Flue gas denitration reducing agent accurate injection control system based on flow feedback

Abstract

The invention discloses a flue gas denitrification reducing agent accurate injection control system based on flow feedback, and relates to the technical field of flue gas denitrification, the system comprises a flue gas flow pipeline hierarchical module, based on NOx concentration, carries out section hierarchical and multi-point injection deployment on a denitrification period, constructs a cascade denitrification structure, and limits NOx concentration decline in a partitioned manner. The control establishment module carries out mathematical reconstruction on a cascade denitration structure, constructs a denitration controller, combines multivariable decoupling decision and tracing simulation, and is connected with a front-end device through a network protocol. The injection decision-making module triggers a denitration period along with the flue gas inlet pipe, executes a first-order reducing agent putting decision according to the flue gas flow, carries out second-order decoupling decision and strategy coupling based on a denitration controller, determines an injection strategy and introduces a tracing medium for simulation verification. The denitration cycle is progressive according to pipeline sections in a stepped manner, and NOx concentration limit is taken as a treatment standard. Therefore, the technical effects of dynamically optimizing the injection strategy and improving the denitration efficiency and the utilization rate of the reducing agent are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas denitration, and particularly to a precise injection control system for a flue gas denitration reducing agent based on flow feedback. Background Art

[0002] Traditional denitration systems usually adopt single-point injection or fixed injection strategies. By injecting a reducing agent (such as ammonia water or urea) into the flue gas pipeline, a chemical reaction occurs with NOx in the flue gas, converting it into nitrogen and water. However, in the prior art, the deployment of injection points is often based on experience or fixed patterns, lacking real-time feedback on the dynamic changes in the NOx concentration in the flue gas pipeline, resulting in difficulty in precisely matching the injection amount and injection position of the reducing agent with the actual requirements. Summary of the Invention

[0003] The present invention provides a precise injection control system for a flue gas denitration reducing agent based on flow feedback to solve the technical problems in the prior art, such as single deployment of injection points, difficulty in coping with complex situations, and unstable denitration effect, and to achieve the technical effects of dynamically optimizing the injection strategy, improving the denitration efficiency, and the utilization rate of the reducing agent.

[0004] The precise injection control system for a flue gas denitration reducing agent based on flow feedback provided by the present invention includes: A flue gas pipeline staging module, which is used for the flue gas pipeline. Constrained by the NOx concentration at the pipeline outlet end, it stages the flue gas pipeline sections and deploys multi-point injection during the denitration cycle to construct a cascaded denitration structure, where each partition has a decreasing limit based on the NOx concentration.

[0005] A control establishment module, which is used to mathematically reconstruct the cascaded denitration structure. Aiming at the multi-variable decoupling decision and tracer simulation of flue gas denitration, a denitration controller is constructed, where the denitration controller is connected to the front-end device deployed in the flue gas pipeline based on a network protocol.

[0006] An injection decision module, which is used to trigger the denitration control cycle as the flue gas enters the pipe. It makes a first-order linear decision on the input amount of the reducing agent according to the flue gas flow rate, performs a second-order decoupling decision and strategy coupling according to the denitration controller, determines the injection strategy and introduces a tracer medium for simulation verification, and outputs the injection control strategy. The denitration control cycle is a progressive multi-round process based on the staging of the flue gas pipeline sections, and the NOx concentration with partition limits is used as the section processing standard.

[0007] In a feasible implementation manner, the execution steps of the flue gas pipeline staging module include: the NOx concentration at the pipeline outlet end is used as the denitration separation standard, the inlet end and the outlet end of the flue gas pipeline are used as the NOx separation cycle, and the pipeline partitions in the flue gas flow direction correspond to multiple denitration separation stages.

[0008] In a feasible implementation manner, the flue gas flow pipeline staging module includes: A denitration pipeline section unit, configured to determine a denitration pipeline section according to the reduction reaction time of the reductant injection and the flue gas flow velocity range.

[0009] A partition deployment unit, configured to partition the flue gas flow pipeline with the denitration pipeline section as the separation stage constraint, wherein at least one position of each partition is deployed with an injection device.

