A method and system for measuring NOx concentration at reactor outlet and controlling ammonia injection amount under different loads

Abstract

The present invention discloses a method and system for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads. The method includes: setting a NOx concentration sampling point at the reactor outlet of the denitrification device to detect the NOx concentration data at the reactor outlet; generating an ammonia spray control scheme, obtaining historical ammonia spray control data, constructing an ammonia spray control optimization model, optimizing and adjusting the ammonia spray control scheme according to real-time boiler coal quantity data, setting the ammonia spray valve opening to spray ammonia, and detecting the NOx concentration value at the reactor outlet in real time, and adjusting the ammonia spray valve opening. The present invention improves the NOx concentration measurement method at the reactor outlet, optimizes the ammonia spray control logic, increases the automatic input rate of the denitrification control system, improves the stability of the NOx automatic control, reduces the amount of ammonia used and the risk of air preheater blockage caused by local overspray of ammonia, reduces the labor intensity of the operating personnel, and realizes the automatic, intelligent, adjustable and controllable NOx concentration at the chimney outlet under different loads and up-to-standard emissions.

Description

Technical Field

[0001] The present invention relates to the technical field of denitration, and in particular to a method and system for measuring NOx concentration at a reactor outlet and controlling ammonia injection amount under different loads. Background Art

[0002] As one of the important indicators of ultra-low flue gas emissions, how to achieve automatic, intelligent, adjustable and controllable nitrogen oxide emissions is an issue that cannot be ignored. Back-pressure heating units use heat to determine electricity, which is greatly affected by changes in steam consumption by heating users. The boiler load adjustment changes are also relatively frequent. The NOx concentration at the reactor inlet is mainly unevenly distributed along the width of the boiler, showing that the NOx concentration in the primary air side area is generally high, and the NOx concentration in the secondary air side area is generally low. At the same time, load changes cause changes in the flue gas flow field in the furnace, and the NOx concentration distribution changes greatly. Although traditional PID control logic is used, the actual control effect is difficult to meet the requirements of energy conservation, environmental protection, and standard emissions. As a result, the ammonia injection system is under manual control for a long time, and there is a phenomenon of local over-spraying of ammonia, which not only reduces the economy and safety of the unit's denitrification, but also brings a huge burden to the operator's body and mind.

[0003] There is a NOx concentration measuring point at the reactor outlet. When the unit load changes greatly, the opening of the ammonia injection valve is manually adjusted according to the NOx concentration at the reactor outlet and the NOx concentration at the chimney outlet to control the amount of ammonia injection and ensure that the NOx concentration at the chimney outlet meets the emission standards. The flue gas flow field in the furnace changes and the NOx concentration is unevenly distributed. The amount of ammonia entering the denitrification reactor on the primary and secondary air sides is controlled by manually adjusting the opening of the 6 ammonia injection grid manual doors on site to improve the denitrification efficiency and prevent local overspray of ammonia. The adjustment is inaccurate and not timely enough. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed. Therefore, the present invention provides a method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads to solve the above problems.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for measuring the NOx concentration at a reactor outlet and controlling the amount of ammonia injection under different loads, comprising: setting a NOx concentration sampling point at the reactor outlet of a denitration device to detect the NOx concentration data at the reactor outlet;

[0008] According to the NOx concentration data at the reactor outlet, an ammonia injection control scheme is generated, and the corresponding valve opening is adjusted to automatically perform ammonia injection control;

[0009] Obtain historical ammonia injection control data, build an ammonia injection control optimization model, optimize and adjust the ammonia injection control plan according to real-time boiler coal quantity data, and respond to the ammonia injection control valve in advance;

[0010] Based on the optimized ammonia injection control scheme, the ammonia injection valve opening is set to inject ammonia, and the NOx concentration value at the reactor outlet is detected in real time to adjust the ammonia injection valve opening.

[0011] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads described in the present invention, a NOx concentration sampling point is set at the reactor outlet of the denitrification device, and the data of the NOx concentration at the reactor outlet is detected, including:

[0012] A NOx concentration sampling point is set at the reactor outlet corresponding to each ammonia injection grid of the denitration device. Each corresponding reactor outlet has a detection hole. The NOx concentration sampling point corresponds to the ammonia injection grid regulating valve one by one and is set at the same horizontal height along the width direction of the boiler;

[0013] The NOx concentration value at the reactor outlet of the NOx concentration sampling point is detected and recorded in real time.

