Ammonia escape control method for SCR (Selective Catalytic Reduction) denitration system

Abstract

The invention relates to the field of pollutant control, and discloses an SCR (selective catalytic reduction) denitration system ammonia escape control method which comprises the following steps: acquiring denitration working conditions of a plurality of denitration bins through an ammonia escape online monitoring system, and analyzing and determining a to-be-checked denitration bin according to the denitration working conditions. And after ammonia escape concentration detection is carried out on each to-be-checked chamber by using the mobile monitoring equipment, a target denitration chamber is screened out. And for the target denitration bin, according to one or more of the opening degree of the guniting valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration and the maintenance record, a corresponding check list is constructed so as to guide maintenance personnel to carry out targeted check and adjustment. And after a preset duration, retesting is performed, and an ammonia escape control effect report is generated, so that the adjustment effect is evaluated and the denitration system is optimized. Therefore, precise control of ammonia escape is realized.

Description

Technical Field

[0001] The present invention relates to the field of pollutant control, and particularly to a method for controlling ammonia slip in an SCR denitration system. Background Art

[0002] During the production process of coke ovens, harmful substances such as nitrogen oxides will be generated. In order to reduce the emissions of harmful substances such as nitrogen oxides in coke oven flue gas, in actual projects, the flue gas is denitrified through an SCR denitration system. Ammonia slip is one of the important parameters for evaluating whether the denitration system operates normally.

[0003] The main factors causing excessive ammonia slip in the denitration device are as follows: (1) The ammonia injection flow distribution of each ammonia injection gun in each bin is uneven, there is uneven local distribution of ammonia in the flue gas, the flue gas velocity is uneven, and the ammonia injection amounts at the outlets of each gun vary greatly. The ammonia slip is relatively higher in places with higher concentration.

[0004] (2) The distribution of nitrogen oxides at the inlet of the denitration chamber is uneven, which does not match the ammonia injection amount of the nozzles of the corresponding ammonia injection grid, and the ammonia injection amount is relatively too large, resulting in high local ammonia slip.

[0005] (3) The catalyst is blocked, and the denitration efficiency decreases. In order to keep the environmental protection parameters from exceeding the standard, more ammonia will be injected, which will cause a vicious cycle; the catalyst is locally blocked and its performance ages, resulting in different catalytic efficiencies at different parts of the catalyst. In order to control the outlet parameters, only the ammonia injection amount can be increased, thereby causing an increase in local ammonia slip.

[0006] (4) The atomization of the gun nozzle is not good. Affected by the impurities in the ammonia water, the impurities block the nozzle, and ammonia gas and flue gas cannot be fully mixed, resulting in a large amount of ammonia slip.

[0007] (5) When the combustion fluctuates, the concentration of nitrogen oxides in the inlet flue gas fluctuates greatly, and the ammonia injection amount often increases, mechanically achieving "up-to-standard emission". Excessive ammonia injection can lead to an increase in ammonia slip.

[0008] (6) The configuration of the ammonia water concentration is also an important factor affecting ammonia slip. If the ammonia water concentration is configured improperly, too high or too low a concentration may cause ammonia slip.

[0009] (7) The reaction temperature is one of the key factors affecting ammonia slip. When the reaction temperature is too low, the reaction rate of nitrogen oxides and ammonia will decrease, which will cause a large amount of NH 3 to escape without participating in the reaction. Therefore, controlling the reaction temperature within an appropriate range is an important means to reduce ammonia slip.

[0010] In the existing denitration systems, the following technical problems often exist: First, the existing technology lacks effective real-time monitoring and analysis tools, and it is impossible to accurately determine which denitrification chambers need to be checked. In addition, traditional inspection and adjustment methods are usually extensive, making it difficult to achieve refined management and efficient ammonia escape control. In addition, the failure to conduct effective effect retests after adjustments also makes it impossible to discover potential problems or optimization solutions in a timely manner, thus affecting the overall denitrification efficiency and environmental compliance of the denitrification system. Second, the existing technology usually adopts a unified detection and treatment method, which is unable to accurately diagnose and differentiate the characteristics of the denitrification chamber with different ammonia injection flow rates, resulting in low resource utilization efficiency and inaccurate problem location, which in turn affects the precise control of ammonia escape and the overall control efficiency, and ultimately reduces the diagnosis and adjustment efficiency of the denitrification system; Third, the existing technology is unable to achieve dynamic identification and targeted adjustment of reaction temperature anomalies, and thus is unable to effectively control the ammonia escape concentration, thereby reducing the reliability and environmental protection effect of the denitrification system. Summary of the invention

[0011] The summary of the invention is used to introduce concepts in a brief form, which will be described in detail in the detailed implementation section below. The summary of the invention is not intended to identify the key features or essential features of the technical solution claimed for protection, nor is it intended to limit the scope of the technical solution claimed for protection.

[0012] The present invention proposes a method for controlling ammonia slip of an SCR denitration system to solve one or more of the technical problems mentioned in the above background technology section.

[0013] The present invention provides an ammonia escape control method for an SCR denitration system, comprising: obtaining a denitration operating condition corresponding to each denitration chamber in a plurality of denitration chambers through an ammonia escape online monitoring system; performing a joint analysis on the denitration operating conditions corresponding to the plurality of denitration chambers to determine at least one denitration chamber to be checked from the plurality of denitration chambers; Using ammonia escape mobile monitoring equipment, each of the at least one denitrification chamber to be checked is tested for ammonia escape concentration, and a real-time ammonia escape concentration corresponding to each denitrification chamber to be checked is obtained; if the real-time ammonia escape concentration is greater than a preset ammonia escape concentration threshold, the corresponding denitrification chamber to be checked is determined as a target denitrification chamber, and a target denitrification chamber group is obtained; For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more items of the shotcrete valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record. The checklist includes multiple check items, so that the maintenance personnel can check and adjust the SCR denitrification system according to the multiple check items in the checklist; After a preset period of time, the ammonia escape concentration of each adjusted target denitrification chamber is retested to obtain the retested ammonia escape concentration corresponding to each target denitrification chamber, and an ammonia escape control effect report is generated based on the retested ammonia escape concentration.

[0014] Optionally, a joint analysis is performed on the denitration conditions corresponding to the multiple denitration chambers to determine at least one denitration chamber to be checked from the multiple denitration chambers, including: Extract the nitrogen oxide concentration at the flue gas inlet from the denitration conditions to obtain the nitrogen oxide concentration at the flue gas inlet corresponding to each denitration chamber; determine the nitrogen oxide concentration at the standard flue gas inlet according to the current coke oven production load conditions, and the coke oven production load conditions are full production or reduced production; According to the nitrogen oxide concentration at the corresponding flue gas inlet and the nitrogen oxide concentration at the standard flue gas inlet, determine the excessive nitrogen oxides at the inlet of each denitrification chamber, the proportion of denitrification chambers exceeding the standard among multiple denitrification chambers and the average nitrogen oxide concentration at the flue gas inlet; if the proportion of denitrification chambers exceeding the standard is greater than the preset proportion value, the current exhaust gas return fan workload is continuously adjusted according to the average nitrogen oxide concentration at the flue gas inlet until the recalculated proportion of denitrification chambers exceeding the standard is less than or equal to the preset proportion value; The actual ammonia escape concentration is extracted from the denitrification operating conditions, and the denitrification chambers whose actual ammonia escape concentration is greater than the preset escape concentration are determined as the denitrification chambers to be checked, thereby obtaining at least one denitrification chamber to be checked.

