A boiler combustion intelligent control method and system based on coal powder wind online monitoring

Abstract

The present application relates to a kind of based on coal powder wind online monitoring boiler combustion intelligent control system, including boiler combustion intelligent control system, multivariate field comprehensive monitoring system, into the furnace coal quality component monitoring system, primary air powder flow rate concentration monitoring system, acoustic temperature field monitoring system, CO online monitoring system, information integration management system, J2EE multilayer architecture body system, intelligent combustion closed-loop control system, primary air level control system, secondary air intelligent air distribution control system and steam-water system optimization control system.The boiler combustion intelligent control method and system based on coal powder wind online monitoring, propose the fine and intelligent operation technical scheme of boiler balance, stable combustion and high efficiency based on coal, powder and wind full cycle real-time online monitoring, replace traditional PID control using the predictive control technology based on online model identification, for steam temperature, steam pressure and NOx etc., with large hysteresis, multivariable and complex coupling control, improve system control quality, realize closed-loop control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control of boiler combustion, in particular to a boiler combustion intelligent control method and system based on online monitoring of coal powder wind. BACKGROUND

[0002] A reasonable boiler combustion state is a result of systematic multi-objective collaborative operation, for example, for the coking control of the heating surface, in addition to starting from the aspects of coal quality and soot blowing, the uniformity of the primary air speed and the deviation degree of the combustion cutting circle formed by the primary air speed, the influence of the secondary air distribution on the coal burnout characteristics under the air staging combustion, and the influence on the indexes of NOx, combustion efficiency, wall temperature and the like need to be considered. At present, the integrated research on the overall target of boiler combustion is a weak link. The published research on intelligent control technology of boiler combustion has different focuses and different algorithms, for example, the boiler combustion optimization system and method based on numerical simulation and artificial intelligence proposed in Chinese patent CN113177352 A focus on using the existing operation data of DCS to obtain the three-dimensional physical field of the boiler through numerical simulation technology, and constructing a correlation knowledge base to guide the optimized operation of the boiler under different conditions, without considering the measurement defects of the existing operation data and the influence of the coal powder wind. For another example, the intelligent control method and system for coal-fired boiler of power station based on neural network prediction proposed in Chinese patent CN110673482 A focus on taking the neural network prediction algorithm as the core, screening the optimal prediction value and calculating the optimal prediction deviation, realizing the advanced control based on the prediction results, and fully tapping the control rules hidden in the historical data, which focuses on the theoretical algorithm model research. At present, the power industry is actively promoting the construction of intelligent power plants. The operation automation and intelligence degree of the boiler combustion system as the core system of the thermal power unit has a great influence on the overall safety, economy and environmental protection of the unit, and is also the difficulty of the current unit operation adjustment. The integrated research on the overall target of boiler combustion is a weak link. SUMMARY

[0003] (I) Technical problems solved

[0004] In view of the deficiencies of the prior art, the present application provides a boiler combustion intelligent control method and system based on online monitoring of coal powder wind, which has the advantages of rapid prediction and adjustment of the change state of the furnace combustion by the desuperheating system, and solves the problem that the power industry is actively promoting the construction of intelligent power plants, and the operation automation and intelligence degree of the boiler combustion system as the core system of the thermal power unit has a great influence on the overall safety, economy and environmental protection of the unit.

