Sintering flue gas denitration optimization operation method and device, electronic equipment and storage medium

Abstract

The application provides a sintering flue gas denitration optimization operation method and device, electronic equipment and storage medium, and belongs to the field of sintering flue gas denitration. The method comprises the following steps: according to the actual shared flue gas amount, the inlet nitrogen oxide concentration, the wind compensation coefficient and the oxygen content conversion compensation coefficient, the feedforward target ammonia injection amount of the first denitration system and the second denitration system is calculated respectively; the oxygen content conversion compensation coefficient is combined to trigger the air leakage investigation and early warning, and the actual ammonia injection amount is closed-loop adjusted based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration; when the inlet nitrogen oxide concentration continuously exceeds the highest concentration threshold for a preset time length, a proportioning adjustment instruction is sent to the sintering proportioning system. The sintering flue gas denitration optimization operation method and device, electronic equipment and storage medium provided by the application solve the flue gas amount distribution imbalance caused by uneven pipeline resistance of the parallel double systems, and realize the precise matching of the denitration loads of the two systems.

Description

Technical Field

[0001] This application belongs to the field of sintering flue gas denitrification technology, and more specifically, relates to sintering flue gas denitrification optimization operation methods and devices, electronic equipment, and storage media. Background Technology

[0002] The sintering process in steel production generates a large amount of industrial flue gas containing nitrogen oxides during the sintering process. A single large sintering machine produces a large volume of flue gas, has numerous sealing points at the machine head and tail, and there is a dynamic contact surface between the trolley and the air box. To achieve ultra-low emission limits, a selective catalytic reduction (SCR) denitrification device is installed downstream of the main flue. Ammonia is injected into the flue, and the ammonia reduces nitrogen oxides to nitrogen and water in the catalyst layer. The total flue gas volume of a single sintering machine is determined by both the total amount of flue gas produced and the maximum capacity of a single denitrification device. Large sintering machines are equipped with two denitrification systems connected in parallel to the main flue, with two branch lines sharing the total flue gas volume. Due to differences in plant space layout, the route length and number of bends in the main flue differ between the two branch lines.

[0003] Chinese patent document CN116931416A discloses a method and system for controlling ammonia injection volume in boiler denitrification based on multi-factor compensation. This scheme is designed for denitrification environments in coal-fired boilers. It collects real-time data on unit load, furnace oxygen content deviation, and nitrogen oxide content at the inlet of the denitrification device. A multi-factor comprehensive compensation value is calculated from these three parameters. This comprehensive compensation value is added to the ammonia injection volume generated by a typical control loop and then input into a PID controller to calculate the initial valve opening. The comprehensive compensation value is further converted into a change in valve opening. The change in valve opening is then superimposed with the initial opening to generate an ammonia injection valve opening command. This method assumes a uniform flue gas flow field within a single flue and uses a single main control loop to achieve closed-loop regulation of the ammonia injection valves of a single denitrification device.

[0004] The control logic is based on a direct mapping between a single flue and a uniform flow field. With two parallel branches configured in the sintering machine, the network resistance of the two branches is inherently uneven due to differences in route length and the number of bends. Only one set of concentration measuring points is installed in the front-end main flue; the ammonia injection opening command generated by this measuring point is simultaneously sent to both branches. After the command is issued, the amount of flue gas entering each branch is determined by the network resistance of that branch, not by the control command. In branches with lower resistance, the actual flow rate exceeds the reaction capacity limit of the catalyst bed. Excess flue gas carries the total amount of reducing agent into the bed, causing the ammonia-to-nitrogen oxide ratio in the bed to exceed the stoichiometric requirement. Unreacted ammonia is discharged with the clean flue gas, resulting in tail-end ammonia escape. In branches with higher resistance, the actual flow rate is lower than the design value evenly distributed according to the total amount. The nitrogen oxide load received by the catalyst bed in this branch is insufficient, and the catalyst active area is not fully utilized. The actual flow rate of the two branches is determined unidirectionally by the pipeline resistance. The difference cannot be perceived by a single measuring point or a single command at the front end, and there is no adjustable actuator to intervene in the redistribution of flue gas between the branches. Summary of the Invention

[0005] The purpose of this application is to provide a method and device for optimizing the operation of sintering flue gas denitrification, electronic equipment, and storage medium, to solve the imbalance in flue gas volume distribution caused by uneven pipeline resistance in parallel dual systems, and to achieve precise matching of denitrification load between the two systems.

[0006] A first aspect of this application provides a method for optimizing the operation of sintering flue gas denitrification, applied to a first denitrification system and a second denitrification system that are linked to a sintering batching system and both equipped with flue gas heat exchangers. The first denitrification system and the second denitrification system operate in parallel. The method includes: Obtain the inlet nitrogen oxide concentration and inlet oxygen content of the common main flue inlet of the denitrification system, as well as the outlet nitrogen oxide concentration and actual ammonia injection rate of the first and second denitrification systems respectively; The inlet nitrogen oxide concentration is compared with multiple preset concentration thresholds to determine the inlet concentration level, wherein the multiple preset concentration thresholds include the highest concentration threshold; Based on the inlet concentration level and the pre-built pipeline resistance model, the damper opening and fan frequency of the first denitrification system and the second denitrification system are adjusted to allocate the actual flue gas volume they are responsible for. The flue gas heat exchanger is subjected to cross-flow diagnosis to generate a cross-flow compensation coefficient. When it is determined that there is cross-flow in the flue gas heat exchanger, the cross-flow compensation coefficient is compensated and assigned a value. An oxygen content conversion compensation coefficient is generated based on the inlet oxygen content. Based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, the feedforward target ammonia injection amount for the first denitrification system and the second denitrification system is calculated respectively. The air leakage investigation and early warning are triggered in combination with the oxygen content conversion compensation coefficient, and the actual ammonia injection amount is adjusted in a closed loop based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration. When the inlet nitrogen oxide concentration continuously exceeds the maximum concentration threshold for a preset duration, a batching adjustment command is sent to the sintering batching system.

[0007] In one possible implementation, the inlet concentration level includes a normal operating condition, a medium operating condition, and a high concentration operating condition that includes the highest concentration threshold, which are divided sequentially based on the multiple preset concentration thresholds; the pre-built pipeline resistance model calculates the resistance coefficient back using the measured damper opening and the actual flue gas volume during operation, and periodically corrects the resistance coefficient-flow characteristic curve. The step of adjusting the damper opening and fan frequency of the first and second denitrification systems based on the inlet concentration level and a pre-built pipeline resistance model to allocate the actual flue gas volume to each system includes: When the condition is determined to be the normal operating condition, the preset initial ratio is used as the initial boundary condition of the pre-built pipeline resistance model, and the damper opening and fan frequency of the first denitrification system and the second denitrification system are adjusted to allocate flue gas volume to the first denitrification system and the second denitrification system. When the condition is determined to be medium, the resistance coefficients of the first denitrification system and the second denitrification system in the pre-built pipeline resistance model are compared. The system with the smaller resistance coefficient is identified as the target denitrification system. The damper opening of the target denitrification system is increased and the fan frequency of the other system is correspondingly reduced, so as to increase the flue gas distribution ratio of the target denitrification system and correspondingly reduce the flue gas distribution ratio of the other system. When the high-concentration condition is determined, based on the real-time feedback of the pre-built pipeline resistance model, the damper opening and the fan frequency are adjusted by a preset progressive increment. After a single adjustment and maintaining a preset stable duration, the updated outlet nitrogen oxide concentration is obtained. Based on the updated outlet nitrogen oxide concentration, the overall weighted outlet concentration is calculated, and the steps of adjusting the damper opening and the fan frequency by a preset progressive increment are repeated until the overall weighted outlet concentration reaches the preset minimum concentration condition.

