A method for fast load change economic safety optimization control of a coal mill group

Abstract

The application provides a kind of quick variable load under coal mill group economic safety optimization control method, it is related to coal-fired generating unit operation control technical field.The method comprises: obtaining the operation associated data of the coal-fired generating unit to be controlled in target variable load period;Determine the load change demand information, the output boundary information of each coal mill under corresponding coal quality and target pulverizing demand information;Generate a plurality of candidate control schemes including coal mill operation combination information and coal quantity distribution information;Determine the target control scheme according to the pulverizing economic evaluation information, the boiler safety evaluation information and environmental protection evaluation information, and generate coal mill group control instruction.Through the method provided in the application, the matching of coal mill operation mode and quick variable load condition can be improved, and the pulverizing economy is mainly considered, and the boiler safety and environmental protection constraints are considered.

Description

Technical Field

[0001] This application belongs to the field of coal-fired power generation unit operation control technology, and in particular relates to an economic and safety optimization control method for a coal mill group under rapid load changes. Background Technology

[0002] As the operation of coal-fired power generating units gradually shifts from traditional stable load operation to flexible peak shaving, rapid response, and wide load range operation, boiler combustion and pulverizing systems face more complex operational requirements. The coal mill, as a crucial piece of equipment in the coal-fired boiler pulverizing system, affects the continuity of pulverized coal supply, boiler combustion stability, pulverizing system energy consumption, and unit operational safety. Maintaining the pulverizing system's compatibility with the boiler's operational needs under conditions of frequent load changes has become a critical aspect of coal-fired power generating unit operation control.

[0003] In related technologies, the operation and control of coal mills in power plant boilers typically rely on operator experience, pre-set operating procedures, or start-up and shutdown adjustments based on current operating parameters to meet the pulverized coal supply required for boiler combustion. This approach can meet basic control needs when load changes are relatively gradual or operating conditions are relatively stable. However, under conditions of rapid load changes and frequent adjustments to operating boundaries, problems such as untimely adjustments to coal mill operating modes, inadequate combination of operating equipment, and insufficient matching between coal distribution and actual boiler demand can easily arise. This can lead to increased energy consumption in the pulverizing system, equipment operation deviating from optimal ranges, frequent start-up and shutdown operations of the coal mill, and even problems such as coal blockage, vibration, overheating, combustion fluctuations, abnormal heating surface temperatures, and increased difficulty in controlling pollutant emissions, affecting the unit's economic efficiency and safe and stable operation.

[0004] Therefore, in the operation and control of power plant boiler pulverizing systems under rapid load changes, frequent load changes, lagging matching of coal mill operation modes, and the difficulty in balancing economic operation and safety management have become urgent problems to be solved. Summary of the Invention

[0005] This application provides a method for optimizing the economic and safety control of a coal mill group under rapid load changes. It aims to address the technical problems of existing coal-fired units where, under rapid load changes, the start-up and shutdown of coal mills and the adjustment of coal feed rate rely on experience or fixed rules, easily leading to lag in matching coal mill operating modes, increased energy consumption in the pulverizing system, and difficulty in simultaneously ensuring the safe and stable operation of the boiler.

[0006] Firstly, this application provides a method for optimizing the economic and safety control of a coal mill group under rapid load changes, the method comprising: The operation correlation data of the coal-fired power unit to be controlled during the target load change period is obtained. The operation correlation data includes the load curve data and unit operation data of the coal-fired power unit to be controlled, as well as the operation status data and coal quality data of each coal mill. Based on the load curve data and the unit operation data, determine the load change demand information corresponding to the target load change period; Based on the operating status data and coal quality data of each coal mill, the output boundary information of each coal mill under the corresponding coal quality is determined. The output boundary information includes maximum output information and economic output information. Based on the load change demand information, the coal quality data of each of the coal mills and the current coal feed rate, the target pulverizing demand information corresponding to the target load change period is determined; Based on the target pulverizing demand information and the output boundary information of each of the coal mills, multiple candidate control schemes are generated. The candidate control schemes include coal mill operation combination information and coal quantity allocation information corresponding to the coal mill operation combination information. Based on the pulverizing economic evaluation information, boiler safety evaluation information and environmental evaluation information corresponding to each of the candidate control schemes, a target control scheme is determined from the multiple candidate control schemes; Based on the target control scheme, a coal mill group control command is generated, which includes a coal feed rate adjustment command for each coal mill; and, when the target control scheme includes changes in the coal mill operating combination, the coal mill group control command also includes a coal mill start-stop control command.

[0007] In one possible design, based on the load curve data and the unit operation data, the load change demand information corresponding to the target load change period is determined, including: Based on the load curve data, determine the current load information and target load information of the coal-fired unit to be controlled during the target load change period; Based on the current load information and the target load information, determine the load change direction and load change amount corresponding to the target load change period; Based on the unit operation data, the direction of load change, and the amount of load change, the load change demand information is determined, which includes load increase demand information or load decrease demand information.

[0008] In one possible design, determining the output boundary information of each coal mill under the corresponding coal quality based on the operating status data and coal quality data of each mill includes: Based on the operating status data of each coal mill, extract the equipment operating characteristic information corresponding to each coal mill; Based on the coal quality data of each of the coal mills, determine the coal quality characteristic information corresponding to each of the coal mills; Based on the equipment operation characteristic information and coal quality characteristic information corresponding to each of the coal mills, determine the output analysis information corresponding to each of the coal mills; Based on the output analysis information of each coal mill, the output boundary information of each coal mill under the corresponding coal quality is determined.

[0009] In one possible design, based on the output analysis information corresponding to each of the coal mills, the maximum output information of each coal mill under the corresponding coal quality is determined, including: Based on the equipment operation characteristic information corresponding to each of the coal mills, the operation constraint characteristic information corresponding to each of the coal mills is determined. The operation constraint characteristic information includes at least one of the following: coal mill differential pressure characteristic, coal mill inlet and outlet air temperature characteristic, coal mill current characteristic, coal mill vibration characteristic, mill inlet air volume characteristic, hot and cold air damper opening characteristic, and separator adjustment characteristic. Based on the operating constraint characteristic information and coal quality characteristic information corresponding to each of the coal mills, the maximum output prediction information corresponding to each of the coal mills is determined; The maximum output prediction information of each coal mill is corrected according to the preset output safety boundary to obtain the maximum output information of each coal mill under the corresponding coal quality.

[0010] In one possible design, based on the output analysis information corresponding to each of the coal mills, the economic output information of each coal mill under the corresponding coal quality is determined, including: Based on the operating status data of each coal mill, the pulverizing energy consumption composition information corresponding to each coal mill is determined. The pulverizing energy consumption composition information includes the power consumption of the coal mill, the power consumption of the coal feeder, the power consumption of the lubrication station, the power consumption of the hydraulic station, the power consumption of the dynamic separator, and the power consumption of the fan. Based on the pulverizing energy consumption composition information and coal feed rate correlation information of each of the coal mills, determine the pulverizing unit consumption information of each of the coal mills under different coal feed rates; Based on the pulverizing unit consumption information of each coal mill under different coal feed rates, determine the pulverizing unit consumption change information of each coal mill. Based on the pulverizing unit consumption change information of each of the coal mills, the economic output information of each of the coal mills under the corresponding coal quality is determined.

[0011] In one possible design, determining the target pulverizing demand information corresponding to the target load change period based on the load change demand information, the coal quality data of each of the coal mills, and the current coal feed rate includes: Based on the coal quality data of each of the coal mills, determine the calorific value information of the coal corresponding to each of the coal mills; Based on the calorific value information of the coal corresponding to each of the coal mills and the current coal feed rate of each of the coal mills, the current pulverizing energy supply information is determined; Based on the load change demand information, determine the target energy supply demand information corresponding to the target load change period; Based on the current pulverizing energy supply information and the target energy demand information, the target pulverizing demand information corresponding to the target variable load period is determined.

[0012] In one possible design, based on the target pulverizing demand information and the output boundary information of each of the coal mills, multiple candidate control schemes are generated, including: Based on the target pulverizing demand information and the output boundary information of the currently operating coal mill, determine the pulverizing adjustment capacity information corresponding to the currently operating coal mill; Based on the target pulverizing demand information and the pulverizing adjustment capacity information, determine the pulverizer start-up and shutdown demand information; Based on the coal mill start-up and shutdown requirements, multiple candidate coal mill operation combinations are determined; Based on the operating combination information of each candidate coal mill and the output boundary information of the corresponding coal mill, the coal quantity allocation information corresponding to each candidate coal mill operating combination information is determined, and multiple candidate control schemes are obtained.

[0013] In one possible design, before determining the target control scheme from among the multiple candidate control schemes based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, the method further includes: Based on the coal allocation information in each of the candidate control schemes, predict the changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each of the candidate control schemes; Based on the information on changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each candidate control scheme, determine the main economic impact information corresponding to each candidate control scheme. Based on the coal allocation information in each of the candidate control schemes, predict the auxiliary economic parameter change information corresponding to each of the candidate control schemes. The auxiliary economic parameter change information includes superheated steam temperature change information, reheated steam temperature change information, superheated steam pressure change information, reheated steam pressure change information, superheated desuperheating water volume change information, and reheated desuperheating water volume change information. Based on the changes in auxiliary economic parameters corresponding to each candidate control scheme, determine the secondary economic impact information corresponding to each candidate control scheme; Based on the primary and secondary economic impact information corresponding to each candidate control scheme, the milling economic evaluation information corresponding to each candidate control scheme is determined.

[0014] In one possible design, before determining the target control scheme from among the multiple candidate control schemes based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, the method further includes: Based on the coal allocation information in each of the candidate control schemes, predict the boiler operating parameter changes and pollutant emission changes corresponding to each of the candidate control schemes; Based on the boiler operating parameter change information and preset boiler safety constraints corresponding to each candidate control scheme, determine the boiler safety evaluation information corresponding to each candidate control scheme; Based on the pollutant emission change information and preset environmental constraints corresponding to each candidate control scheme, the environmental evaluation information corresponding to each candidate control scheme is determined.

[0015] In one possible design, based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each of the candidate control schemes, a target control scheme is determined from the multiple candidate control schemes, including: Based on the boiler safety evaluation information and environmental evaluation information corresponding to each of the candidate control schemes, a set of feasible control schemes is determined from the multiple candidate control schemes; Based on the milling economic evaluation information corresponding to each feasible control scheme in the set of feasible control schemes, determine the scheme priority information corresponding to each feasible control scheme; Based on the priority information of each feasible control scheme, the target control scheme is determined from the set of feasible control schemes; Wherein, if the target control scheme includes pulverizer start-up control, the pulverizer to be started is determined according to the preset start-up sequence; if the target control scheme includes pulverizer shutdown control, the pulverizer to be shut down is determined according to the preset shutdown sequence.

[0016] Secondly, this application provides a coal mill group economic and safety optimization control device, the device comprising: a module for executing the aforementioned method embodiment of the first aspect.

[0017] Thirdly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed, implement the method described in the first aspect or various possible designs of the first aspect.