[0010] In a feasible implementation manner, the injection decision module includes: A first-order linear decision unit, configured to determine an agent linear relationship with the flue gas flow rate as the independent variable and the reductant input amount as the dependent variable.

[0011] A flow rate detection unit, configured to detect and obtain the flue gas flow rate at the inlet of the flue gas flow pipeline.

[0012] A linear decision unit, configured to perform a linear decision on the reductant input amount for the flue gas flow rate according to the agent linear relationship, and determine a first-order strategy.

[0013] In a feasible implementation manner, the execution steps of the flow rate detection unit include: deploying a flow meter at the inlet of the flue gas flow pipeline, and based on the flow meter, detecting the flow rate of the incoming flue gas in batches at preset time nodes.

[0014] In a feasible implementation manner, the injection decision module includes: A coupling variable determination unit, configured to determine the coupling variables of flue gas denitration, wherein the coupling variables at least include NOx concentration, ammonia slip rate, and flue gas temperature.

[0015] A sensing data receiving unit, configured to import the first-order strategy into the denitration controller and receive the sensing data of the front-end device, wherein the sensing data at least includes flue gas composition and flue gas temperature.

[0016] A multivariable decoupling decision unit, configured to perform a multivariable decoupling decision according to the sensing data and the first-order strategy, and determine a strategy group.

[0017] A strategy group coupling unit, configured to couple the strategy group and determine the injection control strategy.

[0018] In a feasible implementation manner, the execution steps of the strategy group coupling unit include: determining a multivariable decoupling method and temporarily storing it, and performing reverse coupling on the strategy group according to the multivariable decoupling method.

[0019] In a feasible implementation manner, the strategy group coupling unit includes: An initialization strategy subunit, configured to couple the strategy group and determine an initialization strategy.

[0020] A tracer simulation subunit, configured to introduce a tracer medium, perform a tracer simulation on the initialization strategy, and determine the injection control strategy, which at least includes an injection angle, an injection rate, and an injection intensity.

[0021] In a feasible implementation manner, the strategy group coupling unit further includes: A guiding component deployment subunit, configured to deploy a smoke flow guiding component and establish a working condition coordination between the smoke flow guiding component and the injection device.

[0022] A simulation effect identification subunit, configured to identify the tracer simulation effect, determine whether the equilibrium relaxation degree is satisfied. If not, coordinate the angle control of the smoke flow guiding component and the injection device for optimization adjustment to determine the injection control strategy.

[0023] In a feasible implementation manner, the injection decision module includes: A periodic execution unit, configured to execute the injection control strategy and complete the injection control in the first cycle stage.

[0024] A backtracking evaluation unit, configured to trigger the front-end device to obtain sensing data when transferring to the second partition port, perform an evaluation in the first cycle stage, and determine a first evaluation coefficient.

[0025] A two-stage compensation decision unit, configured to use the NOx concentration in the second partition as a processing standard, perform two-stage decision-making with the first evaluation coefficient as compensation processing, and drive the injection device to perform denitrification control.

[0026] The present invention discloses a precise injection control system for flue gas denitration reducing agent based on flow feedback, including: a flue gas pipeline staging module stages and deploys multi-point injection for the flue gas pipeline, forms a cascaded denitration structure with the NOx concentration at the pipeline outlet end as a constraint, and sets a decreasing limit based on the NOx concentration in each partition; a control establishment module mathematically reconstructs the cascaded denitration structure, constructs a denitration controller aiming at multi-variable decoupling decision-making and tracer simulation of flue gas denitration, and connects to the front-end device of the flue gas pipeline through a network protocol; an injection decision module triggers the denitration control cycle with the incoming flue gas, executes a first-order linear decision on the input amount of the reducing agent according to the flue gas flow rate, combines with the denitration controller for second-order decoupling decision-making and strategy coupling, finally determines the injection strategy, and introduces a tracer medium for simulation verification, and completes the denitration treatment progressively with the sectional limit of the NOx concentration as the standard. The precise injection control system for flue gas denitration reducing agent based on flow feedback disclosed by the present invention solves the technical problems of single injection point deployment, difficulty in coping with complex situations, and unstable denitration effect, and realizes the technical effects of dynamically optimizing the injection strategy, improving the denitration efficiency and the utilization rate of the reducing agent. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the precise injection control system for flue gas denitration reducing agent based on flow feedback of the present invention.