[0008] In another possible implementation, the step of adjusting the damper opening and the fan frequency in a preset, progressive manner includes: Based on the inlet nitrogen oxide concentration and the respective outlet nitrogen oxide concentration, the actual denitrification efficiency of the first denitrification system and the second denitrification system is calculated in real time. When the difference between the actual denitrification efficiencies of the two systems exceeds a preset difference threshold, the system with the higher actual denitrification efficiency is identified as the system to be added. When neither the first denitrification system nor the second denitrification system has reached the preset operating load limit, the flue gas volume of the system to be added is increased, and the damper opening and the fan frequency of the system to be added are adjusted according to the preset gradual increase.

[0009] In another possible implementation, the step of performing cross-flow diagnosis on the flue gas heat exchanger to generate a cross-flow compensation coefficient, and assigning a compensation value to the cross-flow compensation coefficient when it is determined that cross-flow exists in the flue gas heat exchanger, includes: The outlet temperature and the actual pressure difference between the inlet and outlet of the flue gas heat exchanger are collected, and the non-periodic fluctuation characteristics of the outlet nitrogen oxide concentration are extracted when the inlet nitrogen oxide concentration is within a preset stable range. When the deviation of the outlet temperature from the design value exceeds a preset temperature deviation threshold, the actual pressure difference between the inlet and outlet is lower than a preset pressure difference benchmark value, and the non-periodic fluctuation characteristic meets at least two of the preset non-periodic fluctuation conditions, it is determined that there is cross-flow. After determining that cross-ventilation exists, the outlet nitrogen oxide concentration at the time of determination is extracted and latched to obtain the latched concentration. The latched concentration is divided by the baseline outlet nitrogen oxide concentration of the period without cross-ventilation to obtain a quotient. The quotient is used as the determination benchmark: when the quotient is less than or equal to 1.00, it is determined that no substantial cross-ventilation has occurred, and the cross-ventilation compensation coefficient is assigned the normal state value of 1.00; when the quotient is greater than 1.00 and less than or equal to a first preset quotient threshold, it is determined to be minor cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the initial value. A preset compensation value is initially set; when the quotient value is greater than the first preset quotient threshold and less than or equal to the second preset quotient threshold, it is determined to be mild cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the first preset compensation value; when the quotient value is greater than the second preset quotient threshold and less than or equal to the third preset quotient threshold, it is determined to be moderate cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the second preset compensation value; when the quotient value is greater than the third preset quotient threshold, it is determined to be severe cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the quotient value.

[0010] In another possible implementation, the step of generating an oxygen content compensation coefficient based on the inlet oxygen content includes: The oxygen content conversion compensation coefficient is obtained by dividing the first difference between the preset atmospheric ambient oxygen content and the preset benchmark oxygen content by the second difference between the atmospheric ambient oxygen content and the inlet oxygen content. Furthermore, the method also includes: When the oxygen content conversion compensation coefficient exceeds the preset conversion alarm threshold, the air leakage investigation and early warning is triggered.

[0011] In another possible implementation, the steps of calculating the feedforward target ammonia injection rates for the first and second denitrification systems based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, triggering a leak detection and early warning based on the oxygen content conversion compensation coefficient, and adjusting the actual ammonia injection rate in a closed loop based on the feedforward target ammonia injection rate and the outlet nitrogen oxide concentration include: The theoretical total demand is obtained by multiplying the actual flue gas volume, the inlet nitrogen oxide concentration, the preset target denitrification efficiency, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, and then performing an equivalent conversion based on the preset molar mass conversion ratio. The feedforward target ammonia injection amount is calculated by dividing the total theoretical demand by the product of the current catalyst activity coefficient and the reducing agent physical property parameters. When the oxygen content conversion compensation coefficient exceeds the preset conversion alarm threshold, the air leakage investigation and early warning is triggered. Based on the feedforward target ammonia injection rate as a base set value, the deviation between the outlet nitrogen oxide concentration and the corresponding target value is obtained, and the actual ammonia injection rate is adjusted in a closed loop by a closed loop controller based on the deviation.

[0012] In another possible implementation, the ingredient adjustment command is used to instruct an increase in the first preset fuel ratio and a corresponding decrease in the second preset fuel ratio, wherein the nitrogen content parameter and volatile matter parameter of the first preset fuel are respectively less than the corresponding parameters of the second preset fuel; The step of sending a batching adjustment command to the sintering batching system includes: The batching adjustment command is sent to the sintering batching system via a communication link carried by the OPC communication protocol; if no execution acknowledgment is received from the sintering batching system within a preset confirmation period, the batching adjustment command is resent and the current closed-loop adjustment state of the actual ammonia injection amount remains unchanged. The quality index of sintered ore after the batching adjustment command is executed is collected. When the quality index of sintered ore exceeds the preset safety limit threshold, a rollback operation is triggered to restore the batching ratio state before the batching adjustment command was executed.

[0013] A second aspect of this application provides a sintering flue gas denitrification optimization operation device, applied to a first denitrification system and a second denitrification system that are linked to a sintering batching system and both equipped with flue gas heat exchangers. The first denitrification system and the second denitrification system operate in parallel to implement a sintering flue gas denitrification optimization operation method, including: The data acquisition module is used to obtain the inlet nitrogen oxide concentration and inlet oxygen content of the common main flue inlet of the denitrification system, as well as the outlet nitrogen oxide concentration and actual ammonia injection amount of the first denitrification system and the second denitrification system, respectively. The operating condition determination module is used to compare the inlet nitrogen oxide concentration with multiple preset concentration thresholds to determine the inlet concentration level, wherein the multiple preset concentration thresholds include the highest concentration threshold. The flue gas distribution optimization module is used to adjust the damper opening and fan frequency of the first denitrification system and the second denitrification system based on the inlet concentration level and the pre-built pipeline resistance model, so as to distribute the actual amount of flue gas they are responsible for. The GGH cross-flow diagnosis module is used to perform cross-flow diagnosis on the flue gas heat exchanger to generate a cross-flow compensation coefficient, and to compensate the cross-flow compensation coefficient when it is determined that there is cross-flow in the flue gas heat exchanger. An oxygen content monitoring and compensation module is used to generate an oxygen content conversion compensation coefficient based on the inlet oxygen content. The ammonia injection control module is used to calculate the feedforward target ammonia injection amount for the first and second denitrification systems based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, respectively; to trigger a leakage detection and early warning based on the oxygen content conversion compensation coefficient; and to adjust the actual ammonia injection amount in a closed loop based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration; and, The sintering batching linkage module is used to send a batching adjustment command to the sintering batching system when the inlet nitrogen oxide concentration continuously exceeds the maximum concentration threshold for a preset time.

