Biomass boiler environment-friendly treatment method based on ultralow-temperature flue gas denitration

Abstract

The invention provides a biomass boiler environment-friendly treatment method based on ultralow-temperature flue gas denitration, and relates to the technical field of flue gas denitration, and the biomass boiler environment-friendly treatment method comprises the following steps: primarily filtering discharged flue gas, carrying out temperature authentication, and introducing the flue gas into a desulfurization reactor; collecting a temperature distribution diagram of the desulfurization reactor, and determining an infrared temperature distribution diagram sequence; carrying out reaction region division to obtain a plurality of divided reaction regions; the nozzle spraying angles and the spraying quantities of the multiple reducing agent spraying guns are analyzed, and the multiple nozzle spraying angles and the multiple spraying quantities are determined; and injecting a reducing agent, and reacting the injected reducing agent with the flue gas under the catalysis of the ultralow-temperature SCR denitration catalyst to complete flue gas denitration. The technical problems that a traditional selective non-catalytic reduction technology and a selective catalytic reduction technology are difficult to adapt to the denitration requirement of the biomass boiler under the low-temperature condition, secondary heating is generally needed, the denitration efficiency is insufficient, the equipment cost is increased, and the environment-friendly emission requirement cannot be met are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas denitrification, and in particular to an environmentally friendly treatment method for a biomass boiler based on ultra-low temperature flue gas denitrification. Background Art

[0002] During the biomass combustion process, NOx emissions are the main source of environmental pollution. Efficient denitrification technology is needed to reduce NOx emissions and meet increasingly stringent environmental emission standards.

[0003] Selective non-catalytic reduction (SNCR) technology is a common biomass boiler denitrification technology. SNCR technology does not require the use of catalysts, but instead injects a reducing agent into the flue gas to cause a reduction reaction between the reducing agent and NOx at high temperature, thereby reducing NOx emissions. SNCR technology is relatively simple and has low investment costs. However, the reaction temperature required by SNCR is between 800-1200°C, and the maximum temperature of the biomass boiler is around 650°C. The influence of temperature will result in a low denitrification rate for the biomass boiler, which will not meet the ultra-low emission requirements.

[0004] Selective catalytic reduction (SCR) technology is another common biomass boiler denitrification technology. By using a denitrification catalyst, NOx in the flue gas reacts with a reducing agent (such as ammonia or urea) under the action of a catalyst to generate harmless substances such as nitrogen and water vapor. This technology has a high denitrification efficiency. However, the flue gas temperature at the biomass boiler outlet is not high, and secondary heating is often required. The system resistance is large and the operating cost is high.

[0005] This application designs an environmentally friendly treatment method for biomass boilers based on ultra-low temperature flue gas denitrification. Compared with traditional technologies, it does not require secondary heating, reduces operating costs, and can meet the environmentally friendly emission requirements of biomass boilers. Summary of the invention

[0006] This application provides an environmentally friendly treatment method for biomass boilers based on ultra-low temperature flue gas denitrification, aiming to solve the technical problems that traditional selective non-catalytic reduction technology and selective catalytic reduction technology are difficult to adapt to the denitrification needs of biomass boilers under low temperature conditions, usually requiring secondary heating, resulting in insufficient denitrification efficiency, increased equipment costs, and failure to meet environmental emission requirements.

[0007] The present application discloses an environmentally friendly treatment method for a biomass boiler based on ultra-low temperature flue gas denitrification, the method comprising: guiding the flue gas discharged by the target biomass boiler through a first pipeline to a flue gas filter for preliminary filtration, performing temperature authentication on the filtered flue gas, and introducing the filtered flue gas through a second pipeline into a desulfurization reactor after the authentication is passed, wherein the desulfurization reactor uses an ultra-low temperature SCR denitrification catalyst to selectively catalytically reduce the flue gas; using an infrared thermal imager to collect a temperature distribution map of the desulfurization reactor in a preset monitoring window to determine an infrared temperature distribution map sequence; traversing the infrared temperature distribution map sequence to monitor the desulfurization reactor; The reaction area is divided to obtain a plurality of divided reaction areas, wherein the plurality of divided reaction areas include a plurality of temperature distribution concentration values; based on the plurality of temperature distribution concentration values ​​and the plurality of divided reaction areas, the nozzle injection angles and injection amounts of the plurality of reducing agent spray guns of the desulfurization reactor are analyzed to determine the plurality of nozzle injection angles and the plurality of injection amounts of the plurality of reducing agent spray guns; based on the plurality of nozzle injection angles and the plurality of injection amounts, the plurality of reducing agent spray guns are controlled to perform reducing agent injection, and under the catalysis of the ultra-low temperature SCR denitrification catalyst, the injected reducing agent reacts with the flue gas in the plurality of divided reaction areas to complete flue gas denitrification.