[0014] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia injection under different loads described in the present invention, the ammonia injection control solution includes:

[0015] Setting a concentration threshold value, and comparing the real-time NOx concentration value with the concentration threshold value;

[0016] If the NOx concentration value is greater than the concentration threshold, the opening of the ammonia injection valve is adjusted accordingly;

[0017] If the NOx concentration value is less than the concentration threshold, the opening of the ammonia injection valve is adjusted accordingly;

[0018] The concentration difference between the NOx concentration value and the concentration threshold is calculated, and the ammonia injection valve opening is controlled according to the ammonia injection valve opening value corresponding to the set concentration difference interval.

[0019] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads described in the present invention, the historical ammonia injection control data obtained includes: boiler coal quantity, reactor outlet NOx concentration value, and ammonia injection valve opening data.

[0020] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads described in the present invention, the construction of the ammonia injection control optimization model includes:

[0021] Performing data preprocessing on the historical ammonia injection control data, wherein the data preprocessing includes processing abnormal values, missing values, and repeated values, and performing data normalization;

[0022] The Pearson correlation coefficient was used to analyze and calculate the correlation between each feature in the ammonia injection control data and the NOx concentration and ammonia injection amount, and the importance of the features was evaluated;

[0023] The features in the ammonia injection control data are converted into numerical values, an ammonia injection control optimization model is constructed through a machine learning algorithm, and the ammonia injection control optimization model is trained and evaluated.

[0024] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads described in the present invention, the model training and evaluation of the ammonia injection control optimization model includes:

[0025] The data set of the historical ammonia injection control data is randomly divided into a training set and a data set in a ratio of 7:3, and the model is evaluated by k-fold cross validation;

[0026] Obtaining optimal hyperparameters through grid search, and automatically adjusting the parameters of the ammonia injection control optimization model through a Bayesian optimization algorithm;

[0027] The performance of the ammonia injection control optimization model was evaluated by mean square error.

[0028] As a preferred solution of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads described in the present invention, the real-time detection of the NOx concentration value at the reactor outlet and the adjustment of the ammonia injection valve opening include:

[0029] The real-time ammonia injection control data is input into the ammonia injection control optimization model, and when the amount of coal in the boiler increases by more than the coal amount threshold within the cycle threshold, an optimized ammonia injection control scheme is output to set the opening of the ammonia injection valve;

[0030] The NOx concentration value at the reactor outlet is detected in real time, and the opening of the ammonia injection valve is adjusted according to the concentration difference between the current NOx concentration value and the concentration threshold.

[0031] In a second aspect, the present invention provides a system for measuring the NOx concentration at a reactor outlet and controlling the amount of ammonia sprayed under different loads, comprising:

[0032] The sampling module is used to set a NOx concentration sampling point at the reactor outlet of the denitration device to detect the NOx concentration data at the reactor outlet;

[0033] A control module, used to generate an ammonia injection control scheme according to the NOx concentration data at the reactor outlet, adjust the corresponding valve opening, and automatically perform ammonia injection control;

[0034] A model building module is used to obtain historical ammonia injection control data, build an ammonia injection control optimization model, optimize and adjust the ammonia injection control scheme according to real-time boiler coal quantity data, and respond to the ammonia injection control valve in advance;

[0035] The adjustment module is used to set the opening of the ammonia injection valve to inject ammonia based on the optimized ammonia injection control scheme, and to detect the NOx concentration value at the reactor outlet in real time to adjust the opening of the ammonia injection valve.

[0036] In a third aspect, the present invention provides an electronic device, comprising:

[0037] Memory and processor;

[0038] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads are implemented.

[0039] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention improves the NOx concentration measurement method at the reactor outlet, optimizes the ammonia injection control logic, increases the automatic input rate of the denitrification control system, improves the stability of NOx automatic control, reduces the ammonia usage and the risk of air preheater blockage caused by local overspray of ammonia, reduces the labor intensity of operators, and realizes automatic, intelligent, adjustable and controllable NOx concentration at the chimney outlet under different loads and meets emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0042] Figure 1 The figure is a schematic diagram of the overall process of a method for measuring the NOx concentration at a reactor outlet and controlling the amount of ammonia injection under different loads according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0046] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0047] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Reference Figure 1 , which is an embodiment of the present invention, provides a method for measuring NOx concentration at a reactor outlet and controlling ammonia injection amount under different loads, comprising:

[0050] S101, setting a NOx concentration sampling point at the reactor outlet of the denitration device to detect NOx concentration data at the reactor outlet;

[0051] S102, generating an ammonia injection control plan based on the NOx concentration data at the reactor outlet, adjusting the corresponding valve opening, and automatically performing ammonia injection control;

[0052] S103, obtaining historical ammonia injection control data, building an ammonia injection control optimization model, optimizing and adjusting the ammonia injection control scheme according to real-time boiler coal quantity data, and responding to the ammonia injection control valve in advance;

[0053] S104, based on the optimized ammonia injection control scheme, the ammonia injection valve opening is set to inject ammonia, and the NOx concentration value at the reactor outlet is detected in real time to adjust the ammonia injection valve opening.

[0054] Preferably, in step S101, a NOx concentration sampling point is set at the outlet of the reactor of the denitration device, and detecting the NOx concentration data at the outlet of the reactor includes:

[0055] A NOx concentration sampling point is set at the reactor outlet corresponding to each ammonia injection grid of the denitrification device. Each corresponding reactor outlet has a detection hole. The NOx concentration sampling point corresponds to the ammonia injection grid regulating valve one by one and is set at the same horizontal height along the width direction of the boiler.

[0056] The NOx concentration value, concentration distribution and changes at the reactor outlet of the NOx concentration sampling point are detected and recorded in real time to accurately reflect the NOx concentration value at the reactor outlet.

[0057] Specifically, the denitrification device is provided with 6 manual doors of the ammonia injection grid, which are arranged at the same horizontal height. Each corresponding reactor outlet is provided with a detection hole, and all detection holes for introducing the NOx concentration at the reactor outlet into the DCS control system are installed with concentration measuring points.

[0058] Preferably, in step S102, generating an ammonia injection control scheme includes:

[0059] Set a concentration threshold value and compare it with the concentration threshold value based on the real-time NOx concentration value;

[0060] If the NOx concentration value is greater than the concentration threshold, the opening of the ammonia injection valve is adjusted;

[0061] If the NOx concentration value is less than the concentration threshold, the opening of the ammonia injection valve is adjusted accordingly;

[0062] The concentration difference between the NOx concentration value and the concentration threshold is calculated, and the ammonia injection valve opening is controlled according to the ammonia injection valve opening value corresponding to the set concentration difference interval.

[0063] The concentration threshold of the reactor outlet corresponding to each ammonia injection grid electric adjustment door can be set to 45 mg / Nm 3 , concentration greater than 45mg / Nm 3 , the valve automatically opens wide, the concentration is less than 45mg / Nm 3 The control valve is automatically closed, and the concentration measuring points and control valve are arranged horizontally along the width of the boiler, one to one, without distinguishing the order of precedence.

[0064] Among them, the ammonia injection valve opening value corresponding to the set concentration difference range can be pre-set according to the actual application scenario.

[0065] Specifically, the reactor outlet concentration was set to 45 mg / Nm 3 When the reactor outlet concentration is greater than 45 mg / Nm 3 The corresponding valve is automatically opened slowly to increase the amount of ammonia sprayed. When the reactor outlet concentration is less than 45mg / Nm 3 The corresponding valve is automatically closed slowly to reduce the amount of ammonia sprayed, so as to maintain the reactor outlet concentration stable at 45mg / Nm 3 This process is a dynamic adjustment of the valve. When the reactor outlet concentration continues to increase to 45mg / Nm 3 , indicating that the ammonia injection amount of a single regulating valve cannot effectively reduce the NOx concentration at the outlet. At this time, the adjacent regulating valve opening can be automatically increased by 5%, and the original opening can be restored after a delay of 5 seconds to enhance the ammonia injection and reduce the NOx concentration.

[0066] It should be noted that the manual doors of the 6 ammonia injection grids have been replaced with electric adjustment doors, which can automatically adjust the valve opening according to the NOx concentration at the reactor outlet corresponding to each ammonia injection grid, so as to realize automatic adjustment of the ammonia injection amount along the width of the furnace. More ammonia is sprayed in areas with high NOx concentration, and less ammonia is sprayed in areas with low NOx concentration. NH3 reacts fully with NOx in the flue gas, and the NOx concentration at the reactor outlet is accurately controlled and adjusted.