[0014] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of the above-described sintering flue gas denitrification optimization operation method.

[0015] In a fourth aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described optimized operation method for denitrification of sintering flue gas.

[0016] The beneficial effects of the sintering flue gas denitrification optimization operation method and apparatus, electronic equipment, and storage medium provided in this application embodiment are as follows: 1. By adjusting the damper opening and fan frequency of the first and second denitrification systems operating in parallel according to the inlet concentration level and the pre-built pipeline resistance model, the actual flue gas volume they are responsible for is allocated. Combined with the cross-flow compensation coefficient and the oxygen content conversion compensation coefficient, the feedforward target ammonia injection volume of the two systems is calculated respectively. This changes the physical state where the flue gas volume is determined solely by the pipeline resistance, and achieves precise matching of the denitrification load of the parallel dual systems, avoiding ammonia escape or catalyst idleness caused by uneven resistance.

[0017] 2. A differentiated allocation strategy is adopted for different inlet concentration levels. Under normal operating conditions, the allocation is based on the initial ratio. Under medium operating conditions, the allocation ratio is optimized by comparing the resistance coefficient. Under high concentration conditions, the damper opening and fan frequency are adjusted according to the preset gradual increase. Based on the overall weighted outlet concentration, the optimization is carried out cyclically until the minimum concentration condition is reached, which improves the adaptability of flue gas volume allocation under different operating conditions and the overall economy of denitrification efficiency.

[0018] 3. By collecting the non-periodic fluctuation characteristics of the flue gas heat exchanger's outlet temperature, inlet and outlet pressure difference, and outlet nitrogen oxide concentration, cross-flow diagnosis is performed and cross-flow compensation coefficients are solidified. At the same time, an oxygen content conversion compensation coefficient is generated based on the inlet oxygen content, and a leakage investigation and early warning is triggered. When the inlet nitrogen oxide concentration continues to exceed the threshold, a batching adjustment command to reduce the fuel nitrogen content is sent to the sintering batching system, and the sinter quality is monitored to trigger a rollback, thereby reducing the risk of negative impact of source intervention on sinter quality. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic flowchart of an optimized operation method for denitrification of sintering flue gas provided in an embodiment of this application; Figure 2 A flowchart illustrating the inlet concentration level determination and flue gas volume allocation strategy provided in an embodiment of this application; Figure 3 This is a structural block diagram of a sintering flue gas denitrification optimization operation device provided in an embodiment of this application; Figure 4 This is a schematic block diagram of an electronic device provided in an embodiment of this application.

[0021] Reference numerals: 300, electronic device; 301, processor; 302, input device; 303, output device; 304, memory; 305, communication bus. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] It is understood that in the embodiments of this application, data such as user information are involved. When the embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with relevant laws, regulations and standards.

[0024] It should be noted that the terms "first," "second," etc., used in the specification, claims, and drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0025] The existing control logic relies on a direct mapping between a single flue and a uniform flow field. With two parallel branches in the sintering machine, the network resistance of the two branches is inherently uneven due to differences in route length and the number of bends. Only one set of concentration measuring points is installed in the main flue at the front end; the ammonia injection opening command generated by this point is simultaneously sent to both branches. After the command is issued, the amount of flue gas entering each branch is determined by the network resistance of that branch, not by the control command. In branches with lower resistance, the actual flow rate exceeds the reaction capacity limit of the catalyst bed. Excess flue gas carries the total amount of reducing agent into the bed, causing the ammonia-to-nitrogen oxide ratio to exceed the stoichiometric requirement. Unreacted ammonia is discharged with the clean flue gas, resulting in tail-end ammonia escape. In branches with higher resistance, the actual flow rate is lower than the design value evenly distributed according to the total amount. The nitrogen oxide load received by the catalyst bed in this branch is insufficient, and the catalyst active area is not fully utilized. The actual flow rate of the two branches is determined unidirectionally by the pipeline resistance. The difference cannot be perceived by a single measuring point or a single command at the front end, and there is no adjustable actuator to intervene in the redistribution of flue gas between the branches.

[0026] To address the aforementioned technical issues, this application provides an optimized operation method for sintering flue gas denitrification, which resolves the imbalance in flue gas volume distribution caused by uneven pipeline resistance in parallel dual systems, and achieves precise matching of denitrification loads between the two systems.

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0028] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the sintering flue gas denitrification optimization operation method provided in this application. The sintering flue gas denitrification optimization operation method provided in this embodiment can be executed by a sintering flue gas denitrification optimization operation device. The method is applied to a first denitrification system and a second denitrification system linked to the sintering batching system. The two denitrification systems are connected in parallel to the main flue of the sintering machine, sharing a single main exhaust fan. Each system is connected to the main flue via an independent branch and is equipped with a flue gas heat exchanger. The branch of the first denitrification system is limited by the plant layout, resulting in a long route, numerous bends, and significant pipeline resistance. The branch of the second denitrification system uses a straight-through connection, resulting in lower pipeline resistance. The method may include the following steps: S1. Acquisition of operating parameters.

[0029] A sampling probe of the continuous emission monitoring system is installed at the flue gas outlet of the sintering machine, which is the common inlet of the two denitrification systems. This probe collects the inlet nitrogen oxide concentration, inlet oxygen content, and inlet flue gas temperature at a sampling period of no more than 1 minute. The nitrogen oxide concentration measurement point of the continuous emission monitoring system uses an extraction analyzer, or an in-situ laser analyzer. Sampling probes of the continuous emission monitoring system are installed at the outlets of the first and second denitrification systems respectively to collect the nitrogen oxide concentrations at the outlets of the first and second denitrification systems. The outlet concentrations of the two branches are measured independently. The distributed control system collects the actual ammonia injection rate, induced draft fan frequency, and damper opening of each of the two denitrification systems, and also collects the inlet and outlet temperatures and inlet and outlet pressure differences of the raw flue gas side and clean flue gas side of the two flue gas heat exchangers. Inlet-side parameters, outlet-side parameters, and equipment-side parameters are integrated into the host computer via an industrial Ethernet network. The industrial Ethernet network can also be carried by a fieldbus. The parameters are aligned by timestamp in the host computer to form a parameter set of the same sampling section, which is used for subsequent steps. The sampling period is 1 minute, which corresponds to the smallest time scale at which fluctuations in the flue gas condition of the sintering machine can be identified in one go. If the period is too long, the concentration jump caused by sudden changes in coal quality will be missed.