[0028] Figure 2 It is a schematic structural diagram of the injection decision module in the precise injection control system for flue gas denitration reducing agent based on flow feedback of the present invention.

[0029] Description of the reference numerals: flue gas pipeline staging module 11, control establishment module 12, injection decision module 13, first-order linear decision unit 131, flow detection unit 132, linear decision unit 133. Detailed Embodiments

[0030] The following will describe the above technical solutions in detail in combination with the drawings in the specification and specific embodiments to better understand the above technical solutions. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited to the example embodiments for explaining the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings rather than all.

[0031] Embodiment Figure 1 It is a schematic structural diagram of the precise injection control system for flue gas denitration reducing agent based on flow feedback of the present invention, wherein the precise injection control system for flue gas denitration reducing agent based on flow feedback includes: The flue gas pipeline staging module 11 is used for the flue gas pipeline. Constrained by the NOx concentration at the outlet end of the pipeline, it stages the flue gas pipeline sections and deploys multi-point injection for the denitration cycle, constructing a cascaded denitration structure. Among them, each partition has a decreasing limit based on the NOx concentration.

[0032] Specifically, the flue gas pipeline staging module is used to divide the flue gas pipeline into multiple sections according to the NOx concentration distribution law, and deploy injection devices in each corresponding section to form a cascaded denitration structure. Among them, the upper limit of the NOx concentration in each partition gradually decreases in the flue gas flow direction, that is, a decreasing limit, to ensure the gradual optimization of the denitration process.

[0033] The above steps help improve the matching degree between the injection amount and position of the reducing agent and the actual NOx concentration distribution by staging the deployment of injection devices, thereby improving the utilization rate of the reducing agent and reducing the risk of local over-injection.

[0034] In some embodiments, the execution steps of the flue gas pipeline staging module 11 include: The NOx concentration at the outlet end of the pipeline is used as the denitration separation standard. Taking the inlet end and the outlet end of the flue gas pipeline as the NOx separation cycle, the pipeline partitions in the flue gas flow direction correspond to multiple denitration separation stages.

[0035] Specifically, taking the inlet end to the outlet end of the flue gas pipeline as a complete NOx separation cycle, at the same time, dividing the pipeline in the flue gas flow direction into multiple sections, each section corresponding to a denitration treatment stage. Among them, multiple denitration separation stages can be grouped and divided based on the NOx concentration change law or the arrangement of injection points.

[0036] Through the above definitions, the system can dynamically adjust the injection strategy to ensure that the NOx concentration in each section gradually decreases and finally reaches the NOx concentration target at the outlet end. This staged design can adapt to the dynamic changes of flue gas flow and NOx concentration, avoiding problems of local over-injection or under-injection caused by single-point injection.

[0037] In some embodiments, the flue gas pipeline staging module 11 includes: The denitration pipeline section unit is used to determine the denitration pipeline section according to the reduction reaction time of the reducing agent injection and the flue gas flow velocity range.

[0038] The partition deployment unit is used to partition the flue gas pipeline with the denitration pipeline section as the separation stage constraint, and injection devices are deployed at at least one position in each partition.

[0039] Specifically, the reduction reaction time is the time required for the reducing agent (such as ammonia water or urea) to chemically react with NOx in the flue gas; the flue gas flow velocity range refers to the flow velocity range of the flue gas in the pipeline. Among them, the flue gas flow velocity significantly affects the mixing efficiency of the reducing agent and the flue gas.

[0040] Specifically, first, according to the chemical properties of the reducing agent and the reaction conditions of the denitrification environment (such as flue gas temperature), calculate the time required for the reducing agent to react with NOx (i.e., the reduction reaction time); at the same time, activate sensors or other monitoring devices (such as pitot tubes) to collect flue gas flow velocity data in the pipeline and determine the flow velocity range; then, combine the reduction reaction time and the flue gas flow velocity range to calculate the length and position of each section to ensure that the reducing agent entering this section can be fully mixed with the flue gas in this section and fully react.

