Combustion control system and equipment under deep peak regulation of coal-fired power plant

Abstract

The invention provides a combustion control system and equipment under deep peak regulation of a coal-fired power plant, and belongs to the technical field of coal-fired boilers. According to the system and the equipment, real-time operation data and exhaust gas component data of a boiler are obtained; then calculating the exhaust gas component data by using a preset calculation model to obtain real-time fired coal quality information; and finally, real-time optimal control parameters are determined according to the real-time in-boiler coal quality information and the operation data, and dynamic control is conducted on the boiler through the real-time optimal control parameters, so that combustion optimization under deep peak regulation is achieved. According to the method, boiler exhaust smoke gas components are monitored and analyzed in real time, in-boiler coal quality information is accurately obtained in combination with a preset calculation model, and combustion control parameters are dynamically adjusted accordingly, so that the influence of coal quality changes on regulation and control of a coal pulverizing system, the theoretical air amount and key operation parameters is effectively solved, and the coal pulverizing efficiency is improved. And meanwhile, the safety risks such as ash deposition, slag bonding and high-temperature corrosion of the hearth are reduced, and the safety and economical efficiency of a coal-fired unit are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-fired boilers, and in particular relates to a combustion control system and equipment under deep peak regulation of a coal-fired power plant. Background Art

[0002] Further promoting the development of clean, low-carbon, flexible and intelligent coal-fired power will provide important technical support for the construction of my country's new power system and the realization of the "dual carbon" goal. The quality of coal entering the furnace is a key parameter for optimizing the operation of coal-fired power plant pulverization, combustion and environmental protection systems, and is crucial to achieving the above goals.

[0003] A large number of key parameters that affect the safe and economical operation of coal-fired units are directly affected by the quality of the coal entering the furnace. For example, coal quality deviation seriously affects the powder output performance of the pulverizing system, causing the theoretical air volume required for unit coal combustion to be unbalanced, which makes it extremely difficult to accurately control key parameters such as coal supply, air supply and water supply of the unit. At the same time, when the boiler burns non-designed coal, the ash content of the coal changes, which can easily lead to safety risks such as ash accumulation and slagging in the furnace and high-temperature corrosion in the furnace. Therefore, it is urgent to provide a combustion control system and equipment for deep peak regulation of coal-fired power plants. Summary of the invention

[0004] In view of this, the present invention aims to provide a combustion control system and equipment for deep peak regulation of a coal-fired power plant, so as to control the boiler according to the quality of the coal entering the furnace and ensure the safe and economical operation of the coal-fired unit.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a combustion control system for deep peak regulation of a coal-fired power plant, comprising:

[0007] Coal quality monitoring module, coal quality soft measurement module and combustion control module;

[0008] The coal quality monitoring module is used to obtain real-time boiler operation data and exhaust gas composition data;

[0009] The coal quality soft measurement module is used to calculate the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace. The calculation model is a model of the corresponding relationship between the exhaust gas composition and the coal element content established based on the material balance principle and the coal combustion chemical process;

[0010] The combustion control module is used to determine the real-time optimal control parameters based on the real-time coal quality information and operating data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

[0011] Furthermore, the preset calculation model is used to calculate the exhaust gas composition data to obtain real-time coal quality information entering the furnace, including:

[0012] Obtain volume share data of various gases from exhaust gas composition data;

[0013] The calculation model is used to calculate the volume share data of various gases to obtain the composition ratio of carbon and sulfur elements in the dry ash-free basis of coal;

[0014] According to the linear relationship between carbon element on dry ash-free basis and hydrogen element and oxygen element, the composition proportion of hydrogen element and oxygen element on dry ash-free basis of coal is calculated;

[0015] The proportion of nitrogen is calculated based on the proportion of carbon, sulfur, hydrogen and oxygen, and the real-time quality information of the coal entering the furnace is determined based on the proportion of each element.