[0018] Fourthly, this application provides a computer program product, which includes computer program code that, when run on a computer, causes the computer to implement the method described in the first aspect or various possible designs of the first aspect.

[0019] This application provides a method for optimizing the economic and safety control of a coal mill group under rapid load changes. This method acquires load curve data, unit operation data, and operating status data and coal quality data of each coal mill during the target load change period for the coal-fired unit under control. This allows for simultaneous understanding of the unit's load adjustment needs and the actual operating status of the pulverizing system. Furthermore, it determines load change demand information based on the load curve data and unit operation data, and determines output boundary information, including maximum output information and economic output information, based on the operating status data and coal quality data of each coal mill. This enables subsequent control to no longer rely solely on the current coal feed rate, fixed thresholds, or manual experience, but rather to make judgments based on the load curve, coal quality conditions, and the actual output capacity of each coal mill. Simultaneously, by determining the target pulverizing demand based on the load change demand information, coal quality data, and current coal feed rate... The goal is to obtain information that enables the target pulverizing demand to represent the energy supply difference and coal quantity adjustment needs during the target load change period relative to the current pulverizing energy supply status. This information will provide a basis for the pulverizer operation combination and coal quantity allocation in the candidate control schemes. Based on this, the target control scheme is determined from multiple candidate control schemes by combining pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information. A group control command for pulverizers, including coal feed adjustment instructions for each pulverizer, is generated. When the target control scheme includes changes in the pulverizer operation combination, pulverizer start-stop control commands are further generated. This approach can meet the pulverizing demand during rapid load changes while taking into account pulverizing economy, boiler safety, and environmental constraints. This will alleviate the problems of frequent load changes, lagging pulverizer operation mode matching, and difficulty in balancing economic operation and safety management under rapid load change conditions. Attached Figure Description

[0020] Figure 1 A flowchart illustrating an economic and safety optimization control method for a coal mill group under rapid load changes, provided in an embodiment of this application; Figure 2 A flowchart illustrating another method for optimizing the economic and safety control of a coal mill group under rapid load changes, provided in an embodiment of this application. Figure 3 A schematic diagram of the structure of a coal mill group economic and safety optimization control device provided in this application embodiment; Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0023] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In this article, the term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B can exist simultaneously, and B exists. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0025] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0026] In the description of this application, unless otherwise stated, "multiple" and "at least two" mean two or more (including two), and similarly, "multiple groups" and "at least two groups" mean two or more (including two groups).

[0027] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, "connected" or "linked" can refer not only to a physical connection, but also to an electrical connection or a signal connection. For instance, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is connected. It can also refer to the internal connection between two components. A signal connection can refer not only to a signal connection through a circuit, but also to a signal connection through a medium, such as radio waves. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, different technical features in this application can be combined with each other.

[0029] The coal-fired generating units under control are those participating in electricity spot trading and adjusting their operation according to grid dispatch load instructions. In the electricity spot trading scenario, real-time electricity trading is usually conducted through bilateral bidding, centralized bidding, and other methods, characterized by timeliness, flexibility, and randomness, and can reflect changes in electricity supply and demand relatively promptly. For the generation side, the load curve issued by the grid side may change frequently in a short period of time, causing coal-fired generating units to continuously operate outside their steady-state design range, thus placing higher demands on the economic operation and safety management of the coal-fired boiler pulverizing system.

[0030] In practical applications, Automatic Generation Control (AGC) systems and Distributed Control Systems (DCS) can be independent systems that interact with each other. The DCS can receive load regulation commands from the AGC system and adjust the load of the controlled coal-fired unit in real time according to the load regulation commands.

[0031] In the embodiments of this application, the current unit load can be transmitted from the DCS to the coal mill group economic and safety optimization control device via a dedicated communication card; the target load after time T within the target load change period can be accessed by the dispatch load curve through a dedicated transmission line to the coal mill group economic and safety optimization control device; the unit operation data and the coal mill operation status data can be acquired by the DCS and transmitted to the coal mill group economic and safety optimization control device.

[0032] Figure 1 This is a flowchart illustrating an economic and safety optimization control method for a coal mill group under rapid load changes, provided as an embodiment of this application. Figure 1 As shown, the method provided in this application embodiment specifically includes S101 to S107, and S101 to S107 will be described in detail below.

[0033] It should be noted that the method provided in this application embodiment can be executed by a coal mill group economic and safety optimization control device. This coal mill group economic and safety optimization control device can be a server, industrial control computer, edge computing device, coal-fired unit operation optimization terminal, or processing equipment integrated into the coal-fired unit control system. This coal mill group economic and safety optimization control device can communicate with a distributed control system, an automatic power generation control system, an online coal quality monitoring device, a boiler operation monitoring system, and a coal mill control system to obtain load curve data, unit operation data, operating status data of each coal mill, and coal quality data of the coal-fired unit to be controlled, and output coal mill group control commands to the corresponding control system.

[0034] S101. Obtain the operation correlation data of the coal-fired unit to be controlled during the target load change period.

[0035] The operational data includes load curve data and unit operation data of the coal-fired power units to be controlled, as well as the operating status data and coal quality data of each coal mill.

[0036] It should be noted that the coal-fired power unit to be controlled is a coal-fired power generation unit equipped with a coal-fired boiler, steam turbine, generator and pulverizing system. The pulverizing system includes multiple coal mills, such as coal mill A, coal mill B, coal mill C, coal mill D, coal mill E and coal mill F.

[0037] The target load change period is a preset time range in the future of the power grid dispatch load curve, such as the load adjustment period within 15 to 60 minutes.

[0038] In one possible implementation, the current unit load P can be transmitted from the distributed control system to the rapid load change coal mill group optimization control device via a dedicated communication card; the target load P′ after time T and the scheduling load curve from the current unit load P to the target load P′ during the target load change period can be connected to the rapid load change coal mill group optimization control device via a dedicated transmission line.

[0039] The load curve data may include at least one of the following: the dispatched load curve during the target load change period, the target load, the load change trend, the load change rate, and the start and end times of the load change.

[0040] The unit's operating data can include boiler main steam parameters, reheat steam parameters, furnace outlet flue gas temperature, desuperheating water volume, exhaust gas temperature, flue gas volume, nitrogen oxide emissions, and unit power supply coal consumption, which can characterize the current operating status of the coal-fired unit under control.

[0041] In one possible embodiment, the operating status data of each coal mill may include coal mill differential pressure, coal mill inlet and outlet air temperature, coal mill current, coal mill vibration parameters, coal mill power consumption, primary air pressure, primary air fan power consumption, hot and cold air damper opening, mill inlet air volume, separator speed or deflector baffle opening, coal feeder coal quantity, coal feeder power consumption, stone coal quantity, lubrication oil station power consumption, hydraulic oil station power consumption, dynamic separator power consumption, total induced draft fan power consumption, and total sealing fan power consumption.

[0042] The coal quality data for each coal mill may include at least one of the following: coal type, lower heating value, moisture content, ash content, volatile matter, and grindability index.

[0043] In one possible implementation, coal quality data for each coal mill can be acquired in real time using an online soft coal quality measurement device installed at the inlet of each coal feeder. This device, based on spectral detection principles, detects the coal quality entering the corresponding coal mill to obtain at least one of the following: coal type, lower heating value, moisture content, ash content, and grindability. The data acquired by the online soft coal quality measurement device can be transmitted to the coal mill group economic and safety optimization control device via a dedicated communication card, industrial communication network, or data acquisition interface, so that subsequent output boundary information and target pulverizing demand information can reflect the real-time changes in the corresponding coal quality of each coal mill.

[0044] S102. Based on the load curve data and unit operation data, determine the load change demand information corresponding to the target load change period.

[0045] After acquiring the operational data, the coal mill group economic and safety optimization control device can perform time-series analysis on the load curve data and verify the current operating status of the coal-fired unit to be controlled in conjunction with the unit's operating data, so as to determine the load adjustment requirements that the pulverizing system needs to respond to during the target load change period and obtain load change demand information.

[0046] Load change demand information is used to characterize the adjustment requirements of the coal-fired power unit to be controlled on the pulverizing system during the target load change period. It may include at least one of the following: load increase / decrease type, load adjustment range, load adjustment intensity, and adjustment response requirements.

[0047] S103. Based on the operating status data and coal quality data of each coal mill, determine the output boundary information of each coal mill under the corresponding coal quality. The output boundary information includes the maximum output information and the economic output information.

[0048] In one possible implementation, the coal mill group economic and safety optimization control device can correlate and analyze the operating status data of each coal mill with coal quality data to determine the output boundary information of each coal mill under the current equipment status and corresponding coal quality conditions. Since the operating status, equipment deterioration degree, and coal type of different coal mills may vary, even if multiple coal mills are in the same controlled coal-fired unit, the actual upper limit of output and the optimal operating range that each coal mill can withstand may differ. Therefore, this step does not directly adopt a uniform rated output value, but rather determines the output boundary information that matches the current operating conditions of each coal mill.

[0049] Maximum output information can be used to characterize the upper limit of output that a corresponding coal mill can achieve while meeting the equipment's operational safety requirements. Economic output information can be used to characterize the output level of a corresponding coal mill under conditions of relatively optimal pulverizing energy consumption or high operating efficiency. By simultaneously determining both maximum and economic output information, subsequent candidate control schemes can be constrained by the safe output upper limit while also taking into account whether the coal mill deviates from its optimal operating range.

[0050] S104. Based on the load change demand information, coal quality data of each coal mill and current coal feed rate, determine the target pulverizing demand information corresponding to the target load change period.

[0051] Among them, the target pulverizing demand information is used to characterize the energy supply difference and coal quantity adjustment demand information between the target load change period and the current pulverizing energy supply status.

[0052] Specifically, the coal quality data of each coal mill can be used to determine the calorific value of the corresponding coal, and the current coal feed rate of each coal mill can be used to characterize the coal supply status of each coal mill in the current pulverizing system. The rapid load change coal mill group optimization control device can determine the current pulverizing energy supply status based on the coal calorific value and the current coal feed rate, and determine the target energy supply demand corresponding to the target load change period according to the load change demand information, thereby obtaining the energy supply difference information between the target load change period and the current pulverizing energy supply status.

[0053] In one possible implementation, the energy supply difference information can be used to characterize the energy supply that the pulverizing system needs to increase or decrease during the target load change period; the coal quantity adjustment demand information can be used to characterize the amount of coal that needs to be increased or decreased to meet the energy supply difference information under the corresponding coal quality conditions of each coal mill. Therefore, the target pulverizing demand information is not directly equivalent to a single target total coal feed, but can simultaneously reflect the impact of load curve changes, coal quality calorific value differences, and the current pulverizing energy supply status on the pulverizing system's adjustment demand. S105. Based on the target pulverizing demand information and the output boundary information of each coal mill, multiple candidate control schemes are generated. The candidate control schemes include coal mill operation combination information and the coal quantity allocation information corresponding to the coal mill operation combination information.

[0054] In one possible implementation, the coal mill group economic and safety optimization control device can match the target pulverizing demand information with the output boundary information of each coal mill to determine multiple coal mill control methods that may meet the pulverizing demand during the target variable load period, and form multiple coal mill control methods into multiple candidate control schemes. Each candidate control scheme includes coal mill operation combination information and coal quantity allocation information corresponding to that coal mill operation combination information.