[0041] Furthermore, according to the division results of the denitrification pipeline sections, divide the flue gas pipeline into multiple sections and deploy reducing agent injection devices (such as at the inlet or intermediate positions) in each section. Among them, each section corresponds to a denitrification separation stage.

[0042] Through the above process, precise staging of the flue gas pipeline and reasonable deployment of the injection devices are achieved, which not only helps improve the utilization rate of the reducing agent, but also contributes to enhancing the dynamic adaptability of the system and ensuring the stability and reliability of the denitrification effect.

[0043] The control establishment module 12 is used to perform mathematical reconstruction on the cascade denitrification structure, aiming at multi-variable decoupling decision-making and tracer simulation of flue gas denitrification, and construct a denitrification controller. Among them, the denitrification controller is connected to the front-end devices deployed in the flue gas pipeline based on a network protocol.

[0044] Specifically, this control establishment module 12 abstracts the denitrification process into an optimization problem with multiple variables (including NOx concentration, flow velocity, temperature, reducing agent concentration, reaction time, etc.) by performing mathematical modeling on the cascade denitrification structure, that is, based on mathematical models (such as reaction kinetic differential equations, etc.).

[0045] Specifically, multi-variable decoupling decision-making is a process of decomposing complex denitrification control problems into multiple independent variables (such as NOx concentration, flue gas flow rate, temperature, etc.) for separate optimization decisions; tracer simulation is a process of verifying the actual effect of the injection strategy by introducing a tracer medium (such as simulated flue gas components). Among them, data such as flue gas composition and temperature are obtained in real time by connecting front-end devices (such as sensors and injection devices) through a network protocol, and multi-variable decoupling decision-making is performed in combination with the first-order linear decision result.

[0046] Exemplarily, the multivariable decoupling decision is implemented by methods such as model predictive control or linear quadratic regulator; the denitration controller is connected to the front-end device through standard industrial protocols (such as Modbus TCP, OPC UA, etc.) to achieve remote parameter distribution and data feedback.

[0047] Through the above process of mathematical modeling and multivariable decoupling decision, the abstract task is decomposed and embodied into the dynamic optimization solution of multiple indicators, thereby improving the decision-making efficiency and helping to adapt to complex working conditions. At the same time, the tracer simulation can verify the effect before the injection strategy is executed, avoiding the instability of the denitration effect caused by strategy mistakes.

[0048] The injection decision module 13 is used to trigger the denitration control cycle with the entry of flue gas, make a first-order linear decision on the reductant input according to the flue gas flow rate, perform a second-order decoupling decision and strategy coupling according to the denitration controller, determine the injection strategy and introduce a tracer medium for simulation verification, and output the injection control strategy. Among them, the denitration control cycle is a progressive multi-round process carried out in stages according to the flue gas pipeline section, and the NOx concentration with partition limit is used as the section processing standard.

[0049] Specifically, the first-order linear decision is a preliminary injection volume estimation decision based on the relationship between the flue gas flow rate and the reductant input; the second-order decoupling decision is a further optimized injection strategy based on the preliminary injection strategy combined with the multivariable decoupling decision, and the actual denitration environment is more comprehensively reflected by introducing the multivariable structure process; furthermore, the strategy coupling is the process of integrating multiple optimized strategies into the final injection control strategy, which helps to ensure the stability and reliability of the injection effect.

[0050] The above process gradually optimizes the injection strategy through a progressive multi-round process, which helps to dynamically adjust the injection volume and injection position (that is, perform a fast second-order decision based on the first-order decision), improve the reductant utilization rate, and ensure the stability and reliability of the denitration effect. At the same time, the introduction of the tracer simulation verification mechanism helps to ensure the reliability of the injection strategy and avoid the instability of the denitration effect caused by strategy mistakes.

