A method, system, and medium for composite agent dosing control in boiler in-furnace water treatment.

Abstract

This application provides a method, system, and medium for controlling the addition of compound chemicals in boiler water treatment. The method includes: acquiring boiler water parameter information; analyzing boiler water quality information based on the boiler water parameter information; analyzing boiler water quality information based on a DCS distributed control system; and outputting a real-time chemical addition control strategy; controlling the operating parameters of the chemical addition pump and the flow rate of the compound chemicals based on the chemical addition control strategy; acquiring the liquid level information of the chemical addition tank; generating compound chemicals replenishment information based on the liquid level drop information of the chemical addition tank; and replenishing the compound chemicals in the chemical addition tank based on the compound chemicals replenishment information. The method also analyzes the boiler water quality information through the DCS distributed control system according to the boiler water quality requirements to generate a dynamic chemical addition control strategy, accurately controlling the dosage of the compound chemicals, improving control accuracy, and simultaneously analyzing whether the compound chemicals in the chemical addition tank meet the requirements during the chemical addition process, thereby rapidly replenishing the compound chemicals.

Description

Technical Field

[0001] This application relates to the field of chemical dosing control technology, and more specifically, to a method, system, and medium for controlling the dosing of composite chemicals based on the in-boiler water treatment of a steam drum boiler. Background Technology

[0002] Steam boiler operation involves a continuous process of evaporation and concentration of boiler water. To ensure safe and efficient boiler operation, continuous water treatment within the boiler is necessary. This is typically achieved by adding agents with scale-inhibiting, scale-removing, and alkaline properties to the steam drum. Currently, the traditional practice is to add trisodium phosphate to the boiler steam drum. This method has been used in the boiler industry for nearly forty years. Its advantages include: low price of trisodium phosphate, water and steam quality indicators meeting operational requirements, and extensive experience in its use. Its disadvantages include: large boiler blowdown volume, significant energy waste, high phosphorus concentration emissions, and environmental impact.

[0003] In recent years, due to the demands for refined management, energy conservation, environmental protection, and coal saving and carbon reduction in the boiler industry, especially in areas with strict environmental requirements that restrict phosphorus emissions, the development of a new type of organic composite agent to replace traditional trisodium phosphate has become particularly necessary. Currently, some companies have conducted large-scale trials and functional improvements on the new agents developed for the boiler industry, achieving good application results. Unlike the simple chemical reaction of trisodium phosphate, the organic composite agent reacts with harmful ions in the boiler water through complexation and recombination, resulting in a high concentration ratio and reducing boiler blowdown rate to below 0.5%, significantly reducing boiler blowdown volume. Simultaneously, it exhibits a polyamine coating effect, forming a hydrophobic protective film on metal heat exchange surfaces, improving operational safety; the discharged water is phosphorus-free, making it environmentally friendly. The use of new composite organic agents to replace traditional trisodium phosphate has become a trend in boiler water treatment within the boiler industry.

[0004] However, controlling the dosage of novel organic compound agents is a problem encountered in the promotion of this new technology. Trisodium phosphate dosage control involves monitoring the phosphate concentration in boiler water using online instruments, combined with boiler steam and water parameters, and controlling the operation time of the dosing pump to determine the dosage. Currently, there are no corresponding online monitoring instruments or equipment for the main components of novel organic agents, making it impossible to control the dosage by controlling the concentration of the main organic components in the boiler water. Currently, the only way to control the operation of the dosing pump is by monitoring the changing trends of boiler steam and water parameters. Due to the long distance between the boiler drum, the online monitoring sampling point, and the dosing station, there is a significant lag in dosing, resulting in untimely and inaccurate dosage control, requiring manual adjustment based on experience.

[0005] In view of the above reasons, this invention provides a dosing control method based on organic composite agents for boiler in-furnace water treatment, solving the problem of controlling the dosage of novel organic agents. The organic composite agent has a strong complexing effect on harmful ions in boiler water, exhibits strong water quality stabilization and regulation functions, and when the pH and conductivity of the boiler water meet the requirements, the boiler steam indicators fully meet the requirements; that is, only the boiler water indicators need to be controlled, not the steam indicators. Boiler water and steam indicators are affected by multiple factors such as feedwater quality, boiler feedwater flow rate, chemical dosage, and blowdown volume. Among these, the change in boiler feedwater flow rate is the main factor affecting water and steam indicator changes. The chemical dosage and feedwater flow rate have a direct linear relationship, and the ratio of the composite agent dosage to the feedwater flow rate is a constant value determined by the characteristics of different composite agents. The dosage can be obtained through high-precision liquid level detection in the dosing tank.

[0006] This invention leverages the advantages of a power plant's DCS system, integrating online monitoring data of boiler water indicators, instantaneous feedwater flow rate, and dosing tank level, and incorporating logical algorithms within the DCS system. Changes in feedwater flow rate serve as the primary regulator for adjusting the dosing dosage, while fluctuations in boiler water indicators provide fine-tuning. It allows for accurate and timely dosing of organic compound chemicals based on boiler load changes and dynamic water quality variations (i.e., feedwater flow changes). Multiple operating modes are set according to boiler load variation ranges, with each range implementing the dosing dosage corresponding to the average load. The dosing dosage is adjusted by controlling the pump's operating time. Fluctuations in boiler water indicators serve as auxiliary fine-tuning factors for the dosing dosage. Summary of the Invention

[0007] The purpose of this application is to provide a method, system, and medium for controlling the addition of compound chemicals based on boiler water treatment in a steam drum boiler. According to the boiler water quality requirements, the boiler water quality information is analyzed by a DCS distributed control system to generate a dynamic chemical addition control strategy, which accurately controls the amount of compound chemicals added, improves control accuracy, and analyzes whether the amount of compound chemicals in the addition tank meets the requirements during the addition process, so as to quickly replenish the compound chemicals.

[0008] This application also provides a method for controlling the addition of composite reagents based on in-boiler water treatment in a steam drum boiler, including:

[0009] Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information;

[0010] Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time.

[0011] The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy;

[0012] Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent;

[0013] Based on the information on the drop in liquid level in the dosing tank, information on replenishing the compound agent is generated, and the compound agent in the dosing tank is replenished based on this information.