[0055] The coal mill operation combination information can be used to characterize the set of coal mills participating in operation during the target load change period, the coal mills maintaining operation, the coal mills that may be started, and / or the coal mills that may be shut down. Coal allocation information can be used to characterize the coal allocation relationship that each operating coal mill needs to undertake under the corresponding coal mill operation combination. By incorporating both the operation combination and coal allocation into the candidate control scheme, problems can be avoided such as only determining the start / stop targets without clarifying the coal allocation relationship, or only allocating coal without considering the rationality of the operating coal mill combination.

[0056] S106. Based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, determine the target control scheme from multiple candidate control schemes.

[0057] In one possible implementation, the coal mill group economic and safety optimization control device can evaluate multiple candidate control schemes separately, determine the corresponding pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information for each candidate control scheme, and determine the target control scheme from the multiple candidate control schemes based on the above evaluation information. The target control scheme can be understood as the preferred control scheme that simultaneously meets pulverizing demand, equipment operation requirements, boiler safety requirements, and environmental protection requirements during the target variable load period.

[0058] Pulverizing economic evaluation information can be used to characterize the impact of candidate control schemes on the energy consumption and economic operation of the pulverizing system; boiler safety evaluation information can be used to characterize the impact of candidate control schemes on boiler combustion stability, heating surface operation, and coal mill safety operation; environmental evaluation information can be used to characterize the impact of candidate control schemes on pollutant emission control. By introducing these three types of evaluation information, we can avoid taking the sole objective of meeting load change demands while neglecting pulverizing economics, boiler safety, or environmental constraints.

[0059] In one possible implementation, the coal mill group economic and safety optimization control device can first eliminate candidate control schemes that do not meet the requirements of boiler safety evaluation information or environmental evaluation information, and then determine the target control scheme from the remaining candidate control schemes based on the pulverizing economic evaluation information; alternatively, it can form a comprehensive evaluation result based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information, and determine the target control scheme based on the comprehensive evaluation result. Thus, the target control scheme can achieve comprehensive selection among multiple candidate control schemes.

[0060] S107. Based on the target control scheme, generate coal mill group control instructions, which include coal feed rate adjustment instructions for each coal mill; and, when the target control scheme includes changes in the coal mill operation combination, the coal mill group control instructions also include coal mill start-stop control instructions.

[0061] After determining the target control scheme, the rapid load change coal mill group optimization control device can generate coal mill group control commands based on the coal mill operation combination information and coal quantity allocation information in the target control scheme. The coal mill group control commands are used to instruct the control actions of each coal mill during the target load change period, so that each coal mill participates in pulverizing and energy supply regulation according to the target control scheme.

[0062] Specifically, the coal feed rate adjustment instruction may include at least one of the following: target coal feed rate for each coal mill, increase in coal feed rate, decrease in coal feed rate, direction of coal feed rate adjustment, rate of coal feed rate adjustment, and timing of coal feed rate adjustment. Since the coal quantity supplied to each coal mill typically needs to be adjusted according to the target pulverizing demand information after the unit load changes during the target load variation period, the coal mill group control instruction includes the coal feed rate adjustment instruction for each coal mill to match the actual coal feed rate of each coal mill with the coal quantity allocation information in the target control scheme.

[0063] In one possible implementation, when the target control scheme does not include changes in the coal mill operating combination, it indicates that the currently operating coal mill combination can meet the target pulverizing demand by adjusting the coal feed rate. In this case, the coal mill group control command may include the coal feed rate adjustment command for each currently operating coal mill, but not the coal mill start-up and shutdown control command.

[0064] In another possible implementation, when the target control scheme includes changes in the coal mill operating combination, it indicates that the target pulverizing demand information and output boundary constraints need to be met by starting standby coal mills or shutting down some operating coal mills. In this case, the coal mill group control command includes not only the coal feed rate adjustment command for each coal mill, but also the coal mill start-up and shutdown control command. The coal mill start-up and shutdown control command may include at least one of the following: coal mill identifier to be started, coal mill identifier to be shut down, start-up and shutdown execution time, and start-up and shutdown sequence.

[0065] This application embodiment acquires load curve data, unit operation data, and operating status data and coal quality data of each coal mill during the target load change period of the coal-fired unit to be controlled. This allows for simultaneous understanding of the unit's load adjustment needs and the actual operating status of the pulverizing system. By determining the load change demand information, the output boundary information of each coal mill under the corresponding coal quality, and the target pulverizing demand information, the generation of candidate control schemes is subject to the joint constraints of load curve demand, coal quality conditions, current pulverizing energy supply status, maximum output, and economic output. Furthermore, the target control scheme is determined through pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information, and a coal mill group control command including coal feed adjustment instructions for each coal mill is generated. When the target control scheme includes changes in the coal mill operating combination, a coal mill start-up and shutdown control command is further generated, thereby alleviating the problems of frequent load changes, lagging matching of coal mill operating modes, and difficulty in balancing economic operation and safety management.

[0066] In one possible embodiment, the method steps shown in S102 can be implemented by S1021 to S1023, which are described in detail below.

[0067] S1021. Based on the load curve data, determine the current load information and target load information of the coal-fired unit to be controlled during the target load change period.

[0068] In one possible implementation, the coal mill group economic and safety optimization control device can perform time-series analysis on the load curve data to determine the start and end times of the target load change period. The unit load corresponding to the start time is determined as the current load information, and the unit load corresponding to the end time or the target control time is determined as the target load information. The current load information characterizes the actual load level of the coal-fired unit to be controlled when entering the target load change period, while the target load information characterizes the load level that the coal-fired unit to be controlled needs to achieve during the target load change period.

[0069] When the load curve data includes a continuous load curve, the coal mill group economic and safety optimization control device can extract the current load point and the target load point from the continuous load curve. When the load curve data includes multiple discrete load command points, it can determine the load point corresponding to the current time and the load point corresponding to the target time within the target load change period based on the time sequence of each discrete load command point. This provides basic data for subsequent judgment of the load change direction and load change amount.

[0070] S1022. Based on the current load information and the target load information, determine the load change direction and load change amount corresponding to the target load change period.

[0071] It should be noted that the coal mill group economic and safety optimization control device can compare the magnitude of the target load information and the current load information to determine the load change direction corresponding to the target load change period. When the target load information is greater than the current load information, the load change direction corresponding to the target load change period can be determined to be an increase in load; when the target load information is less than the current load information, the load change direction corresponding to the target load change period can be determined to be a decrease in load; when the difference between the target load information and the current load information is within a preset fluctuation range, the load change direction corresponding to the target load change period can be determined to be a small adjustment or maintenance of load.

[0072] The coal mill group economic and safety optimization control device can determine the load change based on the difference between the target load information and the current load information, and can determine the load change rate by combining the duration of the target load change period.

[0073] S1023. Based on the unit operation data, load change direction and load change amount, determine the load change demand information, which includes load increase demand information or load decrease demand information.

[0074] Specifically, the coal mill group economic and safety optimization control device can initially determine the adjustment demand of the coal-fired unit to be controlled on the pulverizing system during the target load change period based on the direction and amount of load change. Then, it verifies this adjustment demand by combining it with unit operating data to obtain load change demand information. By incorporating unit operating data for verification, it avoids forming pulverizing adjustment demand solely based on the difference between the target load and the current load, thus making the load change demand information more closely match the current operating status of the unit.

[0075] In one possible embodiment, the method steps shown in S103 can be implemented by S1031 to S1034, which are described in detail below.

[0076] S1031. Based on the operating status data of each coal mill, extract the corresponding equipment operating characteristic information of each coal mill.

[0077] It should be noted that the coal mill group economic and safety optimization control device can extract features from the operating status data of each coal mill to obtain the corresponding equipment operating feature information. The equipment operating feature information is used to characterize the equipment status, load-bearing capacity, and operating stability of each coal mill under the current operating conditions.

[0078] Specifically, the coal mill group economic and safety optimization control device can perform data cleaning, outlier removal, time alignment, and statistical analysis on the operating status data of each coal mill, and extract features that reflect the actual operating status of the coal mills. The equipment operating feature information may include at least one of the following: coal mill load level characteristics, air-coal matching characteristics, operating stability characteristics, energy consumption characteristics, temperature characteristics, vibration characteristics, and regulating component status characteristics.

[0079] S1032. Based on the coal quality data of each coal mill, determine the coal quality characteristic information corresponding to each coal mill.

[0080] It should be noted that the coal mill group economic and safety optimization control device can determine the coal quality characteristic information corresponding to each coal mill based on the coal quality data of each mill. The coal quality characteristic information is used to characterize the impact of different coal qualities on the output capacity, pulverizing efficiency, and boiler power supply capacity of the coal mills.

[0081] Specifically, coal quality characteristic information may include at least one of the following: coal type identification information, lower heating value information, moisture content information, ash content information, volatile matter information, and grindability information.

[0082] S1033. Based on the equipment operation characteristic information and coal quality characteristic information corresponding to each coal mill, determine the output analysis information corresponding to each coal mill.

[0083] It should be noted that the coal mill group economic and safety optimization control device can correlate the equipment operation characteristic information and coal quality characteristic information of the same coal mill to obtain the output analysis information of that coal mill. The output analysis information is used to characterize the output capacity, economic operation status, and output adjustment range of the coal mill under the combined effect of the current equipment status and the current coal quality conditions.

[0084] Specifically, the coal mill group economic and safety optimization control device can determine whether the coal mill is currently experiencing issues such as limited output, operational fluctuations, high energy consumption, or insufficient stability based on equipment operating characteristic information. It can also combine coal quality characteristic information to determine the impact of current coal quality on coal mill output improvement, coal feed adjustment, and pulverizing efficiency.

[0085] S1034. Based on the output analysis information of each coal mill, determine the output boundary information of each coal mill under the corresponding coal quality.

[0086] It should be noted that the coal mill group economic and safety optimization control device can determine the output boundary information of each coal mill under the corresponding coal quality based on the output analysis information of each coal mill. The output boundary information includes maximum output information and economic output information. The maximum output information is used to characterize the upper limit of the output of the corresponding coal mill under the condition of meeting the equipment safety operation requirements, while the economic output information is used to characterize the output level or output range of the corresponding coal mill under the condition of relatively optimal pulverizing energy consumption.

[0087] In one possible embodiment, the method steps shown in S1034 can be implemented by Sa1 to Sa7, which are described in detail below.

[0088] Sa1. Based on the equipment operation characteristic information corresponding to each coal mill, determine the operation constraint characteristic information corresponding to each coal mill.

[0089] The operational constraint characteristics include at least one of the following: differential pressure characteristics of the coal mill, inlet and outlet air temperature characteristics of the coal mill, current characteristics of the coal mill, vibration characteristics of the coal mill, inlet air volume characteristics of the mill, opening characteristics of the hot and cold air regulating valves, and adjustment characteristics of the separator.