[0008] One or more technical solutions provided in this application have at least the following technical effects or advantages: The flue gas emitted by the target biomass boiler is processed through preliminary filtration and temperature certification to ensure that the flue gas entering the desulfurization reactor is within the appropriate temperature range, so that the flue gas temperature meets the optimal reaction temperature of the SCR denitrification catalyst, and avoids low catalyst efficiency caused by excessively high or low temperatures; through infrared thermal imaging technology, the temperature distribution inside the reactor is dynamically monitored, and the spatial distribution of temperature data is obtained to help identify areas with large temperature changes, provide accurate temperature data for subsequent reaction area division, and ensure the accuracy of subsequent processing; the temperature distribution map sequence is traversed, different temperature areas in the reactor are divided, and temperature concentration areas are identified to ensure that the reducing agent can react with nitrogen oxides in the flue gas in a targeted manner, thereby improving the denitrification reaction Efficiency; Based on the divided reaction area temperature data and temperature distribution concentration value, analyze and optimize the injection angle and injection amount of the reducing agent spray gun to avoid excessive or insufficient injection. By accurately adjusting the injection position and injection amount, it can ensure that the reducing agent is in full contact with the reaction area of ​​the target flue gas, thereby improving the reaction efficiency and reducing the consumption of the reducing agent during the denitrification process; According to the determined injection angle and injection amount, accurately control the reducing agent injection of the spray gun to ensure that the reducing agent reacts fully with the flue gas, minimize the NOx content in the flue gas, and complete the denitrification process. The overall method combines temperature monitoring, data analysis and automatic control technology to achieve precise management and optimization of the flue gas denitrification process, reduce manual intervention, and improve the automation level and reliability of the system.

[0009] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of an environmentally friendly treatment method for a biomass boiler based on ultra-low temperature flue gas denitrification is provided for the embodiment of the present application.

[0011] Figure 2 A schematic flow chart of determining multiple temperature distribution concentration values ​​in an environmentally friendly treatment method for a biomass boiler based on ultra-low temperature flue gas denitrification is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0012] The embodiments of the present application provide an environmentally friendly treatment method for biomass boilers based on ultra-low temperature flue gas denitrification, thereby solving the technical problems that traditional selective non-catalytic reduction technology and selective catalytic reduction technology are difficult to adapt to the denitrification needs of biomass boilers under low temperature conditions, usually requiring secondary heating, resulting in insufficient denitrification efficiency, increased equipment costs, and failure to meet environmental emission requirements.

[0013] After introducing the basic principles of the present application, various non-limiting implementation methods of the present application will be specifically described below in conjunction with the drawings in the specification.

[0014] like Figure 1 As shown, the embodiment of the present application provides an environmentally friendly treatment method for a biomass boiler based on ultra-low temperature flue gas denitrification, the method comprising: The flue gas emitted by the target biomass boiler is guided to the flue gas filter through the first pipe for preliminary filtration, and the filtered flue gas is temperature authenticated. After passing the authentication, it is introduced into the desulfurization reactor through the second pipe, wherein the desulfurization reactor uses an ultra-low temperature SCR denitrification catalyst to perform selective catalytic reduction on the flue gas.

[0015] The flue gas comes from the target biomass boiler emissions, and its components mainly include pollutants such as sulfur dioxide, nitrogen oxides, particulate matter, and water vapor. The flue gas temperature usually ranges from 120℃ to 150℃. The influence of temperature will cause the biomass boiler to have a low denitrification rate and fail to meet the ultra-low emission requirements.

[0016] The flue gas is guided to the flue gas filter through the first pipe, which has the characteristics of high temperature resistance and corrosion resistance, and ensures that the pressure loss during the flue gas transportation is small to ensure the stability of the flue gas flow. The flue gas filter can use a bag filter or an electrostatic precipitator to remove particulate matter (such as fly ash) in the flue gas to reduce the risk of catalyst surface contamination in the subsequent desulfurization and denitrification processes.