[0067] Preferably, in step S103, historical ammonia injection control data are obtained, including: boiler coal quantity, reactor outlet NOx concentration value, and ammonia injection valve opening data, wherein the boiler coal quantity includes the total boiler coal quantity and the change in the total coal quantity, and the ammonia injection control data may also include boiler load, reactor temperature and pressure, and other operating parameters related to ammonia injection (such as air flow, fuel type, etc.).

[0068] Preferably, in step S103, constructing an ammonia injection control optimization model includes:

[0069] Perform data preprocessing on historical ammonia injection control data, including abnormal value, missing value, duplicate value processing, and data normalization;

[0070] The Pearson correlation coefficient was used to analyze and calculate the correlation between each feature in the ammonia injection control data and the NOx concentration and ammonia injection amount, and the importance of the features was evaluated;

[0071] The features in the ammonia injection control data are converted into numerical data, and the non-numerical data are converted into numerical data. An ammonia injection control optimization model is constructed through a machine learning algorithm, and the ammonia injection control optimization model is trained and evaluated.

[0072] Specifically, in data cleaning, outlier processing uses statistical methods (such as Z-score, IQR) to identify and remove outliers; missing value processing uses interpolation methods (such as linear interpolation, polynomial interpolation) or model-based methods to fill missing values; duplicate value processing is used to delete duplicate data records; data format unification ensures that the format of all data fields is consistent for subsequent processing.

[0073] Preferably, in step S103, model training and evaluation of the ammonia injection control optimization model includes:

[0074] The data set of historical ammonia injection control data is randomly divided into a training set and a data set in a ratio of 7:3, and the model is evaluated by k-fold (such as 5-fold or 10-fold) cross validation;

[0075] Obtain the optimal hyperparameters through grid search, and automatically adjust the parameters of the ammonia injection control optimization model through the Bayesian optimization algorithm;

[0076] The performance of the ammonia injection control optimization model was evaluated by the mean square error, which measures the average square difference between the model prediction and the actual value.

[0077] It should be noted that the denitrification control logic uses an advanced learning algorithm. During the operation of the system, data will be continuously collected and analyzed, including key parameters such as the total coal volume, the NOx concentration at the reactor outlet, and the opening of the ammonia injection valve. By learning the correlation and regularity between these data, the system can gradually optimize its control strategy and remember the optimal opening of the ammonia injection valve under different operating conditions.

[0078] Data storage and memory function: the system is equipped with an efficient data storage module for storing the learned control strategies and key parameters. When the coal quantity changes suddenly, it can quickly output the corresponding control strategy and automatically adjust the opening of the ammonia injection valve.

[0079] In practical applications, in order to ensure the accuracy and reliability of the denitrification system control logic, the following factors need to be considered:

[0080] Data quality: Ensure that the collected data is accurate, complete, and timely so that the system can learn the true control laws.

[0081] Algorithm optimization: Continuously learn and optimize algorithms to adapt to control requirements under different working conditions.

[0082] System stability: Ensure that the system remains stable during operation to avoid control failure due to malfunction or misoperation.

[0083] Manual intervention: Although the system has automatic and intelligent control functions, manual intervention and adjustment are still required in some special cases.

[0084] Specifically, the total coal volume is 30 t / h during normal operation, and the reactor outlet concentration is set to 45 mg / Nm 3 When the coal quantity suddenly drops to 20t / h, based on the consideration of advance adjustment, the ammonia injection valve is automatically opened by 10%. Because the reaction has a process, it is delayed and waited for 10s, and then adjusted automatically as normal.

[0085] It should be noted that the coal quantity suddenly changes during the operation of the boiler due to changes in the type of coal (for example, switching from high calorific value coal to low calorific value coal, or vice versa). Even if the load of the boiler remains unchanged, the total amount of coal required may also change. This sudden change in the amount of coal (i.e., "mutation") will affect the NOx concentration at the reactor outlet. Changes in NOx concentration and sudden changes in the amount of coal will cause changes in the combustion process, thereby affecting the amount of NOx generated. If the control system cannot be adjusted in time, the NOx concentration at the reactor outlet may exceed the set range of safe or economical operation. When the coal quantity suddenly changes, the present embodiment can quickly identify the current coal quantity and automatically adjust the ammonia injection valve to the corresponding opening.