[0090] It should be noted that the coal mill group economic and safety optimization control device can filter out features that reflect the limited output state and safe operating boundary of each coal mill from the equipment operation characteristic information corresponding to each coal mill, and obtain the corresponding operation constraint characteristic information of each coal mill. The operation constraint characteristic information is used to characterize whether the coal mill has high differential pressure, abnormal air temperature, current close to the limit, increased vibration, insufficient air volume, limited valve opening, or limited separator adjustment capacity under the current operating state.

[0091] In one possible implementation, the differential pressure characteristics of the coal mill can be used to reflect the internal flow state and coal blockage risk; the inlet and outlet air temperature characteristics can be used to reflect the drying capacity and thermal state of the coal mill; the current characteristics can be used to reflect the load level of the coal mill; the vibration characteristics can be used to reflect the operational stability of the equipment; the inlet air volume characteristics can be used to reflect the primary air's powder-carrying and drying capacity; the opening characteristics of the hot and cold air dampers can be used to reflect the air temperature regulation margin; and the separator regulation characteristics can be used to reflect the coal powder fineness regulation status. By extracting the above-mentioned operational constraint characteristic information, a constraint basis can be provided for subsequent prediction of maximum output.

[0092] Sa2. Based on the operating constraint characteristic information and coal quality characteristic information corresponding to each coal mill, determine the maximum output prediction information corresponding to each coal mill.

[0093] It should be noted that the coal mill group economic and safety optimization control device can perform correlation analysis between the operating constraint characteristic information and coal quality characteristic information of each coal mill to determine the maximum output prediction information of each coal mill under the current operating constraints and corresponding coal quality conditions. The maximum output prediction information is used to characterize the upper limit of output predicted based on the current equipment status and coal quality conditions of the coal mill before safety boundary correction.

[0094] In one possible implementation, the coal mill group economic and safety optimization control device can use a preset output prediction model to determine the maximum output prediction information. The preset output prediction model can be trained based on historical operating data, or it can be established using a combination of historical operating data, performance test data, and operational experience parameters. Since factors such as the lower heating value, moisture content, ash content, and grindability of different coal qualities affect the pulverizing capacity of the coal mill, incorporating both operational constraint characteristic information and coal quality characteristic information when determining the maximum output prediction information can make the prediction result closer to the actual output capacity of the corresponding coal mill under the current coal quality conditions.

[0095] Specifically, the preset output prediction model can be trained based on the operating data of each coal mill within a historical statistical period, which can be the past 3 months, the past 6 months, or other preset periods. The historical operating data used to train the preset output prediction model can include at least one of the following: coal mill differential pressure, coal mill inlet and outlet air temperature, coal mill current, coal mill vibration parameters, coal mill power consumption, primary air pressure, primary air fan power consumption, hot and cold air damper opening, mill inlet air volume, separator speed or deflector baffle opening, coal feeder coal quantity, and stone coal quantity. The coal mill group economic and safety optimization control device can use a machine learning algorithm model to train and optimize the above-mentioned historical operating data, operating constraint feature information, and coal quality feature information to obtain the maximum output prediction information of each coal mill under the corresponding coal quality.

[0096] Sa3. Based on the preset output safety boundary, the maximum output prediction information of each coal mill is corrected to obtain the maximum output information of each coal mill under the corresponding coal quality.

[0097] It should be noted that after obtaining the maximum output prediction information, the coal mill group economic and safety optimization control device can correct the maximum output prediction information according to the preset output safety boundary to obtain the maximum output information of each coal mill under the corresponding coal quality. The preset output safety boundary can be used to limit the output range that the coal mill can reach while meeting the requirements of safe and stable operation, and to prevent the maximum output prediction information from exceeding the safety limit that the current equipment state of the coal mill can withstand.

[0098] In one possible implementation, the preset output safety boundary can be determined by combining performance test standards for power plant coal mills and pulverizing systems, equipment operating procedures, equipment protection limits, and historical safe operating data. For example, the output safety boundary of a corresponding coal mill can be determined based on at least one of the following: differential pressure limit, outlet temperature limit, current limit, vibration limit, air volume limit, coal powder fineness requirements, and stone coal discharge status. This avoids the maximum output prediction information obtained solely through model prediction exceeding the current safe operating capacity of the equipment.

[0099] When the maximum output prediction information exceeds the preset output safety boundary, the maximum output prediction information can be corrected to an output value that meets the preset output safety boundary; when the maximum output prediction information does not exceed the preset output safety boundary, the maximum output prediction information can be used as the maximum output information of the corresponding coal mill, or it can be conservatively corrected in combination with the safety margin.

[0100] Sa4. Based on the operating status data of each coal mill, determine the pulverizing energy consumption composition information corresponding to each coal mill.

[0101] The energy consumption composition information for pulverizing includes at least one of the following: coal mill power consumption, coal feeder power consumption, lubrication station power consumption, hydraulic station power consumption, dynamic separator power consumption, and fan-allocated power consumption.

[0102] It should be noted that the coal mill group economic and safety optimization control device can extract data related to pulverizing energy consumption from the operating status data of each coal mill, and aggregate them according to the energy consumption source to obtain the pulverizing energy consumption composition information corresponding to each coal mill. The pulverizing energy consumption composition information is used to characterize the electrical energy consumed directly or indirectly by the corresponding coal mill during the pulverizing process, so as to evaluate the pulverizing economy of the coal mill under different coal feed rates.

[0103] In one possible implementation, the power consumption of the coal mill can be used to characterize the electrical energy consumed during the operation of the coal mill itself; the power consumption of the coal feeder can be used to characterize the electrical energy consumed during the process of transporting raw coal to the coal mill; the power consumption of the lubrication station and hydraulic station can be used to characterize the electrical energy consumed during the operation of the coal mill auxiliary systems; the power consumption of the dynamic separator can be used to characterize the electrical energy consumed during the coal powder separation and fineness adjustment process; and the power consumption allocated to the blower can be used to characterize the portion of the power consumption of common auxiliary equipment such as primary air fans, induced draft fans, and sealing fans that is allocated to the corresponding coal mill. By analyzing the composition of the above energy consumption, the impact of auxiliary system energy consumption and common system energy consumption can be avoided by using only the power consumption of the coal mill itself to evaluate the pulverizing economy.

[0104] Sa5. Based on the pulverizing energy consumption composition information and coal feed rate correlation information of each coal mill, determine the pulverizing unit consumption information of each coal mill under different coal feed rates.

[0105] It should be noted that the coal mill group economic and safety optimization control device can match the pulverizing energy consumption composition information of each coal mill with the coal feed rate correlation information to determine the pulverizing unit consumption information of each coal mill under different coal feed rates. The coal feed rate correlation information can be used to characterize the changes in coal feed rate of each coal mill at different operating times, different operating ranges, or different coal feed rate levels, so that the pulverizing energy consumption can be correlated with the corresponding coal feed rate.

[0106] In one possible implementation, the unit pulverizing energy consumption information can be determined based on the relationship between pulverizing energy consumption and coal feed rate at a given coal feed rate. That is, at a certain coal feed rate level, the energy consumption of the pulverizer itself and related auxiliary equipment can be summarized or converted, and combined with the actual coal feed rate at that level, the unit pulverizing energy consumption of the pulverizer at that feed rate can be obtained. Thus, pulverizing energy consumption information for the same pulverizer at multiple coal feed rate levels can be obtained, providing a data basis for subsequently judging the trend of pulverizing energy consumption changing with coal feed rate.

[0107] In one possible implementation, for any coal mill, the pulverizing energy consumption per unit volume of the mill under the corresponding coal quality can be determined based on the mill's pulverizing energy consumption composition information and coal feed rate correlation information for that specific coal quality. Taking coal mill A pulverizing coal type 1 as an example, its pulverizing energy consumption per unit volume can be determined by the following formula: ;in, The unit consumption (kW·h / t) of pulverizing coal by mill A for coal type 1. The power consumption (kW·h) of mill A for coal type 1 is given. The power consumption (kW·h) of the coal feeder for coal mill A in coal type 1. The power consumption (kW·h) of the lubrication station for coal mill A in coal type 1. The power consumption (kW·h) of the hydraulic oil station for coal mill A in coal type 1. The dynamic separator power consumption (kW·h) of pulverizer A for coal type 1. The total power consumption of the primary air fan of the unit (kW·h). The total power consumption of the induced draft fan of the unit (kW·h). Let n be the total power consumption of the unit's sealing fan (kW·h), and n be the number of coal mills currently in operation. This refers to the coal feeder quantity for coal mill A in coal type 1.

[0108] Furthermore, the pulverizing unit consumption information can be calculated separately under different coal feed rates, and the change information of pulverizing unit consumption can be determined based on the correspondence between the pulverizing unit consumption information and the coal feed rate. When the pulverizing unit consumption of pulverizer A reaches its minimum value under coal type 1, the corresponding coal feed rate can be determined as the economic output information of pulverizer A under coal type 1. For other pulverizers and other coal types, the same method can be used to determine the economic output information under the corresponding coal quality.

[0109] In one possible implementation, the coal mill group economic and safety optimization control device can acquire data on coal feed rate, number of operating coal mills, coal mill power consumption, coal feeder power consumption, lubrication station power consumption, hydraulic station power consumption, dynamic separator power consumption, total primary air fan power consumption, total induced draft fan power consumption, and total sealing fan power consumption within a historical statistical period. Combined with real-time coal quality data, the device uses machine learning algorithm models to train and optimize to determine the lowest or minimum coal feed rate for each coal mill under the corresponding coal quality, thereby obtaining the economic output information of each coal mill under the corresponding coal quality.

[0110] Sa6. Based on the pulverizing unit consumption information of each coal mill under different coal feed rates, determine the pulverizing unit consumption change information of each coal mill.

[0111] It should be noted that the coal mill group economic and safety optimization control device can perform trend analysis on the pulverizing unit consumption information of each coal mill under different coal feed rates, and obtain the pulverizing unit consumption change information of each coal mill. The pulverizing unit consumption change information is used to characterize the change law of the coal mill's pulverizing unit consumption with changes in coal feed rate, for example, it can characterize the trend of pulverizing unit consumption decreasing, stabilizing, or increasing.

[0112] In one possible implementation, the coal mill group economic and safety optimization control device can perform fitting, optimization, or interval analysis on the pulverizing unit consumption information under different coal feed rates based on historical operating samples, current operating samples, or similar operating condition samples to determine the coal feed rate range with lower pulverizing unit consumption. Since the equipment status, coal quality conditions, and auxiliary system energy consumption of different coal mills vary, their pulverizing unit consumption variation information may also differ. Therefore, determining the pulverizing unit consumption variation information for each coal mill separately can more accurately reflect the economic operating characteristics of each coal mill.

[0113] Sa7. Based on the pulverizing unit consumption change information of each coal mill, determine the economic output information of each coal mill under the corresponding coal quality.

[0114] It should be noted that the coal mill group economic and safety optimization control device can determine the coal feed rate corresponding to the lowest or minimum level of pulverizing unit consumption based on the pulverizing unit consumption change information of each coal mill. This coal feed rate, or the output range corresponding to it, is then defined as the economic output information of each coal mill under the corresponding coal quality. This economic output information characterizes the operating output level of the corresponding coal mill that achieves optimal pulverizing economy under the current coal quality conditions.