[0005] (II) Technical solutions

[0006] In order to achieve the above object, the present application provides the following technical scheme: a boiler combustion intelligent control system based on coal powder wind online monitoring, comprising a boiler combustion intelligent control system, a multivariate field comprehensive monitoring system, a coal quality component monitoring system, a primary air powder flow velocity and concentration monitoring system, a sound wave temperature field monitoring system, a CO online monitoring system, an information integrated management system, a J2EE multilayer architecture system, an intelligent combustion closed loop control system, a primary air regulation control system, a secondary air intelligent air distribution control system and a steam-water system optimization control system, the output end of the boiler combustion intelligent control system is electrically connected with the input end of the multivariate field comprehensive monitoring system, the output end of the multivariate field comprehensive monitoring system is electrically connected with the input end of the coal quality component monitoring system, the output end of the coal quality component monitoring system is electrically connected with the input end of the primary air powder flow velocity and concentration monitoring system, the output end of the primary air powder flow velocity and concentration monitoring system is electrically connected with the input end of the sound wave temperature field monitoring system, the output end of the sound wave temperature field monitoring system is electrically connected with the input end of the CO online monitoring system, the output end of the CO online monitoring system is electrically connected with the input end of the information integrated management system, the output end of the information integrated management system is electrically connected with the input end of the J2EE multilayer architecture system, the output end of the boiler combustion intelligent control system is electrically connected with the input end of the intelligent combustion closed loop control system, the output end of the intelligent combustion closed loop control system is electrically connected with the input end of the primary air regulation control system, the output end of the primary air regulation control system is electrically connected with the input end of the secondary air intelligent air distribution control system, and the output end of the secondary air intelligent air distribution control system is electrically connected with the input end of the steam-water system optimization control system.

[0007] Further, the secondary air intelligent air distribution control system comprises a closed loop air supply predictive control system, an intelligent SOFA air rate regulation system and a secondary air box air distribution control system, the output end of the closed loop air supply predictive control system is electrically connected with the input end of the intelligent SOFA air rate regulation system, and the output end of the intelligent SOFA air rate regulation system is electrically connected with the input end of the secondary air box air distribution control system.

[0008] Further, the CO online monitoring system is composed of a CEMS sampling probe integrated system, a heater, a back flushing switching device, a sampling pipeline system, a negative pressure generator, a CO analyzer, a measuring cell and a CO concentration monitoring instrument.

[0009] Further, the information integrated management system is presented from the following aspects: a safety guarantee system, a standard specification system, a three-dimensional model library, a three-dimensional platform engine, a visual display, a data management subsystem and an operation and maintenance support subsystem.

[0010] Further, the multi-variable field comprehensive monitoring system can perform information fusion on the coal quality composition monitoring system, the primary air powder flow rate and concentration monitoring system, the acoustic wave temperature field monitoring system, and the CO online monitoring system, and can perform online monitoring on key field information of the boiler combustion process.

[0011] Further, the coal quality composition monitoring system can perform online and continuous analysis and diagnosis on industrial components and characteristics of the coal quality in the whole process, the primary air powder flow rate and concentration monitoring system can realize real-time online measurement of the non-contact full cross-section primary air powder flow rate and concentration based on an array type electrostatic induction technology, the acoustic wave temperature field monitoring system can realize real-time online monitoring of high-temperature flue gas in the furnace based on a flue gas temperature measurement method based on acoustic waves, and the CO online monitoring system can measure the CO concentration of a large-scale flue cross-section by using a full cross-section CO concentration mixed sampling technology, and can obtain accurate measurement of the CO concentration distribution of the air preheater inlet flue.

[0012] Further, the information integration management system can be presented to the user in a graphical manner, thereby helping the front-line operators to better understand the change of the combustion field, and presenting the effect of the combustion adjustment in real time in cooperation with the closed-loop control logic of the system.

[0013] Further, the J2EE multi-layer architecture system is divided into three parts of a presentation layer, a business logic layer, and a data layer, and the coupling degree of the functions and technologies between the layers of the platform can be reduced to the minimum.

[0014] Further, the intelligent combustion closed-loop control system can realize intelligent operation control of the total amount of the secondary air and the flow rate of the secondary air small damper by using intelligent modeling and advanced control technology.

[0015] A boiler combustion intelligent control method based on coal powder air online monitoring, comprising the following steps:

[0016] 1) The multi-variable field comprehensive monitoring system and the intelligent combustion closed-loop control system can be controlled to be turned on by the boiler combustion intelligent control system.