[0014] Optionally, in the composite agent dosing control method for boiler in-furnace water treatment described in this application embodiment, obtaining boiler water parameter information and analyzing boiler water quality information based on the boiler water parameter information specifically includes:

[0015] Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity, and boiler feedwater flow rate;

[0016] Water quality standard information is set based on the steam quality standards and blowdown requirements of steam drum boilers. The water quality standard information includes at least the standard pH value, standard conductivity and standard feedwater flow rate.

[0017] The pH value of the boiler water is compared with the standard pH value to obtain the pH deviation rate; the online conductivity of the boiler water is compared with the standard conductivity to obtain the conductivity deviation rate; the boiler feedwater flow rate is compared with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate.

[0018] Analysis of abnormal data in boiler water parameters based on pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate;

[0019] Based on the analysis of abnormal data, the boiler water quality information is evaluated according to the water quality evaluation rules to obtain boiler water quality information.

[0020] Optionally, in the composite chemical dosing control method for boiler in-furnace water treatment described in this application embodiment, the dosing control strategy is output in real time based on the analysis of boiler water quality information by a DCS distributed control system, specifically including:

[0021] The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit.

[0022] The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor;

[0023] Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform.

[0024] Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information;

[0025] The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

[0026] Optionally, in the composite agent dosing control method for boiler in-furnace water treatment described in this application embodiment, controlling the operating parameters of the dosing pump and the flow rate of the composite agent based on the dosing control strategy specifically includes:

[0027] Water quality standard information is set based on the steam and water quality standards and wastewater discharge requirements of steam drum boilers;

[0028] The boiler water quality information is compared with the water quality standard information to obtain the water quality difference value;

[0029] Based on matching corresponding dosing control strategies to water quality differences;

[0030] Dosing parameters are generated based on the dosing control strategy. The dosing parameters include the operating parameters of the dosing pump, the flow rate of the compound agent, and the total amount of the compound agent. The operating parameters of the dosing pump include the operating power, operating time, flow rate, and pressure of the dosing pump.

[0031] Obtain the current flow rate of the compound agent, compare the current flow rate with the set flow rate value, and obtain the flow rate difference;

[0032] Correction information is generated based on the flow difference, and the operating parameters of the dosing pump are adjusted according to the correction information.

[0033] Optionally, in the composite agent dosing control method based on boiler in-furnace water treatment described in this application embodiment, obtaining the liquid level information of the dosing tank and analyzing the liquid level drop status information of the dosing tank based on the flow rate of the composite agent specifically includes:

[0034] Analysis of compound agent flow rate per unit time based on dosing control strategy;

[0035] Set an analysis time window, which includes several time nodes, denoted as time node 1, time node 2, ..., time node N;

[0036] The liquid level information of the dosing tank at the first time node and the Mth time node are compared to obtain the liquid level difference, where M is a positive integer greater than 1 and less than N;

[0037] Information on the drop in liquid level in the dosing tank within a given time window is generated based on the liquid level difference.

[0038] Optionally, in the composite agent dosing control method based on boiler in-furnace water treatment described in this application embodiment, composite agent replenishment information is generated based on the liquid level drop information of the dosing tank, and the composite agent in the dosing tank is replenished based on the composite agent replenishment information, specifically including:

[0039] Analyze the rate of liquid level drop by acquiring information on the liquid level descent status of the dosing tank.

[0040] Obtain the volume and current liquid level of the dosing tank, and calculate the total amount of compound agent currently in the dosing tank based on the volume and current liquid level;

[0041] The usage time of the compound agent is calculated based on the rate of liquid level drop and the total amount of compound agent currently in the dosing tank.

[0042] The replenishment time points are set based on the usage time of the compound drug, and the compound drug is replenished accordingly.

[0043] The raw materials for the preparation of the composite agent include two or more combinations of complexing agents, corrosion inhibitors, dispersants, alkalizing agents, and defoamers.

[0044] Secondly, embodiments of this application provide a composite chemical dosing control system based on boiler drum water treatment. The system includes a memory and a processor. The memory includes a program for a composite chemical dosing control method based on boiler drum water treatment. When the program for the composite chemical dosing control method based on boiler drum water treatment is executed by the processor, it implements the following steps:

[0045] Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information;

[0046] Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time.

[0047] The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy;

[0048] Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent;

[0049] Based on the information on the drop in liquid level in the dosing tank, information on replenishing the compound agent is generated, and the compound agent in the dosing tank is replenished based on this information.

[0050] Optionally, in the composite chemical dosing control system for boiler in-furnace water treatment described in this application embodiment, acquiring boiler water parameter information and analyzing boiler water quality information based on the boiler water parameter information specifically includes:

[0051] Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity, and boiler feedwater flow rate;

[0052] Water quality standard information is set based on the steam quality standards and blowdown requirements of steam drum boilers. The water quality standard information includes at least the standard pH value, standard conductivity and standard feedwater flow rate.

[0053] The pH value of the boiler water is compared with the standard pH value to obtain the pH deviation rate;

[0054] The online conductivity of boiler water is compared with the standard conductivity to obtain the conductivity deviation rate;

[0055] The boiler feedwater flow rate is compared with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate;

[0056] Analysis of abnormal data in boiler water parameters based on pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate;

[0057] Based on the analysis of abnormal data, the boiler water quality information is evaluated according to the water quality evaluation rules to obtain boiler water quality information.

[0058] Optionally, in the composite chemical dosing control system based on boiler in-furnace water treatment described in this application embodiment, the boiler water quality information is analyzed based on the DCS distributed control system, and the dosing control strategy is output in real time, specifically including:

[0059] The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit.

[0060] The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor;

[0061] Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform.

[0062] Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information;

[0063] The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

[0064] Thirdly, embodiments of this application also provide a computer-readable storage medium, which includes a program for a composite agent dosing control method based on boiler in-furnace water treatment. When the program for the composite agent dosing control method based on boiler in-furnace water treatment is executed by a processor, it implements the steps of the composite agent dosing control method based on boiler in-furnace water treatment as described in any of the above claims.