[0115] In one possible implementation, when there is a clear minimum point in the pulverizing unit consumption change information, the coal feed rate corresponding to that minimum point can be determined as the economic output information; similarly, when there is a range of low and gradually changing pulverizing unit consumption in the pulverizing unit consumption change information, that range can also be determined as the economic output range. Therefore, when generating candidate control schemes, the economic output information can be used to determine whether each coal mill is in an optimal operating state, avoiding situations where some coal mills deviate from the economic operating range for extended periods simply to meet the target pulverizing demand during rapid load changes.

[0116] In one possible embodiment, the method steps shown in S104 can be implemented by S1041 to S1044, which are described in detail below.

[0117] S1041. Based on the coal quality data of each coal mill, determine the calorific value information of the corresponding coal quality for each coal mill.

[0118] It should be noted that the coal mill group economic and safety optimization control device can analyze the coal quality data corresponding to each coal mill to determine the calorific value information of the coal currently being ground by each mill. Calorific value information can be used to characterize the heat level that a unit mass of coal can provide to the boiler, for example, it can be the lower heating value information. Since different coal mills may correspond to different coal types, and the calorific values ​​of different coal types differ, it is necessary to determine the calorific value information of the coal corresponding to each coal mill separately so that the current coal feed rate of each coal mill can be converted into the corresponding energy contribution.

[0119] In one possible implementation, the calorific value information of the coal corresponding to each coal mill can be obtained by an online coal quality monitoring device, or provided by a fuel management system, coal quality test data, or a historical coal quality database. The coal mill group economic and safety optimization control device can associate the calorific value information of each coal mill with the corresponding coal quality, forming a correspondence between coal mills, coal quality, and calorific value, thereby providing a basis for determining the current pulverizing energy supply information.

[0120] S1042. Determine the current pulverizing energy supply information based on the calorific value information of the coal corresponding to each pulverizer and the current coal feed rate of each pulverizer.

[0121] It should be noted that the coal mill group economic and safety optimization control device can match the calorific value information of the coal corresponding to each coal mill with the current coal feed rate of each coal mill to determine the current energy contribution of each coal mill to the boiler, and further summarize to obtain the current pulverizing energy supply information. The current pulverizing energy supply information is used to characterize the total energy supply status that the current pulverizing system can provide to the boiler combustion system under the existing coal mill operating combination and current coal feed rate conditions.

[0122] Specifically, for any given coal mill, the current energy supply for that mill can be determined based on its current coal feed rate and the calorific value of the corresponding coal. Then, the current energy supply for each mill is summarized to obtain the current pulverizing energy supply information. This process avoids representing the pulverizing system's supply capacity solely by the total coal feed rate, while ignoring the impact of differences in calorific values ​​of different coal types on the actual heat input to the boiler.

[0123] S1043. Based on the load change demand information, determine the target energy supply demand information corresponding to the target load change period.

[0124] It should be noted that the coal mill group economic and safety optimization control device can determine the boiler input energy change requirements of the controlled coal-fired unit to meet the load change during the target load change period based on load change demand information, thus obtaining target energy supply demand information. Target energy supply demand information is used to characterize the energy supply level that the boiler combustion system needs to achieve during the target load change period, or the energy supply that needs to be increased or decreased relative to the current pulverizing energy supply information.

[0125] In one possible implementation, when load change demand information represents an increase in load demand, the target energy supply demand information can be used to indicate the increase in boiler input heat required during the target load change period; conversely, when load change demand information represents a decrease in load demand, the target energy supply demand information can be used to indicate the decrease in boiler input heat required during the target load change period. This allows the adjustment demand on the unit load side to be converted into the energy supply demand on the boiler combustion side, providing a basis for subsequently determining the amount of coal that the pulverizing system should adjust.

[0126] S1044. Based on the current pulverizing energy supply information and the target energy demand information, determine the target pulverizing demand information corresponding to the target load change period.

[0127] It should be noted that the coal mill group economic and safety optimization control device can compare the current pulverizing energy supply information with the target energy demand information to determine the target energy supply level that the pulverizing system needs to achieve during the target load change period, and obtain the target pulverizing demand information accordingly. The target pulverizing demand information may include at least one of the following: the energy supply that the pulverizing system needs to increase, the energy supply that needs to decrease, the target coal supply heat, the target coal quantity adjustment demand, and the demand range of each coal mill participating in the coal quantity adjustment.

[0128] In one possible implementation, if the target energy demand is higher than the current pulverizing energy demand, the target pulverizing demand indicates that the pulverizing system needs to increase its pulverized coal supply capacity; if the target energy demand is lower than the current pulverizing energy demand, the target pulverizing demand indicates that the pulverizing system needs to reduce its pulverized coal supply capacity; if the target energy demand is close to the current pulverizing energy demand, the target pulverizing demand indicates that the pulverizing system needs to make minor adjustments or maintain its current supply status. Therefore, when generating candidate control schemes, the target pulverizing demand can be used to determine whether only the coal feed rate of the currently operating coal mill needs to be adjusted, or whether the coal mill operating combination needs to be changed.

[0129] In one possible implementation, the coal mill group economic and safety optimization control device can determine the target pulverizing demand information based on the principle of energy conservation.

[0130] Specifically, the coal consumption b for power supply of each unit in the typical load section can be approximated as a fixed value over a period of time. The sum of the heat input to the boiler from all coal mills is equal to the sum of the input heat calculated based on the coal consumption for power supply and the power generation, thus satisfying formula (2).

[0131] Formula (2) in, This indicates the total heat input to the boiler. This represents the amount of coal produced by mill A under the operating conditions of coal type 1. This indicates the lower heating value of coal type 1.

[0132] Assuming the current unit load is P and the unit load after time T is P′, the boiler input heat corresponding to the current load satisfies the following formula (3).

[0133] Formula (3) in, The coal consumption for power supply under load P (kg / kWh) generally increases as the unit load decreases. However, for a fixed load P, this value can be approximated as constant for a considerable period of time. That is, the coal consumption for power supply under a certain load is constant. This value is generally determined by periodic tests. The calorific value of standard coal. It is 29308 kJ / kg.

[0134] Combining formula (2) and formula (3), we can obtain formula (4).

[0135] Formula (4) in, If the load is a constant that varies only with the load, then the total heat of each coal mill is proportional to the load. Therefore, the target pulverizing demand information corresponding to the target load variation period can be determined based on the current unit load P, the unit load P′ after time T, the coal quantity of each coal mill, and the lower heating value of each coal type.

[0136] In one possible embodiment, the method steps shown in S105 can be implemented by S1051 to S1054, which are described in detail below.

[0137] S1051. Based on the target pulverizing demand information and the output boundary information of the currently operating coal mill, determine the pulverizing adjustment capacity information corresponding to the currently operating coal mill.

[0138] It should be noted that the coal mill group economic and safety optimization control device can first determine the coal mill currently in operation and obtain the maximum output and economic output information of the currently operating coal mill; then, it matches the target pulverizing demand information with the output boundary information of the currently operating coal mill to determine the pulverizing adjustment capacity information that the currently operating coal mill can provide during the target variable load period.

[0139] Pulverizing adjustment capacity information can be used to characterize the ability of currently operating coal mills to meet target pulverizing demands by adjusting the coal feed rate without changing the operating configuration. Specifically, in a load increase scenario, pulverizing adjustment capacity information can characterize the output increase potential of the currently operating coal mill relative to its maximum output; in a load decrease scenario, pulverizing adjustment capacity information can characterize whether the currently operating coal mill can still maintain its operating range corresponding to the economic output information after reducing the coal feed rate. By determining the pulverizing adjustment capacity information, a basis can be provided for subsequent judgments on whether it is necessary to start the standby coal mill or shut down some of the operating coal mills.

[0140] S1052. Determine the start-up and shutdown requirements of the coal mill based on the target pulverizing demand information and the pulverizing adjustment capacity information.

[0141] It should be noted that the coal mill group economic and safety optimization control device can compare the target pulverizing demand information with the pulverizing adjustment capacity information of the currently operating coal mills to determine whether the current combination of operating coal mills can meet the pulverizing demand corresponding to the target variable load period, and determine the coal mill start-up and shutdown demand information accordingly.

[0142] In one possible implementation, if the target pulverizing demand information indicates a need to increase pulverizing supply, and the pulverizing adjustment capacity information of the currently operating coal mills can cover the increased demand, then the coal mill start-up and shutdown demand information can indicate that no new coal mills need to be started. If the pulverizing adjustment capacity information of the currently operating coal mills cannot cover the increased demand, then the coal mill start-up and shutdown demand information can indicate that at least one standby coal mill needs to be started. Correspondingly, if the target pulverizing demand information indicates a need to reduce pulverizing supply, and the currently operating coal mills can still operate within the economic output range after reducing the coal feed rate, then the coal mill start-up and shutdown demand information can indicate that no coal mills need to be shut down. If continuing to maintain the current combination of operating coal mills will cause some coal mills to operate below economic output, then the coal mill start-up and shutdown demand information can indicate that at least one operating coal mill needs to be shut down.

[0143] In one possible implementation, if the target load change period is a load increase scenario, i.e., P′>P, the coal mill group economic and safety optimization control device can determine whether a new coal mill needs to be started based on the maximum output information of the currently operating coal mills.

[0144] For example, if there are currently 4 coal mills B, C, D and E in operation, and coal mills B, C, D and E correspond to coal types 2, 3, 4 and 5 respectively, when formula (5) is satisfied, the current 4 coal mills can meet the load increase by increasing the amount of coal, and there is no need to start a new coal mill.

[0145] Formula (5) in, , This indicates the maximum output of mill B under coal type 2 conditions. This indicates the maximum output of mill C under coal type 3 conditions. This indicates the maximum output of mill D in the case of coal type 4. This indicates the maximum output of the E-mill under coal type 5 conditions; , This indicates the current coal feed rate of mill B under coal type 2. This indicates the current coal feed rate of mill C under coal type 3. This indicates the current coal feed rate of mill D under coal type 4. This indicates the current coal feed rate of the E coal mill under coal type 5.

[0146] At this point, the four coal mills can increase the coal supply according to the load curve at time T. , , , , and satisfy formula (6).

[0147] Formula (6) When formula (8) is satisfied, it means that the current 4 coal mills cannot meet the increasing load by increasing the coal quantity, and a new coal mill needs to be started to meet the load required by the grid dispatching. At this time, coal mill A is started preferentially (when increasing the load, the coal mills are started from bottom to top). Coal mill A burns coal type 1, and the low calorific value (kJ / kg) of the coal quality is q1, and the output reaches mA1 at time T. At this time, formula (9) should be satisfied. Formula (8) Formula (9) During the above process of increasing the load, based on satisfying the energy balance of formula (6) or formula (9), the coal quantity of each coal mill can be optimized by further combining the pulverized coal economy evaluation information, boiler safety evaluation information, and environmental protection evaluation information to determine the corresponding coal quantity distribution information.

