; for smaller concentration deviation, a relatively moderate adjustment amount is generated to maintain stable operation of the system.

[0116] The calculation of the reference adjustment amount also introduces an amplitude limiting protection mechanism, which ensures that the single adjustment amplitude is within a reasonable range by setting upper and lower limits of the adjustment amount. At the same time, the reference adjustment amount is dynamically corrected according to the deviation trend. When it is monitored that the deviation continues to expand, the adjustment intensity is appropriately increased; when the deviation shows a convergent trend, the adjustment intensity is correspondingly reduced. This intelligent adjustment amount calculation strategy ensures both the rapidity of leveling control and the stability of the adjustment process.

[0117] In step S4314, the reference adjustment amount is added to the total ammonia injection flow set value of the first flue and the second flue respectively, and reverse symmetric adjustment is performed on the first flue and the second flue.

[0118] After the reference adjustment amount is calculated, it is applied to the total ammonia injection flow control loop of the two flues. In specific implementation, for the flue with higher concentration, the reference adjustment amount is subtracted from the total ammonia injection flow set value; for the flue with lower concentration, the same adjustment amount is added to the original set value. This reverse symmetric adjustment method can quickly and effectively eliminate the concentration deviation between the two flues while maintaining the total ammonia injection amount of the system basically unchanged, avoiding the adverse effects of leveling operation on the total denitration efficiency of the system.

[0119] During the adjustment of the ammonia injection process, the ammonia injection flow and concentration changes of the two flues are monitored in real time, and the adjustment effect is dynamically optimized through a closed-loop feedback mechanism. When it is monitored that the response of a certain flue is slow, the adjustment component of that side is appropriately increased; when overshoot occurs, the adjustment effort is timely reduced. At the same time, an adjustment rate limit is set to ensure smooth changes in ammonia injection flow and prevent shocks to downstream equipment. The fine leveling control strategy has been successfully applied in multiple power plants, indicating that it can effectively solve the long-standing concentration imbalance problem of dual-flue units.

[0120] By establishing a load condition self-adaptive flue balancing adjustment mechanism, generating a reference adjustment amount based on the accurately calculated concentration deviation and intelligently selected adjustment coefficient, and implementing dual-flue leveling control using a reverse symmetric adjustment strategy, the concentration difference between the flues is effectively eliminated, the uniformity and stability of the denitration system operation are significantly improved, and the adaptability to different operating conditions is enhanced, providing reliable protection for the environmental protection standard of the unit in the full load range.

[0121] Further, the synchronization adjustment distribution to the total ammonia injection flow of the first flue and the second flue in step S430 includes: Step S4321, the dynamic change rate of the overall average value of the first flue and the second flue in the continuous multiple adjustment rounds is calculated respectively.

[0122] In the actual operation of dual-flue thermal power units, due to differences in flue structure, catalyst activity or flow field resistance, the response characteristics of the two flues to ammonia injection adjustment often differ significantly. To accurately grasp the dynamic response characteristics of each flue, the dynamic change rate of the first flue and the second flue is calculated by analyzing the change trend of the overall average value in continuous multiple adjustment rounds. This change rate is obtained by processing time series data through linear regression method, which can quantitatively represent the speed of change of the concentration value of each flue with time. When the unit load changes or the ammonia injection amount is adjusted, this dynamic monitoring can timely reflect the inertia characteristics of each flue system, providing an important basis for subsequent intelligent leveling.

[0123] The calculation of the dynamic change rate uses the sliding time window technique, selects the data of the last 8-12 adjustment rounds for regression analysis, and ensures the timeliness and accuracy of the calculation results. In actual application, a data validity verification mechanism is also established to automatically exclude invalid data points caused by measurement abnormalities, ensuring the reliability of the change rate calculation. Through continuous monitoring of the dynamic change rates of the two flues, the flue with slow response can be accurately identified, providing data support for implementing differentiated leveling strategies and effectively solving the leveling difficulty problem caused by uneven flue characteristics.

[0124] Step S4322, calculate the ratio of the first flue dynamic change rate and the second flue dynamic change rate as the flue response rate ratio.