[0015] Optionally, for each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the shotcrete valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, including: For each target denitration chamber, determine the opening of the spraying valve on the spraying grid branch pipe. If the opening of the spraying valve is greater than the first set opening, the corresponding target denitration chamber is determined as a large-flow ammonia denitration chamber. If the opening of the spraying valve is less than the second set opening, the corresponding target denitration chamber is determined as a small-flow ammonia denitration chamber. If the opening of the spraying valve is greater than the second set opening and less than the first set opening, the corresponding target denitration chamber is determined as a medium-flow ammonia denitration chamber. For a large-flow ammonia denitration chamber, extract the first nitrogen oxide concentration data corresponding to the first detection port and the second nitrogen oxide concentration data corresponding to the second detection port from the denitration working conditions; wherein, the first nitrogen oxide concentration data includes the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet, and the second nitrogen oxide concentration data includes the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet; calculate the first denitration efficiency corresponding to the first detection port according to the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet; calculate the second denitration efficiency corresponding to the second detection port according to the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet; if the difference between the first denitration efficiency and the second denitration efficiency is greater than the preset difference threshold, then include the first type of inspection items in the candidate inspection item set in the corresponding inspection list, wherein each inspection item in the candidate inspection item set is configured with multiple attribute information, and the multiple attribute information includes a category number, an introduction condition, an independence identifier, and an associated inspection item, and the first type of inspection items characterizes the inspection and adjustment of the denitration uniformity of the denitration chamber.

[0016] Optionally, for each target denitration chamber in the target denitration chamber group, construct a corresponding inspection list according to one or more of the slurry spraying valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, and further includes: For a large-flow ammonia denitration chamber, if the difference between the first denitration efficiency and the second denitration efficiency is less than or equal to the preset difference threshold, then determine the average denitration efficiency according to the first denitration efficiency and the second denitration efficiency, and compare the average denitration efficiency with the reference denitration efficiency. If the average denitration efficiency is less than the reference denitration efficiency, then include the second type of inspection items in the candidate inspection item set in the corresponding inspection list, wherein the second type of inspection items characterizes the inspection and adjustment of the flue gas outlet valve or the flue gas inlet valve of the denitration chamber.

[0017] Optionally, for each target denitration chamber in the target denitration chamber group, construct a corresponding inspection list according to one or more of the slurry spraying valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, and further includes: For a medium-flow ammonia denitration chamber or a small-flow ammonia denitration chamber, calculate the actual ratio of the slurry spraying valve opening and the nitrogen oxide concentration at the flue gas inlet. If the actual ratio is greater than the preset ratio, then include a third type of inspection item in the candidate inspection item set in the corresponding inspection list, wherein the third type of inspection items characterizes the inspection and adjustment of the slurry spraying valve opening on the ammonia injection grid branch pipe to reduce the ammonia flow rate; track the ammonia escape concentration and the nitrogen oxide concentration at the flue gas outlet after reducing the ammonia flow rate to obtain the change trend of the ammonia escape concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet; According to the independence identifier, determine whether each third - type inspection item included in the inspection list is an independent inspection item; if it is not an independent inspection item, query at least one associated inspection item of the third - type inspection item included in the inspection list and the introduction condition of each associated inspection item; According to the change trend of ammonia slip concentration, the change trend of nitrogen oxide concentration at the flue gas outlet, and the introduction condition of each associated inspection item, screen out the associated inspection items whose introduction conditions are met from at least one associated inspection item as the target associated inspection items; include the target associated inspection items in the corresponding inspection list.

[0018] Optionally, for each target denitration chamber in the target denitration chamber group, construct a corresponding inspection list according to one or more of the slurry spraying valve opening degree, nitrogen oxide concentration at the flue gas inlet, nitrogen oxide concentration at the flue gas outlet, real - time ammonia slip concentration, and maintenance records, further including: If the third - type inspection item included in the inspection list is an independent inspection item, determine whether the ammonia slip control effect meets the standard according to the change trend of ammonia slip concentration and the change trend of nitrogen oxide concentration at the flue gas outlet; if the ammonia slip control effect does not meet the standard, by querying the maintenance records in the historical time period, determine the most recent implementation time of each inspection item and the standard maintenance interval duration, and include the inspection items whose time interval between the most recent implementation time and the current time is greater than the standard maintenance interval duration in the corresponding inspection list.

[0019] Optionally, a method for controlling ammonia slip in an SCR denitration system of the present invention further includes: For each target denitration chamber in the target denitration chamber group, obtain the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet from the denitration working conditions; calculate the difference between the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet, and compare the difference with a preset difference; if the difference is greater than or equal to the preset difference, include the fourth - type inspection item in the candidate inspection item set in the corresponding inspection list, where the fourth - type inspection item characterizes the inspection and adjustment of the damage condition of the dust removal filter bag.

[0020] The present invention has the following beneficial effects: 1. The fine control and effective control of ammonia escape are realized, thereby improving the operation efficiency and environmental protection effect of the overall denitration system. Specifically, the denitration working conditions of multiple denitration chambers are obtained through the on-line ammonia escape monitoring system, and the denitration chambers to be investigated are determined by analyzing the denitration working conditions. After the ammonia escape concentration of each chamber to be investigated is detected by using mobile monitoring equipment, the target denitration chambers are screened out. For the target denitration chambers, an inspection list is constructed based on one or more of the slurry spraying valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance records to guide the maintenance personnel to conduct targeted inspections and adjustments. After a preset time period, a remeasurement is carried out and an ammonia escape control effect report is generated to evaluate the adjustment effect and optimize the denitration system. By monitoring multiple denitration chambers in real time, jointly analyzing them and screening out the target denitration chambers, abnormal situations of ammonia escape concentration can be quickly and accurately detected. And the problem denitration chambers can be accurately located, reducing the blind inspections and repeated adjustments in the traditional methods, thus realizing the fine and effective control of ammonia escape and improving the operation efficiency and environmental protection effect of the overall denitration system.

[0021] 2. The overall control efficiency of ammonia escape is improved, and the diagnosis and adjustment efficiency of the denitration system are enhanced. Specifically, for the target denitration chamber group, the target denitration chambers are classified into large-flow, medium-flow, and small-flow ammonia denitration chambers according to the slurry spraying valve opening. For the large-flow denitration chambers, the nitrogen oxide concentration data corresponding to multiple detection ports are extracted, and the denitration efficiency difference is calculated. If the efficiency difference exceeds the threshold, it is determined as the first type of inspection item and listed in the inspection list. If the efficiency difference is within the threshold, the average denitration efficiency is calculated and compared with the reference efficiency. If it is lower than the reference, it is determined as the second type of inspection item and listed in the inspection list. For the medium-flow or small-flow denitration chambers, the actual ratio of the slurry spraying valve opening to the nitrogen oxide concentration at the flue gas inlet is calculated and compared with the preset ratio. If the actual ratio is too high, it is determined as the third type of inspection item and listed in the inspection list, and the changing trends of the ammonia escape concentration and the nitrogen oxide concentration at the flue gas outlet after adjustment are tracked. According to these trends and the conditions of relevant inspection items, the target inspection items to be executed are screened out and listed in the inspection list. Through hierarchical detection and differentiated inspection lists, combined with dynamic working condition analysis, the ammonia escape is precisely controlled in a targeted manner, which not only improves the overall control efficiency of ammonia escape, but also improves the diagnosis and adjustment efficiency of the denitration system.

[0022] 3. The concentration of ammonia slip is precisely controlled, enhancing the reliability and environmental protection effect of the denitration system. Specifically, first, the reaction temperature data of each denitration chamber is extracted from the denitration working conditions, compared with the standard reaction temperature range, low-temperature anomalies or high-temperature anomalies are identified, and the corresponding temperature deviation values are calculated; then, the heating intensity mode of the hot blast stove is generated according to the low-temperature deviation value, and the combustion parameters of the coke oven are adjusted according to the high-temperature deviation value; finally, the inspection items and adjustment measures corresponding to the anomaly type are listed in the inspection list, with the low-temperature anomaly corresponding to the inspection and adjustment of the hot blast stove, and the high-temperature anomaly corresponding to the inspection and adjustment of the coke oven combustion parameters, thereby achieving precise control of the catalyst reaction temperature, and then precisely controlling the ammonia slip concentration, enhancing the reliability and environmental protection effect of the denitration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In combination with the accompanying drawings and with reference to the following specific embodiments, the above and other features, advantages, and aspects of the various embodiments of the present invention will become more apparent. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic, and the elements and elements are not necessarily drawn to scale.

[0024] Figure 1 is a flowchart of a method for controlling ammonia slip in an SCR denitration system of the present invention; Figure 2 is an exemplary structural schematic diagram of an SCR denitration system of a method for controlling ammonia slip in an SCR denitration system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0026] In addition, it should be noted that, for the sake of convenience of description, only the parts related to the relevant invention are shown in the drawings. Without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0027] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules, or units, and are not used to limit the order of the functions executed by these devices, modules, or units or their interdependent relationships.