[0017] After preliminary filtration, the temperature of the flue gas is measured in real time by a temperature sensor, such as a thermocouple or infrared thermometer. The flue gas temperature must meet the operating requirements of the ultra-low temperature SCR denitrification catalyst and reach below 150°C. If the flue gas temperature exceeds the target range, the temperature can be adjusted by natural cooling or adjusting the preset cooling equipment.

[0018] After the flue gas temperature passes the certification, it enters the second pipeline and is transported to the desulfurization reactor. The ultra-low temperature SCR denitrification catalyst used in the desulfurization reactor is usually supported by titanium oxide, supplemented by vanadium oxide or tungsten oxide as an active component. Under ultra-low temperature conditions (below 150°C), it can efficiently convert nitrogen oxides into harmless nitrogen and water. Selective catalytic reduction refers to the selective catalytic reaction between nitrogen oxides in the flue gas and the injected reducing agent on the catalyst surface. Under ultra-low temperature conditions, the SCR denitrification catalyst can effectively avoid side reactions (such as ammonia oxidation) and improve the reduction efficiency.

[0019] The temperature distribution diagram of the desulfurization reactor is collected in a preset monitoring window by using an infrared thermal imager to determine the infrared temperature distribution diagram sequence.

[0020] Select an infrared thermal imager with high resolution and sufficient temperature measurement range to ensure that it can accurately capture the temperature changes on the inner surface of the desulfurization reactor. The preset monitoring windows include a time window and a space window to determine the measurement duration and reactor position. The time window is the selected collection time period, such as collecting once every 5 minutes, to ensure that the monitoring covers different working conditions of the desulfurization reactor; the space window is the designated monitoring area of ​​the infrared thermal imager to ensure that key positions of the desulfurization reactor are covered, such as the reactor wall, spray gun position, etc.

[0021] Within the preset time window, the infrared thermal imager collects temperature data from the preset spatial window of the reactor at the set sampling frequency. Each collection will generate an infrared temperature distribution map to show the temperature conditions on the reactor surface. Each temperature distribution map will correspond to a time point and mark the temperature values ​​of different areas. All collected temperature distribution maps are arranged in chronological order to form an infrared temperature distribution map sequence. Each map represents the temperature conditions of the reactor at a certain moment, reflecting the dynamic temperature changes of the reactor.

[0022] The desulfurization reactor is divided into reaction areas by traversing the infrared temperature distribution map sequence to obtain a plurality of divided reaction areas, wherein the plurality of divided reaction areas include a plurality of temperature distribution concentration values.

[0023] The mean temperature of each temperature point is calculated according to the infrared temperature distribution map sequence to obtain the infrared temperature mean distribution map. The infrared temperature mean data are clustered into multiple temperature center areas. The temperature concentration value in each area is close. The reaction areas are divided according to these clustering results. Each divided reaction area is marked, and its temperature concentration value is recorded and corresponded to the specific position of the reactor. In this way, it is possible to accurately understand which areas have higher temperatures and which areas have lower temperatures, thereby providing guidance for optimizing injection control.

[0024] The nozzle injection angles and injection amounts of the multiple reducing agent spray guns of the desulfurization reactor are analyzed based on the multiple temperature distribution concentration values ​​and the multiple divided reaction areas to determine the multiple nozzle injection angles and multiple injection amounts of the multiple reducing agent spray guns.

[0025] The temperature distribution in the reaction area directly affects the injection effect of the reducing agent. Areas with higher temperatures require more reducing agent injection to ensure the completeness of the reaction. For high-temperature areas, the injection amount can be increased or the injection angle of the nozzle can be adjusted so that the injected reducing agent can cover more high-temperature areas, thereby improving the efficiency of the reduction reaction. Areas with lower temperatures require less injection amount. For low-temperature areas, by reducing the injection amount or adjusting the injection angle, the injection agent is only locally injected into the low-temperature area, which can avoid excessive reducing agent entering the low-temperature area and causing waste of resources.

[0026] According to the temperature concentration value of different areas, the injection angle of the reducing agent spray gun nozzle is adjusted to ensure that the reducing agent can be evenly distributed to each reaction area. The optimal injection scheme for each area is determined through the optimization algorithm to obtain multiple nozzle injection angles and multiple injection amounts of multiple reducing agent spray guns.