[0086] Through this embodiment, the denitrification device can automatically adapt to the situation where the boiler burns coal of different calorific values ​​with the same load but different total coal volume. This adaptability not only improves the flexibility of the system, but also reduces the risk of manual intervention and misoperation, and realizes more intelligent and automated control adjustment, which helps to ensure that the NOx concentration at the reactor outlet can be effectively controlled under different operating conditions.

[0087] Preferably, in step S104, real-time detection of the NOx concentration value at the reactor outlet and adjustment of the ammonia injection valve opening include:

[0088] The real-time ammonia injection control data is input into the ammonia injection control optimization model. When the coal quantity of the boiler increases beyond the coal quantity threshold within the cycle threshold, the optimized ammonia injection control scheme is output and the opening of the ammonia injection valve is set.

[0089] The NOx concentration value at the reactor outlet is detected in real time, and the opening of the ammonia injection valve is adjusted according to the concentration difference between the current NOx concentration value and the concentration threshold.

[0090] It should be noted that after the optimized ammonia injection control scheme sets the valve opening, that is, after the ammonia injection valve quickly responds to the initially set opening, the present embodiment will also make fine adjustments based on the real-time feedback of the NOx concentration at the reactor outlet, aiming to further accurately control the NOx concentration to ensure that the emission concentration always remains within the set range, while avoiding excessive or insufficient ammonia injection to improve the denitrification efficiency and economy.

[0091] The present invention improves the NOx concentration measurement method at the reactor outlet, optimizes the ammonia injection control logic, increases the automatic input rate of the denitrification control system, improves the stability of NOx automatic control, reduces the amount of ammonia used and the risk of air preheater blockage caused by local overspray of ammonia, reduces the labor intensity of operators, and realizes automatic, intelligent, adjustable and controllable NOx concentration at the chimney outlet under different loads to meet emission standards.

[0092] The above is a schematic scheme of a method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed at different loads in this embodiment. It should be noted that the technical scheme of the NOx concentration measurement at the reactor outlet and the control system of the amount of ammonia sprayed at different loads and the technical scheme of the NOx concentration measurement at the reactor outlet and the control method of the amount of ammonia sprayed at different loads are of the same concept. The details not described in detail in the technical scheme of the NOx concentration measurement at the reactor outlet and the control system of the amount of ammonia sprayed at different loads in this embodiment can be referred to the description of the technical scheme of the NOx concentration measurement at the reactor outlet and the control method of the amount of ammonia sprayed at different loads.

[0093] In this embodiment, the reactor outlet NOx concentration measurement and ammonia injection amount control system under different loads include:

[0094] The sampling module is used to set a NOx concentration sampling point at the reactor outlet of the denitration device to detect the NOx concentration data at the reactor outlet;

[0095] The control module is used to generate an ammonia injection control plan based on the NOx concentration data at the reactor outlet, adjust the corresponding valve opening, and automatically perform ammonia injection control;

[0096] The model building module is used to obtain historical ammonia injection control data, build an ammonia injection control optimization model, optimize and adjust the ammonia injection control plan according to the real-time boiler coal quantity data, and respond to the ammonia injection control valve in advance;

[0097] The adjustment module is used to set the opening of the ammonia injection valve to inject ammonia based on the optimized ammonia injection control scheme, and to detect the NOx concentration value at the reactor outlet in real time to adjust the opening of the ammonia injection valve.

[0098] This embodiment also provides an electronic device suitable for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia injection under different loads, including:

[0099] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads as proposed in the above embodiment.

[0100] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads proposed in the above embodiment is implemented.

[0101] The storage medium proposed in this embodiment and the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads proposed in the above embodiment belong to the same inventive concept. The technical details not described in detail in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0102] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for measuring NOx concentration at a reactor outlet and controlling ammonia injection amount under different loads, characterized in that: include: A NOx concentration sampling point is set at the reactor outlet of the denitration device to detect the NOx concentration data at the reactor outlet; According to the NOx concentration data at the reactor outlet, an ammonia injection control scheme is generated, and the corresponding valve opening is adjusted to automatically perform ammonia injection control; Obtain historical ammonia injection control data, build an ammonia injection control optimization model, optimize and adjust the ammonia injection control plan according to real-time boiler coal quantity data, and respond to the ammonia injection control valve in advance; Based on the optimized ammonia injection control scheme, the ammonia injection valve opening is set to inject ammonia, and the NOx concentration value at the reactor outlet is detected in real time to adjust the ammonia injection valve opening.

2. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads according to claim 1, characterized in that: A NOx concentration sampling point is set at the reactor outlet of the denitrification device, and the NOx concentration data at the reactor outlet are detected, including: A NOx concentration sampling point is set at the reactor outlet corresponding to each ammonia injection grid of the denitration device. Each corresponding reactor outlet has a detection hole. The NOx concentration sampling point corresponds to the ammonia injection grid regulating valve one by one and is set at the same horizontal height along the width direction of the boiler; The NOx concentration value at the reactor outlet of the NOx concentration sampling point is detected and recorded in real time.

3. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads as claimed in claim 2, characterized in that: The generated ammonia injection control scheme includes: Setting a concentration threshold value, and comparing the real-time NOx concentration value with the concentration threshold value; If the NOx concentration value is greater than the concentration threshold, the opening of the ammonia injection valve is adjusted accordingly; If the NOx concentration value is less than the concentration threshold, the opening of the ammonia injection valve is adjusted accordingly; The concentration difference between the NOx concentration value and the concentration threshold is calculated, and the ammonia injection valve opening is controlled according to the ammonia injection valve opening value corresponding to the set concentration difference interval.

4. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads according to claim 1 or 3, characterized in that: The historical ammonia injection control data obtained include: boiler coal quantity, reactor outlet NOx concentration value, and ammonia injection valve opening data.

5. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads as claimed in claim 4, characterized in that: The construction of the ammonia injection control optimization model includes: Performing data preprocessing on the historical ammonia injection control data, wherein the data preprocessing includes processing abnormal values, missing values, and repeated values, and performing data normalization; The Pearson correlation coefficient was used to analyze and calculate the correlation between each feature in the ammonia injection control data and the NOx concentration and ammonia injection amount, and the importance of the features was evaluated; The features in the ammonia injection control data are converted into numerical values, an ammonia injection control optimization model is constructed through a machine learning algorithm, and the ammonia injection control optimization model is trained and evaluated.

6. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia injection under different loads as claimed in claim 5, characterized in that: Model training and evaluation of the ammonia injection control optimization model include: The data set of the historical ammonia injection control data is randomly divided into a training set and a data set in a ratio of 7:3, and the model is evaluated by k-fold cross validation; Obtaining optimal hyperparameters through grid search, and automatically adjusting the parameters of the ammonia injection control optimization model through a Bayesian optimization algorithm; The performance of the ammonia injection control optimization model was evaluated by mean square error.

7. The method for measuring the NOx concentration at the reactor outlet and controlling the amount of ammonia injection under different loads as claimed in claim 6, characterized in that: Real-time detection of the NOx concentration at the reactor outlet and adjustment of the ammonia injection valve opening include: The real-time ammonia injection control data is input into the ammonia injection control optimization model, and when the amount of coal in the boiler increases by more than the coal amount threshold within the cycle threshold, an optimized ammonia injection control scheme is output to set the opening of the ammonia injection valve; The NOx concentration value at the reactor outlet is detected in real time, and the opening of the ammonia injection valve is adjusted according to the concentration difference between the current NOx concentration value and the concentration threshold.

8. A system for measuring NOx concentration at the reactor outlet and controlling the amount of ammonia sprayed under different loads, characterized in that: include, The sampling module is used to set a NOx concentration sampling point at the reactor outlet of the denitration device to detect the NOx concentration data at the reactor outlet; A control module, used to generate an ammonia injection control scheme according to the NOx concentration data at the reactor outlet, adjust the corresponding valve opening, and automatically perform ammonia injection control; A model building module is used to obtain historical ammonia injection control data, build an ammonia injection control optimization model, optimize and adjust the ammonia injection control scheme according to real-time boiler coal quantity data, and respond to the ammonia injection control valve in advance; The adjustment module is used to set the opening of the ammonia injection valve to inject ammonia based on the optimized ammonia injection control scheme, and to detect the NOx concentration value at the reactor outlet in real time to adjust the opening of the ammonia injection valve.

9. An electronic device, characterized in that: include: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: It stores computer executable instructions, which, when executed by a processor, implement the steps of the method for measuring the NOx concentration at the reactor outlet and controlling the ammonia injection amount under different loads as described in any one of claims 1 to 7.

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