[0028] It should be noted that the modifiers "one" and "more than one" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly specified in the context, it should be understood as "one or more".

[0029] The names of the messages or information exchanged between multiple devices of the present invention are only for illustrative purposes and are not used to limit the scope of these messages or information.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0031] As Figure 1 shown, a flowchart of a method for controlling ammonia slip in an SCR denitration system according to the present invention is shown, which specifically includes the following steps: Step 101, obtain the denitration working conditions corresponding to each denitration chamber in multiple denitration chambers through an ammonia slip online monitoring system; perform a combined analysis on the denitration working conditions corresponding to the multiple denitration chambers to determine at least one denitration chamber to be investigated from the multiple denitration chambers.

[0032] In some embodiments, the ammonia slip online monitoring system is used to monitor the denitration working conditions of the denitration chambers in real time. Among them, the ammonia slip online monitoring system can be a background server. A denitration chamber refers to a single processing unit in an SCR (Selective Catalytic Reduction) denitration system for carrying out the reduction reaction of nitrogen oxides. The SCR denitration system is a nitrogen oxide emission reduction technology widely used in the industrial field. As Figure 2 shown, the SCR denitration system includes a denitration silo (i.e., a denitration chamber) and a coke oven chimney, etc. Each denitration chamber usually includes equipment such as a catalyst, a reaction zone, and gas flow control, aiming to convert nitrogen oxides in the waste gas into nitrogen and water vapor. The denitration working condition is the state information of the denitration chamber during operation. The denitration working condition includes multiple denitration chamber numbers, the nitrogen oxide concentration corresponding to each denitration chamber number, and the initial ammonia slip concentration corresponding to each denitration chamber number, etc. On this basis, first, the working condition data of each denitration chamber are continuously collected through the sensors corresponding to each denitration chamber. Then, the sensors establish a communication connection with the ammonia slip online monitoring system and transmit the working condition data to the ammonia slip online monitoring system. On this basis, a statistical analysis is performed on the denitration working conditions of the multiple denitration chambers, the abnormalities in the denitration working conditions are identified, and the denitration chamber corresponding to the denitration chamber number with abnormal conditions is marked as the denitration chamber to be investigated. As an example, the denitration working conditions of 7 denitration chambers are obtained through the ammonia slip online monitoring system, the nitrogen oxide concentration and the actual ammonia slip concentration at the flue gas inlet of each denitration chamber are analyzed, 4 abnormal denitration chambers are identified, and these 4 abnormal denitration chambers are all marked as the denitration chambers to be investigated.

[0033] Step 102: Use an ammonia slip mobile monitoring device to detect the ammonia slip concentration in each denitrification chamber to be investigated among at least one denitrification chamber to be investigated, and obtain the real-time ammonia slip concentration corresponding to each denitrification chamber to be investigated. If the real-time ammonia slip concentration is greater than the preset ammonia slip concentration threshold, determine the corresponding denitrification chamber to be investigated as the target denitrification chamber, and obtain the target denitrification chamber group.

[0034] In some embodiments, the ammonia slip mobile monitoring device is a portable monitoring device used to accurately measure the ammonia slip concentration in the denitrification chamber. Among them, the ammonia slip mobile monitoring device includes a sensor module and a data processing module. On this basis, according to the denitrification chambers to be investigated determined by the ammonia slip online monitoring system, measurement points are set at key positions in each denitrification chamber to be investigated. The ammonia gas concentration values at the measurement points are collected multiple times by the sensor module and the average ammonia gas concentration is calculated by the data processing module to obtain the real-time ammonia slip concentration corresponding to each denitrification chamber to be investigated. Among them, the real-time ammonia slip concentration refers to the ammonia gas concentration data directly measured on-site by the ammonia slip mobile monitoring device. The preset ammonia slip concentration threshold refers to the maximum allowable ammonia slip concentration value set according to the denitrification system operation specifications or environmental protection standards. On this basis, the real-time ammonia slip concentration of each denitrification chamber to be investigated is compared with the preset ammonia slip concentration threshold. The denitrification chambers to be investigated with a real-time ammonia slip concentration greater than the preset ammonia slip concentration threshold are marked as target denitrification chambers, and all target denitrification chambers are summarized to form a target denitrification chamber group. Among them, the target denitrification chamber refers to the denitrification chamber in the denitrification chambers to be investigated whose real-time ammonia slip concentration exceeds the preset ammonia slip concentration threshold. The target denitrification chamber group is a set composed of all target denitrification chambers, and the target denitrification chamber group includes multiple denitrification chamber numbers. As an example, a certain factory has a total of 5 denitrification chambers (numbered A, B, C, D, E). The ammonia slip mobile monitoring device is used to detect these denitrification chambers one by one to obtain the real-time ammonia slip concentration of each chamber. The detection data is as follows: the real-time ammonia slip concentration of chamber A is 20 ppm; the real-time ammonia slip concentration of chamber B is 45 ppm; the real-time ammonia slip concentration of chamber C is 60 ppm; the real-time ammonia slip concentration of chamber D is 25 ppm; the real-time ammonia slip concentration of chamber E is 75 ppm. The preset ammonia slip concentration threshold is 50 ppm. By comparing the real-time ammonia slip concentration with the threshold, it is obtained that the chambers with a real-time ammonia slip concentration greater than the preset ammonia slip concentration threshold are chamber C and chamber E. Chamber C and chamber E are determined as the target denitrification chambers, and the target denitrification chamber group is combined.

[0035] Step 103, for each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the shotcrete valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration and the maintenance record, and the checklist includes multiple inspection items so that maintenance personnel can inspect and adjust the SCR denitrification system according to the multiple inspection items in the checklist.

[0036] In some embodiments, according to the denitration chamber number corresponding to each target denitration chamber, the spray valve opening, the nitrogen oxide concentration at the flue gas inlet, and the nitrogen oxide concentration at the flue gas outlet of the corresponding target denitration chamber are searched in the denitration working condition. Among them, the spray valve opening refers to the size of the valve opening on the spray ammonia grid branch pipe that controls the ammonia flow rate. The nitrogen oxide concentration at the flue gas inlet refers to the concentration of nitrogen oxides in the flue gas before entering the target denitration chamber. The nitrogen oxide concentration at the flue gas outlet refers to the concentration of nitrogen oxides in the flue gas after passing through the target denitration chamber. The maintenance record of the target denitration chamber is searched in the maintenance database. Among them, the maintenance database includes the denitration chamber number and maintenance record. The maintenance record includes the maintenance history of the equipment, the operating status of the equipment, the time of the last maintenance, known faults and other information. By analyzing the spray valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, one or more of the maintenance records and the real-time ammonia escape concentration, the preliminary diagnosis result of the operating status of the denitration chamber is obtained. According to the preliminary diagnosis results, possible problems are introduced into the corresponding inspection items and the inspection items are summarized to construct a checklist. Among them, the checklist is a detailed operation guide formulated for the maintenance personnel corresponding to the inspection terminal, including the items that need to be checked and adjusted in the target denitrification chamber. The constructed checklist is distributed to the maintenance personnel corresponding to the maintenance terminal. The maintenance personnel check the possible problems of the target denitrification chamber item by item according to the checklist and adjust or repair the problems found.

[0037] Step 104, after a preset time period, re-measure the ammonia escape concentration of each adjusted target denitrification chamber to obtain the re-measured ammonia escape concentration corresponding to each target denitrification chamber, and generate an ammonia escape control effect report based on the re-measured ammonia escape concentration.

[0038] In some embodiments, the preset duration refers to a time period set after adjusting the working state of the denitrification chamber. On this basis, after the preset duration, the ammonia escape concentration of each adjusted target denitrification chamber is measured again using ammonia escape mobile monitoring equipment to obtain the re-measured ammonia escape concentration corresponding to each target denitrification chamber. Among them, re-measuring the ammonia escape concentration refers to re-measuring the ammonia escape concentration of the adjusted chamber through an ammonia escape concentration monitoring device. According to the re-measured ammonia escape concentration, it is determined whether the standard is met and an ammonia escape control effect report is generated, wherein the ammonia escape control effect report is an analysis and summary report of the adjusted ammonia escape concentration, which includes comparative analysis, adjustment effect evaluation and other information.