[0065] As can be seen from the above, the composite agent dosing control method, system, and medium based on boiler water treatment in a steam drum boiler provided in this application acquires boiler water parameter information, analyzes boiler water quality information based on the boiler water parameter information, analyzes boiler water quality information based on the DCS distributed control system, and outputs a dosing control strategy in real time; controls the operating parameters of the dosing pump and the flow rate of the composite agent based on the dosing control strategy; acquires the liquid level information of the dosing tank; generates composite agent replenishment information based on the liquid level drop information of the dosing tank, and replenishes the composite agent in the dosing tank based on the composite agent replenishment information; analyzes the boiler water quality information through the DCS distributed control system according to the boiler water quality requirements, thereby generating a dynamic dosing control strategy, accurately controlling the amount of composite agent added, improving control accuracy, and simultaneously analyzing whether the composite agent in the dosing tank meets the requirements during the dosing process, thereby quickly replenishing the composite agent. Attached Figure Description

[0066] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 A flowchart of a composite agent dosing control method based on boiler in-furnace water treatment provided in this application embodiment;

[0068] Figure 2 A flowchart illustrating the boiler water quality information acquisition process of a composite agent dosing control method for boiler water treatment based on an embodiment of this application.

[0069] Figure 3 A block diagram of a composite chemical dosing control system based on boiler in-furnace water treatment provided in this application embodiment. Detailed Implementation

[0070] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0071] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0072] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating a composite agent dosing control method based on boiler in-furnace water treatment in some embodiments of this application. This composite agent dosing control method based on boiler in-furnace water treatment is used in a terminal device and includes the following steps:

[0073] S101, Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information;

[0074] S102 analyzes boiler water quality information based on the DCS distributed control system and outputs dosing control strategies in real time.

[0075] S103 controls the operating parameters of the dosing pump and the flow rate of the compound agent based on the dosing control strategy;

[0076] S104, Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent;

[0077] S105, Generate compound agent replenishment information based on the liquid level drop information of the dosing tank, and replenish the compound agent in the dosing tank based on the compound agent replenishment information.

[0078] It should be noted that this application utilizes a DCS distributed control system for real-time, timely, and automatic chemical dosing and precise control of boiler steam and water parameters, achieving energy conservation and emission reduction in the boiler blowdown system. It leverages existing operator stations and DCS communication without requiring any hardware modifications, making implementation quick and convenient. Furthermore, the communication method is implemented by requiring only the user to provide the system's Modbus address table. Since the existing operator stations and DCS system are on a local area network with a relatively small data volume (estimated to be less than 100 points), standard Modbus / TCP communication is prioritized, eliminating the need for OPC software. The application software monitors the DCS communication status; if communication is abnormal, control is transferred to the DCS.

[0079] Furthermore, the steam-water index of this application is stable, and the boiler blowdown rate can be reduced by more than 80%, from the usual 3%~5% to below 0.5%. This can significantly reduce the amount of chemicals used. For a boiler evaporation rate of 1 ton / hour, the amount of compound chemicals used is about 0.008~0.015 kg / h, which can also significantly save on chemical costs. The boiler water salt dissolving capacity is enhanced, and the boiler water concentration ratio is increased from 20~30 times when using trisodium phosphate to 200~300 times. This reduces the need for frequent manual operation of the fixed and continuous discharge valves, reduces the chance of valve failure, and significantly reduces the amount of boiler wastewater discharged, thereby significantly reducing the amount of demineralized water produced and saving corresponding costs.

[0080] Please refer to Figure 2 , Figure 2 This is a flowchart illustrating the boiler water quality information acquisition process of a composite reagent dosing control method for boiler water treatment in a steam drum boiler, as described in some embodiments of this application. According to embodiments of the present invention, acquiring boiler water parameter information and analyzing boiler water quality information based on this parameter information specifically includes:

[0081] S201, Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity and boiler feedwater flow rate;

[0082] S202, Based on the steam quality standards and blowdown requirements of the steam drum boiler, water quality standard information is set. The water quality standard information shall include at least the standard pH value, standard conductivity and standard feedwater flow rate.

[0083] S203, compare the pH value of the boiler water with the standard pH value to obtain the pH deviation rate; compare the online conductivity of the boiler water with the standard conductivity to obtain the conductivity deviation rate; compare the boiler feedwater flow rate with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate;

[0084] S204, based on the analysis of abnormal data of boiler water parameters using pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate;

[0085] S205, based on abnormal data analysis, boiler water quality information is evaluated according to water quality evaluation rules to obtain boiler water quality information.

[0086] It should be noted that by collecting real-time parameters such as the online pH value of the boiler water, the online conductivity of the boiler water, the boiler feedwater flow rate, the liquid level of the compound agent storage tank, and the dosing flow rate as comprehensive input signals, and through a dedicated computer logic algorithm, an output signal is generated to control the dosing pump, thereby achieving a precise and timely dosing operation.

[0087] Specifically, the actual dosage of the reagent in this application is approximately 0.01 kg / hour for a boiler evaporation rate of 1 ton / hour. That is to say, for a boiler evaporation rate of 100 tons / hour, the dosage of the reagent is approximately 1 kg per hour. The dosage of the reagent added to the boiler is calculated by estimating the drop in the liquid level of the dosing tank, thereby estimating the concentration of the reagent in the boiler water. At the same time, the reagent concentration has a corresponding relationship with the pH value range and conductivity range monitored by the control system.

[0088] According to an embodiment of the present invention, based on the analysis of boiler water quality information by a DCS distributed control system, a real-time chemical dosing control strategy is output, specifically including:

[0089] The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit.

[0090] The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor;

[0091] Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform.

[0092] Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information;

[0093] The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

[0094] It should be noted that the developed application software inputs evaluation indicators, including but not limited to boiler water pH value, conductivity, feedwater volume, steam output, and blowdown volume, into a historical database. The next step is to clean the data, refine it multiple times to form a logical framework, and then integrate it into the factory's existing DCS control system.

[0095] Specifically, the agencies responsible for administering the medication include:

[0096] Metering pump set: adopts variable frequency metering pump (such as plunger pump), DCS adjusts the frequency (0~50Hz) through 4-20mA signal, with an accuracy of ±1%, and starts as needed;

[0097] Chemical storage tank: Equipped with a liquid level sensor (ultrasonic or magnetic float), DCS monitors the remaining chemical level in real time and issues an early warning;

[0098] DCS adopts a multi-level hardware architecture, decomposing control functions into devices at different levels to avoid the single point of failure problem of centralized control.

[0099] The field control layer (bottom distributed core) includes:

[0100] Field controllers (Control Stations): Directly connected to sensors and actuators, responsible for local data acquisition, logic control, and closed-loop regulation (such as PID control). Each controller independently handles control tasks for a specific area or process, such as temperature and pressure control in a chemical reactor.