[0016] Furthermore, the calculation expression of the calculation model is as follows:

[0017]

[0018] in,

[0019]

[0020] In the formula, , , , and They represent the composition ratios of carbon, sulfur, hydrogen, oxygen and nitrogen in the dry ash-free basis of coal respectively; and They represent the gas volume fractions of carbon dioxide and sulfur dioxide in the exhaust flue gas respectively; , and Respectively represent the sum of the standard gas amounts of carbon dioxide and sulfur dioxide, the standard gas amount of nitrogen, and the standard gas amount of oxygen calculated on a dry basis; represents the correction amount for unburned carbon loss; , , and All are dry ash-free composition characteristic coefficients; To take into account the unburned losses, the standard theoretical air volume is calculated on a dry basis; is the exhaust excess air coefficient, is the volume fraction of oxygen in air.

[0021] Furthermore, the exhaust excess air coefficient Determine according to the following calculation:

[0022] .

[0023] Furthermore, the correction for unburned carbon loss is Determine according to the following calculation:

[0024]

[0025] In the formula, is the average unburned carbon content in the ash, To receive the base ash, To receive base moisture, and are the proportions of fly ash and bottom ash, respectively. and are the carbon contents of fly ash and bottom slag, respectively.

[0026] Furthermore, the data obtained from the exhaust gas composition data at least includes the volume share data of oxygen and sulfur dioxide, the volume share data of carbon dioxide Determined by the following calculation:

[0027]

[0028] In the formula, is the fuel property factor expressed as the element content on a dry ash-free basis, It is the gas volume share of oxygen in the exhaust gas.

[0029] Furthermore, the fuel property coefficient expressed as the element content on a dry ash-free basis Determined by the following calculation:

[0030] .

[0031] Furthermore, the real-time optimal control parameters are determined based on the real-time coal quality information and operation data, including:

[0032] Calculate the received volatile matter content and the total air volume of the boiler based on the real-time coal quality information entering the furnace;

[0033] Determine the real-time dynamic secondary air door opening and burnout air door opening according to the received base volatile matter content;

[0034] The boiler combustion is controlled dynamically in real time according to the total air volume of the boiler, the opening of the secondary air door and the opening of the burnout air door.

[0035] Furthermore, the combustion control module performs combustion control through a signal generator and a PID controller. The signal generator is used to determine a control signal according to the total air volume of the boiler, the secondary air door opening and the burnout air door opening. The PID controller is used to change a corresponding set value according to the control signal.

[0036] In a second aspect, the present invention provides a combustion control device for deep peak regulation of a coal-fired power plant, comprising:

[0037] Data acquisition and communication module, used to communicate with the DCS system and MIS system respectively to obtain real-time boiler operation data and exhaust gas composition data;

[0038] The data analysis and processing module is used to calculate the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace. The calculation model is a model of the corresponding relationship between the exhaust gas composition and the coal element content established based on the material balance principle and the coal combustion chemical process;

[0039] The control module is used to determine the real-time optimal control parameters according to the real-time coal quality information and operation data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

[0040] In summary, the present invention provides a combustion control system and equipment under deep peak regulation of coal-fired power plants. The system and equipment obtain the real-time operation data and exhaust gas composition data of the boiler; then use the preset calculation model to calculate the exhaust gas composition data to obtain real-time coal quality information entering the furnace. The calculation model is a model of the correspondence between exhaust gas composition and coal element content established according to the material balance principle and the coal combustion chemical process; finally, the real-time optimal control parameters are determined according to the real-time coal quality information entering the furnace and the operation data, and the boiler is dynamically controlled with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation. The present invention monitors and analyzes the exhaust gas composition of the boiler in real time, combines the preset calculation model to accurately obtain the coal quality information entering the furnace, and dynamically adjusts the combustion control parameters accordingly, thereby effectively solving the impact of coal quality changes on the pulverizing system, theoretical air volume and key operation parameter regulation, while reducing safety risks such as furnace ash accumulation and high-temperature corrosion, and improving the safety and economy of coal-fired units. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0042] Figure 1 A structural block diagram of a combustion control system for deep peak regulation of a coal-fired power plant provided by an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the connection between an intelligent plug-in control system and a DCS provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] See also Figure 1 This embodiment provides a combustion control system for deep peak regulation of a coal-fired power plant, including: a coal quality monitoring module, a coal quality soft measurement module and a combustion control module.