[0039] In these embodiments, refined and effective control of ammonia escape is achieved, thereby improving the operating efficiency and environmental protection effect of the overall denitrification system. Specifically, the denitrification conditions of multiple denitrification chambers are obtained through the ammonia escape online monitoring system, and the denitrification chambers to be checked are determined based on the denitrification condition analysis. After the ammonia escape concentration of each chamber to be checked is detected by mobile monitoring equipment, the target denitrification chamber is screened out. For the target denitrification chamber, a corresponding checklist is constructed based on one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record to guide the maintenance personnel to conduct targeted inspections and adjustments. After a preset period of time, retesting is performed and an ammonia escape control effect report is generated to evaluate the adjustment effect and optimize the denitrification system. Real-time monitoring of multiple denitrification chambers, joint analysis, and screening of target denitrification chambers can quickly and accurately detect abnormal ammonia escape concentrations. It can also accurately locate the problem out-of-stock compartment, reducing the blind troubleshooting and repeated adjustments in traditional methods, thereby achieving refined and effective control of ammonia escape and improving the operating efficiency and environmental protection effect of the overall denitrification system.

[0040] In some embodiments, in order to further solve the second technical problem described in the background technology section, that is, "the prior art generally adopts a unified detection and processing method, which is unable to accurately diagnose and differentiate the characteristics of denitrification chambers with different ammonia injection flow rates, resulting in low resource utilization efficiency and inaccurate problem location, thereby affecting the precise control of ammonia escape and the overall control efficiency, and ultimately reducing the diagnosis and adjustment efficiency of the denitrification system", in some embodiments of the present invention, the denitrification conditions corresponding to multiple denitrification chambers are jointly analyzed to determine at least one denitrification chamber to be checked from multiple denitrification chambers, including: Step 1: Extract the nitrogen oxide concentration at the flue gas inlet from the denitrification conditions to obtain the nitrogen oxide concentration at the flue gas inlet corresponding to each denitrification chamber; determine the standard nitrogen oxide concentration at the flue gas inlet according to the current coke oven production load conditions, and the coke oven production load conditions are full production or reduced production.

[0041] In some embodiments, the nitrogen oxide concentration at the flue gas inlet of each denitration chamber is continuously collected through a sensor for measuring the nitrogen oxide concentration corresponding to each denitration chamber, and the collected nitrogen oxide concentration at the flue gas inlet is transmitted to the ammonia slip online monitoring system, which processes the original data. On this basis, a denitration chamber number is assigned to each denitration chamber, and then the processed nitrogen oxide concentration data is classified according to the denitration chamber number and integrated into the denitration working condition. Among them, the denitration working condition can be stored in the form of a database. On this basis, the "nitrogen oxide concentration at the inlet" field is queried from the denitration working condition to obtain the nitrogen oxide concentration at the flue gas inlet corresponding to each denitration chamber. The current coke oven production load working condition is obtained from the coke oven operation status information. Among them, the coke oven production load working condition describes the load status of the coke oven operation, and the coke oven production load working condition is full production or reduced production. Among them, the coke oven operation status information includes the current coke oven production load working condition. In practice, when the coke oven production load working condition is full production, the standard nitrogen oxide concentration at the flue gas inlet corresponding to full production is queried in the historical coke oven operation database. When the coke oven production load working condition is reduced production, the first standard concentration is adjusted according to the reduction ratio to obtain the standard nitrogen oxide concentration at the flue gas inlet corresponding to reduced production. Among them, the standard nitrogen oxide concentration at the flue gas inlet is a reference value for the nitrogen oxide concentration at the flue gas inlet under a specific coke oven production load working condition. The historical coke oven operation database includes the coke oven production load working condition and the corresponding standard nitrogen oxide concentration at the flue gas inlet. As an example, the standard nitrogen oxide concentration at the flue gas inlet during full production in the historical database is 350 mg per cubic meter. When the reduction ratio is 80%, the standard nitrogen oxide concentration is 280 mg per cubic meter.

[0042] Step 2: Determine the nitrogen oxide over-standard situation at the inlet corresponding to each denitration chamber, the proportion of over-standard denitration chambers among multiple denitration chambers, and the average nitrogen oxide concentration at the flue gas inlet according to the corresponding nitrogen oxide concentration at the flue gas inlet and the standard nitrogen oxide concentration at the flue gas inlet; if the proportion of over-standard denitration chambers is greater than the preset proportion value, the working load of the current waste gas recycle fan is continuously adjusted according to the average nitrogen oxide concentration at the flue gas inlet until the recalculated proportion of over-standard denitration chambers is less than or equal to the preset proportion value.

[0043] In some embodiments, for each denitration chamber, the nitrogen oxide concentration at the flue gas inlet is compared with the nitrogen oxide concentration at the standard flue gas inlet to determine the over-standard situation of the nitrogen oxide at the flue gas inlet of the corresponding denitration chamber. Among them, the over-standard situation of the nitrogen oxide at the flue gas inlet is over-standard or normal. If the nitrogen oxide concentration at the flue gas inlet is greater than the nitrogen oxide concentration at the standard flue gas inlet, the over-standard situation of the nitrogen oxide at the flue gas inlet is over-standard; if the nitrogen oxide concentration at the flue gas inlet is less than or equal to the nitrogen oxide concentration at the standard flue gas inlet, the over-standard situation of the nitrogen oxide at the flue gas inlet is normal. The denitration chamber with the over-standard situation of the nitrogen oxide at the flue gas inlet is determined as the over-standard denitration chamber. The number of over-standard denitration chambers and the number of denitration chambers are respectively counted, and the number of over-standard denitration chambers is divided by the number of denitration chambers, and then multiplied by one hundred percent to obtain the proportion of over-standard denitration chambers among multiple denitration chambers. First, the nitrogen oxide concentrations at the flue gas inlets of all denitration chambers are added up and then divided by the number of denitration chambers to obtain the average nitrogen oxide concentration at the flue gas inlet. Among them, the average nitrogen oxide concentration at the flue gas inlet refers to the average value of the nitrogen oxide concentrations at the flue gas inlets of all denitration chambers. The preset proportion value is a preset over-standard proportion threshold. On this basis, if the proportion of over-standard denitration chambers is greater than the preset proportion value, it is necessary to change the waste gas flow distribution by adjusting the working load of the waste gas recirculation fan to reduce the over-standard situation. Among them, the waste gas recirculation fan is used to control the amount of nitrogen oxide at the flue gas inlet. As an example, a certain factory has a total of 6 denitration chambers (numbered A, B, C, D, E, F), and it is necessary to analyze the over-standard situation and adjust the working load of the waste gas recirculation fan according to the nitrogen oxide concentration at the flue gas inlet and the nitrogen oxide concentration at the standard flue gas inlet. The nitrogen oxide concentration at the flue gas inlet of each denitration chamber is detected and compared with the nitrogen oxide concentration at the standard flue gas inlet. It is determined that the over-standard denitration chambers are A, C, and D. The number of over-standard denitration chambers is counted as 3, and the total number of denitration chambers is counted as 6, and the over-standard proportion is obtained as 50%. Then, the nitrogen oxide concentrations at the flue gas inlets of the 6 denitration chambers are added up and divided by the total number of denitration chambers to obtain the average nitrogen oxide concentration at the flue gas inlet. The preset over-standard proportion value is 40%. Since the current over-standard proportion is greater than the preset over-standard proportion value, the average nitrogen oxide concentration at the flue gas inlet is compared with the preset average nitrogen oxide concentration at the flue gas inlet to obtain a deviation value. According to the deviation value, query in the preset fan adjustment coefficient table to obtain the corresponding fan adjustment coefficient. Among them, the fan adjustment coefficient table includes the deviation range of the average nitrogen oxide concentration at the flue gas inlet and the corresponding fan adjustment direction and fan frequency. The current working load of the waste gas recirculation fan is continuously adjusted according to the fan adjustment coefficient. After adjustment, the nitrogen oxide concentration at the flue gas inlet is monitored again to determine whether further adjustment is needed until the proportion of over-standard denitration chambers is less than or equal to the preset proportion value.