[0101] I / O modules: Connect to the controller to realize the input and output of analog quantities (such as temperature and flow rate) and digital quantities (such as switching signals), and support hot-swapping for easy maintenance;

[0102] Field instruments: These include sensors (such as temperature sensors and pressure transmitters) and actuators (such as control valves and motors), which are distributed in the production field and interact directly with the controlled object.

[0103] The operation monitoring layer includes;

[0104] Operator Station: Engineers and operators monitor the overall system status and issue operating commands through a graphical user interface (HMI), but do not directly participate in real-time control, thus avoiding the impact of human intervention on decentralized control.

[0105] Engineer Station: Used for system configuration, programming and maintenance. It can remotely download control programs to field controllers to achieve centralized configuration of distributed control logic.

[0106] Management includes;

[0107] Data server: Collects data from various controllers, stores and analyzes it to provide decision support for production management, but does not interfere with the real-time control process.

[0108] According to an embodiment of the present invention, controlling the operating parameters of the dosing pump and the flow rate of the compound agent based on a dosing control strategy specifically includes:

[0109] Water quality standard information is set based on the steam and water quality standards and wastewater discharge requirements of steam drum boilers;

[0110] The boiler water quality information is compared with the water quality standard information to obtain the water quality difference value;

[0111] Based on matching corresponding dosing control strategies to water quality differences;

[0112] Dosing parameters are generated based on the dosing control strategy. The dosing parameters include the operating parameters of the dosing pump, the flow rate of the compound agent, and the total amount of the compound agent. The operating parameters of the dosing pump include the operating power, operating time, flow rate, and pressure of the dosing pump.

[0113] Obtain the current flow rate of the compound agent, compare the current flow rate with the set flow rate value, and obtain the flow rate difference;

[0114] Correction information is generated based on the flow difference, and the operating parameters of the dosing pump are adjusted according to the correction information.

[0115] It should be noted that by analyzing water quality differences to match the optimal dosing control strategy, the dosing accuracy is improved. By analyzing the flow rate of compound agents, the operating parameters of the dosing pump are dynamically adjusted to ensure that the total dosing amount, dosing pressure, and dosing flow rate always meet the requirements.

[0116] Specifically, the steam and water quality standards for drum boilers are based on factors such as the boiler's specific parameters, operating conditions, and water quality characteristics. The following are the water quality indicators and their standard ranges:

[0117] pH value: Typically controlled between 9 and 10. A pH value that is too high or too low can corrode the metal materials of the boiler. A suitable pH value helps form a protective film on the metal surface, preventing corrosion.

[0118] Boiler water conductivity: Conductivity reflects the content of electrolytes in water. Generally, the conductivity is required to be less than 60 μS / cm to ensure the purity of the water and prevent corrosion and scaling problems caused by excessive electrolyte content.

[0119] Phosphate: For boilers treated with phosphate, the phosphate content is typically controlled between 2-6 mg / L. The role of phosphate is to form soluble complexes with calcium and magnesium ions in the water, preventing scale formation.

[0120] Based on the different water quality differences, corresponding dosing control strategies are matched:

[0121] Abnormal pH value: When the pH value is below the standard range, it indicates that the water quality is acidic. An appropriate amount of alkaline agent, such as sodium hydroxide or sodium carbonate, can be added to raise the pH value. If the pH value is above the standard range, the water quality is alkaline. An appropriate amount of acidic agent, such as phosphoric acid or sulfuric acid, can be added to adjust the pH. However, it is important to control the dosage to avoid excessive pH fluctuations.

[0122] High conductivity: High conductivity indicates an excessive electrolyte content in the water, which may require increased wastewater discharge and appropriate adjustment of the dosage. If the increased conductivity is due to an overdose of a certain agent, the dosage of that agent should be reduced. If it is caused by changes in the source water quality, further desalination measures may be necessary, such as adding ion exchange resin or reverse osmosis equipment.

[0123] Abnormal phosphate content: If the phosphate content is lower than the standard value, it may lead to scale formation, and the amount of phosphate added should be increased appropriately; if the phosphate content is too high, it will not only waste the reagent, but may also cause phosphate to hide. In this case, the amount of phosphate added should be reduced and the sewage discharge should be strengthened to reduce the phosphate content.

[0124] According to an embodiment of the present invention, obtaining the liquid level information of the dosing tank and analyzing the liquid level drop status information of the dosing tank based on the flow rate of the compound agent specifically includes:

[0125] Analysis of compound agent flow rate per unit time based on dosing control strategy;

[0126] Set an analysis time window, which includes several time nodes, denoted as time node 1, time node 2, ..., time node N;

[0127] The liquid level information of the dosing tank at the first time node and the Mth time node are compared to obtain the liquid level difference, where M is a positive integer greater than 1 and less than N;

[0128] Information on the drop in liquid level in the dosing tank within a given time window is generated based on the liquid level difference.

[0129] It should be noted that by analyzing the changes in liquid level at different time points, the state of liquid level decline can be accurately analyzed.

[0130] According to an embodiment of the present invention, compound agent replenishment information is generated based on the liquid level drop information of the dosing tank, and the compound agent in the dosing tank is replenished based on the compound agent replenishment information, specifically including:

[0131] Analyze the rate of liquid level drop by acquiring information on the liquid level descent status of the dosing tank.

[0132] Obtain the volume and current liquid level of the dosing tank, and calculate the total amount of compound agent currently in the dosing tank based on the volume and current liquid level;

[0133] The usage time of the compound agent is calculated based on the rate of liquid level drop and the total amount of compound agent currently in the dosing tank.

[0134] The replenishment time points are set based on the usage time of the compound drug, and the compound drug is replenished accordingly.

[0135] The raw materials for the compound agent include two or more combinations of complexing agents, corrosion inhibitors, dispersants, alkalizing agents, and defoamers. Unlike trisodium phosphate, which only has a single chemical reaction, the compound agent undergoes complexation and recombination reactions in boiler water, and there is absolutely no phosphate hiding phenomenon. The organic components have their own functions, and the components can complement and synergistically interact with each other. They can undergo complexation reactions with Ca2+, Mg2+, iron, copper, silicate ions, etc., and can solubilize silicon and disperse iron and copper, reducing the carryover of iron and copper impurities in steam, and there is no salt carryover phenomenon in steam.