[0148] In a possible implementation manner, if the target variable load period is a load reduction scenario, that is, P′ < P, the economic and safety optimization control device for the coal mill group can judge whether it is necessary to stop some coal mills according to the economic output information of the currently operating coal mills.

[0149] Exemplarily, if the current 4 coal mills B, C, D, and E are operating, when formula (10) is satisfied, the current 4 coal mills can meet the load reduction by reducing the coal quantity, and it can ensure that the coal quantity of each coal mill remains above its respective economic output, and there is no need to stop the existing coal mills.

[0150] Formula (10) Among them, , is the economic output of coal mill B under coal type 2, is the economic output of coal mill C under coal type 3, is the economic output of coal mill D under coal type 4, is the economic output of coal mill E under coal type 5.

[0151] At this time, the 4 coal mills can reduce the coal quantity according to the load curve within time T , , , , and satisfy formula (11).

[0152] Formula (11) When formula (12) is satisfied, it means that the current four coal mills can no longer meet the load reduction by reducing the amount of coal. It is necessary to reduce the amount of coal in some coal mills to below the economic output, which leads to a decrease in the stability of the coal mills and insufficient economic efficiency and safety of the unit. Therefore, it is necessary to shut down one of the coal mills.

[0153] For example, the E coal mill can be shut down first, and the E coal mill can be shut down at time T, in which case formula (13) should be satisfied.

[0154] Formula (13) During the above load reduction process, based on the energy balance of formula (11) or formula (13), the coal quantity of the remaining coal mills can be optimized by combining the economic evaluation information of pulverizing, the safety evaluation information of the boiler and the environmental evaluation information, so as to determine the corresponding coal quantity allocation information.

[0155] The coal mills (mills B, C, and D) increase the coal supply while ensuring energy balance according to formula (13), and simultaneously minimizing the coal consumption change Δb in formula (7), thus achieving the best economic performance for the unit. This also takes into account water-cooled wall temperature, superheater wall temperature, and nitrogen oxide emissions not exceeding standards. A model is established using machine learning algorithms for optimization calculations. , , The optimal amount of coal.

[0156] S1053. Based on the coal mill start-up and shutdown requirements, determine the operating combination information of multiple candidate coal mills.

[0157] It should be noted that the coal mill group economic and safety optimization control device can generate multiple candidate coal mill operation combinations between currently operating coal mills and available standby coal mills based on coal mill start-up and shutdown demand information. The candidate coal mill operation combination information can be used to characterize the possible combinations of the number of coal mills in operation during the target load change period, the specific identifiers of operating coal mills, the identifiers of coal mills to be started, and / or the identifiers of coal mills to be shut down.

[0158] In one possible implementation, when the pulverizer start-up / shutdown demand information indicates that the current operating combination does not need to be changed, the candidate pulverizer operating combination information may include combinations that maintain the current operating pulverizers unchanged; when the pulverizer start-up / shutdown demand information indicates that the pulverizers need to be started, the candidate pulverizer operating combination information may include combinations that add one or more standby pulverizers to the current operating pulverizers; when the pulverizer start-up / shutdown demand information indicates that the pulverizers need to be shut down, the candidate pulverizer operating combination information may include combinations that remove one or more pulverizers from the current operating pulverizers. By generating multiple candidate pulverizer operating combination information, multiple alternatives can be provided for subsequent coal allocation and scheme evaluation, avoiding the lack of optimization space in the control scheme due to directly determining a single start-up / shutdown result.

[0159] S1054. Based on the operating combination information of each candidate coal mill and the output boundary information of the corresponding coal mill, determine the coal quantity allocation information corresponding to the operating combination information of each candidate coal mill, and obtain multiple candidate control schemes.

[0160] It should be noted that the coal mill group economic and safety optimization control device can determine the corresponding coal quantity allocation information for each candidate coal mill operating combination, combined with the output boundary information of each coal mill in that combination. The coal quantity allocation information can be used to characterize the target coal feed, coal quantity increase / decrease, or coal quantity adjustment range undertaken by each operating coal mill under that candidate coal mill operating combination.

[0161] When determining coal allocation information, the goal is to ensure that the coal allocation results for each operating coal mill meet the target pulverizing requirements and that the coal feed rate of each operating coal mill is within the allowable range of the corresponding output boundary information. For load increase scenarios, coal allocation information can prioritize allocation within the output increase range of currently operating coal mills; for load decrease scenarios, coal allocation information can prioritize keeping each operating coal mill within the operating range corresponding to the economic output information. Therefore, the candidate control scheme not only includes the combination relationship of which coal mills are operating, but also the allocation relationship of how much coal each operating coal mill handles.

[0162] In one possible embodiment, prior to the method step shown in S106, the method further includes Sc1 to Sc8, which will be described in detail below.

[0163] Sc1. Based on the coal allocation information in each candidate control scheme, predict the changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each candidate control scheme.

[0164] The coal mill group economic and safety optimization control device can predict the changes in economic parameters of the pulverizing system and boiler side under the corresponding coal mill operation combination based on the coal quantity allocation information in each candidate control scheme, and obtain information on changes in pulverizing unit consumption, flue gas temperature, and flue gas volume.

[0165] Specifically, different coal distribution information will lead to different coal feed rates for each operating coal mill, which in turn will affect the pulverizing unit consumption, pulverizing power consumption, and distribution of pulverized coal supply to the furnace for each coal mill. At the same time, different coal mills correspond to different burner areas, and changes in coal distribution may also cause changes in the furnace heat load distribution, further affecting the flue gas temperature and flue gas volume.

[0166] Sc2. Based on the information on changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each candidate control scheme, determine the main economic impact information corresponding to each candidate control scheme.

[0167] The coal mill group economic and safety optimization control device can use information on changes in pulverizing unit consumption, flue gas temperature, and flue gas volume as the main basis for economic evaluation to determine the main economic impact information corresponding to each candidate control scheme. The main economic impact information is used to characterize the degree of influence of the candidate control scheme on the power consumption of the pulverizing system, boiler flue gas heat loss, and unit power supply coal consumption.

[0168] Sc3. Based on the coal allocation information in each candidate control scheme, predict the changes in the auxiliary economic parameters corresponding to each candidate control scheme.

[0169] Among them, the auxiliary economic parameter change information includes superheated steam temperature change information, reheated steam temperature change information, superheated steam pressure change information, reheated steam pressure change information, superheated desuperheating water volume change information, and reheated desuperheating water volume change information.

[0170] The coal mill group economic and safety optimization control device can also predict the impact of the corresponding candidate control scheme on the boiler steam-water parameters and desuperheating water volume after its execution, based on the coal allocation information in each candidate control scheme, and obtain auxiliary economic parameter change information. This auxiliary economic parameter change information is used to characterize the impact of changes in coal allocation on boiler thermal parameters and desuperheating water consumption.

[0171] Sc4. Based on the changes in auxiliary economic parameters corresponding to each candidate control scheme, determine the secondary economic impact information corresponding to each candidate control scheme.

[0172] The coal mill group economic and safety optimization control device can determine the secondary economic impact information corresponding to each candidate control scheme based on information on changes in superheated steam temperature, reheated steam temperature, superheated steam pressure, reheated steam pressure, superheated desuperheating water volume, and reheated desuperheating water volume. This secondary economic impact information characterizes the auxiliary impact of candidate control schemes on the unit's economic operating status by affecting steam temperature, steam pressure, and desuperheating water volume.

[0173] Sc5. Based on the primary and secondary economic impact information corresponding to each candidate control scheme, determine the milling economic evaluation information corresponding to each candidate control scheme.

[0174] The coal mill group economic and safety optimization control device can determine the pulverizing economic evaluation information corresponding to each candidate control scheme based on the main and secondary economic impact information of each candidate control scheme. The pulverizing economic evaluation information can be used to characterize the comprehensive economic performance of the candidate control scheme in terms of pulverizing unit consumption, boiler flue gas loss, steam temperature and pressure deviation, desuperheating water volume change, and unit power supply coal consumption change.

[0175] In one possible implementation, the coal allocation information in different candidate control schemes will cause changes in pulverizing unit consumption, flue gas temperature, flue gas volume, superheated steam temperature, reheated steam temperature, superheated steam pressure, reheated steam pressure, superheated desuperheating water volume, and reheated desuperheating water volume. The changes in unit economic efficiency caused by the unit changes in these parameters can be quantified as their impact on the unit's coal consumption for power generation. The values ​​of the impact of the unit changes in these parameters on the unit's coal consumption for power generation are b1, b2, b3, b4, b5, b6, b7, b8, and b9, respectively. b1, b2, b3, b4, b5, b6, b7, b8, and b9 can be positive or negative depending on the parameter characteristics. The overall coal consumption change caused by the changes in various parameters after coal addition is... , The calculation formula is shown in formula (7).

[0176]

[0177] Formula (7) in, This represents the change in coal consumption. , , , These represent the changes in pulverizing unit consumption for pulverizers B, C, D, and E, respectively, under the corresponding coal quality. , , , These represent the coal quantity for mills B, C, D, and E, respectively, under the corresponding coal quality; P represents the unit load. This refers to the change in flue gas temperature. This represents the change in flue gas volume; This represents the change in superheated steam temperature. This represents the change in reheat steam temperature. This represents the change in superheated steam pressure. This represents the change in reheat steam pressure. This refers to the change in the amount of water used for superheating and desuperheating. This represents the change in the reheat cooling water volume.

[0178] In one possible implementation, the change in coal consumption It can be a positive or negative value. Change in coal consumption. The smaller the value, the lower the unit's coal consumption for power generation under the corresponding candidate control scheme, and the better the overall economic performance of the unit. Therefore, the change in coal consumption can be... As an important evaluation basis for pulverizing economic evaluation information, and on the basis of satisfying boiler safety evaluation information and environmental evaluation information, candidate control schemes with smaller coal consumption changes are given priority as target control schemes.

[0179] In one possible implementation, the key economic impact information can be converted into economic evaluation values, economic evaluation levels, or economic ranking information corresponding to candidate control schemes. A higher economic evaluation value indicates that the corresponding candidate control scheme, while meeting the target pulverizing requirements, has a smaller negative impact on pulverizing energy consumption and unit economy. Therefore, pulverizing economic evaluation information can serve as an important basis for determining the target control scheme from multiple candidate control schemes in S106.

[0180] Sc6. Based on the coal allocation information in each candidate control scheme, predict the changes in boiler operating parameters and pollutant emissions corresponding to each candidate control scheme.

[0181] The coal mill group economic and safety optimization control device can also predict, based on the coal allocation information, the potential changes in boiler operating parameters and pollutant emissions after the execution of each candidate control scheme. The boiler operating parameter changes characterize the impact of the candidate control scheme on the safe and stable operation of the boiler, while the pollutant emission changes characterize the impact on environmental emission control.