[0044] Step 3: Extract the actual ammonia slip concentration from the denitrification operation condition, and determine the denitrification chambers with the actual ammonia slip concentration greater than the preset slip concentration as the denitrification chambers to be investigated, obtaining at least one denitrification chamber to be investigated.

[0045] In some embodiments, the preset slip concentration is a preset ammonia slip concentration threshold for screening abnormal denitrification chambers. On this basis, the actual ammonia slip concentration is read from the denitrification operation condition through the ammonia slip online monitoring system, and the extracted actual ammonia slip concentration is compared with the preset slip concentration. If the actual ammonia slip concentration is greater than the preset threshold, the corresponding denitrification chamber is marked as a denitrification chamber to be investigated. Among them, there is at least one denitrification chamber to be investigated.

[0046] For each target denitrification chamber in the target denitrification chamber group, construct a corresponding inspection list according to one or more of the slurry injection valve opening, nitrogen oxide concentration at the flue gas inlet, nitrogen oxide concentration at the flue gas outlet, real-time ammonia slip concentration, and maintenance records, including: Step 1: For each target denitrification chamber, determine the opening of the slurry injection valve on the ammonia injection grid branch pipe. If the opening of the slurry injection valve is greater than the first set opening, the corresponding target denitrification chamber is determined as a large-flow ammonia denitrification chamber. If the opening of the slurry injection valve is less than the second set opening, the corresponding target denitrification chamber is determined as a small-flow ammonia denitrification chamber. If the opening of the slurry injection valve is greater than the second set opening and less than the first set opening, the corresponding target denitrification chamber is determined as a medium-flow ammonia denitrification chamber.

[0047] In some embodiments, for each target denitration chamber, compare the opening degree of the slurry spraying valve on the ammonia injection grid branch pipe with the set valve opening degree threshold to determine which type of flow denitration chamber the corresponding target denitration chamber belongs to. Among them, the opening degree of the slurry spraying valve on the ammonia injection grid branch pipe refers to the opening degree of the slurry spraying valve connected to the ammonia injection grid branch pipe, which controls the size of the ammonia flow rate. The opening degree of the slurry spraying valve (usually expressed as a percentage) directly affects the ammonia injection amount and the ammonia slip concentration. The larger the valve opening degree, the more ammonia is injected. Among them, the ammonia injection grid branch pipe refers to the pipe connecting to the slurry spraying valve and the ammonia injection grid. The first set opening degree is a preset valve opening degree threshold, representing the standard of a relatively large ammonia flow rate. On this basis, if the opening degree of the slurry spraying valve is greater than the first set opening degree, mark the corresponding target denitration chamber as a large-flow ammonia denitration chamber. Among them, a large-flow ammonia denitration chamber means that this denitration chamber uses a relatively large ammonia flow rate for denitration treatment. The second set opening degree is another set valve opening degree threshold, representing the standard of a relatively small ammonia flow rate. On this basis, if the opening degree of the slurry spraying valve is less than the second set opening degree, mark the corresponding target denitration chamber as a small-flow ammonia denitration chamber. Among them, a small-flow ammonia denitration chamber means that this denitration chamber uses a relatively small ammonia flow rate for denitration treatment. If the opening degree of the slurry spraying valve is greater than the second set opening degree and less than the first set opening degree, mark the corresponding target denitration chamber as a medium-flow ammonia denitration chamber. Among them, a medium-flow ammonia denitration chamber means that this denitration chamber uses a medium ammonia flow rate.

[0048] Step 2, for the large-flow ammonia denitration chamber, extract the first nitrogen oxide concentration data corresponding to the first detection port and the second nitrogen oxide concentration data corresponding to the second detection port from the denitration working conditions; among them, the first nitrogen oxide concentration data includes the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet, and the second nitrogen oxide concentration data includes the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet; calculate the first denitration efficiency corresponding to the first detection port according to the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet; calculate the second denitration efficiency corresponding to the second detection port according to the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet; if the difference between the first denitration efficiency and the second denitration efficiency is greater than the preset difference threshold, include the first type of inspection items in the candidate inspection item set in the corresponding inspection list. Among them, each inspection item in the candidate inspection item set is configured with multiple attribute information, and the multiple attribute information includes a category number, an introduction condition, an independence flag, and an associated inspection item. The first type of inspection items represents inspecting and adjusting the denitration uniformity of the denitration chamber.

[0049] In some embodiments, the first detection port and the second detection port are two monitoring positions respectively set for the denitration chamber, used to detect the concentration of nitrogen oxides in the flue gas. The concentration of nitrogen oxides detected at the first detection port and the second detection port is recorded in the denitration working condition. The denitration working condition also includes the nitrogen oxide concentration corresponding to the first detection port and the nitrogen oxide concentration corresponding to the second detection port. On this basis, for the large-flow ammonia denitration chamber, first determine the denitration chamber number corresponding to the large-flow ammonia denitration chamber, and query the nitrogen oxide concentration data corresponding to the first detection port and the nitrogen oxide concentration data corresponding to the second detection port from the denitration working condition to obtain the first nitrogen oxide concentration data and the second nitrogen oxide concentration data. Among them, the first nitrogen oxide concentration data includes the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet, and the second nitrogen oxide concentration data includes the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet. Among them, the nitrogen oxide concentration at the first flue gas inlet refers to the nitrogen oxide concentration measured at the flue gas inlet of the first detection port of the denitration chamber. The nitrogen oxide concentration at the first flue gas outlet refers to the nitrogen oxide concentration measured at the flue gas outlet of the first detection port of the denitration chamber. The nitrogen oxide concentration at the second flue gas inlet refers to the nitrogen oxide concentration measured at the flue gas inlet of the second detection port of the denitration chamber. The nitrogen oxide concentration at the second flue gas outlet refers to the nitrogen oxide concentration measured at the flue gas outlet of the second detection port of the denitration chamber.

[0050] On this basis, by calculating the ratio of the nitrogen oxide concentration data at the flue gas inlet of the first detection port to the nitrogen oxide concentration data at the flue gas outlet of the first detection port, the denitration efficiency of the first detection port is obtained. By calculating the ratio of the nitrogen oxide concentration data at the flue gas inlet and the flue gas outlet of the second detection port, the denitration efficiency of the second detection port is obtained. Among them, the denitration efficiency refers to the effect of the denitration system in removing nitrogen oxides from the flue gas, usually expressed as the ratio of the difference between the nitrogen oxide concentrations of the inlet gas and the outlet gas to the nitrogen oxide concentration of the inlet gas. The higher the denitration efficiency, the better the denitration effect. The preset difference threshold is a value set by the system to determine whether the difference between the denitration efficiencies is large enough to require further inspection. On this basis, the difference between the first denitration efficiency and the second denitration efficiency is compared to determine whether it exceeds the preset difference threshold. If the difference is greater than the set threshold, the introduction condition of the first type of inspection item in the candidate inspection item set is met, and the first type of inspection item in the candidate inspection item set is included in the inspection list. Among them, the first type of inspection item is used to characterize that the maintenance personnel need to check the uniformity of ammonia distribution in the denitration chamber and make adjustments to the inspection items that are confirmed to be abnormal after the inspection. Each inspection item in the candidate inspection item set is configured with multiple attribute information, and the multiple attribute information includes a category number, an introduction condition, an independence flag, and an associated inspection item. Among them, the category number is the number that uniquely identifies each type of inspection item. The introduction condition is to describe the specific conditions that meet the inspection item. The independence flag is used to indicate whether this inspection item is associated with other inspection items. The associated inspection item is used to describe other inspection tasks related to this item.

[0051] For each target denitration chamber in the target denitration chamber group, according to one or more of the slurry spraying valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, a corresponding inspection list is constructed, and it also includes: For the large-flow ammonia denitration chamber, if the difference between the first denitration efficiency and the second denitration efficiency is less than or equal to the preset difference threshold, the average denitration efficiency is determined according to the first denitration efficiency and the second denitration efficiency, and the average denitration efficiency is compared with the reference denitration efficiency. If the average denitration efficiency is less than the reference denitration efficiency, the second type of inspection item in the candidate inspection item set is included in the corresponding inspection list. Among them, the second type of inspection item characterizes the inspection and adjustment of the flue gas outlet valve or the flue gas inlet valve of the denitration chamber.