[0030] S2, Determination of inlet concentration level.

[0031] The host computer extracts the inlet nitrogen oxide concentration from the parameter set and compares it one by one with multiple preset concentration thresholds to determine the inlet concentration level. Two preset concentration thresholds are set: a lower threshold of 250 mg / Nm³ and a higher threshold of 350 mg / Nm³, with the higher threshold also serving as the highest concentration threshold. 250 mg / Nm³ corresponds to the upper limit of the operating condition where the two denitrification systems can stably meet the standard by allocating flue gas according to the design ratio; 350 mg / Nm³ corresponds to the operating limit where relying solely on end-of-pipe ammonia injection has approached the upper limit of the catalytic bed reaction. An inlet nitrogen oxide concentration not exceeding 250 mg / Nm³ is defined as a normal operating condition; an inlet nitrogen oxide concentration greater than 250 mg / Nm³ but not exceeding 350 mg / Nm³ is defined as a medium operating condition; and an inlet nitrogen oxide concentration greater than 350 mg / Nm³ is defined as a high-concentration operating condition, including the highest concentration threshold. The two thresholds are adjusted based on the design processing capacity of the specific sintering machine's denitrification system. The inlet concentration level is output as a level signal to the flue gas volume dynamic allocation stage and simultaneously provided to the feed batching linkage stage for use. Under medium and high concentration operating conditions, the response frequency of flue gas volume distribution and ammonia injection control increases accordingly.

[0032] S3, Dynamic distribution of flue gas volume.

[0033] After receiving the inlet concentration level signal, the flue gas distribution optimization module calls the pre-built pipeline resistance model to adjust the damper opening and fan frequency of the first and second denitrification systems. The adjustment amount of damper opening and fan frequency is clamped by their respective preset upper and lower limits. The pipeline resistance model is established through calibration tests before the system is put into operation. The calibration test changes the damper opening of the two denitrification systems step by step, records the corresponding resistance coefficient and flow rate, and obtains the resistance coefficient-flow rate characteristic curve of each system under different damper openings. During operation, the resistance coefficient is recalculated based on the measured damper opening and the actual amount of flue gas distributed, and the characteristic curve is periodically corrected to compensate for the resistance drift caused by catalyst ash accumulation.

[0034] like Figure 2 As shown, taking the inlet nitrogen oxide concentration obtained during the data acquisition phase as the trigger point, the system executes the inlet nitrogen oxide concentration level determination and flue gas volume allocation strategy downwards according to the parallel branch architecture: Under normal operating conditions, the flue gas volume is allocated according to the preset initial ratio, with the first denitrification system accounting for 60% to 70% of the total flue gas volume and the second denitrification system accounting for 30% to 40%. Under medium operating conditions, the flue gas allocation optimization module compares the resistance coefficients corresponding to the current damper openings of the two systems in the pipeline resistance model, identifies the one with the smaller resistance coefficient as the target denitrification system, increases the damper opening of the target denitrification system, and reduces the fan frequency of the other denitrification system. The flue gas sharing ratio of the target denitrification system increases from the design value to 40% to 50%, so that the denitrification efficiency of the two systems returns to their respective optimal operating ranges.

[0035] Under high-concentration conditions, the flue gas distribution optimization module adjusts the damper opening and fan frequency in a preset, progressive manner, with each adjustment not exceeding 5% of the total flue gas volume. The specific flue gas volume distribution method under high-concentration conditions is as follows: The first step is to calculate the current actual denitrification efficiency of each system: ;in, This indicates the measured concentration of nitrogen oxides at the inlet, in mg / Nm³. and These represent the outlet nitrogen oxide concentrations of the first and second denitrification systems, respectively, in mg / Nm³. and These represent the actual denitrification efficiencies of the first and second denitrification systems, respectively. The second step, if ( If the efficiency is greater than 5 percentage points, priority will be given to increasing the flue gas volume to the less efficient system. It is expected that each 5% transfer of flue gas volume can improve the efficiency of the system by about 2-3 percentage points. The third step is to establish a flue gas volume allocation model with the objective function of minimizing the overall weighted NOx concentration at the outlet: The constraints are that the operating load of System 1 does not exceed 110% of the design value, and the operating load of System 2 does not exceed 120% of the design value; among which, and These represent the actual flue gas volumetric flow rates of the first and second denitrification systems, respectively, in Nm³ / h. This represents the overall weighted average concentration after the two systems are combined, in mg / Nm³. The fourth step involves a gradual strategy where each adjustment does not exceed 5% of the total flue gas volume. After each adjustment, the system is kept stable for 15 minutes to observe the outlet data. Once the target is met, further adjustments are made to avoid significant fluctuations. Simultaneously, an early warning is issued to the sintering batching system.

[0036] The calculation principle of the above allocation method is explained as follows: (1) Denitrification efficiency formula The principle is based on the material balance method in chemical engineering. The total inbound NOx minus the total outbound NOx, divided by the total inbound NOx, gives the proportion of NOx removed, reflecting the actual NOx removal capacity of each system under current conditions. Measured data from the continuous emission monitoring system can be directly substituted into the calculation for real-time processing.

[0037] (2) Weighted average objective function The principle is based on the flow-weighted average method. The total NOx concentration after the outlets of the two systems are combined is equal to the flow-weighted average of the outlet concentrations of each system. When adjusting... and When allocating the proportions, As this changes, the optimization goal becomes finding the one that makes... Minimum allocation point. The constraints (System 1 ≤ 110%, System 2 ≤ 120% of design load) are the engineering safety margins to prevent overload operation of a single system from causing fan surge or catalyst bed breakdown.

[0038] (3) The principle of the 5% gradual flow adjustment strategy is the step-by-step trial method in process control. Due to the large volume and high inertia of the sintering flue gas system, the data of the continuous emission monitoring system has a delay of 3-5 sampling cycles (about 10-15 minutes). If the flue gas volume distribution is adjusted drastically at once, it may lead to system instability and outlet concentration overshoot. The gradual strategy of using a small step of 5% at a time and observing for 15 minutes each time can gradually approach the optimal distribution point while ensuring system stability. After the preset stabilization time is over, the updated outlet nitrogen oxide concentration is obtained. The outlet nitrogen oxide concentration of each system is weighted and summed according to the actual flue gas volume of each system and then divided by the total flue gas volume to obtain the overall weighted outlet concentration. If the overall weighted outlet concentration does not reach the preset minimum concentration condition, the adjustment is continued until the overall weighted outlet concentration reaches the preset minimum concentration condition.