[0125] After obtaining the dynamic change rates of the two flues, the ratio of the two is calculated by division operation to obtain the standardized flue response rate ratio. This ratio eliminates the influence of the absolute rate value dimension and can clearly reflect the difference in the relative response ability of the two flues. When the ratio is greater than 1, it indicates that the first flue responds faster than the second flue; when the ratio is less than 1, it indicates that the second flue has faster response characteristics. This relative comparison method can accurately determine the difference in dynamic characteristics between the flues and provide accurate quantitative basis for subsequent weight allocation.

[0126] In actual operation, the response rate ratio is monitored and filtered in real time, and the moving average algorithm is used to eliminate the influence of instantaneous fluctuations, ensuring the stability and reliability of the ratio. At the same time, the change range of the ratio is also protected, and when an abnormal speed ratio is monitored, a backup strategy is automatically enabled to prevent control errors caused by abnormal measurement. This fine processing mechanism ensures the stable operation of the leveling control system under various working conditions, significantly improving the robustness and reliability of the system.

[0127] Step S4323, based on the flue response rate ratio, calculate the dynamic allocation weight, wherein the flue with slower dynamic change rate is given higher allocation weight.

[0128] According to the calculated flue response rate ratio, the dynamic allocation weight is generated through a pre-set weight calculation function. This function uses an inverse proportional relationship to assign a larger allocation weight to the flue with slower response rate, thereby giving it more adjustment resources in the leveling process. For example, when the response rate of a flue is only half of another flue, its allocation weight may be 1.5-2 times that of the other flue. This weight allocation strategy can effectively compensate for the differences in dynamic characteristics between the flues and ensure that both flues can reach the leveling target simultaneously.

[0129] The calculation of the dynamic allocation weight also takes into account the stability requirements of the system, and by setting upper and lower limits of the weight, excessive compensation is prevented. A smooth transition algorithm is used, so that when the response rate ratio changes, the allocation weight will gradually adjust to the target value at a pre-set rate, avoiding control disturbances caused by sudden changes in weight. At the same time, a weight self-learning mechanism is established to automatically optimize the weight calculation parameters based on historical leveling effects, continuously improving the accuracy and adaptability of the leveling control.

[0130] Step S4324, differentially allocate the reference adjustment amount according to the dynamic allocation weight, and superimpose it on the total ammonia injection flow set value of the corresponding flue.

[0131] After obtaining the dynamically allocated weight, the reference adjustment amount is allocated in proportion to the weight to generate specific adjustment instructions for each flue. For the flue with slower response, more adjustment amount will be allocated due to its larger allocation weight, thereby accelerating its response speed. For the flue with faster response, relatively less adjustment amount is allocated to prevent it from overshooting. This differentiated allocation strategy can effectively coordinate the adjustment progress of the two flues to ensure that they can reach the concentration balance state synchronously.

[0132] During the execution of the adjustment instructions, the concentration change of each flue is monitored in real time, and the allocation weight is dynamically optimized. When it is monitored that the adjustment effect of a certain flue deviates from the expectation, the allocation weight thereof is adjusted in time to ensure the smooth progress of the leveling process. Meanwhile, the rate limit and amplitude limit of 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 shows that it can effectively solve the problem of different step of leveling caused by the difference in dynamic characteristics of flues.

[0133] By monitoring the dynamic response characteristics of the double flues in real time, the allocation weight is intelligently calculated based on the response rate ratio, and the reference adjustment amount is allocated differently, effectively solving the problem of different step of leveling caused by the difference in flue characteristics, significantly improving the accuracy and efficiency of double flue concentration leveling, and ensuring that the optimal leveling state can be quickly and smoothly reached under various operating conditions, providing reliable protection for the safe and stable operation of the unit.

[0134] In addition to the basic concentration control function, a perfect operation state evaluation system is established. By continuously monitoring the concentration change trend, valve adjustment frequency, ammonia injection amount fluctuation and other indicators of each partition, the operation state of the system is comprehensively evaluated. When persistent concentration abnormalities or frequent valve actions are detected in a certain partition, operation optimization suggestions are automatically generated to guide the operation personnel to make corresponding adjustments and maintenance. The system can also automatically identify potential problems such as catalyst activity decline and ammonia injection grid blockage, providing important basis for preventive maintenance of equipment.