[0046] The coal quality monitoring module is used to obtain real-time boiler operation data and exhaust gas composition data.

[0047] It should be noted that the coal quality monitoring module is responsible for collecting key data during boiler operation, including but not limited to operating parameters such as temperature, pressure, flow rate, and components in exhaust gas (such as carbon dioxide, sulfur dioxide, oxygen, etc.). These data are crucial for subsequent analysis of coal quality characteristics because they directly reflect the current coal combustion situation.

[0048] The coal quality soft measurement module is used to calculate the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace. The calculation model is a model of the correspondence between the exhaust gas composition and the coal element content, which is established based on the principle of material balance and the chemical process of coal combustion.

[0049] It should be noted that soft sensing is a model-based approach that uses readily available process variables to estimate key variables that are difficult to measure directly.

[0050] In this embodiment, soft sensing technology is used to estimate the actual coal quality information entering the boiler. This is usually done through a preset calculation model, which is based on the principle of material balance (that is, all materials entering the system must be equal to the materials leaving the system plus any materials accumulated in the system) and the basic chemical reaction process of coal combustion. In simple terms, it is to reversely infer the specific properties of the original coal based on the known exhaust gas composition.

[0051] The combustion control module is used to determine the real-time optimal control parameters based on the real-time coal quality information and operating data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

[0052] It should be noted that the combustion control module can dynamically adjust the working state of the boiler based on the information obtained from the coal quality soft measurement module and other operating parameters, ensuring that a higher efficiency level can be achieved and potential safety hazards can be reduced even when using non-design coal types.

[0053] For example, different qualities of coal require different amounts of oxygen for complete combustion. By accurately understanding the coal quality information, the amount of air supplied to the boiler can be set more accurately to ensure that the fuel is fully burned while avoiding additional energy loss or NOx caused by excessive oxygen supply. x Generates more.

[0054] In addition to the total required air volume, the ratio and distribution of primary and secondary air also need to be considered in order to better organize the combustion process in the furnace, reduce the formation of local high-temperature areas, and reduce the risk of slagging.

[0055] For deep peak load regulation, rapid response to grid dispatch instructions is crucial. Combustion control optimized based on real-time coal quality data can help units reach target load points faster while maintaining good efficiency levels.

[0056] The present embodiment provides a combustion control system for deep peak regulation of a coal-fired power plant. By real-time monitoring and analysis of the exhaust gas composition of the boiler, combined with a preset calculation model, the quality information of the coal entering the furnace is accurately obtained, and the combustion control parameters are dynamically adjusted accordingly, thereby effectively solving the impact of coal quality changes on the pulverizing system, theoretical air volume and key operating parameter regulation, while reducing safety risks such as ash accumulation and slagging in the furnace and high-temperature corrosion, thereby improving the safety and economy of the coal-fired unit.

[0057] In one embodiment, the exhaust gas composition data is calculated using a preset calculation model to obtain real-time coal quality information entering the furnace, including:

[0058] Step 1: Obtain the volume share data of each type of gas from the exhaust gas composition data.

[0059] It should be noted that the volume share refers to the volume percentage of a certain component in a mixture. For example, in the flue gas produced by combustion, the volume proportion of CO2, O2, SO2 and other gases.

[0060] Step 2: Use the calculation model to calculate the volume share data of various gases to obtain the composition ratio of carbon and sulfur elements in the dry ash-free basis of coal.

[0061] It should be noted that dry ash-free basis (DAF) refers to the state of coal after removing moisture and ash. This can more accurately reflect the combustible part of coal.

[0062] Step 3: Based on the linear relationship between carbon on a dry ash-free basis and hydrogen and oxygen elements, calculate the composition ratio of hydrogen and oxygen elements in the dry ash-free basis of coal.

[0063] It should be noted that this step constructs a mathematical relationship between carbon, hydrogen and oxygen. Based on the C obtained in the previous step, the content of H and O can be estimated according to a preset linear relationship.