[0136] It should be noted that the replenishment of the compound agent is to replenish the total amount of the compound agent. The compound agent is an odorless, colorless, non-toxic, alkaline liquid, which is made by compounding organic polyamines, polycarboxylate salts, chelating agents, alkalizing agents, defoamers and deionized water through a process. This compound agent does not contain any phosphorus element, so it will not have an adverse impact on the environment and can reduce the environmental protection pressure on production units.

[0137] The organic complex substances in the compound chemical regulator react with Ca2+, Mg2+ and other ions to destroy or prevent the formation of crystal buds, promote lattice distortion, and increase the salt dissolving capacity of boiler water. Even when the boiler water concentration reaches 200-300 times, the boiler water can still meet and exceed national standards, resulting in a significant reduction in wastewater discharge.

[0138] The composite agent contains polar amine groups and non-polar alkyl groups, forming a hydrophobic film on the metal surface. It has a polyamine coating function, which can effectively prevent corrosive media from corroding the metal and improve the safety of boiler operation.

[0139] To ensure the quality standards of steam and water in the boiler drum and meet the requirements for blowdown, the trisodium phosphate treatment method requires testing multiple indicators such as boiler water pH, conductivity, phosphate, and boiler feedwater flow rate. However, the composite agent treatment used in this invention only requires testing two indicators: boiler water pH and conductivity, to meet the requirements.

[0140] The use of compound agents reduces sewage discharge, simplifying the sewage discharge process and improving system reliability. Regular sewage discharge has been changed from once per shift to once every 5-7 days, reducing the frequency of operation and significantly decreasing the chance of valve failure. Continuous sewage discharge has been changed from the original opening of more than 30% to a constant minimum opening, avoiding the need to constantly adjust the valve opening.

[0141] In summary, this application, combined with the factory's existing DCS control system, enables timely and automatic chemical dosing and precise control of boiler steam and water parameters, thereby achieving energy conservation and emission reduction in the boiler blowdown system.

[0142] Utilizing existing operator stations and DCS communication, implementation is quick and convenient without any changes to the hardware structure.

[0143] Users only need to provide the Modbus address table required by the system. The existing operator stations and DCS system are on a local area network, and the data volume is small (estimated to be within 100 points), so standard Modbus / TCP communication is preferred, and OPC software does not need to be installed. The application software monitors the communication status of the DCS; if communication is abnormal, control is switched to the DCS. To ensure boiler control and operational safety, data is not transmitted to the cloud platform.

[0144] Even in the event of abnormal operating conditions such as power outages, the DCS control system will not affect the safe control of the boiler.

[0145] DCS control can reduce or eliminate human error, ensuring the safe and stable operation of the boiler.

[0146] To better understand this invention, the dosing scheme will be further explained.

[0147] Automatic control operates under the following conditions:

[0148] 1. The boiler and the chemical dosing pump are controlled on a one-to-one basis; there are three independent control units for the three boilers.

[0149] 2. Each dosing pump should be run once per hour, and the flow rate should be calibrated according to this method (generally, it should be run more than 12 times).

[0150] 3. The continuous blowdown of each boiler needs to be manually adjusted to a slightly open state, and the blowdown should be performed once every 3 to 5 days. The appropriate degree of slight opening of the continuous blowdown valve should be based on whether the boiler water and other indicators can meet the requirements and a steady-state balance should be established.

[0151] 4. Theoretical dosage: 0.01 kg per ton / hour of boiler feedwater;

[0152] 5. Parameters for a single dosing tank:

[0153] The dosing tank is 1 cubic meter in size and 1000 mm in diameter, excluding the tank head section.

[0154] Automatic operation scheme:

[0155] Input the instantaneous boiler feedwater variable: instantaneous boiler feedwater rate t / h (0000.0);

[0156] Control parameters:

[0157] Dosing time per hour (s);

[0158] Time Mode:

[0159] Each boiler can be set with an hourly operating time (s) and an interval time (s); the dosage can be manually adjusted, which is suitable for boilers operating under consistently stable load conditions (fluctuation range 85%~100%).

[0160] Load operation mode:

[0161] Note: The operation mode is based on a fixed continuous blowdown opening. When the boiler water parameters and blowdown volume need to be adjusted, the dosing time must be adjusted accordingly.

[0162] The flow rate of the chemical dosing pump for Boiler No. 1 was calibrated, and the continuous blowdown opening was kept constant under the current boiler feedwater quality conditions and various indicator parameters, resulting in the range of variation for chemical dosing time.

[0163] When the boiler feedwater flow rate fluctuates, the hourly dosing time and the dosage change accordingly. Different dosing times are implemented based on the percentage of boiler load; at the same time, the pH and conductivity limits of the boiler water are controlled (the boiler's rated load is 150 t / h).

[0164] Procedure for boiler rated load greater than 100%: When the average boiler feedwater flow rate in the previous hour is greater than 150t / h and the boiler rated load is ≥100%, the hourly chemical dosing time is 94s.

[0165] 100%~86% Boiler Rated Load Program: The average boiler feedwater rate in the previous hour is 130-150t / h. When 100%>86% of the boiler rated load is implemented, the hourly chemical dosing time is 84 seconds.

[0166] 86%~73% Boiler Rated Load Program: The average boiler feedwater rate in the previous hour is 110-130t / h. When 85% > Boiler Rated Load ≥ 73%, the hourly chemical dosing time is 78 seconds.

[0167] 73%~60% Boiler Rated Load Program: The average boiler feedwater rate in the previous hour is 90-110 t / h. When 73% > Boiler Rated Load ≥ 60%, the hourly chemical dosing time is 68 s.

[0168] Boiler rated load program (60%~53%): If the average boiler feedwater rate in the previous hour is 80-90 t / h, and the boiler rated load is 60% > 53%, the hourly chemical dosing time is 64 s.

[0169] 53%~46% Boiler Rated Load Program: The average boiler feedwater rate in the previous hour was 70-80t / h. When 53% > Boiler Rated Load ≥ 46%, the hourly chemical dosing time is 58 seconds.

[0170] 46%~40% Boiler Rated Load Program: The average boiler feedwater rate in the previous hour was 60-70t / h, 46% > Boiler Rated Load ≥ 40%, and the hourly chemical dosing time was 48s.

[0171] 40%~20% of boiler rated load: The average boiler feedwater rate in the previous hour was 30-60t / h. If 40% > boiler rated load ≥ 20%, the hourly chemical dosing time is 38s.

[0172] 20%~0% Boiler Rated Load: If the average boiler feedwater flow rate in the previous hour is less than 30t / h, and 20% > Boiler Rated Load ≥ 0%, stop adding chemicals. Shut down the boiler at rated load.