[0039] Under high-concentration conditions, especially when facing extreme conditions including the highest concentration threshold, the flue gas distribution optimization module calculates the actual denitrification efficiency of the two systems in real time based on the inlet nitrogen oxide concentration and their respective outlet nitrogen oxide concentrations. The actual denitrification efficiency of the first denitrification system is the difference between the inlet nitrogen oxide concentration and the outlet nitrogen oxide concentration of the first denitrification system divided by the inlet nitrogen oxide concentration. The actual denitrification efficiency of the second denitrification system is obtained in the same way. When the difference between the actual denitrification efficiencies exceeds a preset difference threshold, the system with the higher actual denitrification efficiency is identified as the system to be added. If neither system reaches the preset operating load limit, the flue gas volume is increased for the system to be added, and the damper opening and fan frequency of the system to be added are adjusted according to a preset gradual increase. The operating load limits of the two systems are taken as the corresponding margins of their respective design loads. After the adjustment, the stable damper opening and fan frequency, combined with the resistance coefficient-flow characteristic curve of the pipeline resistance model, are used to calculate the actual flue gas volume shared by each of the two denitrification systems. This flue gas volume is then output to the ammonia injection calculation stage.

[0040] S4. Air leakage diagnosis and oxygen content conversion compensation.

[0041] The flue gas heat exchanger crossflow diagnosis module obtains the outlet temperature of the clean flue gas side and the actual pressure difference between the inlet and outlet of the flue gas heat exchanger. During periods when the inlet nitrogen oxide concentration is within a preset stable range, it extracts the aperiodic fluctuation characteristics of the outlet nitrogen oxide concentration. The preset stable range limits the inlet concentration to remain essentially constant, allowing fluctuations in the outlet concentration to be attributed to the heat exchanger's sealing condition rather than inlet disturbances. A deviation of the clean flue gas side outlet temperature from the design value exceeding 10°C indicates that high-temperature flue gas from the original flue gas side has entered the clean flue gas side through the sealing gap; an actual pressure difference between the inlet and outlet is lower than the preset pressure difference benchmark value, indicating an increased sealing gap; and the aperiodic fluctuation characteristics of the outlet nitrogen oxide concentration meet the preset aperiodic fluctuation conditions, indicating intermittent crossflow of high-concentration original flue gas. Crossflow is determined to exist when the deviation of the outlet temperature from the design value exceeds a preset temperature deviation threshold, the actual pressure difference between the inlet and outlet is lower than the preset pressure difference benchmark value, and the aperiodic fluctuation characteristics meet at least two of the preset aperiodic fluctuation conditions. After determining the presence of cross-ventilation, the outlet nitrogen oxide concentration at the time of determination is extracted and latched to obtain the latched concentration. The latched concentration is divided by the baseline outlet nitrogen oxide concentration of the period without cross-ventilation history to obtain the quotient. The quotient is used as the determination benchmark: when the quotient is less than or equal to 1.00, it is determined that no substantial cross-ventilation has occurred, and the cross-ventilation compensation coefficient is assigned the normal state value of 1.00; when the quotient is greater than 1.00 and less than or equal to the first preset quotient threshold, it is determined to be slight cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the initial preset compensation value; when the quotient is greater than the first preset quotient threshold and less than or equal to the second preset quotient threshold, it is mild cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the first preset compensation value; when the quotient is greater than the second preset quotient threshold and less than or equal to the third preset quotient threshold, it is moderate cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the second preset compensation value; when the quotient is greater than the third preset quotient threshold, it is severe cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the quotient to achieve dynamic adaptive compensation under extremely high concentrations. This quotient reflects the artificially inflated concentration ratio on the clean flue gas side due to the cross-contamination of the original flue gas. If no cross-contamination is determined, the obtained cross-contamination compensation coefficient is the normal value of 1.00.

[0042] In a specific embodiment, the first preset quotient threshold can be 1.05, the second preset quotient threshold can be 1.10, and the third preset quotient threshold can be 1.20; correspondingly, the initial preset compensation value is fixed at 1.02, the first preset compensation value is fixed at 1.08, and the second preset compensation value is fixed at 1.15.

[0043] The oxygen content monitoring and compensation module calculates the first difference between the ambient oxygen content of 21% and the preset benchmark oxygen content of 13%, and then calculates the second difference between the ambient oxygen content of 21% and the inlet oxygen content. Dividing the first difference by the second difference yields the oxygen content conversion compensation coefficient. This coefficient represents the dilution ratio of flue gas caused by air leakage in the sintering machine. When the inlet oxygen content is higher than the benchmark oxygen content, the coefficient is greater than 1. When the inlet oxygen content is lower than the preset upper limit, this coefficient is included in the subsequent ammonia injection calculation. When the inlet oxygen content reaches or exceeds the preset upper limit, the coefficient is frozen and an air leakage detection and warning is directly triggered. When the oxygen content conversion compensation coefficient exceeds the preset conversion alarm threshold of 1.10, an air leakage detection and warning is triggered, pointing to the sintering machine head and tail seals, the trolley and air box contact seals, and the air box flue welds. The air leakage compensation coefficient and the oxygen content conversion compensation coefficient are output together to the ammonia injection calculation stage.

[0044] S5, ammonia injection closed-loop regulation and batching linkage.

[0045] The ammonia injection control module calculates the feedforward target ammonia injection amount for both the first and second denitrification systems based on the actual flue gas volume, inlet nitrogen oxide concentration, cross-flow compensation coefficient, and oxygen content conversion compensation coefficient. It triggers a leak detection and early warning based on the oxygen content conversion compensation coefficient and adjusts the actual ammonia injection amount in a closed loop based on the feedforward target ammonia injection amount and outlet nitrogen oxide concentration. Specifically, the module multiplies the actual flue gas volume, inlet nitrogen oxide concentration, preset target denitrification efficiency, cross-flow compensation coefficient, and oxygen content conversion compensation coefficient, and performs an equivalent conversion using a preset molar mass conversion ratio to obtain the theoretical total demand for the system. This theoretical total demand is then divided by the product of the catalyst's current activity coefficient and the reducing agent's physical properties to obtain the feedforward target ammonia injection amount. Dividing by the catalyst's current activity coefficient takes into account the catalyst's activity decay over time, and dividing by the reducing agent's physical properties converts the nitrogen oxide reduction demand into the actual supply of reducing agent. The reducing agent's physical properties include the reducing agent's mass concentration and density.

[0046] The ammonia injection rate for each system is calculated using the following formula:

[0047] In the formula, This refers to the ammonia injection rate, expressed in L / h. The measured concentration of nitrogen oxides at the inlet of this system is expressed in mg / Nm³. The standard flue gas volume allocated to this system, in Nm³ / h; For the target denitrification efficiency, substitute it as a percentage and take 85 to 92; This is the crosswind compensation coefficient; The oxygen content conversion compensation coefficient; The current activity coefficient of the catalyst is 0.95 to 1.00, and it decreases with operating time for new catalysts. The value represents the mass concentration of ammonia solution. Substitute the decimal value into the equation; for a 25% concentration of ammonia solution, use 0.25. The density of ammonia water is approximately 0.91 kg / L.