[0064] Step 4: Calculate the proportion of nitrogen based on the proportions of carbon, sulfur, hydrogen and oxygen, and determine the real-time quality information of coal entering the furnace based on the proportions of each element.

[0065] It should be noted that since the contents of the four elements C, S, H, and O are already known, and the sum of the main elements in coal is close to 100%, the content of N can be calculated. Finally, combining the information of all these elements, a complete description of the quality characteristics of the coal currently entering the furnace is formed.

[0066] This embodiment can effectively convert the easily measured exhaust gas components into the internal composition of coal that is difficult to measure directly through a calculation model. Such soft sensing methods are essential for real-time monitoring and adjustment of the operation of coal-fired power plants, especially when facing different qualities of coal, which can help maintain the best combustion efficiency, reduce pollution emissions, and improve the safety and economy of overall operations.

[0067] In a further embodiment, a calculation model is proposed, and the calculation expression of the model is as follows:

[0068] (1)

[0069] (2)

[0070] (3)

[0071] (4)

[0072] (5)

[0073] in,

[0074]

[0075] In the formula, , , , and They represent the composition ratios of carbon, sulfur, hydrogen, oxygen and nitrogen in the dry ash-free basis of coal respectively; and They represent the gas volume fractions of carbon dioxide and sulfur dioxide in the exhaust flue gas respectively; , and Respectively represent the sum of the standard gas amounts of carbon dioxide and sulfur dioxide, the standard gas amount of nitrogen, and the standard gas amount of oxygen calculated on a dry basis; represents the correction amount for unburned carbon loss; , , and All are dry ash-free composition characteristic coefficients; To take into account the unburned losses, the standard theoretical air volume is calculated on a dry basis; is the exhaust excess air coefficient, is the volume fraction of oxygen in air.

[0076] The H:C and O:C chemical bonds in coal play a major role second only to the C:C chemical bond. daf —C daf , O daf —C daf There is a good linear relationship between them; Formulas (3) and (4) express the dry ash-free hydrogen and dry ash-free oxygen of coal as linear functions of dry ash-free carbon, and their feasibility has also been confirmed by other studies, which shows that the typical variability of coal does not lie in its dry ash-free composition, but in its moisture and ash content. Using the laboratory analysis results of hundreds of typical domestic coals, the coefficients A1, A2, B1, and B2 in Formulas (3) and (4) can be determined.

[0077] This embodiment proposes a detailed calculation model to estimate the proportion of various elements in the dry ash-free basis (DAF) of coal, which is of great significance for the efficient operation and energy conservation and emission reduction of coal-fired power plants.

[0078] In a further embodiment, the exhaust excess air coefficient Determine according to the following calculation:

[0079] .

[0080] In a further embodiment, the correction amount for unburned carbon loss is Determine according to the following calculation:

[0081]

[0082] In the formula, is the average unburned carbon content in the ash, To receive the base ash, To receive base moisture, and are the proportions of fly ash and bottom ash, respectively. and are the carbon contents of fly ash and bottom slag, respectively.

[0083] In a further embodiment, the data obtained from the exhaust gas composition data at least includes volume share data of oxygen and sulfur dioxide, volume share data of carbon dioxide, Determined by the following calculation:

[0084]

[0085] In the formula, is the fuel property factor expressed as the element content on a dry ash-free basis, It is the gas volume share of oxygen in the exhaust gas.

[0086] In a further embodiment, the fuel property coefficient expressed as the element content on a dry ash-free basis Determined by the following calculation:

[0087] .

[0088] In combination with the above embodiment, when performing soft measurement of coal quality information entering the furnace, the above equations form an equation group, where C daf , H daf , O daf 、N daf , S daf , γCO2 and other six variables as unknowns; by measuring the oxygen content γO2, sulfur dioxide content γSO2, fly ash carbon content C fh The volume fraction of oxygen in the air φ, the volume fraction of fly ash 、Bottom slag share 、Carbon content of bottom slag C dz , coefficients A1, A2, B1, B2, etc. as constants, the dry ash-free element content C of coal can be completed daf , H daf , O daf 、N daf , S daf Solution; The received base moisture M in the equation group ar The calculation is performed by measuring the operating parameters of the coal mill; the received ash content A in the equation group ar Correction is performed through system energy balance analysis and iterative calculation.