[0027] Based on the multiple nozzle injection angles and the multiple injection amounts, the multiple reducing agent spray guns are controlled to perform reducing agent injection. Under the catalysis of the ultra-low temperature SCR denitration catalyst, the injected reducing agent reacts with the flue gas in the multiple divided reaction areas to complete the flue gas denitration.

[0028] According to the set multiple nozzle injection angles and multiple injection amounts, the angle and amount of reducing agent injection are adjusted by controlling the corresponding multiple electronically controlled valves of the reducing agent spray guns. The injected reducing agent will cover various reaction areas. Under the catalysis of the ultra-low temperature SCR catalyst, the injected reducing agent reacts with the NOx in the flue gas to denitrify the flue gas.

[0029] Furthermore, if Figure 2 As shown, including: The temperature mean of each temperature point in the infrared temperature distribution map sequence is calculated to obtain an infrared temperature mean distribution map; the infrared temperature mean distribution map is subjected to temperature neighborhood flooding segmentation to determine a plurality of divided reaction areas; the plurality of divided reaction areas are traversed to perform temperature mean concentration analysis to determine a plurality of temperature distribution concentration values.

[0030] Based on the acquired infrared temperature distribution map sequence, the temperature mean in all time series is calculated for each temperature point in the map to obtain an infrared temperature mean distribution map, which reflects the average temperature of each location during the entire monitoring time.

[0031] The infrared temperature mean distribution map is used for flood segmentation. By calculating the neighborhood temperature distribution of each pixel, areas with similar temperatures can be identified and divided into independent reaction areas. Areas with similar temperatures are classified as the same reaction area. Through temperature neighborhood flood segmentation, multiple divided reaction areas can be determined. Each divided area will serve as an independent reaction area with unified temperature characteristics, which will help optimize the reductant injection strategy.

[0032] The temperature means contained in the multiple divided reaction areas are extracted to obtain multiple regional temperature mean value sets. The medians of the multiple regional temperature mean value sets are used as starting points to perform center point iterative analysis until a preset number of iterations is reached to obtain multiple temperature distribution concentration values, which represent the temperature characteristics of different reaction areas.

[0033] Furthermore, the infrared temperature mean distribution map is subjected to temperature neighborhood flooding segmentation to determine a plurality of divided reaction areas, including: Extract the temperature point corresponding to the minimum infrared temperature mean value in the infrared temperature mean distribution map, and use it as the starting point for flooding segmentation; take each temperature point in the infrared temperature mean distribution map as a mountain, and the infrared temperature mean value corresponding to each temperature point as the mountain height, perform mountain simulation on the infrared temperature mean distribution map, and obtain a simulated mountain area; take the flooding segmentation starting point as the water injection point, inject water into the simulated mountain area, and as the water level rises, the water surface submerges at least one mountain, and judge whether the difference in mountain height between the submerged multiple mountains and the flooding segmentation starting point is greater than or equal to a preset neighborhood bandwidth. If so, generate multiple dividing ridge lines, and continue to inject water into the simulated mountain area until the mountain corresponding to the maximum mountain height in the simulated mountain area is submerged, and obtain a dividing ridge line set, wherein the multiple dividing ridge lines rise as the water level rises; perform neighborhood division on the infrared temperature mean distribution map based on the dividing ridge line set, and determine the multiple divided reaction areas.

[0034] From the infrared temperature mean distribution map, find the minimum value among all temperature points. This temperature point represents the valley area in the temperature distribution map. This temperature point is used as the starting point for flood segmentation. This point is where the simulated water flow begins. The water flow will expand to the surrounding areas and divide different areas.

[0035] Each temperature point in the infrared temperature mean distribution map is regarded as a mountain, and the corresponding infrared temperature mean of each temperature point is regarded as the mountain height. This is similar to the modeling of terrain in geographic information systems, where the temperature value represents the height of the terrain, points with higher temperatures represent mountain tops, and points with lower temperatures represent valleys. Through the mountain simulation process, a simulated mountain area map is formed. This map shows the temperature distribution of the entire reactor, thus providing a basis for the subsequent division of reaction areas.