[0173] When executing the above procedure,

[0174] First, determine if the average conductivity of the boiler water in the hour preceding the event is greater than 40 μS / cm. If so, halve the dosing time. Continue this process until the average conductivity of the boiler water in the hour preceding the event is less than 33 μS / cm, then resume the normal dosing time.

[0175] Second judgment: If the average pH of the boiler water in the hour before the occurrence is less than 9.2, the dosing time will be increased by 50%; until the average pH of the boiler water in the hour before the occurrence is greater than 9.3, the normal dosing time will be restored.

[0176] Third judgment: If the average pH of the boiler water is ≥9.6 in the hour prior to the occurrence, stop adding chemicals for this cycle.

[0177] Please refer to Figure 3 , Figure 3 This is a block diagram of a composite chemical dosing control system based on in-furnace water treatment in a steam drum boiler, as described in some embodiments of this application. Secondly, embodiments of this application provide a composite chemical dosing control system based on in-furnace water treatment in a steam drum boiler. The system includes a memory and a processor. The memory includes a program for a composite chemical dosing control method based on in-furnace water treatment in a steam drum boiler. When the processor executes the program for the composite chemical dosing control method based on in-furnace water treatment in a steam drum boiler, it implements the following steps:

[0178] Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information;

[0179] Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time.

[0180] The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy;

[0181] Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent;

[0182] Based on the information on the drop in liquid level in the dosing tank, information on replenishing the compound agent is generated, and the compound agent in the dosing tank is replenished based on this information.

[0183] It should be noted that this application utilizes a DCS distributed control system for real-time, timely, and automatic chemical dosing and precise control of boiler steam and water parameters, achieving energy conservation and emission reduction in the boiler blowdown system. It leverages existing operator stations and DCS communication without requiring any hardware modifications, making implementation quick and convenient. Furthermore, the communication method is implemented by requiring only the user to provide the system's Modbus address table. Since the existing operator stations and DCS system are on a local area network with a relatively small data volume (estimated to be less than 100 points), standard Modbus / TCP communication is prioritized, eliminating the need for OPC software. The application software monitors the DCS communication status; if communication is abnormal, control is transferred to the DCS.

[0184] According to an embodiment of the present invention, obtaining boiler water parameter information and analyzing boiler water quality information based on the boiler water parameter information specifically includes:

[0185] Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity, and boiler feedwater flow rate;

[0186] Water quality standard information is set based on the steam quality standards and blowdown requirements of steam drum boilers. The water quality standard information should include at least the standard pH value, standard conductivity and standard feedwater flow rate.

[0187] The pH value of the boiler water is compared with the standard pH value to obtain the pH deviation rate;

[0188] The online conductivity of boiler water is compared with the standard conductivity to obtain the conductivity deviation rate;

[0189] The boiler feedwater flow rate is compared with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate;

[0190] Analysis of abnormal data in boiler water parameters based on pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate;

[0191] Based on the analysis of abnormal data, the boiler water quality information is evaluated according to the water quality evaluation rules to obtain boiler water quality information.

[0192] It should be noted that by collecting real-time parameters such as the online pH value of the boiler water, the online conductivity of the boiler water, the boiler feedwater flow rate, the liquid level of the compound agent storage tank, and the dosing flow rate as comprehensive input signals, and through a dedicated computer logic algorithm, an output signal is generated to control the dosing pump, thereby achieving a precise and timely dosing operation.

[0193] According to an embodiment of the present invention, based on the analysis of boiler water quality information by a DCS distributed control system, a real-time chemical dosing control strategy is output, specifically including:

[0194] The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit.

[0195] The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor;

[0196] Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform.

[0197] Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information;

[0198] The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

[0199] It should be noted that the developed application software inputs evaluation indicators, including but not limited to boiler water pH value, conductivity, feedwater volume, steam output, and blowdown volume, into a historical database. The next step is to clean the data, refine it multiple times to form a logical framework, and then integrate it into the factory's existing DCS control system.

[0200] Specifically, the agencies responsible for administering the medication include:

[0201] Metering pump set: adopts variable frequency metering pump (such as plunger pump), DCS adjusts the frequency (0~50Hz) through 4-20mA signal, with an accuracy of ±1%, and starts as needed;

[0202] Chemical storage tank: Equipped with a liquid level sensor (ultrasonic or magnetic float), DCS monitors the remaining chemical level in real time and issues an early warning;

[0203] DCS adopts a multi-level hardware architecture, decomposing control functions into devices at different levels to avoid the single point of failure problem of centralized control.

[0204] The field control layer (bottom distributed core) includes:

[0205] Field controllers (Control Stations): Directly connected to sensors and actuators, responsible for local data acquisition, logic control, and closed-loop regulation (such as PID control). Each controller independently handles control tasks for a specific area or process, such as temperature and pressure control in a chemical reactor.

[0206] I / O modules: Connect to the controller to realize the input and output of analog quantities (such as temperature and flow rate) and digital quantities (such as switching signals), and support hot-swapping for easy maintenance;

[0207] Field instruments: These include sensors (such as temperature sensors and pressure transmitters) and actuators (such as control valves and motors), which are distributed in the production field and interact directly with the controlled object.

[0208] The operation monitoring layer includes;

[0209] Operator Station: Engineers and operators monitor the overall system status and issue operating commands through a graphical user interface (HMI), but do not directly participate in real-time control, thus avoiding the impact of human intervention on decentralized control.

[0210] Engineer Station: Used for system configuration, programming and maintenance. It can remotely download control programs to field controllers to achieve centralized configuration of distributed control logic.

[0211] Management includes;

[0212] Data server: Collects data from various controllers, stores and analyzes it to provide decision support for production management, but does not interfere with the real-time control process.

[0213] According to an embodiment of the present invention, controlling the operating parameters of the dosing pump and the flow rate of the compound agent based on a dosing control strategy specifically includes:

[0214] Water quality standard information is set based on the steam and water quality standards and wastewater discharge requirements of steam drum boilers;

[0215] The boiler water quality information is compared with the water quality standard information to obtain the water quality difference value;

[0216] Based on matching corresponding dosing control strategies to water quality differences;

[0217] Dosing parameters are generated based on the dosing control strategy. The dosing parameters include the operating parameters of the dosing pump, the flow rate of the compound agent, and the total amount of the compound agent. The operating parameters of the dosing pump include the operating power, operating time, flow rate, and pressure of the dosing pump.