[0089] In one embodiment, the real-time optimal control parameters are determined based on the real-time coal quality information and operation data, including:

[0090] Step 1: Calculate the received volatile matter content and the total air volume of the boiler based on the real-time coal quality information:

[0091] It should be noted that through the above-mentioned coal quality monitoring module and coal quality soft measurement module, C ar , A ar 、M ar elemental composition, while the volatile matter V ar It can be approximately calculated by mass balance:

[0092]

[0093] Based on the monitored elemental composition, the oxygen required for complete combustion of unit fuel (1g) can be calculated. If the air pollutants are calculated based on the generation of NO and SO2, the required amount of oxygen is:

[0094]

[0095] The air mass m required for complete combustion air (g) is:

[0096]

[0097] Assuming an ideal excess air ratio , the air density is , then the actual required air volume is:

[0098]

[0099] Consider the amount of coal fed into the furnace , then the total air volume of the boiler is:

[0100]

[0101] Step 2: Determine the real-time dynamic secondary air damper opening and burnout air damper opening according to the received base volatile matter content.

[0102] It should be noted that the initial setting of the secondary air damper opening is based on the data of previous combustion tests, which reflect the optimal air distribution under different working conditions. On this basis, a coarse adjustment loop based on coal quality monitoring is added. This loop will further adjust the opening of the secondary air damper according to the real-time calculated volatile content of the coal. Coal with higher volatile content requires more secondary air to support its rapid release of combustible gas, while coal with lower volatile content requires less secondary air to avoid problems caused by excessive oxygen supply.

[0103] Similar to the secondary air damper, the initial opening of the burnout damper is also based on the previous combustion test results. Similarly, a coarse adjustment loop based on coal quality monitoring is added, especially to adjust the opening of the burnout damper according to the change of volatile content. The burnout air is mainly used to ensure that the fuel is fully burned at the end of the furnace. For coals with high volatile content, a larger burnout damper opening may be required to ensure complete combustion; for coals with low volatile content, the opening can be appropriately reduced to avoid unnecessary air entry.

[0104] In addition, the amount of fuel can be coordinated and controlled based on the analysis of the quality of the coal entering the furnace. That is, the coal quality analysis data, especially the low calorific value data, is used to adjust the output of the pulverizer so that the energy released into the furnace matches the boiler demand. The low calorific value refers to the heat released when the unit mass of fuel is completely burned. It is one of the important indicators for evaluating coal quality. By adjusting the amount of fuel in real time, it is ensured that the boiler can provide sufficient steam production, while avoiding unstable combustion or reduced efficiency due to excessive or insufficient fuel.

[0105] Step 3: Control boiler combustion dynamically in real time based on the total air volume of the boiler, the secondary air door opening and the burnout air door opening.

[0106] The above control links can dynamically adjust various operating parameters according to real-time coal quality information, thereby improving combustion efficiency and economic benefits while ensuring safety. This refined management method is not only applicable to conventional operating conditions, but is also particularly suitable for handling complex operating conditions such as deep peak load regulation, providing power plants with greater flexibility and adaptability.

[0107] In a further embodiment, the combustion control module performs combustion control through a signal generator and a PID controller, the signal generator is used to determine the control signal according to the total air volume of the boiler, the secondary air valve opening and the burnout air valve opening, and the PID controller is used to change the corresponding set value according to the control signal.

[0108] Proportional-Integral-Derivative (PID) controllers are used to precisely adjust the actual air volume to achieve a target value. The PID controller compares the deviation between the set point (ideal air volume) and the actual measured value and adjusts the output signal accordingly to control the fan or other air volume control device.

[0109] The above is a detailed introduction to an embodiment of a combustion control system for deep peak regulation of a coal-fired power plant of the present invention. The following is a detailed introduction to an embodiment of a combustion control device for deep peak regulation of a coal-fired power plant of the present invention.