[0051] In some embodiments, as Figure 2 shown, the injection decision module 13 includes: The first-order linear decision unit 131 is used to determine the surrogate linear relationship with the flue gas flow rate as the independent variable and the reductant input as the dependent variable.

[0052] The flow rate detection unit 132 is used to detect and obtain the flue gas flow rate at the inlet of the flue gas pipeline.

[0053] The linear decision unit 133 is used to make a linear decision on the reductant input according to the surrogate linear relationship for the flue gas flow rate and determine the first-order strategy.

[0054] Specifically, the first-order linear decision-making unit 131 obtains historical data or online data, uses the flue gas flow rate as the independent variable and the reductant input amount as the dependent variable, and thus fits and determines the surrogate linear relationship between the two. This surrogate linear relationship is a relatively general concentration relationship determined based on statistics and is used to provide a mathematical model basis for subsequent decision-making. For example, by performing statistical analysis or least-squares fitting on the flue gas flow rate and reductant input amount data under multiple working conditions, the slope and intercept are obtained.

[0055] Specifically, the flow rate detection unit 132 detects and collects flue gas flow rate data in real time through a flow rate sensor installed at the inlet of the flue gas pipeline; the linear decision-making unit 133, based on the flue gas flow rate data collected by the above flow rate detection unit 132 and the linear surrogate relationship determined by the first-order linear decision-making unit 131, calculates by substituting the flue gas flow rate data into the surrogate linear relationship to obtain the reductant input amount recommended in the first-order strategy.

[0056] The above linear decision-making method helps to achieve fast response and real-time control, ensuring that the dosing decisions of the system under various working conditions have a certain degree of prediction accuracy and real-time performance.

[0057] In some implementation manners, the execution steps of the flow rate detection unit include: deploying a flow meter at the inlet of the flue gas pipeline, and based on the flow meter, detecting the flow rate of the flue gas entering the pipeline in batches at preset time nodes.

[0058] Specifically, the flow meter is used to measure the flow rate of a fluid (such as flue gas) (such as a pitot tube); the preset time node is a preset time interval for collecting flow rate data in batches.

[0059] Specifically, first, install a flow meter at the inlet of the flue gas pipeline to ensure that it can accurately measure the flow rate of the flue gas entering the pipeline. At the same time, according to the system requirements and the characteristics of the working conditions, preset the time nodes for flow rate detection (such as every minute, every hour, etc.). Among them, the higher the monitoring requirement, the shorter the corresponding time interval. Then, activate the flow meter to collect flue gas flow rate data in batches according to the preset time nodes and transmit the data to the injection decision-making module.

[0060] In some embodiments, the injection decision-making module 13 includes: A coupling variable determination unit for determining the coupling variables for flue gas denitration, where the coupling variables at least include NOx concentration, ammonia slip rate, and flue gas temperature.

[0061] A sensing data receiving unit for importing the first-order strategy into the denitration controller and receiving the sensing data of the front-end device, where the sensing data at least includes flue gas components and flue gas temperature.

[0062] A multivariable decoupling decision-making unit is used to perform multivariable decoupling decision-making based on the sensing data and the first-order strategy to determine a strategy group.

[0063] A strategy group coupling unit is used to couple the strategy group to determine the injection control strategy.

[0064] Specifically, the coupling variables for flue gas denitration are multiple variables that affect the flue gas denitration effect, and there are mutual influences between the variables.

[0065] Specifically, the first-order strategy (set of preliminary injection quantity estimations) is imported into the denitration controller, and at the same time, the real-time sensing data collected by the front-end devices (such as NOx sensors, temperature sensors, etc.) is imported into the denitration controller. Among them, the sensing data at least includes flue gas components and temperature; then, the sensing data and the first-order strategy are decomposed into multiple independent variables, and optimization decisions are made for each independent variable to generate multiple strategy groups. For example, the injection quantity is adjusted according to the NOx concentration, and the injection angle is adjusted according to the flue gas temperature. After the optimization is completed, the multiple strategy groups are integrated into the final injection control strategy for output to guide the injection device to perform precise injection.