[0036] The starting point of flood segmentation is used as the water injection point. Starting from this water injection point, water gradually expands to the surrounding mountainous areas. This is a simulated water surface rising process. The water surface will cover the area in the simulated mountain map. As the water surface rises, the water surface begins to cover more mountains. During the covering process, it is determined whether one or more mountains are covered by the water surface. The covered mountains are the parts that need to be divided into reaction areas. It is determined whether the height difference of the covered multiple mountains (that is, the temperature difference between the mountains covered by the water surface and the mountains at the starting point of flood segmentation) is greater than or equal to the preset neighborhood bandwidth. The neighborhood bandwidth is the temperature difference threshold used to determine whether they belong to the same area, which controls the division accuracy of the reaction area.

[0037] If the judgment result is yes, multiple dividing ridge lines are generated. The dividing ridge lines are the boundary lines representing different reaction areas, indicating the different requirements for injecting reducing agents in these areas; if the judgment result is no, that is, the height difference is less than the preset neighborhood bandwidth, water continues to be injected into the simulated mountain area until it submerges the mountain corresponding to the maximum mountain height in the simulated mountain area. This is the mountain with the highest temperature in the simulated mountain area, and this mountain marks the extreme area of ​​the temperature distribution map.

[0038] As the water level continues to rise, more mountains will be covered. Whenever the height difference of a new mountain meets the conditions, a new dividing ridge line will be generated. Finally, as the water level reaches the maximum mountain height in the simulated mountain area, the multiple dividing ridge lines generated form a dividing ridge line set, which represents the temperature distribution area inside the desulfurization reactor and the boundaries of each reaction zone.

[0039] The infrared temperature mean distribution map is divided into neighborhoods according to the set of dividing ridge lines, and multiple divided reaction areas are determined based on the division results. Through the generation process of dividing ridge lines, a clear boundary can be provided for each reaction area, which is helpful to optimize the denitrification process of the desulfurization reactor. Through precise temperature area division, the reducing agent can be injected according to different temperature requirements, thereby achieving more efficient flue gas denitrification.

[0040] Furthermore, performing neighborhood division on the infrared temperature mean distribution map based on the set of dividing ridge lines to determine the multiple divided reaction areas includes: The infrared temperature mean distribution map is divided according to the set of dividing ridge lines to obtain a plurality of initial divided reaction neighborhoods; nearest neighbor fusion is performed according to the area sizes of the plurality of initial divided reaction neighborhoods, and the plurality of divided reaction areas are obtained according to the fusion results.

[0041] According to the obtained set of dividing ridge lines, the infrared temperature mean distribution map is divided into multiple areas. Each ridge line represents the boundary of a reaction neighborhood. Each initial divided reaction neighborhood corresponds to a temperature block in the temperature distribution map. The temperature distribution within the block is relatively concentrated and the variation range is small.

[0042] The areas of multiple initially divided reaction neighborhoods are calculated. The neighborhoods with smaller areas have little effect on the injection strategy and need to be properly fused. Specifically, a minimum area threshold is set. If the area of ​​a neighborhood is smaller than the minimum area threshold, it is fused with the adjacent area. The temperature mean difference of the adjacent neighborhoods must also be within a certain range to ensure that the temperature distribution of the fused region is still uniform. All initially divided reaction neighborhoods are traversed. After nearest neighbor fusion, the areas with too small areas are merged to obtain multiple divided reaction areas. The fused areas are more in line with the requirements, and the temperature distribution in each neighborhood is still concentrated, ensuring the efficiency of the subsequent reactor injection strategy.

[0043] Furthermore, traversing the plurality of divided reaction regions to perform temperature mean concentration analysis and determine a plurality of temperature distribution concentration values ​​includes: Based on the infrared temperature mean distribution map, the temperature means contained in the multiple divided reaction areas are extracted to obtain multiple regional temperature mean sets; the medians of the multiple regional temperature mean sets are respectively used as multiple concentrated analysis starting points, and center point iterations are performed in the multiple regional temperature mean sets according to a preset iteration step until a preset number of iterations is met, and the multiple regional temperature means corresponding to the multiple target center points obtained in the last iteration are used as the multiple temperature distribution concentration values.

[0044] For each divided reaction area, the temperature mean of all temperature points in the area is obtained to form a corresponding temperature mean set, and the temperature mean set of each divided reaction area is aggregated to form multiple regional temperature mean sets.