[0110] This embodiment provides a combustion control device for deep peak regulation of a coal-fired power plant, including:

[0111] The data acquisition and communication module is used to communicate with the DCS system and the MIS system respectively to obtain the real-time operation data of the boiler and the exhaust gas composition data.

[0112] The data analysis and processing module is used to calculate the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace. The calculation model is a model of the correspondence between the exhaust gas composition and the coal element content, which is established based on the principle of material balance and the chemical process of coal combustion.

[0113] The control module is used to determine the real-time optimal control parameters according to the real-time coal quality information and operation data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

[0114] It should be noted that the data acquisition and communication module is responsible for communicating with DCS and MIS to obtain the operating data required for calculation and control. DCS (Distributed Control System) is a distributed control system responsible for monitoring and controlling various equipment and processes in coal-fired power plants. MIS (Management Information System) is a management information system, which is usually used to store and manage various operating data and historical records of coal-fired power plants.

[0115] The control module is used to realize automatic control operations, including PID algorithm, control logic and real-time control strategy.

[0116] The data analysis and processing module is used to analyze and optimize various indicators and parameters in the control process and generate control analysis and optimization reports.

[0117] Large power plants generally use distributed control systems (DCS) to achieve automated control in the process of power production. In order to further improve combustion efficiency and economy, the combustion optimization control device of this embodiment is introduced as an external system. These devices need to communicate with the existing DCS system in real time to ensure timely data exchange and effective execution of control instructions.

[0118] In terms of communication protocol, the combustion optimization control equipment uses the Modbus protocol to exchange data with the DCS system. Modbus is a communication protocol widely used in the field of industrial control and is supported by many DCS hardware manufacturers. The intelligent external controller establishes two-way communication with the DCS system through the MODBUS communication card. At the same time, the external controller is also connected to the plant-level management information system (MIS) to obtain coal type and quality data. These data are transmitted in the form of 4~20mA analog signals.

[0119] The intelligent external controller consists of two parts: the host computer and the slave computer. The host computer is responsible for the configuration and debugging of the control strategies such as the total air volume and the damper opening. Once the debugging is completed, the host computer will no longer be involved in the daily operation. The slave computer performs specific control tasks according to the control strategy provided by the host computer, including the real-time closed-loop control of the total air volume, the secondary damper opening, the burnout damper opening and the coal mill unit.

[0120] The intelligent external controller includes a data analysis and processing module, which is used to develop software to implement the following functions: soft measurement of coal quality, that is, calculating the real-time quality information of coal entering the furnace based on the exhaust gas composition and other monitoring data; optimization calculation, that is, optimizing the total air volume, secondary air door opening, burnout air door opening and control variables of the pulverizer unit; data visualization, that is, providing a graphical interface to display key parameters and optimization results.

[0121] The intelligent plug-in controller is equipped with an optimization control program, which encapsulates the developed data analysis modules (such as coal quality soft measurement algorithm and low-load operation boiler combustion optimization control algorithm) to form a unified overall program. The program provides standardized input data interface and output instruction interface to the outside. The optimization control program runs on an industrial-grade server and provides a Web-based visual operation interface for remote monitoring and adjustment. The program not only receives real-time monitoring data from the DCS system, but also optimizes and adjusts the operating variables according to multiple operating reference indicators, thereby realizing refined management of the boiler combustion process.

[0122] This embodiment provides a design of an intelligent external controller based on combustion optimization control equipment, which aims to achieve more efficient and flexible combustion control through advanced data analysis technology and optimization algorithms combined with the existing DCS system. It can not only adapt to the changes in coal of different qualities, but also cope with complex working conditions such as deep peak regulation, thereby improving the overall operating efficiency and economic benefits of the power station.