[0048] Oxygen content conversion compensation coefficient Calculate using the following formula:

[0049] In the formula, The baseline oxygen content is set at 13%. This formula is derived from the general form of pollutant concentration conversion specified in the Technical Specification for Continuous Monitoring of Flue Gas Emissions from Stationary Sources. 21 represents the normal atmospheric oxygen content, the denominator represents the amount of oxygen consumed in the actual flue gas, and the numerator represents the amount of oxygen consumed under the baseline oxygen content condition. The ratio of the two reflects the degree of flue gas dilution caused by air leakage in the sintering machine. Greater than hour A value greater than 1 indicates that the calculated concentration is higher than the measured concentration for the same actual concentration. Taking 15% as an example, It is approximately 1.33. This coefficient, together with the air leakage compensation coefficient, is used as a multiplication factor in the feedforward calculation of the basic ammonia injection amount, and, combined with the oxygen content conversion compensation coefficient, independently triggers the air leakage detection and early warning.

[0050] The ammonia injection control module uses the feedforward target ammonia injection rate as the base setpoint. The PID controller takes the deviation between the measured system outlet nitrogen oxide concentration and the target value, and adds the output correction to the base setpoint to perform closed-loop correction on the actual ammonia injection rate. The feedforward component compensates for foreseeable changes in flue gas volume and concentration, while the feedback component eliminates model errors and unmodeled disturbances. The proportional, integral, and derivative parameters of the PID controller are tuned based on the step response characteristics of the denitrification system.

[0051] After the inlet nitrogen oxide concentration has continuously exceeded the maximum concentration threshold of 350 mg / Nm³ for a preset period of time, the simple end-point ammonia injection adjustment has approached the upper limit of the catalytic bed reaction capacity. The sintering batching linkage module sends a batching adjustment command to the sintering batching system. The command instructs the sintering batching system to increase the first preset fuel ratio and correspondingly decrease the second preset fuel ratio. The nitrogen content and volatile matter parameters of the first preset fuel are lower than the corresponding parameters of the second preset fuel. After the ratio adjustment, the generation of fuel-type nitrogen oxides in the sintering process decreases, and the inlet nitrogen oxide concentration drops from the source. The batching adjustment command is sent via a communication link carried by the OPC communication protocol. If no execution confirmation is received from the sintering batching system within a preset confirmation period, the command is resent, and the current closed-loop adjustment state of the end-point denitrification system regarding the actual ammonia injection rate remains unchanged. The sintering batching linkage module collects the sinter quality indicators after executing the batching adjustment command. When the sinter quality indicators exceed the preset safety threshold, a rollback operation is triggered to restore the batching ratio to the state before the batching adjustment command was executed, thus avoiding damage to the sinter quality from source intervention. A preset duration of 30 minutes is recommended.

[0052] Based on the same inventive concept, this application also provides a sintering flue gas denitrification optimization operation device for implementing the above-mentioned sintering flue gas denitrification optimization operation method. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations in the embodiments of the sintering flue gas denitrification optimization operation device provided below can be found in the limitations of the sintering flue gas denitrification optimization operation method above, and will not be repeated here.

[0053] This application provides an optimized operation device for denitrification of sintering flue gas, such as... Figure 3As shown, the sintering flue gas denitrification optimization operation device is applied to the first and second denitrification systems, which are linked with the sintering batching system. The first and second denitrification systems are connected in parallel to the main flue of the sintering machine and each is equipped with a flue gas heat exchanger. The device includes a data acquisition module, an operating condition judgment module, a flue gas distribution optimization module, a GGH cross-flow diagnosis module, an oxygen content monitoring and compensation module, an ammonia injection control module, and a sintering batching linkage module.

[0054] The data acquisition module includes continuous emission monitoring equipment located at the sintering machine flue gas outlet, continuous emission monitoring equipment located at the outlets of the first and second denitrification systems, and a distributed control system data acquisition interface. The continuous emission monitoring equipment at the sintering machine flue gas outlet is configured to acquire the inlet nitrogen oxide concentration, inlet oxygen content, and inlet flue gas temperature. The continuous emission monitoring equipment at the outlets of the two denitrification systems is configured to acquire the nitrogen oxide concentrations at the outlets of the first and second denitrification systems, respectively. The distributed control system data acquisition interface is configured to acquire the actual ammonia injection rate, induced draft fan frequency, damper opening, and inlet and outlet temperatures and pressure differences of the two flue gas heat exchangers for each of the two denitrification systems. The data acquisition module is coupled to the host computer via an industrial Ethernet network.

[0055] The operating condition determination module is communicatively coupled to the data acquisition module and is configured to compare the inlet nitrogen oxide concentration with multiple preset concentration thresholds to determine the inlet concentration level. The multiple preset concentration thresholds include the highest concentration threshold.

[0056] The flue gas distribution optimization module is communicatively coupled to the operating condition determination module. It has a built-in pre-built pipeline resistance model and is configured to adjust the damper opening and fan frequency of the first and second denitrification systems based on the inlet concentration level and the pipeline resistance model. It is also configured to provide the actual flue gas volume shared by the first and second denitrification systems.

[0057] The GGH cross-flow diagnostic module is communicatively coupled to the data acquisition module and is configured to perform cross-flow diagnosis on the flue gas heat exchanger to generate a cross-flow compensation coefficient. When cross-flow is detected in the flue gas heat exchanger, the outlet nitrogen oxide concentration at the time of determination is extracted and latched. The latched concentration is divided by the baseline outlet nitrogen oxide concentration of a period without cross-flow history records, and the resulting quotient is used to solidify and assign a value to the cross-flow compensation coefficient.

[0058] The oxygen content monitoring and compensation module is communicatively coupled to the data acquisition module and is configured to generate an oxygen content conversion compensation coefficient based on the inlet oxygen content.

[0059] The ammonia injection control module is communicatively coupled to the flue gas distribution optimization module, the GGH crossflow diagnostic module, and the oxygen content monitoring and compensation module. It is configured to calculate the feedforward target ammonia injection amount for both the first and second denitrification systems based on the actual flue gas volume, inlet nitrogen oxide concentration, crossflow compensation coefficient, and oxygen content-based compensation coefficient. It triggers a leak detection and early warning based on the oxygen content-based compensation coefficient and adjusts the actual ammonia injection amount in a closed-loop manner based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration. The ammonia injection control module includes a computational unit for feedforward calculation and a PID controller for closed-loop correction; the PID controller performs closed-loop correction based on the deviation between the outlet nitrogen oxide concentration and the target value.

[0060] The sintering batching linkage module is communicatively coupled to the working condition determination module and communicatively coupled to the sintering batching system via a communication link. It is configured to send a batching adjustment command to the sintering batching system when the inlet nitrogen oxide concentration continuously exceeds the maximum concentration threshold for a preset time. It is configured to obtain the sinter quality index after executing the batching adjustment command and to trigger a rollback operation when the sinter quality index exceeds the preset safety limit threshold.