[0182] Specifically, different coal distribution methods in coal mills will alter the heat load input of the corresponding burner zones, potentially affecting boiler operating parameters such as water-cooled wall temperature, superheater wall temperature, reheater wall temperature, superheated steam temperature, reheated steam temperature, superheated steam pressure, reheated steam pressure, desuperheating water volume, and combustion stability. Simultaneously, changes in coal distribution and combustion status may also affect pollutant emission indicators such as nitrogen oxide emissions. Therefore, before determining the target control scheme, it is necessary to predict the aforementioned safety and environmentally related changes to avoid candidate control schemes, while economically superior, causing boiler operational risks or exceeding environmental limits.

[0183] Sc7. Based on the boiler operating parameter change information and preset boiler safety constraints corresponding to each candidate control scheme, determine the boiler safety evaluation information corresponding to each candidate control scheme.

[0184] The coal mill group economic and safety optimization control device can compare the boiler operating parameter change information corresponding to each candidate control scheme with the preset boiler safety constraints to determine the boiler safety evaluation information corresponding to each candidate control scheme. The preset boiler safety constraints may include at least one of the following: heating surface wall temperature constraint, steam temperature and pressure constraint, desuperheating water volume constraint, combustion stability constraint, and coal mill safe operation constraint.

[0185] In one possible implementation, if the boiler operating parameter changes corresponding to a candidate control scheme meet preset boiler safety constraints, then the candidate control scheme can be determined to be boiler-safe and feasible. If there are issues such as excessive wall temperature, deviations in steam temperature and pressure, abnormal increases in desuperheating water volume, decreased combustion stability, or increased pulverizer operating risks, then the boiler safety evaluation result of the candidate control scheme can be lowered, or the candidate control scheme can be determined as a scheme that does not meet safety requirements. Therefore, boiler safety evaluation information can be used to constrain the selection of subsequent target control schemes, avoiding sacrificing boiler safety in pursuit of pulverizing economics.

[0186] Sc8. Based on the pollutant emission change information and preset environmental constraints corresponding to each candidate control scheme, determine the environmental assessment information corresponding to each candidate control scheme.

[0187] In one possible implementation, the coal mill group economic and safety optimization control device can compare the pollutant emission change information corresponding to each candidate control scheme with preset environmental constraints to determine the environmental evaluation information corresponding to each candidate control scheme. The preset environmental constraints may include at least one of nitrogen oxide emission limits, flue gas emission control requirements, and unit operation environmental assessment requirements.

[0188] In one possible implementation, if the predicted pollutant emission changes after the implementation of a candidate control scheme still meet the preset environmental constraints, then the candidate control scheme can be determined to be environmentally feasible. If the prediction results indicate a risk of pollutant emissions exceeding limits, the environmental evaluation result of the candidate control scheme can be reduced, or it can be excluded from subsequent options. Thus, environmental evaluation information can be used together with pulverizing economic evaluation information and boiler safety evaluation information to determine the target control scheme, ensuring that the final selected target control scheme simultaneously considers economic operation, safety management, and environmental constraints.

[0189] The embodiments of this application can evaluate each candidate control scheme from three aspects: pulverizing economy, boiler safety, and environmental constraints, before determining the target control scheme. Therefore, when selecting from multiple candidate control schemes in S106, it is possible not only to determine whether the candidate control scheme meets the target pulverizing requirements, but also to further determine its impact on pulverizing unit consumption, boiler operating safety, and pollutant emissions, thereby improving the overall feasibility and operational stability of the target control scheme.

[0190] In one possible embodiment, the method steps shown in S106 can be implemented by S1061 to S1063, which are described in detail below.

[0191] S1061. Based on the boiler safety evaluation information and environmental evaluation information corresponding to each candidate control scheme, determine the set of feasible control schemes from multiple candidate control schemes.

[0192] The coal mill group economic and safety optimization control device can first screen the feasibility of multiple candidate control schemes based on the boiler safety evaluation information and environmental evaluation information corresponding to each candidate control scheme. Candidate control schemes with boiler safety risks or environmental exceedance risks will be eliminated, resulting in a set of feasible control schemes. Each feasible control scheme in the set meets the target pulverizing requirements and has an execution basis under boiler safety and environmental constraints.

[0193] In one possible implementation, when the boiler safety evaluation information corresponding to a candidate control scheme indicates a risk of exceeding limits in the heating surface wall temperature, steam temperature and pressure, desuperheating water volume, combustion stability, or coal mill operating status, the candidate control scheme can be eliminated from the pool of candidate control schemes. Similarly, when the environmental evaluation information corresponding to a candidate control scheme indicates a risk of exceeding pollutant emission limits, the candidate control scheme can also be eliminated. Through the above processing, the subsequent determination of the target control scheme can be prioritized based on safety and environmental feasibility, avoiding the pursuit of pulverizing economy at the expense of the safe and stable operation of the unit.

[0194] S1062. Based on the economic evaluation information of milling corresponding to each feasible control scheme in the set of feasible control schemes, determine the priority information of each feasible control scheme.

[0195] After obtaining the set of feasible control schemes, the coal mill group economic and safety optimization control device can sort or classify the feasible control schemes according to the pulverizing economic evaluation information corresponding to each scheme, thereby obtaining the scheme priority information corresponding to each feasible control scheme. The scheme priority information is used to characterize the economic merits of each feasible control scheme after meeting safety and environmental protection requirements.

[0196] In one possible implementation, pulverizing economic evaluation information can reflect the impact of feasible control schemes on the trends of pulverizing unit energy consumption, flue gas heat loss, pulverizing power consumption, and unit power supply coal consumption. The coal mill group economic and safety optimization control device can assign higher priority to feasible control schemes with better pulverizing economic evaluation information and lower priority to feasible control schemes with poorer pulverizing economic evaluation information. Therefore, under the premise that safety and environmental constraints are already met, further selection of control schemes that are beneficial to reducing pulverizing energy consumption and improving unit economy is possible.

[0197] S1063. Based on the priority information of each feasible control scheme, determine the target control scheme from the set of feasible control schemes.

[0198] The coal mill group economic and safety optimization control device can select the highest priority feasible control scheme from the set of feasible control schemes as the target control scheme based on the priority information of each feasible control scheme. The target control scheme may include the target coal mill operation combination information and the corresponding coal quantity allocation information, which will serve as the basis for generating subsequent coal mill group control commands.

[0199] In one possible implementation, if multiple feasible control schemes with the same or similar priorities exist, the coal mill group economic and safety optimization control device can further determine the target control scheme from among the multiple feasible control schemes by combining factors such as the number of coal mill start-ups and shutdowns, the stability of the operating combination, the current operating time of the coal mill, the need for balanced equipment use, or the preset preferences of the operators. This can reduce unnecessary frequent start-ups and shutdowns of the coal mills and improve the executability of the target control scheme in actual operation.

[0200] In the case where the target control scheme includes pulverizer start-up control, the pulverizer to be started is determined according to the preset start-up sequence; in the case where the target control scheme includes pulverizer shutdown control, the pulverizer to be shut down is determined according to the preset shutdown sequence.

[0201] In one possible implementation, when the target control scheme includes pulverizer start-up control, the pulverizer group economic and safety optimization control device can determine the pulverizers to be started based on a preset start-up sequence. For example, during load increase, the pulverizers to be started can be determined from the available pulverizers according to the preset start-up sequence; for opposed combustion boilers, the balance of the number of operating pulverizers on the front and rear walls can also be considered to avoid excessive heat load concentration in a single combustion zone.

[0202] In one possible implementation, when the target control scheme includes pulverizer shutdown control, the pulverizer group economic and safety optimization control device can determine the pulverizers to be shut down based on a preset shutdown sequence. For example, during load reduction, the pulverizers to be shut down can be determined from the currently operating pulverizers according to the preset shutdown sequence; simultaneously, by combining the economic output information and maximum output information of the remaining pulverizers after shutdown, it can be ensured that the remaining pulverizers can meet the target pulverizing requirements and remain within a relatively optimal operating range as much as possible.

[0203] This application's embodiments first determine a set of feasible control schemes based on boiler safety and environmental assessment information, then determine the priority information of each feasible control scheme based on pulverizing economic assessment information, and finally determine the target control scheme accordingly. Therefore, the process of determining the target control scheme reflects the control logic of "first satisfying safety and environmental constraints, then selecting the economically optimal option," ensuring that the final selected coal mill operating combination and coal allocation method not only meet the pulverizing requirements under rapid load changes but also take into account boiler safety, environmental constraints, and pulverizing economics.

[0204] Figure 2 This is a schematic flowchart illustrating a method for optimizing the economic and safety control of a coal mill group under rapid load changes, as provided in an embodiment of this application. Figure 2As shown, the coal mill group economic and safety optimization control device can first determine the economic output and maximum output of each coal mill under different coal qualities based on the calculation relationship of the pulverizing unit consumption of each coal mill, combined with the historical operating data, online coal quality measurement data, and machine learning algorithm model training and optimization results obtained by the distributed control system (DCS). Then, it acquires the current load P, the target load P′ after time T, the actual coal quantity, coal quality, and corresponding calorific value of the currently operating coal mills, and determines the relationship between P and P′. When P′ is greater than P, it is determined that the coal-fired unit to be controlled is in the process of increasing load, and based on the principle of energy conservation, it is determined whether the heat difference Q1 required for the load increase is greater than the increaseable heat difference Q2 between the maximum output and actual output of each currently operating coal mill. If Q1 is greater than Q2, it is determined that a new coal mill needs to be started, and the coal mills are prioritized to be started from bottom to top during the load increase process. If Q1 is not greater than Q2, it is determined that the currently operating coal mills can meet the load increase requirements by increasing the coal quantity. When P′ is less than P, it is determined that the coal-fired unit under control is in a load reduction process. Based on the principle of energy conservation, it is determined whether the heat difference Q1 required for load reduction is greater than the heat difference Q2 that can be reduced between the actual output and economic output of each operating coal mill. If Q1 is greater than Q2, it is determined that some coal mills need to be shut down, and the coal mills are shut down in order from top to bottom during the load reduction process. If Q1 is not greater than Q2, it is determined that the load reduction requirement can be met by reducing the amount of coal in the currently operating coal mills. Based on determining whether to start up, stop, add coal, or reduce coal, further, with energy balance as a constraint, the focus is on indicators such as pulverizing unit consumption, flue gas temperature, flue gas volume, steam temperature, steam pressure, and heating surface wall temperature, while also taking into account environmental indicators such as nitrogen oxide emissions. A model is established using machine learning algorithms and optimized to obtain a coal mill group control scheme under rapid load change conditions.

[0205] Figure 3 This is a schematic diagram of a coal mill group economic and safety optimization control device provided in an embodiment of this application. Figure 3 As shown, the coal mill group economic and safety optimization control device 300 includes a data acquisition module 301, a load demand determination module 302, an output boundary determination module 303, a target pulverizing demand determination module 304, a candidate scheme generation module 305, a target scheme determination module 306, and a control command generation module 307.

[0206] The data acquisition module 301 is used to acquire the operation-related data of the coal-fired unit to be controlled during the target load change period. The operation-related data includes the load curve data and unit operation data of the coal-fired unit to be controlled, as well as the operation status data and coal quality data of each coal mill.

[0207] The load demand determination module 302 is used to determine the load change demand information corresponding to the target load change period based on load curve data and unit operation data.