[0123] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combustion control system for deep peak regulation of a coal-fired power plant, characterized in that: include: Coal quality monitoring module, coal quality soft measurement module and combustion control module; The coal quality monitoring module is used to obtain real-time boiler operation data and exhaust gas composition data; The coal quality soft measurement module is used to calculate the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace. The calculation model is a model of the corresponding relationship between the exhaust gas composition and the coal element content established based on the material balance principle and the coal combustion chemical process; The combustion control module is used to determine the real-time optimal control parameters according to the real-time coal quality information entering the furnace and the operating data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

2. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 1, characterized in that: The exhaust gas composition data is calculated using a preset calculation model to obtain real-time coal quality information entering the furnace, including: Obtaining volume share data of various gases from the exhaust gas composition data; Using the calculation model, the volume share data of the various gases are calculated to obtain the composition ratios of carbon and sulfur in the dry ash-free basis of coal; According to the linear relationship between carbon element on dry ash-free basis and hydrogen element and oxygen element, the composition proportion of hydrogen element and oxygen element on dry ash-free basis of coal is calculated; The composition ratio of the nitrogen element is calculated based on the composition ratio of the carbon element, the sulfur element, the hydrogen element and the oxygen element, and the real-time coal quality information entering the furnace is determined based on the composition ratio of each element.

3. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 2, characterized in that: The calculation expression of the calculation model is as follows: in, In the formula, , , , and They represent the composition ratios of carbon, sulfur, hydrogen, oxygen and nitrogen in the dry ash-free basis of coal respectively; and They represent the gas volume fractions of carbon dioxide and sulfur dioxide in the exhaust flue gas respectively; , and Respectively represent the sum of the standard gas amounts of carbon dioxide and sulfur dioxide, the standard gas amount of nitrogen, and the standard gas amount of oxygen calculated on a dry basis; represents the correction amount for unburned carbon loss; , , and All are dry ash-free composition characteristic coefficients; To take into account the unburned losses, the standard theoretical air volume is calculated on a dry basis; is the exhaust excess air coefficient, is the volume fraction of oxygen in air.

4. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 3, characterized in that: Exhaust Excess Air Coefficient Determine according to the following calculation: 。 5. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 3, characterized in that: The correction amount for the unburned carbon loss is Determine according to the following calculation: In the formula, is the average unburned carbon content in the ash, To receive the base ash, To receive base moisture, and are the proportions of fly ash and bottom ash, respectively. and are the carbon contents of fly ash and bottom slag, respectively.

6. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 3, characterized in that: The data obtained from the exhaust gas composition data at least include the volume share data of oxygen and sulfur dioxide, the volume share data of carbon dioxide Determined by the following calculation: In the formula, is the fuel property factor expressed as the element content on a dry ash-free basis, It is the gas volume share of oxygen in the exhaust gas.

7. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 6, characterized in that: The fuel property coefficient expressed as the element content on a dry ash-free basis Determined by the following calculation: 。 8. The combustion control system for deep peak regulation of a coal-fired power plant according to any one of claims 1 to 7, characterized in that: Determining the real-time optimal control parameters according to the real-time coal quality information entering the furnace and the operation data includes: Calculate the received volatile matter content and the total air volume of the boiler according to the real-time coal quality information entering the furnace; Determining the real-time dynamic secondary air door opening and burnout air door opening according to the received base volatile matter content; The boiler combustion is dynamically controlled in real time according to the total air volume of the boiler, the secondary air door opening and the burnout air door opening.

9. The combustion control system for deep peak regulation of a coal-fired power plant according to claim 8, characterized in that: The combustion control module performs combustion control through a signal generator and a PID controller. The signal generator is used to determine a control signal according to the total air volume of the boiler, the secondary air door opening and the burnout air door opening. The PID controller is used to change a corresponding set value according to the control signal.

10. A combustion control device for deep peak regulation of a coal-fired power plant, characterized in that: include: Data acquisition and communication module, used to communicate with the DCS system and MIS system respectively to obtain real-time boiler operation data and exhaust gas composition data; A data analysis and processing module, for calculating the exhaust gas composition data using a preset calculation model to obtain real-time coal quality information entering the furnace, wherein the calculation model is a model of the corresponding relationship between the exhaust gas composition and the coal element content established according to the material balance principle and the coal combustion chemical process; The control module is used to determine the real-time optimal control parameters according to the real-time coal quality information entering the furnace and the operating data, and dynamically control the boiler with the real-time optimal control parameters to achieve combustion optimization under deep peak regulation.

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