[0218] Obtain the current flow rate of the compound agent, compare the current flow rate with the set flow rate value, and obtain the flow rate difference;

[0219] Correction information is generated based on the flow difference, and the operating parameters of the dosing pump are adjusted according to the correction information.

[0220] It should be noted that by analyzing water quality differences to match the optimal dosing control strategy, the dosing accuracy is improved. By analyzing the flow rate of compound agents, the operating parameters of the dosing pump are dynamically adjusted to ensure that the total dosing amount, dosing pressure, and dosing flow rate always meet the requirements.

[0221] According to an embodiment of the present invention, obtaining the liquid level information of the dosing tank and analyzing the liquid level drop status information of the dosing tank based on the flow rate of the compound agent specifically includes:

[0222] Analysis of compound agent flow rate per unit time based on dosing control strategy;

[0223] Set an analysis time window, which includes several time nodes, denoted as time node 1, time node 2, ..., time node N;

[0224] The liquid level information of the dosing tank at the first time node and the Mth time node are compared to obtain the liquid level difference, where M is a positive integer greater than 1 and less than N;

[0225] Information on the drop in liquid level in the dosing tank within a given time window is generated based on the liquid level difference.

[0226] It should be noted that by analyzing the changes in liquid level at different time points, the state of liquid level decline can be accurately analyzed.

[0227] According to an embodiment of the present invention, compound agent replenishment information is generated based on the liquid level drop information of the dosing tank, and the compound agent in the dosing tank is replenished based on the compound agent replenishment information, specifically including:

[0228] Analyze the rate of liquid level drop by acquiring information on the liquid level descent status of the dosing tank.

[0229] Obtain the volume and current liquid level of the dosing tank, and calculate the total amount of compound agent currently in the dosing tank based on the volume and current liquid level;

[0230] The usage time of the compound agent is calculated based on the rate of liquid level drop and the total amount of compound agent currently in the dosing tank.

[0231] The replenishment time points are set based on the usage time of the compound drug, and the compound drug is replenished accordingly.

[0232] The raw materials for making compound agents include two or more combinations of complexing agents, corrosion inhibitors, dispersants, alkalizing agents, and defoamers.

[0233] It should be noted that the compound agent is an odorless, colorless, non-toxic, alkaline liquid, made from organic polyamines, polycarboxylate salts, chelating agents, alkalizing agents, defoamers, and deionized water through a complex process. This compound agent does not contain any phosphorus, therefore it will not have any adverse effects on the environment and can reduce the environmental protection pressure on production units.

[0234] The organic complex substances in the compound chemical regulator react with Ca2+, Mg2+ and other ions to destroy or prevent the formation of crystal buds, promote lattice distortion, and increase the salt dissolving capacity of boiler water. Even when the boiler water concentration reaches 200-300 times, the boiler water can still meet and exceed national standards, resulting in a significant reduction in wastewater discharge.

[0235] The composite agent contains polar amine groups and non-polar alkyl groups, forming a hydrophobic film on the metal surface. It has a polyamine coating function, which can effectively prevent corrosive media from corroding the metal and improve the safety of boiler operation.

[0236] To ensure the quality standards of steam and water in the boiler drum and meet the requirements for blowdown, the trisodium phosphate treatment method requires testing multiple indicators such as the pH value, conductivity, phosphate content, and boiler feedwater flow rate of the boiler water. However, the composite agent treatment used in this invention only requires testing two indicators, the pH value and conductivity of the boiler water, to meet the requirements.

[0237] The use of compound agents reduces sewage discharge, simplifying the sewage discharge process and improving system reliability. Regular sewage discharge has been changed from once per shift to once every 5-7 days, reducing the frequency of operation and significantly decreasing the chance of valve failure. Continuous sewage discharge has been changed from the original opening of more than 30% to a constant minimum opening, avoiding the need to constantly adjust the valve opening.

[0238] A third aspect of the present invention provides a computer-readable storage medium including a program for a compound chemical dosing control method based on boiler water treatment in a steam drum boiler. When the program is executed by a processor, it implements the steps of the compound chemical dosing control method based on boiler water treatment in a steam drum boiler as described above.

[0239] This invention discloses a method, system, and medium for controlling the addition of compound chemicals in boiler water treatment. The method involves acquiring boiler water parameter information, analyzing boiler water quality information based on these parameters, and using a DCS (Distributed Control System) to analyze the boiler water quality information and output a real-time chemical addition control strategy. This strategy controls the operating parameters of the dosing pump and the flow rate of the compound chemicals. It also acquires the liquid level information of the dosing tank, generates compound chemicals replenishment information based on the tank's liquid level drop, and replenishes the compound chemicals in the tank accordingly. Furthermore, the DCS analyzes the boiler water quality information according to the boiler water quality requirements to generate a dynamic chemical addition control strategy, precisely controlling the amount of compound chemicals added, improving control accuracy. Simultaneously, the method analyzes whether the amount of compound chemicals in the tank meets the requirements during the addition process, allowing for rapid replenishment of the compound chemicals.

[0240] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0241] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0242] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0243] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0244] Alternatively, if the integrated units of the present invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

Claims

1. A method for controlling the addition of composite reagents based on in-boiler water treatment in a steam drum boiler, characterized in that, include: Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information; Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time. The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy; Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent; Based on the information on the drop in liquid level in the dosing tank, information on replenishing the compound agent is generated, and the compound agent in the dosing tank is replenished based on the information on replenishing the compound agent. Among them, the flow analysis of the compound reagent based on the liquid level drop information in the dosing tank specifically includes: Analysis of compound agent flow rate per unit time based on dosing control strategy; Set an analysis time window, which includes several time nodes, denoted as time node 1, time node 2, ..., time node N; The liquid level information of the dosing tank at the first time node and the Mth time node are compared to obtain the liquid level difference, where M is a positive integer greater than 1 and less than N; Based on the liquid level difference, analyze the liquid level drop status information of the dosing tank within the analysis time window; Specifically, the process involves generating compound agent replenishment information based on the drop in the dosing tank level, and then replenishing the compound agent in the dosing tank based on this information. This includes: Analyze the rate of liquid level drop by acquiring information on the liquid level descent status of the dosing tank. Obtain the volume and current liquid level of the dosing tank, and calculate the total amount of compound agent currently in the dosing tank based on the volume and current liquid level; The usage time of the compound agent is calculated based on the rate of liquid level drop and the total amount of compound agent currently in the dosing tank. The replenishment time points are set based on the usage time of the compound agent, and the compound agent is replenished accordingly; The raw materials for the preparation of the composite agent include two or more combinations of complexing agents, corrosion inhibitors, dispersants, alkalizing agents, and defoamers.