[0052] In some embodiments, for a large-flow ammonia denitration chamber, if the difference between the first denitration efficiency and the second denitration efficiency is less than or equal to a preset difference threshold, the average value of the first denitration efficiency and the second denitration efficiency is calculated to obtain the average denitration efficiency. The average denitration efficiency is compared with a preset reference denitration efficiency. When the average denitration efficiency is lower than the reference denitration efficiency, the introduction condition of the second type of inspection item in the candidate inspection item set is satisfied, and the second type of inspection item in the candidate inspection item set is included in the inspection list of the corresponding denitration chamber. Among them, the reference denitration efficiency is a preset target efficiency value, indicating the denitration performance standard that the chamber should achieve under ideal conditions. The second type of inspection item is the inspection of the flue gas outlet valve or the flue gas inlet valve, which is used to characterize that the maintenance personnel need to check the operating state of the valve (such as whether the opening is reasonable, whether there is blockage or leakage, etc.), and make adjustments for the inspection items that have been confirmed to be abnormal.

[0053] For each target denitration chamber in the target denitration chamber group, an inspection list is constructed according to one or more of the opening of the slurry spraying valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia slip concentration, and the maintenance record, and further includes: Step 1, for a medium-flow ammonia denitration chamber or a small-flow ammonia denitration chamber, calculate the actual ratio of the opening of the slurry spraying valve and the nitrogen oxide concentration at the flue gas inlet. If the actual ratio is greater than the preset ratio, a third type of inspection item in the candidate inspection item set is included in the corresponding inspection list. Among them, the third type of inspection item characterizes the inspection and adjustment of the opening of the slurry spraying valve on the ammonia injection grid branch pipe to reduce the ammonia flow rate; track the ammonia slip concentration and the nitrogen oxide concentration at the flue gas outlet after reducing the ammonia flow rate to obtain the change trend of the ammonia slip concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet.

[0054] In some embodiments, for the medium-flow ammonia denitration chamber or the small-flow ammonia denitration chamber, the ratio of the slurry spraying valve opening to the nitrogen oxide concentration at the flue gas inlet is calculated to obtain the actual ratio of the slurry spraying valve opening to the nitrogen oxide concentration at the flue gas inlet. Among them, the actual ratio is used to evaluate the matching degree between the ammonia injection amount and the nitrogen oxide concentration in the flue gas. The preset ratio is a threshold set in advance and is used to judge whether the slurry spraying valve opening is reasonable. On this basis, if the actual ratio is greater than the preset ratio, the introduction condition of a third type of inspection item in the candidate inspection item set is satisfied, and the third type of inspection item in the candidate inspection item set is included in the corresponding inspection list. Among them, the third type of inspection item is used to check whether there are problems such as abnormal opening, blockage, and mechanical failure of the slurry spraying valves of the ammonia injection grid branches. The maintenance personnel corresponding to the maintenance terminal adjust the opening of the slurry spraying valve according to the inspection results to reduce the ammonia flow rate. After reducing the ammonia flow rate, the change data of the ammonia slip concentration and the nitrogen oxide concentration at the flue gas outlet are monitored at a high frequency within the target time period, and the monitored ammonia slip concentration and nitrogen oxide concentration data at the flue gas outlet are marked according to the time stamp and stored in the database. Data is extracted from the database, and the change rate of the concentration over time is calculated to obtain the change trend of the ammonia slip concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet. Among them, the change trend of the ammonia slip concentration reflects the law of the ammonia slip concentration changing with time. The change trend of the nitrogen oxide concentration at the flue gas outlet reflects the law of the nitrogen oxide concentration at the flue gas outlet changing with time.

[0055] Step 2: According to the independence identifier, determine whether each third type of inspection item included in the inspection list is an independent inspection item; if it is not an independent inspection item, query at least one associated inspection item of the third type of inspection item included in the inspection list and the introduction condition of each associated inspection item.

[0056] In some embodiments, the independence identifier of each third type of inspection item included in the inspection list is identified. If the identified independence identifier indicates that it is not an independent inspection item, further query at least one associated inspection item of the third type of inspection item included in the inspection list and the introduction condition of each associated inspection item.

[0057] Step 3: According to the change trend of the ammonia slip concentration, the change trend of the nitrogen oxide concentration at the flue gas outlet, and the introduction condition of each associated inspection item, screen out the associated inspection items whose introduction conditions are met from at least one associated inspection item as the target associated inspection items; include the target associated inspection items in the corresponding inspection list.

[0058] In some embodiments, the introduction conditions of the associated inspection items are retrieved, and the corresponding introduction conditions are matched with the change trend of the ammonia slip concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet. Screen out the associated inspection items that meet the introduction conditions from at least one associated inspection item as the target associated inspection items. Add the screened target associated inspection items to the inspection list.

[0059] For each target denitration chamber in the target denitration chamber group, a corresponding inspection checklist is constructed based on one or more of the spray valve opening, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia slip concentration, and the maintenance records. It also includes: If the third type of inspection item included in the inspection checklist is an independent inspection item, determine whether the ammonia slip control effect meets the standard according to the change trend of the ammonia slip concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet. If the ammonia slip control effect does not meet the standard, determine the most recent implementation time of each inspection item and the standard maintenance interval duration by querying the maintenance records within the historical time period, and list the inspection items whose time interval between the most recent implementation time and the current time is greater than the standard maintenance interval duration in the corresponding inspection checklist.

[0060] In some embodiments, identify the independence identifier of each third type of inspection item included in the inspection checklist. If the identified independence identifier indicates an independent inspection item, set the compliance determination rules corresponding to the ammonia slip concentration and the nitrogen oxide concentration at the flue gas outlet respectively. If the compliance determination rules are met, determine that the ammonia slip control effect meets the standard. If the compliance determination rules are not met, determine that the ammonia slip control effect does not meet the standard. For the case where the ammonia slip control effect does not meet the standard, query the maintenance records within the historical time period according to the category number corresponding to the current inspection item. Among them, the maintenance records within the historical time period are stored in the local database, including fields such as the category number of the inspection item, the most recent implementation time, and the result. On this basis, first extract the fields of "the most recent implementation time" and "the standard maintenance interval duration" from the maintenance records within the historical time period to obtain the specific values corresponding to the most recent implementation time and the specific value corresponding to the standard maintenance interval duration. Then calculate the time interval between the most recent implementation time and the current time and compare it with the standard maintenance interval duration. Screen out the inspection items with a time interval greater than the standard maintenance interval duration and list the corresponding inspection items in the inspection checklist.

[0061] Among them, a method for controlling ammonia slip in an SCR denitration system according to the present invention further includes: For each target denitration chamber in the target denitration chamber group, obtain the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet from the denitration working conditions; calculate the difference between the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet, and compare the difference with a preset difference; if the difference is greater than or equal to the preset difference, include the fourth type of inspection item in the candidate inspection item set in the corresponding inspection checklist, where the fourth type of inspection item is used to inspect and adjust the damage condition of the dust removal filter bag.

[0062] In some embodiments, after the dust concentration data is collected in real time by arranging dust concentration sensors at the inlet and outlet, a communication connection is established with the ammonia slip online monitoring system, and the dust concentration data is transmitted to the ammonia slip online monitoring system. The ammonia slip online monitoring system classifies and stores the received dust concentration data according to the denitration chamber number into the denitration working conditions. The information corresponding to the "dust concentration at the flue gas inlet" field and the information corresponding to the "dust concentration at the flue gas outlet" field are read from the denitration working conditions to obtain the data of the dust concentration at the flue gas inlet and the data of the dust concentration at the flue gas outlet. Among them, the dust concentration at the flue gas inlet refers to the concentration of particulate matter in the flue gas before entering the denitration chamber. The dust concentration at the flue gas outlet refers to the concentration of particulate matter in the flue gas after denitration and dust removal treatment. The preset difference is the normal difference range between the inlet and outlet dust concentrations set based on experience and experimental data. On this basis, first, the difference between the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet is calculated. Then, the calculated difference is compared with the preset difference. If the difference is greater than or equal to the preset difference, the introduction condition of the fourth type of inspection item in the candidate inspection item set is satisfied, and the fourth type of inspection item in the candidate inspection item set is included in the inspection list. Among them, the fourth type of inspection item characterizes the inspection of the damage condition of the dust removal filter bags and the replacement of the damaged dust removal filter bags.