[0045] For each regional temperature mean set, the median is counted as the starting point of the concentration analysis because it has little impact on the extreme values ​​and can stably reflect the central trend of the set. Starting from the median, the center point value is gradually adjusted in the regional temperature mean set according to the preset iteration step until the preset number of iterations is reached. The final center point value is the target temperature distribution concentration value.

[0046] Further, including: Taking the multiple concentrated analysis starting points as the center and the preset iteration step as the radius, multiple starting concentrated analysis neighborhoods are constructed; and a center point iteration formula is obtained, wherein the center point iteration formula is: ; in, is the iteration center point, To start with, we focus on analyzing the mean temperature of multiple regions in the neighborhood. is the mean temperature of the ith region among multiple region temperature means, To focus on the starting point of analysis, is a weight kernel function built based on the Gaussian function.

[0047] The multiple concentrated analysis starting points are updated in the multiple starting concentrated analysis neighborhoods using the center point iteration formula until the preset number of iterations is met, and the multiple regional temperature means corresponding to the multiple target center points obtained in the last iteration are used as the multiple temperature distribution concentration values.

[0048] Specifically, the medians of multiple regional temperature mean sets are used as multiple concentrated analysis starting points. Multiple initial concentrated analysis neighborhoods are constructed with these medians as the center and a preset iteration step as the radius. The preset iteration step can be set to 1°C, 0.5°C, etc.

[0049] The main purpose of the center point iteration formula is to gradually adjust the center point position of the centralized analysis through mathematical calculations so that it can more accurately represent the data concentration trend in a region. The center point iteration formula is as follows: ; Among them, the weight kernel function It is constructed based on the Gaussian function. Its core function is to highlight the temperature points that are closer to the center point in the current neighborhood and weaken the points that are farther away. The weighted average of all temperature values ​​in the neighborhood is calculated to obtain a new center point value. After each iteration, the new center point will be closer to the true center of the temperature distribution in the neighborhood. After multiple iterations, the final center point can reflect the concentration trend of the temperature values ​​in the neighborhood. This process effectively solves the interference of discrete points in the data distribution and finally extracts a reliable temperature concentration value.

[0050] In multiple starting concentrated analysis neighborhoods, multiple concentrated analysis starting points are substituted into the center point iteration formula respectively, and the center point is gradually updated. When the preset number of iterations is reached, the iteration is stopped, and the last iteration result is taken as the target center point, that is, the concentrated value of the temperature distribution in the neighborhood, which eliminates the interference of outliers and can more accurately reflect the regional temperature distribution characteristics.

[0051] Further, including: A spray gun parameter identifier is pre-built; and the plurality of temperature distribution concentration values ​​and the plurality of divided reaction regions are analyzed using the spray gun parameter identifier to determine the plurality of nozzle injection angles and the plurality of injection amounts.

[0052] Pre-build a spray gun parameter identifier, which is a machine learning model used to convert input data, such as temperature distribution concentration values ​​and reaction area divisions, into optimized nozzle injection angles and injection amounts. Specifically, collect historical data from the operation of the desulfurization reactor, including temperature distribution concentration values, reaction area division characteristics, and actual nozzle parameters, including injection angles and injection amounts. Use historical data to train machine learning models, such as multivariate regression, support vector machines, neural networks, etc., to predict nozzle parameters. Train and verify the identifier model multiple times to ensure that its output accuracy meets the requirements of the denitrification reaction. The final spray gun parameter identifier can receive real-time input and output matching nozzle injection angles and injection amounts.

[0053] The temperature distribution concentration value and the characteristics of the divided reaction areas are input into the spray gun parameter identifier, the relationship between the temperature of each area and the required reducing agent amount is analyzed, the optimal injection direction of the nozzle and the reducing agent injection amount are determined, and multiple nozzle injection angles and multiple injection amounts are output to achieve precise reducing agent injection for each reaction area, ensuring the adequacy and efficiency of the denitrification reaction.

[0054] Further, including: A flue gas NOx concentration monitoring device is arranged at the outlet of the desulfurization reactor, and the monitoring data of the flue gas NOx concentration monitoring device within a preset feedback monitoring window is extracted to obtain a flue gas NOx concentration monitoring data set; it is determined whether the flue gas NOx concentration monitoring data set contains data that exceeds a preset flue gas NOx concentration threshold value, and if so, environmental protection treatment early warning information is obtained.