[0061] The details of the flue gas volume allocation ratio, cross-flow judgment criteria combination, compensation coefficient value range and ammonia injection volume calculation involved in each module have been described in detail in the aforementioned method embodiments and will not be repeated here.

[0062] The above modules are implemented in electronic devices in the form of software functional modules. The electronic devices include processors, memory, and communication buses connecting the processor and memory. The memory stores computer programs, and the processor executes the computer programs to realize the functions of each module.

[0063] See Figure 4 , Figure 4 This is a schematic block diagram of an electronic device provided according to an embodiment of this application. Figure 4 The electronic device 300 in this embodiment may include one or more processors 301, one or more input devices 302, one or more output devices 303, and one or more memories 304. The processors 301, input devices 302, output devices 303, and memories 304 communicate with each other via a communication bus 305. The memories 304 store computer programs, including program instructions. The processors 301 execute the program instructions stored in the memories 304. Specifically, the processors 301 are configured to invoke the program instructions to perform the functions of each module / unit in the above-described device embodiments, for example... Figure 3 The functions of each module are shown.

[0064] It should be understood that, in the embodiments of this application, the processor 301 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0065] Input device 302 may include a touchpad, a fingerprint sensor (for collecting the user's fingerprint information and fingerprint orientation information), a microphone, etc., and output device 303 may include a display (LCD, etc.), a speaker, etc.

[0066] The memory 304 may include read-only memory and random access memory, and provides instructions and data to the processor 301. A portion of the memory 304 may also include non-volatile random access memory. For example, the memory 304 may also store device type information.

[0067] In specific implementations, the processor 301, input device 302, and output device 303 described in the embodiments of this application can execute the implementation methods described in the embodiments of this application, or they can execute the implementation methods of the electronic devices described in the embodiments of this application, which will not be repeated here.

[0068] In another embodiment of this application, a computer-readable storage medium is provided. This computer-readable storage medium stores a computer program, which includes program instructions. When executed by a processor, the program instructions implement all or part of the processes in the methods described above. Alternatively, the computer program can instruct related hardware to implement these processes. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0069] The computer-readable storage medium can be an internal storage unit of the electronic device in any of the foregoing embodiments, such as a hard disk or memory of the electronic device. The computer-readable storage medium can also be an external storage device of the electronic device, such as a plug-in hard disk, SmartMediaCard (SMC), Secure Digital (SD) card, FlashCard, etc., equipped on the electronic device. Furthermore, the computer-readable storage medium can include both internal and external storage units of the electronic device. The computer-readable storage medium is used to store computer programs and other programs and data required by the electronic device. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0070] Those skilled in the art will recognize that the modules / units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0071] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the electronic devices and units described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed electronic devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules / units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules, units, or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces or modules / units, or it may be an electrical, mechanical, or other form of connection.

[0073] The modules / units described as separate components may or may not be physically separate. Similarly, the components shown as modules / units may or may not be physical modules / units; they may be located in one place or distributed across multiple network modules / units. Some or all of the modules / units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0074] Furthermore, the functional modules / units in the various embodiments of this application can be integrated into one processing module / unit, or each module / unit can exist physically separately, or two or more modules / units can be integrated into one module / unit. The integrated modules / units described above can be implemented in hardware or in the form of software functional modules / units.

[0075] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optimized operation method for denitrification of sintering flue gas, characterized in that, The method is applied to a first denitrification system and a second denitrification system that are linked to a sintering batching system and both are equipped with flue gas heat exchangers. The first denitrification system and the second denitrification system operate in parallel. The method includes: Obtain the inlet nitrogen oxide concentration and inlet oxygen content of the common main flue inlet of the denitrification system, as well as the outlet nitrogen oxide concentration and actual ammonia injection rate of the first and second denitrification systems respectively; The inlet nitrogen oxide concentration is compared with multiple preset concentration thresholds to determine the inlet concentration level, wherein the multiple preset concentration thresholds include the highest concentration threshold; Based on the inlet concentration level and the pre-built pipeline resistance model, the damper opening and fan frequency of the first denitrification system and the second denitrification system are adjusted to allocate the actual flue gas volume they are responsible for. The flue gas heat exchanger is subjected to cross-flow diagnosis to generate a cross-flow compensation coefficient. When it is determined that there is cross-flow in the flue gas heat exchanger, the cross-flow compensation coefficient is compensated and assigned a value. An oxygen content conversion compensation coefficient is generated based on the inlet oxygen content. Based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, the feedforward target ammonia injection amount for the first denitrification system and the second denitrification system is calculated respectively. The air leakage investigation and early warning are triggered in combination with the oxygen content conversion compensation coefficient, and the actual ammonia injection amount is adjusted in a closed loop based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration. When the inlet nitrogen oxide concentration continuously exceeds the maximum concentration threshold for a preset duration, a batching adjustment command is sent to the sintering batching system.

2. The optimized operation method for sintering flue gas denitrification according to claim 1, characterized in that, The inlet concentration level includes normal operating conditions, medium operating conditions, and high concentration operating conditions including the highest concentration threshold, which are divided sequentially based on the multiple preset concentration thresholds; the pre-built pipeline resistance model calculates the resistance coefficient back using the measured damper opening and the actual flue gas volume during operation, and periodically corrects the resistance coefficient-flow characteristic curve. The step of adjusting the damper opening and fan frequency of the first and second denitrification systems based on the inlet concentration level and a pre-built pipeline resistance model to allocate the actual flue gas volume to each system includes: When the condition is determined to be the normal operating condition, the preset initial ratio is used as the initial boundary condition of the pre-built pipeline resistance model, and the damper opening and fan frequency of the first denitrification system and the second denitrification system are adjusted to allocate flue gas volume to the first denitrification system and the second denitrification system. When the condition is determined to be medium, the resistance coefficients of the first denitrification system and the second denitrification system in the pre-built pipeline resistance model are compared. The system with the smaller resistance coefficient is identified as the target denitrification system. The damper opening of the target denitrification system is increased and the fan frequency of the other system is correspondingly reduced, so as to increase the flue gas distribution ratio of the target denitrification system and correspondingly reduce the flue gas distribution ratio of the other system. When the high-concentration condition is determined, based on the real-time feedback of the pre-built pipeline resistance model, the damper opening and the fan frequency are adjusted by a preset progressive increment. After a single adjustment and maintaining a preset stable duration, the updated outlet nitrogen oxide concentration is obtained. Based on the updated outlet nitrogen oxide concentration, the overall weighted outlet concentration is calculated, and the steps of adjusting the damper opening and the fan frequency by a preset progressive increment are repeated until the overall weighted outlet concentration reaches the preset minimum concentration condition.

3. The optimized operation method for sintering flue gas denitrification according to claim 2, characterized in that, The step of gradually adjusting the damper opening and the fan frequency according to a preset increment includes: Based on the inlet nitrogen oxide concentration and the respective outlet nitrogen oxide concentration, the actual denitrification efficiency of the first denitrification system and the second denitrification system is calculated in real time. When the difference between the actual denitrification efficiencies of the two systems exceeds a preset difference threshold, the system with the higher actual denitrification efficiency is identified as the system to be added. When neither the first denitrification system nor the second denitrification system has reached the preset operating load limit, the flue gas volume of the system to be added is increased, and the damper opening and the fan frequency of the system to be added are adjusted according to the preset gradual increase.