[0135] Correspondingly, please refer to Figure 4 The second aspect of the embodiment of the present application provides a NO x The partition synchronous measurement ammonia injection control system is characterized in that the flue gas sampling probes are arranged in the several partitions of the flue of the thermal power generating unit, the flue gas samples collected by each flue gas sampling probe are sent to the flue gas analyzer in turn, and the ammonia injection control system comprises: The data acquisition module 1 is used for synchronously latching the flue gas samples of the several partitions of the flue of the thermal power generating unit, obtaining the NO x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration of each partition of the flue cross section. x The concentration field distribution represents the spatial distribution of nitrogen oxide concentration of each partition of the flue cross section. An instruction generating module 2 is configured to generate an optimized control instruction of the ammonia injection valve of each zone based on the NO x The concentration field distribution is obtained, and the optimized control instruction of the ammonia injection valve of each zone is generated. A zone control module 3 is configured to adjust the opening of the ammonia injection valve of the corresponding zone according to the optimized control instruction, so as to realize precise ammonia injection of the zone.

[0136] Correspondingly, a third aspect of the embodiment of the present application provides an electronic device, comprising at least one processor and a memory connected with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above-mentioned NO x The ammonia injection control method based on the zone synchronization measurement.

[0137] Correspondingly, a fourth aspect of the embodiment of the present application provides a computer readable storage medium, which stores computer instructions, and the instructions are executed by a processor to implement the above-mentioned NO x The ammonia injection control method based on the zone synchronization measurement.

[0138] The embodiment of the present application aims to protect a NO x The ammonia injection control method based on the zone synchronization measurement has the following effects: 1. By using the synchronization latching and measurement technology, the NO x The concentration field distribution is obtained, and the optimized control instruction of the ammonia injection valve of each zone is generated. 2. By calculating the concentration distribution unevenness, zone concentration stability and other indexes in real time, the control round, action amplitude and intensity coefficient and other key parameters are dynamically adjusted, so as to realize the precise matching of the control strategy and the current running state of the system; no matter facing frequent load changes or responding to the dynamic response difference of different zones, the control intensity and response speed can be automatically adjusted to achieve the best balance between rapid correction and stable operation, so as to maintain excellent control quality in the whole working condition range. 3. The operation risk of the equipment itself is prevented by dilution wind lower limit protection, valve lower limit protection and other measures; the control system can still reliably operate when some measurement points are abnormal by means of measurement device fault diagnosis and automatic rejection mechanism; in addition, the linkage of the double flue leveling logic and the load working condition avoids the downstream equipment blockage caused by uneven ammonia injection, reduces the dependence of the system on manual intervention, and ensures the continuous, stable and safe operation of the system in the industrial field.

[0139] Those skilled in the art will understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0140] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems), and computer program products of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0141] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0142] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0143] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

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.

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. 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.

3. The NOx-based exhaust gas treatment system of claim 2, wherein the NOx-based exhaust gas treatment system is a selective catalytic reduction system. x The method for synchronizing the partitioned measurement of the ammonia injection control, characterized in that, 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; Based on the preset intensity coefficient and the action amplitude value, the optimization control instruction for adjusting the opening degree of the ammonia injection valve of the corresponding partition is generated in combination with the concentration deviation.

4. The NOx-based system of claim 3, wherein the NOx-based system is a selective catalytic reduction (SCR) system. x The method for synchronizing the measurement of the partition, characterized in that, 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.

5. The NOx-based system of claim 3, 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, 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 values.

6. The NOx-based exhaust gas treatment system of claim 3, wherein the NOx-based exhaust gas treatment system is a selective catalytic reduction (SCR) system. 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 is generated in combination with the concentration deviation based on the preset intensity coefficient and the action amplitude value, which comprises the following steps. The concentration deviation is processed in sections, and different combination strategies of 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.

7. The NOx-based exhaust gas treatment system of claim 2, wherein the NOx-based exhaust gas treatment system is a selective catalytic reduction system. x The method for synchronizing the partitioned measurements of the ammonia injection control, characterized in that, 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.

8. The NOx-based composition of any one of claims 1-7 x The method for synchronizing the measurement of the partition, characterized in that, 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.

9. The NOx-based system of claim 8, wherein the NOx-based system is a selective catalytic reduction (SCR) system. x The method for synchronizing the measurement of the zones, 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.

10. The NOx-based system of claim 8, wherein the NOx-based system is a NOx storage reduction (NSR) catalyst. 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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