[0063] In these embodiments, the overall control efficiency of ammonia slip is improved, and the diagnosis and adjustment efficiency of the denitration system is enhanced. Specifically, for the target denitration chamber group, the target denitration chambers are classified into large-flow, medium-flow, and small-flow ammonia denitration chambers according to the opening degree of the slurry injection valve. For the large-flow denitration chambers, the nitrogen oxide concentration data corresponding to multiple detection ports are extracted, and the denitration efficiency difference is calculated. If the efficiency difference exceeds the threshold, it is determined as the first type of inspection item and included in the inspection list. If the efficiency difference is within the threshold, the average denitration efficiency is calculated and compared with the reference efficiency. If it is lower than the reference, it is determined as the second type of inspection item and included in the inspection list. For the medium-flow or small-flow denitration chambers, the actual ratio of the opening degree of the slurry injection valve to the nitrogen oxide concentration at the flue gas inlet is calculated and compared with the preset ratio. If the actual ratio is too high, it is determined as the third type of inspection item and included in the inspection list, and the change trends of the ammonia slip concentration after adjustment and the nitrogen oxide concentration at the flue gas outlet are tracked. According to these trends and the conditions of relevant inspection items, the target inspection items to be executed are screened out and included in the inspection list. Through hierarchical detection and differentiated inspection lists, combined with dynamic working condition analysis, the ammonia slip is precisely controlled, which not only improves the overall control efficiency of ammonia slip but also improves the diagnosis and adjustment efficiency of the denitration system.

[0064] In some embodiments, to further solve Technical Problem 3 described in the background art section, that is, "the prior art cannot achieve dynamic identification and targeted adjustment of abnormal reaction temperatures, thus unable to effectively control ammonia slip concentration, reducing the reliability and environmental protection effect of the denitration system", some embodiments of the present invention further include the following steps: Step 1, for each target denitration chamber in the target denitration chamber group, extract reaction temperature data from the denitration operating conditions; determine the temperature anomaly situation based on the reaction temperature data and the standard reaction temperature range, where the temperature anomaly situation is a low-temperature anomaly or a high-temperature anomaly; if the temperature anomaly situation is a low-temperature anomaly, generate a low-temperature temperature deviation value based on the minimum value of the standard reaction temperature range and the reaction temperature data; if the temperature anomaly situation is a high-temperature anomaly, generate a high-temperature temperature deviation value based on the maximum value of the standard reaction temperature range and the reaction temperature data.

[0065] In some embodiments, use the temperature sensors corresponding to each denitration chamber to collect reaction temperature data in real time and transmit the reaction temperature data to the ammonia slip online monitoring system. The ammonia slip online monitoring system establishes a communication connection with the temperature sensors, receives the reaction temperature data, and integrates the reaction temperature data into the denitration operating conditions. According to the denitration chamber number corresponding to the target denitration chamber, search for the reaction temperature data in the denitration operating conditions. Among them, the reaction temperature data represents the real-time temperature data of the catalyst layer in the denitration reaction, and is used to evaluate whether the reaction is carried out within an effective temperature range. The standard reaction temperature range refers to the ideal temperature interval required for the denitration catalytic reaction. On this basis, compare the extracted actual temperature data with the upper and lower limits of the range. If the temperature is lower than the minimum value, it is marked as a low-temperature anomaly. If the temperature is higher than the maximum value, it is marked as a high-temperature anomaly. Among them, the temperature anomaly situation is a low-temperature anomaly or a high-temperature anomaly. A low-temperature anomaly means that the reaction temperature data is lower than the minimum value of the standard reaction temperature range. Low temperature will cause insufficient catalyst activity, reduce the reduction reaction rate of nitrogen oxides, and decrease the denitration efficiency. Ammonia is not completely reacted, increasing the risk of ammonia slip. A high-temperature anomaly means that the reaction temperature data is higher than the maximum value of the standard reaction temperature range. High temperature may cause catalyst deactivation or accelerated aging, reduce its service life, increase side reactions, and affect the environmental protection effect. If the temperature anomaly situation is a low-temperature anomaly, subtract the reaction temperature data from the minimum value of the standard reaction temperature range to obtain the low-temperature temperature deviation value; if the temperature anomaly situation is a high-temperature anomaly, subtract the maximum value of the standard reaction temperature range from the reaction temperature data to obtain the high-temperature temperature deviation value. Among them, the low-temperature temperature deviation value represents the degree of low-temperature anomaly and is used to guide the adjustment of the heating equipment. The high-temperature temperature deviation value represents the degree of high-temperature anomaly and is used to adjust the combustion parameters.

[0066] Step 2, generate the heating intensity mode of the hot blast stove according to the low-temperature temperature deviation value; adjust the coke oven combustion parameters according to the high-temperature temperature deviation value.

[0067] In some embodiments, first, a heating intensity mode table is established in advance, which includes the low-temperature temperature deviation range and the corresponding heating intensity modes in the table. The heating intensity modes can be low, medium, or high. Then, the low-temperature temperature deviation value is queried to fall within the low-temperature temperature deviation range in the table, and the corresponding heating intensity mode is determined. Among them, the heating intensity mode of the hot blast stove is the working mode of the hot blast stove generated according to the low-temperature temperature deviation value, which is used to control the heating output intensity of the hot blast stove to ensure that the reaction temperature is raised to the standard range. The combustion parameters such as the fuel supply amount and air ratio are dynamically adjusted according to the high-temperature deviation value. Among them, the coke oven combustion parameters are the key control variables in the coke oven combustion process, such as the fuel supply amount, air ratio, combustion temperature setting, etc.

[0068] Step 3, if the temperature anomaly is a low-temperature anomaly, the first subclass of the fifth type of inspection items in the candidate inspection item set and the heating intensity mode are included in the inspection list; if the temperature anomaly is a high-temperature anomaly, the second subclass of the fifth type of inspection items in the candidate inspection item set and the coke oven combustion parameters are included in the inspection list. Among them, the first subclass of inspection items represents the inspection and adjustment of the hot blast stove, and the second subclass of inspection items represents the inspection and adjustment of the parameters of the coke oven combustion.

[0069] In some embodiments, if the temperature anomaly is a low-temperature anomaly, the introduction condition of the first subclass of the fifth type of inspection items in the candidate inspection item set is met, and the first subclass of inspection items and the heating intensity mode are added to the inspection list. If the temperature anomaly is a high-temperature anomaly, the introduction condition of the second subclass of the fifth type of inspection items in the candidate inspection item set is met, and the second subclass of inspection items and the coke oven combustion parameters to be adjusted are included in the inspection list. Among them, the first subclass of inspection items is related to the low-temperature anomaly, checks the equipment status and operating parameters of the hot blast stove, and adjusts the hot blast stove according to the heating intensity mode. The second subclass of inspection items is related to the high-temperature anomaly, and checks and adjusts the combustion parameters of the coke oven.

[0070] In these embodiments, the concentration of ammonia escape is accurately controlled, and the reliability and environmental protection effect of the denitration system are improved. Specifically, first, the reaction temperature data of each denitration chamber is extracted from the denitration working condition, compared with the standard reaction temperature range, low-temperature anomalies or high-temperature anomalies are identified, and the corresponding temperature deviation values are calculated; then, the heating intensity mode of the hot blast stove is generated according to the low-temperature deviation value, and the combustion parameters of the coke oven are adjusted according to the high-temperature deviation value; finally, the inspection items and adjustment measures corresponding to the anomaly type are included in the inspection list, the low-temperature anomaly corresponds to the inspection and adjustment of the hot blast stove, and the high-temperature anomaly corresponds to the inspection and adjustment of the coke oven combustion parameters, so as to achieve the accurate control of the catalyst reaction temperature, and then accurately control the ammonia escape concentration, and improve the reliability and environmental protection effect of the denitration system.