4. The optimized operation method for sintering flue gas denitrification according to claim 1, characterized in that, The step of performing cross-flow diagnosis on the flue gas heat exchanger to generate a cross-flow compensation coefficient, and assigning a compensation value to the cross-flow compensation coefficient when it is determined that cross-flow exists in the flue gas heat exchanger, includes: The outlet temperature and the actual pressure difference between the inlet and outlet of the flue gas heat exchanger are collected, and the non-periodic fluctuation characteristics of the outlet nitrogen oxide concentration are extracted when the inlet nitrogen oxide concentration is within a preset stable range. When the deviation of the outlet temperature from the design value exceeds a preset temperature deviation threshold, the actual pressure difference between the inlet and outlet is lower than a preset pressure difference benchmark value, and the non-periodic fluctuation characteristic meets at least two of the preset non-periodic fluctuation conditions, it is determined that there is cross-flow. After determining that cross-ventilation exists, the outlet nitrogen oxide concentration at the time of determination is extracted and latched to obtain the latched concentration. The latched concentration is divided by the baseline outlet nitrogen oxide concentration of the period without cross-ventilation to obtain a quotient. The quotient is used as the determination benchmark: when the quotient is less than or equal to 1.00, it is determined that no substantial cross-ventilation has occurred, and the cross-ventilation compensation coefficient is assigned the normal state value of 1.00; when the quotient is greater than 1.00 and less than or equal to a first preset quotient threshold, it is determined to be minor cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the initial value. A preset compensation value is initially set; when the quotient value is greater than the first preset quotient threshold and less than or equal to the second preset quotient threshold, it is determined to be mild cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the first preset compensation value; when the quotient value is greater than the second preset quotient threshold and less than or equal to the third preset quotient threshold, it is determined to be moderate cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the second preset compensation value; when the quotient value is greater than the third preset quotient threshold, it is determined to be severe cross-ventilation, and the cross-ventilation compensation coefficient is fixed and assigned the quotient value.

5. The optimized operation method for sintering flue gas denitrification according to claim 4, characterized in that, The step of generating an oxygen content compensation coefficient based on the inlet oxygen content includes: The oxygen content conversion compensation coefficient is obtained by dividing the first difference between the preset atmospheric ambient oxygen content and the preset benchmark oxygen content by the second difference between the atmospheric ambient oxygen content and the inlet oxygen content. Furthermore, the method also includes: When the oxygen content conversion compensation coefficient exceeds the preset conversion alarm threshold, the air leakage investigation and early warning is triggered.

6. The optimized operation method for sintering flue gas denitrification according to claim 5, characterized in that, The steps of calculating the feedforward target ammonia injection rates for the first and second denitrification systems based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, triggering a leak detection and early warning based on the oxygen content conversion compensation coefficient, and adjusting the actual ammonia injection rate in a closed loop based on the feedforward target ammonia injection rate and the outlet nitrogen oxide concentration include: The theoretical total demand is obtained by multiplying the actual flue gas volume, the inlet nitrogen oxide concentration, the preset target denitrification efficiency, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient, and then performing an equivalent conversion based on the preset molar mass conversion ratio. The feedforward target ammonia injection amount is calculated by dividing the total theoretical demand by the product of the current catalyst activity coefficient and the reducing agent physical property parameters. When the oxygen content conversion compensation coefficient exceeds the preset conversion alarm threshold, the air leakage investigation and early warning is triggered. Based on the feedforward target ammonia injection rate as a base set value, the deviation between the outlet nitrogen oxide concentration and the corresponding target value is obtained, and the actual ammonia injection rate is adjusted in a closed loop by a closed loop controller based on the deviation.

7. The optimized operation method for sintering flue gas denitrification according to claim 1, characterized in that, The ingredient adjustment command is used to instruct the increase of the first preset fuel ratio and the corresponding decrease of the second preset fuel ratio, wherein the nitrogen content parameter and volatile matter parameter of the first preset fuel are respectively less than the corresponding parameters of the second preset fuel; The step of sending a batching adjustment command to the sintering batching system includes: The batching adjustment command is sent to the sintering batching system via a communication link carried by the OPC communication protocol; if no execution acknowledgment is received from the sintering batching system within a preset confirmation period, the batching adjustment command is resent and the current closed-loop adjustment state of the actual ammonia injection amount remains unchanged. The quality index of sintered ore after the batching adjustment command is executed is collected. When the quality index of sintered ore exceeds the preset safety limit threshold, a rollback operation is triggered to restore the batching ratio state before the batching adjustment command was executed.

8. A sintering flue gas denitrification optimization operation device, applied to a first denitrification system and a second denitrification system that are linked to the sintering batching system and both are equipped with flue gas heat exchangers, wherein the first denitrification system and the second denitrification system operate in parallel, for implementing the sintering flue gas denitrification optimization operation method as described in any one of claims 1 to 7, characterized in that, include: The data acquisition module is used to obtain the inlet nitrogen oxide concentration and inlet oxygen content of the common main flue inlet of the denitrification system, as well as the outlet nitrogen oxide concentration and actual ammonia injection amount of the first denitrification system and the second denitrification system, respectively. The operating condition determination module is used to compare the inlet nitrogen oxide concentration with multiple preset concentration thresholds to determine the inlet concentration level, wherein the multiple preset concentration thresholds include the highest concentration threshold. The flue gas distribution optimization module is used to adjust the damper opening and fan frequency of the first denitrification system and the second denitrification system based on the inlet concentration level and the pre-built pipeline resistance model, so as to distribute the actual amount of flue gas they are responsible for. The GGH cross-flow diagnosis module is used to perform cross-flow diagnosis on the flue gas heat exchanger to generate a cross-flow compensation coefficient, and to compensate the cross-flow compensation coefficient when it is determined that there is cross-flow in the flue gas heat exchanger. An oxygen content monitoring and compensation module is used to generate an oxygen content conversion compensation coefficient based on the inlet oxygen content. The ammonia injection control module is used to calculate the feedforward target ammonia injection amount for the first denitrification system and the second denitrification system respectively based on the actual flue gas volume, the inlet nitrogen oxide concentration, the cross-flow compensation coefficient, and the oxygen content conversion compensation coefficient. It triggers a leak detection and early warning based on the oxygen content conversion compensation coefficient, and adjusts the actual ammonia injection amount in a closed loop based on the feedforward target ammonia injection amount and the outlet nitrogen oxide concentration. as well as, The sintering batching linkage module is used to send a batching adjustment command to the sintering batching system when the inlet nitrogen oxide concentration continuously exceeds the maximum concentration threshold for a preset time.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7.

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