[0208] The output boundary determination module 303 is used to determine the output boundary information of each coal mill under the corresponding coal quality based on the operating status data and coal quality data of each coal mill. The output boundary information includes the maximum output information and the economic output information.

[0209] The target pulverizing demand determination module 304 is used to determine the target pulverizing demand information corresponding to the target load change period based on load change demand information, coal quality data of each coal mill and current coal feed rate.

[0210] The candidate scheme generation module 305 is used to generate multiple candidate control schemes based on the target pulverizing demand information and the output boundary information of each coal mill. The candidate control schemes include coal mill operation combination information and coal quantity allocation information corresponding to the coal mill operation combination information.

[0211] The target scheme determination module 306 is used to determine the target control scheme from multiple candidate control schemes based on the pulverizing economic evaluation information, boiler safety evaluation information and environmental evaluation information corresponding to each candidate control scheme.

[0212] The control command generation module 307 is used to generate coal mill group control commands based on the target control scheme. The coal mill group control commands include coal mill start-stop control commands and / or coal feed rate adjustment commands.

[0213] It should be noted that the specific process of each module in the coal mill group economic and safety optimization control device executing the above method has been described in detail in the above embodiments, and this embodiment does not make specific limitations on it.

[0214] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 4 As shown, the electronic device 400 provided in this embodiment includes a memory 401 and a processor 402.

[0215] The memory 401 can be a separate physical unit, connected to the processor 402 via a bus 404. Alternatively, the memory 401 and processor 402 can be integrated and implemented in hardware. The memory 401 stores program instructions, which the processor 402 calls to execute the operations performed by the coal mill group economic and safety optimization control device in any of the above method embodiments.

[0216] Optionally, when some or all of the methods in the above embodiments are implemented by software, the electronic device 400 may also include only the processor 402. A memory 401 for storing programs is located outside the electronic device 400, and the processor 402 is connected to the memory via circuits / wires to read and execute the programs stored in the memory. The processor 402 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 402 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0217] Memory 401 may include volatile memory, such as random-access memory (RAM); memory may also include non-volatile memory, such as flash memory, hard disk drive (HDD) or solid-state drive (SSD); memory may also include combinations of the above types of memory.

[0218] For example, this application provides a chip, including: an interface circuit and a logic circuit. The interface circuit is used to receive signals from other chips outside the chip and transmit them to the logic circuit, or to send signals from the logic circuit to other chips outside the chip. The logic circuit is used to perform the operations performed by the coal mill group economic and safety optimization control device in the above method embodiments.

[0219] For example, this application provides a computer-readable storage medium storing computer program instructions thereon, which are executed by a processor of an electronic device to cause the electronic device to perform the operations performed by the coal mill group economic and safety optimization control device in the above method embodiments.

[0220] For example, this application provides a computer program product that, when run on an electronic device, causes the electronic device to perform the operations executed by the coal mill group economic and safety optimization control device in the above method embodiments.

[0221] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for optimizing the economic and safety control of a coal mill group under rapid load changes, characterized in that, The method includes: The operation correlation data of the coal-fired power unit to be controlled during the target load change period is obtained. The operation correlation data includes the load curve data and unit operation data of the coal-fired power unit to be controlled, as well as the operation status data and coal quality data of each coal mill. Based on the load curve data and the unit operation data, determine the load change demand information corresponding to the target load change period; Based on the operating status data and coal quality data of each coal mill, the output boundary information of each coal mill under the corresponding coal quality is determined. The output boundary information includes maximum output information and economic output information. Based on the load change demand information, the coal quality data of each of the coal mills, and the current coal feed rate, the target pulverizing demand information corresponding to the target load change period is determined; wherein, the target pulverizing demand information is used to characterize the energy supply difference information and coal quantity adjustment demand information of the target load change period relative to the current pulverizing energy supply state. Based on the target pulverizing demand information and the output boundary information of each of the coal mills, multiple candidate control schemes are generated. The candidate control schemes include coal mill operation combination information and coal quantity allocation information corresponding to the coal mill operation combination information. Based on the pulverizing economic evaluation information, boiler safety evaluation information and environmental evaluation information corresponding to each of the candidate control schemes, a target control scheme is determined from the multiple candidate control schemes; Based on the target control scheme, a coal mill group control command is generated, which includes a coal feed rate adjustment command for each coal mill; and, when the target control scheme includes changes in the coal mill operating combination, the coal mill group control command also includes a coal mill start-stop control command.

2. The method according to claim 1, characterized in that, Based on the load curve data and the unit operation data, determine the load change demand information corresponding to the target load change period, including: Based on the load curve data, determine the current load information and target load information of the coal-fired unit to be controlled during the target load change period; Based on the current load information and the target load information, determine the load change direction and load change amount corresponding to the target load change period; Based on the unit operation data, the direction of load change, and the amount of load change, the load change demand information is determined, which includes load increase demand information or load decrease demand information.

3. The method according to claim 1, characterized in that, The step of determining the output boundary information of each coal mill under the corresponding coal quality based on the operating status data and coal quality data of each coal mill includes: Based on the operating status data of each coal mill, extract the equipment operating characteristic information corresponding to each coal mill; Based on the coal quality data of each of the coal mills, determine the coal quality characteristic information corresponding to each of the coal mills; Based on the equipment operation characteristic information and coal quality characteristic information corresponding to each of the coal mills, determine the output analysis information corresponding to each of the coal mills; Based on the output analysis information of each coal mill, the output boundary information of each coal mill under the corresponding coal quality is determined.

4. The method according to claim 3, characterized in that, Based on the output analysis information corresponding to each of the coal mills, the maximum output information of each coal mill under the corresponding coal quality is determined, including: Based on the equipment operation characteristic information corresponding to each of the coal mills, the operation constraint characteristic information corresponding to each of the coal mills is determined. The operation constraint characteristic information includes at least one of the following: coal mill differential pressure characteristic, coal mill inlet and outlet air temperature characteristic, coal mill current characteristic, coal mill vibration characteristic, mill inlet air volume characteristic, hot and cold air damper opening characteristic, and separator adjustment characteristic. Based on the operating constraint characteristic information and coal quality characteristic information corresponding to each of the coal mills, the maximum output prediction information corresponding to each of the coal mills is determined; The maximum output prediction information of each coal mill is corrected according to the preset output safety boundary to obtain the maximum output information of each coal mill under the corresponding coal quality.

5. The method according to claim 3, characterized in that, Based on the output analysis information corresponding to each of the coal mills, the economic output information of each coal mill under the corresponding coal quality is determined, including: Based on the operating status data of each coal mill, the pulverizing energy consumption composition information corresponding to each coal mill is determined. The pulverizing energy consumption composition information includes the power consumption of the coal mill, the power consumption of the coal feeder, the power consumption of the lubrication station, the power consumption of the hydraulic station, the power consumption of the dynamic separator, and the power consumption of the fan. Based on the pulverizing energy consumption composition information and coal feed rate correlation information of each of the coal mills, determine the pulverizing unit consumption information of each of the coal mills under different coal feed rates; Based on the pulverizing unit consumption information of each coal mill under different coal feed rates, determine the pulverizing unit consumption change information of each coal mill. Based on the pulverizing unit consumption change information of each of the coal mills, the economic output information of each of the coal mills under the corresponding coal quality is determined.

6. The method according to claim 2, characterized in that, The step of determining the target pulverizing demand information corresponding to the target load change period based on the load change demand information, the coal quality data of each of the coal mills, and the current coal feed rate includes: Based on the coal quality data of each of the coal mills, determine the calorific value information of the coal corresponding to each of the coal mills; Based on the calorific value information of the coal corresponding to each of the coal mills and the current coal feed rate of each of the coal mills, the current pulverizing energy supply information is determined; Based on the load change demand information, determine the target energy supply demand information corresponding to the target load change period; Based on the current pulverizing energy supply information and the target energy demand information, the target pulverizing demand information corresponding to the target variable load period is determined.

7. The method according to claim 6, characterized in that, The process involves generating multiple candidate control schemes based on the target pulverizing demand information and the output boundary information of each coal mill, including: Based on the target pulverizing demand information and the output boundary information of the currently operating coal mill, determine the pulverizing adjustment capacity information corresponding to the currently operating coal mill; Based on the target pulverizing demand information and the pulverizing adjustment capacity information, determine the pulverizer start-up and shutdown demand information; Based on the coal mill start-up and shutdown requirements, multiple candidate coal mill operation combinations are determined; Based on the operating combination information of each candidate coal mill and the output boundary information of the corresponding coal mill, the coal quantity allocation information corresponding to each candidate coal mill operating combination information is determined, and multiple candidate control schemes are obtained.

8. The method according to claim 7, characterized in that, Before determining the target control scheme from the multiple candidate control schemes based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, the method further includes: Based on the coal allocation information in each of the candidate control schemes, predict the changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each of the candidate control schemes; Based on the information on changes in pulverizing unit consumption, flue gas temperature, and flue gas volume corresponding to each candidate control scheme, determine the main economic impact information corresponding to each candidate control scheme. Based on the coal allocation information in each of the candidate control schemes, predict the auxiliary economic parameter change information corresponding to each of the candidate control schemes. The auxiliary economic parameter change information includes superheated steam temperature change information, reheated steam temperature change information, superheated steam pressure change information, reheated steam pressure change information, superheated desuperheating water volume change information, and reheated desuperheating water volume change information. Based on the changes in auxiliary economic parameters corresponding to each candidate control scheme, determine the secondary economic impact information corresponding to each candidate control scheme; Based on the primary and secondary economic impact information corresponding to each candidate control scheme, the milling economic evaluation information corresponding to each candidate control scheme is determined.

9. The method according to claim 8, characterized in that, Before determining the target control scheme from the multiple candidate control schemes based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, the method further includes: Based on the coal allocation information in each of the candidate control schemes, predict the boiler operating parameter changes and pollutant emission changes corresponding to each of the candidate control schemes; Based on the boiler operating parameter change information and preset boiler safety constraints corresponding to each candidate control scheme, determine the boiler safety evaluation information corresponding to each candidate control scheme; Based on the pollutant emission change information and preset environmental constraints corresponding to each candidate control scheme, the environmental evaluation information corresponding to each candidate control scheme is determined.

10. The method according to claim 9, characterized in that, Based on the pulverizing economic evaluation information, boiler safety evaluation information, and environmental evaluation information corresponding to each candidate control scheme, a target control scheme is determined from the multiple candidate control schemes, including: Based on the boiler safety evaluation information and environmental evaluation information corresponding to each of the candidate control schemes, a set of feasible control schemes is determined from the multiple candidate control schemes; Based on the milling economic evaluation information corresponding to each feasible control scheme in the set of feasible control schemes, determine the scheme priority information corresponding to each feasible control scheme; Based on the priority information of each feasible control scheme, the target control scheme is determined from the set of feasible control schemes; Wherein, if the target control scheme includes pulverizer start-up control, the pulverizer to be started is determined according to the preset start-up sequence; if the target control scheme includes pulverizer shutdown control, the pulverizer to be shut down is determined according to the preset shutdown sequence.

Images