[0066] The above process, through multivariable decoupling decision-making, helps to optimize each variable separately, thereby improving the accuracy of the injection strategy; among them, the fusion action of the strategy group coupling unit ensures the coordination between multiple strategies and avoids the instability of the injection effect caused by variable conflicts.

[0067] In some implementation manners, the execution steps of the strategy group coupling unit include: determining the multivariable decoupling method and temporarily storing it, and performing reverse coupling on the strategy group according to the multivariable decoupling method.

[0068] Specifically, multivariable decoupling refers to a method of decomposing complex coupling variables into independent variables. Among them, available multivariable decoupling methods include: relative gain matrix (RGA), reverse decoupling control, etc.; reverse coupling is the process of recombining independent variables into an overall control strategy after decoupling to ensure the coordination between variables.

[0069] In some implementation manners, the strategy group coupling unit includes: An initialization strategy subunit is used to couple the strategy group to determine an initialization strategy.

[0070] A tracer simulation subunit is used to introduce a tracer medium to perform tracer simulation on the initialization strategy to determine the injection control strategy, which at least includes injection angle, injection rate, and injection intensity.

[0071] Specifically, the initialization strategy subunit is mainly used to couple and integrate multiple strategy groups according to preset rules or initial settings to determine the initial dosing or control strategy (initialization strategy). Optionally, the preset rules or initial settings are determined by the collected historical data, operating parameters, environmental variables, etc.

[0072] Specifically, the tracer simulation subunit dynamically simulates the above-mentioned initialization strategy by introducing a tracer medium. Among them, the tracer simulation is realized through physical modeling and numerical simulation technologies, and is used to obtain the diffusion, mixing and reaction conditions of the tracer medium during the actual spraying process in real time, so as to provide data support for further optimizing and adjusting control parameters to determine a more accurate and practical demand-adapted spraying control strategy.

[0073] Specifically, the spraying control strategy at least includes: spraying angle, which determines the direction and range of the dosing medium entering the target area; spraying rate, which adjusts the dosing speed of the medium according to real-time flow or concentration requirements; spraying intensity, which reflects the impact force or diffusion effect generated by the medium during spraying to ensure the achievement of the predetermined treatment efficiency.

[0074] Through the above implementation methods, a reasonable control scheme and the feedback of tracer simulation can be quickly generated based on the initial data, so as to continuously improve and optimize the spraying control strategy, and thus better adapt to the actual operating conditions.

[0075] In some implementation methods, the strategy group coupling unit further includes: The smoke flow guiding component deployment subunit is used to deploy the smoke flow guiding component and establish the working condition coordination between the smoke flow guiding component and the spraying device.

[0076] The simulation effect identification subunit is used to identify the tracer simulation effect, determine whether the equilibrium relaxation degree is satisfied, and if not, coordinate the angle control of the smoke flow guiding component and the spraying device for optimization adjustment to determine the spraying control strategy.

[0077] Specifically, the smoke flow guiding component is a device for adjusting the flow direction and speed of flue gas, and is used to optimize the gas flow pattern in the flue to ensure the full mixing of the reducing agent and the flue gas. Among them, the smoke flow guiding component has the working condition coordination with the spraying device, that is, it can be adaptively adjusted according to the working state of the spraying device, so as to ensure good mixing effects under different spraying working conditions. Exemplarily, the above-mentioned working condition coordination is determined based on experiments or simulation experiments.

[0078] Specifically, the simulation effect identification subunit is used to identify the effect of the tracer simulation, judge whether the equilibrium relaxation degree is satisfied, and perform optimization adjustment when necessary, where the equilibrium relaxation degree refers to the error range allowed for the spraying strategy when meeting the denitration target.

[0079] Specifically, identify the effect of the tracer simulation, and determine whether the equilibrium relaxation degree is satisfied. If the tracer result does not meet the equilibrium relaxation degree, the smoke flow guiding component and the injection device angle are synchronously and collaboratively controlled and optimized to ensure a more balanced medium distribution and reaction during the actual injection process. Optionally, the collaborative control optimization is implemented based on the same method principle as the tracer simulation, that is, the collaborative control optimization based on simulation.