2. The composite reagent dosing control method based on boiler in-furnace water treatment according to claim 1, characterized in that, Obtain boiler water parameter information and analyze boiler water quality information based on the boiler water parameter information, specifically including: Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity, and boiler feedwater flow rate; Water quality standard information is set based on the steam quality standards and blowdown requirements of steam drum boilers. The water quality standard information includes at least the standard pH value, standard conductivity and standard feedwater flow rate. The pH value of the boiler water is compared with the standard pH value to obtain the pH deviation rate; the online conductivity of the boiler water is compared with the standard conductivity to obtain the conductivity deviation rate; the boiler feedwater flow rate is compared with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate. Analysis of abnormal data in boiler water parameters based on pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate; Based on the analysis of abnormal data, the boiler water quality information is evaluated according to the water quality evaluation rules to obtain boiler water quality information.

3. The composite reagent dosing control method based on boiler in-furnace water treatment according to claim 2, characterized in that, Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time, specifically including: The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit. The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor; Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform. Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information; The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

4. The composite reagent dosing control method based on boiler in-furnace water treatment according to claim 3, characterized in that, The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy, specifically including: Water quality standard information is set based on the steam and water quality standards and wastewater discharge requirements of steam drum boilers; The boiler water quality information is compared with the water quality standard information to obtain the water quality difference value; Based on matching corresponding dosing control strategies to water quality differences; Dosing parameters are generated based on the dosing control strategy. The dosing parameters include the operating parameters of the dosing pump, the flow rate of the compound agent, and the total amount of the compound agent. The operating parameters of the dosing pump include the operating power, operating time, flow rate, and pressure of the dosing pump. Obtain the current flow rate of the compound agent, compare the current flow rate with the set flow rate value, and obtain the flow rate difference; Correction information is generated based on the flow difference, and the operating parameters of the dosing pump are adjusted according to the correction information.

5. A composite reagent dosing control system based on in-boiler water treatment in a steam drum boiler, characterized in that, The system includes a memory and a processor. The memory contains a program for a compound chemical dosing control method based on boiler water treatment in a steam drum boiler. When the processor executes the program for the compound chemical dosing control method based on boiler water treatment in a steam drum boiler, it performs the following steps: Obtain boiler water parameter information and analyze boiler water quality information based on boiler water parameter information; Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time. The operating parameters of the dosing pump and the flow rate of the compound agent are controlled based on the dosing control strategy; Obtain the liquid level information of the dosing tank and analyze the liquid level drop status information of the dosing tank based on the flow rate of the compound agent; Based on the information on the drop in liquid level in the dosing tank, information on replenishing the compound agent is generated, and the compound agent in the dosing tank is replenished based on the information on replenishing the compound agent. Among them, the flow analysis of the compound reagent based on the liquid level drop information in the dosing tank specifically includes: Analysis of compound agent flow rate per unit time based on dosing control strategy; Set an analysis time window, which includes several time nodes, denoted as time node 1, time node 2, ..., time node N; The liquid level information of the dosing tank at the first time node and the Mth time node are compared to obtain the liquid level difference, where M is a positive integer greater than 1 and less than N; Based on the liquid level difference, analyze the liquid level drop status information of the dosing tank within the analysis time window; Specifically, the process involves generating compound agent replenishment information based on the drop in the dosing tank level, and then replenishing the compound agent in the dosing tank based on this information. This includes: Analyze the rate of liquid level drop by acquiring information on the liquid level descent status of the dosing tank. Obtain the volume and current liquid level of the dosing tank, and calculate the total amount of compound agent currently in the dosing tank based on the volume and current liquid level; The usage time of the compound agent is calculated based on the rate of liquid level drop and the total amount of compound agent currently in the dosing tank. The replenishment time points are set based on the usage time of the compound agent, and the compound agent is replenished accordingly; The raw materials for the preparation of the composite agent include two or more combinations of complexing agents, corrosion inhibitors, dispersants, alkalizing agents, and defoamers.

6. The composite reagent dosing control system based on boiler in-furnace water treatment according to claim 5, characterized in that, Obtain boiler water parameter information and analyze boiler water quality information based on the boiler water parameter information, specifically including: Obtain boiler water parameter information, including boiler water pH value, boiler water online conductivity, and boiler feedwater flow rate; Water quality standard information is set based on the steam quality standards and blowdown requirements of steam drum boilers. The water quality standard information includes at least the standard pH value, standard conductivity and standard feedwater flow rate. The pH value of the boiler water is compared with the standard pH value to obtain the pH deviation rate; The online conductivity of boiler water is compared with the standard conductivity to obtain the conductivity deviation rate; The boiler feedwater flow rate is compared with the standard feedwater flow rate to obtain the feedwater flow rate deviation rate; Analysis of abnormal data in boiler water parameters based on pH deviation rate, conductivity deviation rate and feedwater flow rate deviation rate; Based on the analysis of abnormal data, the boiler water quality information is evaluated according to the water quality evaluation rules to obtain boiler water quality information.

7. The composite reagent dosing control system based on boiler in-furnace water treatment according to claim 6, characterized in that, Based on the DCS distributed control system, boiler water quality information is analyzed, and dosing control strategies are output in real time, specifically including: The DCS distributed control system includes an online detection terminal, a data acquisition platform, and a dosing execution unit. The online detection terminal and data acquisition platform include a frequency converter, a level gauge, a conductivity meter, a pH meter, and a flow sensor; Data such as boiler water pH, conductivity, feedwater volume, steam output, and blowdown volume are acquired through a data acquisition platform. Based on the online detection terminal, the boiler water pH value, conductivity, feedwater flow rate, steam output, and blowdown flow rate are detected and analyzed to analyze boiler water quality information; The corresponding chemical dosing control strategy is matched based on the boiler water quality information.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a program for a compound chemical dosing control method based on boiler in-furnace water treatment. When the program is executed by a processor, it implements the steps of the compound chemical dosing control method based on boiler in-furnace water treatment as described in any one of claims 1 to 4.

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