[0071] The above description is only some preferred embodiments of the present invention and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present invention that have similar functions.

Claims

1. A method for controlling ammonia escape in an SCR denitration system, characterized in that: include: The denitration working condition corresponding to each denitration chamber in the plurality of denitration chambers is obtained through an ammonia escape online monitoring system; Performing a joint analysis on the denitration conditions corresponding to the plurality of denitration chambers to determine at least one denitration chamber to be checked from the plurality of denitration chambers; Using the ammonia escape mobile monitoring device, respectively detect the ammonia escape concentration of each denitration chamber to be checked in the at least one denitration chamber to be checked, and obtain the real-time ammonia escape concentration corresponding to each denitration chamber to be checked; if the real-time ammonia escape concentration is greater than the preset ammonia escape concentration threshold, the corresponding denitration chamber to be checked is determined as the target denitration chamber, and the target denitration chamber group is obtained; For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, wherein the checklist includes multiple inspection items, so that the maintenance personnel can inspect and adjust the SCR denitrification system according to the multiple inspection items in the checklist; After a preset period of time, the ammonia escape concentration of each adjusted target denitrification chamber is retested to obtain the retested ammonia escape concentration corresponding to each target denitrification chamber, and an ammonia escape control effect report is generated based on the retested ammonia escape concentration.

2. The method for controlling ammonia slip of an SCR denitration system according to claim 1, characterized in that: The jointly analyzing the denitration conditions corresponding to the plurality of denitration chambers to determine at least one denitration chamber to be checked from the plurality of denitration chambers includes: Extract the nitrogen oxide concentration at the flue gas inlet from the denitration conditions to obtain the nitrogen oxide concentration at the flue gas inlet corresponding to each denitration chamber; determine the nitrogen oxide concentration at the standard flue gas inlet according to the current coke oven production load conditions, and the coke oven production load conditions are full production or reduced production; According to the corresponding nitrogen oxide concentration at the flue gas inlet and the nitrogen oxide concentration at the standard flue gas inlet, determine the excessive nitrogen oxide at the inlet corresponding to each denitrification chamber, the proportion of denitrification chambers exceeding the standard among multiple denitrification chambers and the average nitrogen oxide concentration at the flue gas inlet; if the proportion of denitrification chambers exceeding the standard is greater than the preset proportion value, the current exhaust gas return fan workload is continuously adjusted according to the average nitrogen oxide concentration at the flue gas inlet until the recalculated proportion of denitrification chambers exceeding the standard is less than or equal to the preset proportion value; The actual ammonia escape concentration is extracted from the denitrification operating conditions, and the denitrification chambers whose actual ammonia escape concentration is greater than the preset escape concentration are determined as the denitrification chambers to be checked, thereby obtaining at least one denitrification chamber to be checked.

3. The method for controlling ammonia slip of an SCR denitration system according to claim 2, characterized in that: For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, including: For each target denitration chamber, determine the opening of the spraying valve on the spraying grid branch pipe. If the opening of the spraying valve is greater than the first set opening, the corresponding target denitration chamber is determined as a large-flow ammonia denitration chamber. If the opening of the spraying valve is less than the second set opening, the corresponding target denitration chamber is determined as a small-flow ammonia denitration chamber. If the opening of the spraying valve is greater than the second set opening and less than the first set opening, the corresponding target denitration chamber is determined as a medium-flow ammonia denitration chamber. For a large-flow ammonia denitrification chamber, first nitrogen oxide concentration data corresponding to the first detection port and second nitrogen oxide concentration data corresponding to the second detection port are extracted from the denitrification working conditions; wherein the first nitrogen oxide concentration data includes the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet, and the second nitrogen oxide concentration data includes the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet; according to the nitrogen oxide concentration at the first flue gas inlet and the nitrogen oxide concentration at the first flue gas outlet, the first denitrification efficiency corresponding to the first detection port is calculated; according to the nitrogen oxide concentration at the second flue gas inlet and the nitrogen oxide concentration at the second flue gas outlet, the second denitrification efficiency corresponding to the second detection port is calculated; if the difference between the first denitrification efficiency and the second denitrification efficiency is greater than a preset difference threshold, the first category of inspection items in the candidate inspection item set is included in the corresponding inspection list, wherein each inspection item in the candidate inspection item set is configured with multiple attribute information, and the multiple attribute information includes category number, introduction condition, independence identifier and associated inspection item, and the first category of inspection items represents the inspection and adjustment of the denitrification uniformity of the denitrification chamber.

4. The method for controlling ammonia slip of an SCR denitration system according to claim 3, characterized in that: For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, and further includes: For a large-flow ammonia denitrification chamber, if the difference between the first denitrification efficiency and the second denitrification efficiency is less than or equal to a preset difference threshold, the average denitrification efficiency is determined based on the first denitrification efficiency and the second denitrification efficiency, and the average denitrification efficiency is compared with the benchmark denitrification efficiency. If the average denitrification efficiency is less than the benchmark denitrification efficiency, the second category of inspection items in the candidate inspection item set are included in the corresponding inspection list, wherein the second category of inspection items represents the inspection and adjustment of the flue gas outlet valve or the flue gas inlet valve of the denitrification chamber.

5. The method for controlling ammonia slip of an SCR denitration system according to claim 4, characterized in that: For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, and further includes: For a medium-flow ammonia denitrification chamber or a small-flow ammonia denitrification chamber, the actual ratio of the opening of the shotcrete valve and the nitrogen oxide concentration at the flue gas inlet is calculated. If the actual ratio is greater than the preset ratio, a third-category inspection item in the candidate inspection item set is included in the corresponding inspection list, wherein the third-category inspection item represents the inspection and adjustment of the opening of the shotcrete valve on the branch pipe of the spray ammonia grid to reduce the ammonia flow; the ammonia escape concentration and the nitrogen oxide concentration at the flue gas outlet are tracked after the ammonia flow is reduced, and the change trend of the ammonia escape concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet are obtained; According to the independence identifier, determine whether each third-category inspection item included in the inspection list is an independent inspection item; if it is not an independent inspection item, query at least one associated inspection item of the third-category inspection item included in the inspection list and the introduction condition of each associated inspection item; According to the changing trend of the ammonia escape concentration, the changing trend of the nitrogen oxide concentration at the flue gas outlet and the introduction condition of each associated inspection item, the associated inspection item whose introduction condition is met is filtered out from the at least one associated inspection item as the target associated inspection item; and the target associated inspection item is included in the corresponding inspection list.

6. The method for controlling ammonia slip of an SCR denitration system according to claim 5, characterized in that: For each target denitrification chamber in the target denitrification chamber group, a corresponding checklist is constructed according to one or more of the opening of the shotcrete valve, the nitrogen oxide concentration at the flue gas inlet, the nitrogen oxide concentration at the flue gas outlet, the real-time ammonia escape concentration, and the maintenance record, and further includes: If the third category inspection item included in the inspection list is an independent inspection item, then the effect of ammonia escape control is determined to be up to standard based on the change trend of the ammonia escape concentration and the change trend of the nitrogen oxide concentration at the flue gas outlet; if the ammonia escape control effect is not up to standard, the most recent implementation time and standard maintenance interval of each inspection item are determined by querying the maintenance records within the historical time period, and the inspection items whose time interval between the most recent implementation time and the current time is greater than the standard maintenance interval are included in the corresponding inspection list.

7. The method for controlling ammonia slip of an SCR denitration system according to claim 6, characterized in that: Also includes: For each target denitrification chamber in the target denitrification chamber group, the dust concentration at the flue gas inlet and the dust concentration at the flue gas outlet are obtained from the denitrification working condition; Calculating the difference between the dust concentration at the smoke inlet and the dust concentration at the smoke outlet, and comparing the difference with a preset difference; If the difference is greater than or equal to the preset difference, the fourth type of inspection item in the candidate inspection item set is included in the corresponding inspection list, wherein the fourth type of inspection item represents the inspection and adjustment of the damage of the dust removal bag.

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