[0080] In some embodiments, the injection decision module 13 includes: A cycle execution unit for executing the injection control strategy to complete the injection control in the first cycle stage.

[0081] A backtracking evaluation unit for triggering the front-end device to obtain sensing data for the first cycle stage evaluation and determining the first evaluation coefficient when flowing to the second partition port.

[0082] A two-stage compensation decision unit for taking the NOx concentration in the second partition as the processing standard, performing two-stage decision-making with the first evaluation coefficient as the compensation process, and driving the injection device to perform denitrification control.

[0083] Specifically, within the preset first cycle stage, the cycle execution unit is responsible for controlling the injection angle, rate, and intensity according to the determined injection control strategy to achieve stable continuous injection; when the flue gas or working condition flows to the second partition port (i.e., the second partition inlet), the backtracking evaluation unit is activated to evaluate the injection control effect in the first cycle stage, including triggering the front-end device at the second partition port to obtain relevant sensing data (such as flue gas composition, NOx concentration, etc.), and calculating and determining the first evaluation coefficient according to the deviation degree between the obtained sensing data and the theoretical expected data. This first evaluation coefficient reflects the execution effect and deviation degree of the injection control strategy in the current cycle.

[0084] Furthermore, taking the NOx concentration in the second partition as the key process index, according to the first evaluation coefficient, the control effect of the first cycle is compensated. For example, if the first evaluation coefficient shows that the effect of the first cycle is not good, the reductant injection amount and mixing intensity in the second partition are increased according to the size of the first evaluation coefficient. Among them, the compensation decision unit performs two-stage decision-making to ensure that the adjustment of the injection device considers both real-time data feedback and historical evaluation results, so as to achieve more accurate denitrification control in the next cycle.

[0085] Through the above-mentioned phased optimization and dynamic compensation mechanism, it helps to ensure that the denitrification effect in the next stage reaches the best, thereby gradually reducing the NOx concentration, ultimately achieving the denitrification target at the outlet end, while improving the utilization rate of the reductant and the overall stability of the system.

[0086] In summary, the precise injection control system for flue gas denitration reductant based on flow feedback provided by the present invention has the following technical effects: The flue gas pipeline is sectionally staged and multi-point injection is deployed through the flue gas pipeline staging module. With the NOx concentration at the outlet end of the pipeline as the constraint, a cascaded denitration structure is formed, and a decreasing limit based on the NOx concentration is set in each partition. The control establishment module mathematically reconstructs the cascaded denitration structure. With the multi-variable decoupling decision-making and tracer simulation of flue gas denitration as the goal, a denitration controller is constructed and connected to the front-end device of the flue gas pipeline through a network protocol. The injection decision module triggers the denitration control cycle with the entry of flue gas into the pipeline, makes a first-order linear decision on the input amount of reductant according to the flue gas flow rate, and combines with the denitration controller for second-order decoupling decision-making and strategy coupling. Finally, the injection strategy is determined, and a tracer medium is introduced for simulation verification. With the sectional limit of the NOx concentration as the standard, the denitration treatment is completed progressively, thereby achieving the technical effects of dynamically optimizing the injection strategy, improving the denitration efficiency, and the utilization rate of the reductant.

[0087] It should be understood that the disclosed embodiments of the present invention and the above descriptions enable those skilled in the art to implement the present invention using the present invention. At the same time, the present invention is not limited to the above-mentioned part of the embodiments. It should be understood that those of ordinary skill in the art can still modify the technical solutions recorded in the foregoing embodiments or equivalently replace some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A flue gas denitrification reducing agent precise injection control system based on flow feedback, characterized in that: include: The smoke pipe grading module is used to divide the smoke pipe sections and deploy multi-point injection for the denitration cycle based on the NOx concentration at the pipe outlet, and build a cascade denitration structure, in which each partition has a decreasing limit based on the NOx concentration; A control establishment module is used to mathematically reconstruct the cascade denitration structure, build a denitration controller with the multivariable decoupling decision and tracer simulation of flue gas denitration as the goal, wherein the denitration controller is connected to the front-end device deployed in the smoke flow pipeline based on a network protocol; The injection decision module is used to trigger the denitrification control cycle as the flue gas enters the pipe, make a first-order linear decision on the amount of reducing agent input according to the flue gas flow rate, execute a second-order decoupling decision and strategy coupling according to the denitrification controller, determine the injection strategy and introduce a tracer medium for simulation verification, and output the injection control strategy; wherein, the denitrification control cycle is a progressive multi-round processing performed in stages according to the smoke flow pipe sections, and the NOx concentration of the zone limit is used as the section processing standard.

2. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 1, characterized in that: The execution steps of the smoke flow pipeline stage module include: the NOx concentration at the pipeline outlet is used as the denitration separation standard, the inlet and outlet ends of the smoke flow pipeline are used as the NOx separation period, and the pipeline partitions in the smoke flow direction correspond to multiple denitration separation stages.

3. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 2, characterized in that: The smoke flow duct hierarchical module comprises: The denitration pipeline section unit is used to determine the denitration pipeline section according to the reduction reaction time of the reducing agent injection and the smoke flow velocity range; The partition deployment unit is used to partition the smoke flow pipeline with the denitrification pipeline section as the separation stage constraint, wherein at least one position of each partition is deployed with an injection device.

4. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 1, characterized in that: The injection decision module comprises: The first-order linear decision-making unit is used to determine the proxy linear relationship with the flue gas flow rate as the independent variable and the reducing agent input as the dependent variable; A flow detection unit, used to detect the smoke flow at the inlet of the smoke flow duct; The linear decision unit is used to make a linear decision on the amount of reducing agent input for the flue gas flow according to the proxy linear relationship, and determine a first-order strategy.

5. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 4, characterized in that: The execution steps of the flow detection unit include: deploying a flow meter at the entrance of the smoke duct, taking preset time nodes as batches, and performing flow detection on the inlet smoke based on the flow meter.

6. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 5, characterized in that: The injection decision module comprises: A coupling variable determination unit, used to determine the coupling variables of flue gas denitrification, wherein the coupling variables at least include NOx concentration, ammonia escape rate, and flue gas temperature; A sensor data receiving unit, used for introducing the first-order strategy into the denitration controller and receiving sensor data from a front-end device, wherein the sensor data at least includes flue gas composition and flue gas temperature; A multivariable decoupling decision unit, used to perform multivariable decoupling decision and determine a strategy group according to the sensor data and the first-order strategy; The strategy group coupling unit is used to couple the strategy group and determine the injection control strategy.

7. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 6, characterized in that: The execution steps of the strategy group coupling unit include: determining a multi-variable decoupling method and temporarily storing it, and reversely coupling the strategy group according to the multi-variable decoupling method.

8. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 7, characterized in that: The strategy group coupling unit includes: An initialization strategy subunit, used to couple the strategy group and determine the initialization strategy; The tracer simulation subunit is used to introduce a tracer medium, perform a tracer simulation on the initialization strategy, and determine the injection control strategy, which at least includes an injection angle, an injection rate, and an injection intensity.

9. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 8, characterized in that: The strategy group coupling unit further includes: A guide assembly deployment subunit, used to deploy a smoke flow guide assembly and establish working condition coordination between the smoke flow guide assembly and the injection device; The simulation effect identification subunit is used to identify the tracer simulation effect and determine whether the balanced relaxation degree is met. If not, it coordinates the angle control of the smoke flow guiding component and the injection device to perform optimization adjustment and determine the injection control strategy.

10. The flue gas denitration reducing agent precise injection control system based on flow feedback according to claim 1, characterized in that: The injection decision module comprises: A cycle execution unit, used for executing the injection control strategy to complete the injection control in the first cycle stage; A retrospective evaluation unit, used for triggering the front-end device to obtain sensor data, perform a first cycle stage evaluation, and determine a first evaluation coefficient when the flow is transferred to the second partition port; The two-stage compensation decision unit is used to use the NOx concentration based on the second partition as a processing standard and the first evaluation coefficient as a compensation processing, execute a two-stage decision and drive the injection device to perform denitrification control.

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