[0055] Use a high-sensitivity NOx analyzer, such as a chemiluminescence CLD sensor or an ultraviolet absorption analyzer, and install the equipment at the outlet of the desulfurization reactor. The location should avoid the airflow interference area to ensure that the sampling point can represent the overall concentration level of the flue gas. Set a feedback monitoring window, such as 5 seconds, 10 seconds or longer, to continuously extract NOx concentration data. Perform NOx concentration monitoring within the feedback monitoring window, and all collected NOx concentration data form a flue gas NOx concentration monitoring data set.

[0056] According to environmental regulations or process requirements, set a maximum allowable flue gas NOx concentration threshold, such as 50ppm, 100ppm, etc., traverse the flue gas NOx concentration monitoring data set, and check whether there is data exceeding the preset flue gas NOx concentration threshold. If there is at least one data that meets the conditions, it is determined that a concentration exceedance event has occurred. At this time, environmental protection processing warning information is generated. The information includes the specific value of the exceeded data, the time window when the exceeded data occurred, the identification of the exceeded area, etc., which is used to send an alarm to the operator to ensure that denitrification meets environmental protection requirements.

[0057] In summary, the environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification provided in the embodiments of the present application has the following technical effects: The flue gas emitted by the target biomass boiler is processed through preliminary filtration and temperature certification to ensure that the flue gas entering the desulfurization reactor is within the appropriate temperature range, so that the flue gas temperature meets the optimal reaction temperature of the SCR denitrification catalyst, and avoids low catalyst efficiency caused by excessively high or low temperatures; through infrared thermal imaging technology, the temperature distribution inside the reactor is dynamically monitored, and the spatial distribution of temperature data is obtained to help identify areas with large temperature changes, provide accurate temperature data for subsequent reaction area division, and ensure the accuracy of subsequent processing; the temperature distribution map sequence is traversed, different temperature areas in the reactor are divided, and temperature concentration areas are identified to ensure that the reducing agent can react with nitrogen oxides in the flue gas in a targeted manner, thereby improving the denitrification reaction Efficiency; Based on the divided reaction area temperature data and temperature distribution concentration value, analyze and optimize the injection angle and injection amount of the reducing agent spray gun to avoid excessive or insufficient injection. By accurately adjusting the injection position and injection amount, it can ensure that the reducing agent is in full contact with the reaction area of ​​the target flue gas, thereby improving the reaction efficiency and reducing the consumption of the reducing agent during the denitrification process; According to the determined injection angle and injection amount, accurately control the reducing agent injection of the spray gun to ensure that the reducing agent reacts fully with the flue gas, minimize the NOx content in the flue gas, and complete the denitrification process. The overall method combines temperature monitoring, data analysis and automatic control technology to achieve precise management and optimization of the flue gas denitrification process, reduce manual intervention, and improve the automation level and reliability of the system.

[0058] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An environmentally friendly treatment method for biomass boilers based on ultra-low temperature flue gas denitrification, characterized in that: The method comprises: The flue gas emitted by the target biomass boiler is guided to the flue gas filter through the first pipeline for preliminary filtration, and the filtered flue gas is temperature certified. After passing the certification, the flue gas is introduced into the desulfurization reactor through the second pipeline, wherein the desulfurization reactor uses an ultra-low temperature SCR denitrification catalyst to selectively catalytically reduce the flue gas; Using an infrared thermal imager to collect a temperature distribution map of the desulfurization reactor in a preset monitoring window to determine an infrared temperature distribution map sequence; Traversing the infrared temperature distribution map sequence to divide the desulfurization reactor into reaction areas to obtain a plurality of divided reaction areas, wherein the plurality of divided reaction areas include a plurality of temperature distribution concentration values; Analyzing the nozzle injection angles and injection amounts of the multiple reducing agent spray guns of the desulfurization reactor based on the multiple temperature distribution concentration values ​​and the multiple divided reaction areas, and determining the multiple nozzle injection angles and multiple injection amounts of the multiple reducing agent spray guns; Based on the multiple nozzle injection angles and the multiple injection amounts, the multiple reducing agent spray guns are controlled to perform reducing agent injection. Under the catalysis of the ultra-low temperature SCR denitration catalyst, the injected reducing agent reacts with the flue gas in the multiple divided reaction areas to complete the flue gas denitration.

2. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 1 is characterized in that: include: Calculating the temperature mean of each temperature point in the infrared temperature distribution diagram sequence to obtain an infrared temperature mean distribution diagram; Performing temperature neighborhood flooding segmentation on the infrared temperature mean distribution map to determine a plurality of divided reaction areas; The plurality of divided reaction regions are traversed to perform temperature mean concentration analysis to determine a plurality of temperature distribution concentration values.

3. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 2 is characterized in that: The infrared temperature mean distribution map is subjected to temperature neighborhood flooding segmentation to determine a plurality of divided reaction areas, including: Extract the temperature point corresponding to the minimum infrared temperature mean value in the infrared temperature mean value distribution map, and use it as the starting point of flooding segmentation; Taking each temperature point in the infrared temperature mean distribution map as a mountain, taking the infrared temperature mean corresponding to each temperature point as the mountain height, performing mountain simulation on the infrared temperature mean distribution map to obtain a simulated mountain area; Taking the flood segmentation starting point as the water injection point, water is injected into the simulated mountain area. As the water level rises, the water surface covers at least one mountain. It is determined whether the difference in height between the multiple mountains covered and the mountain at the flood segmentation starting point is greater than or equal to the preset neighborhood bandwidth. If so, multiple dividing ridge lines are generated, and water is continuously injected into the simulated mountain area until the mountain corresponding to the maximum mountain height in the simulated mountain area is covered, and a set of dividing ridge lines is obtained, wherein the multiple dividing ridge lines rise as the water level rises; The infrared temperature mean distribution map is neighborhood-partitioned based on the set of partitioning ridge lines to determine the plurality of partitioning reaction areas.

4. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 3 is characterized in that: Performing neighborhood division on the infrared temperature mean distribution map based on the set of dividing ridge lines to determine the multiple divided reaction areas includes: Dividing the infrared temperature mean distribution map according to the set of dividing ridge lines to obtain a plurality of initial divided reaction neighborhoods; The nearest neighbor fusion is performed according to the area sizes of the multiple initial divided reaction neighborhoods, and the multiple divided reaction areas are obtained according to the fusion result.

5. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 2 is characterized in that: Traversing the plurality of divided reaction regions to perform temperature mean concentration analysis and determine a plurality of temperature distribution concentration values, including: Extracting the temperature mean values ​​contained in the plurality of divided reaction regions based on the infrared temperature mean distribution map to obtain a plurality of regional temperature mean value sets; The medians of the multiple regional temperature mean sets are respectively used as multiple concentrated analysis starting points, and center point iterations are performed in the multiple regional temperature mean sets according to a preset iteration step until a preset number of iterations is met, and the multiple regional temperature means corresponding to the multiple target center points obtained in the last iteration are used as the multiple temperature distribution concentration values.

6. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 5, characterized in that: include: Taking the multiple concentrated analysis starting points as the center and the preset iteration step as the radius, construct multiple starting concentrated analysis neighborhoods; Obtain a center point iteration formula, wherein the center point iteration formula is: ； in, is the iteration center point, To start with, we focus on analyzing the mean temperature of multiple regions in the neighborhood. is the mean temperature of the ith region among multiple region temperature means, To focus on the starting point of analysis, is a weight kernel function built based on the Gaussian function; The multiple concentrated analysis starting points are updated in the multiple starting concentrated analysis neighborhoods using the center point iteration formula until the preset number of iterations is met, and the multiple regional temperature means corresponding to the multiple target center points obtained in the last iteration are used as the multiple temperature distribution concentration values.

7. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 1, characterized in that: include: Pre-built gun parameter identifier; The plurality of temperature distribution concentration values ​​and the plurality of divided reaction regions are analyzed by the spray gun parameter identifier to determine the plurality of nozzle injection angles and the plurality of injection amounts.

8. The environmentally friendly treatment method for biomass boiler based on ultra-low temperature flue gas denitrification according to claim 1, characterized in that: include: Arrange a flue gas NOx concentration monitoring device at the outlet of the desulfurization reactor, extract monitoring data of the flue gas NOx concentration monitoring device within a preset feedback monitoring window, and obtain a flue gas NOx concentration monitoring data set; It is determined whether the flue gas NOx concentration monitoring data set contains data exceeding a preset flue gas NOx concentration threshold value, and if so, environmental protection treatment warning information is obtained.

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