[0017] 2) The multi-variable field comprehensive monitoring system can be installed on a newly designed boiler equipment, and the online monitoring of key field information of the boiler combustion process can be realized by using the industrial components of the coal quality, the primary air powder flow rate and concentration, the furnace cross-section temperature field, and the CO full cross-section measurement technology.

[0018] 3) According to the online monitoring requirements of the multi-variable field comprehensive monitoring system on the boiler, the coal quality composition monitoring system, the primary air powder flow rate and concentration monitoring system, the acoustic wave temperature field monitoring system, the CO online monitoring system, and the information integration management system can perform detailed online monitoring on the key field information of the boiler.

[0019] 4) The coal quality entering the furnace composition monitoring system can perform online and timely continuous analysis and diagnosis on the industrial components and characteristics of the coal quality entering the furnace, the primary air powder flow rate concentration monitoring system can perform full cross-section sensing and measurement on the coal powder flowing through the pipeline, the acoustic wave temperature field monitoring system can enable the operating personnel to visually and clearly observe the combustion state in the furnace, the CO online monitoring system can measure the CO concentration of the large-scale flue cross-section to obtain accurate measurement of the CO concentration distribution of the air preheater inlet flue, and the information integration management system can enable the operating personnel to better understand the change of the combustion field;

[0020] 5) According to the combustion condition of the boiler and the online monitoring condition, the J2EE multi-layer architecture system can minimize the functional and technical coupling degree between the layers of the platform;

[0021] 6) The intelligent combustion closed-loop control system is installed on the newly designed boiler equipment, and intelligent operation control of the total amount of secondary air and the flow of secondary air small damper is realized through intelligent modeling and advanced control technology;

[0022] 7) According to the online monitoring condition of the intelligent combustion closed-loop control system, the primary air regulation control system, the secondary air intelligent air distribution control system and the steam-water system optimization control system can accurately control each key system of the boiler;

[0023] 8) The primary air regulation control system can analyze and calculate the measured parameters, and send control signals to the coal powder concentration and flow rate regulation device to the electric actuators of each device for action;

[0024] 9) The secondary air intelligent air distribution control system can control the closed-loop air supply prediction control system, the intelligent SOFA air rate regulation system and the secondary air box air distribution control system;

[0025] 10) The closed-loop air supply prediction control system uses model identification technology to establish an accurate dynamic model between the air supply fan dynamic blade opening, the primary air fan dynamic blade opening, the boiler main control and the oxygen content, the intelligent SOFA air rate regulation system can control the SCR inlet NOx, the reheat steam temperature, the acoustic wave temperature field average value and the front screen outlet superheated steam temperature, and the secondary air box air distribution control system can adjust the total opening of the left and right large air boxes, and control the balance combustion in the depth direction of the furnace according to the total opening ratio of the front and rear large air boxes;

[0026] 11) According to the data obtained by online monitoring, the steam-water system optimization control system can construct a furnace radiation intensity index through data fusion technology, which can more accurately express the influence of combustion on the steam-water parameters.

[0027] (Three) beneficial effects

[0028] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0029] 1. The intelligent control method and system for boiler combustion based on online monitoring of coal powder and wind, the intelligent control system for boiler combustion can control the opening and closing of the multi-variable field comprehensive monitoring system and the intelligent combustion closed-loop control system, the coal quality composition monitoring system, the primary air powder flow rate and concentration monitoring system, the acoustic wave temperature field monitoring system, the CO online monitoring system, the information integration management system and the J2EE multi-layer architecture system in the multi-variable field comprehensive monitoring system can realize online monitoring of key field information in the boiler combustion process according to the industrial composition of the coal quality, the primary air powder flow rate and concentration, the cross-section temperature field of the furnace, and the CO full cross-section measurement technology, and the complex combustion field monitoring information in the furnace is fused through the combustion field information integration technology to provide a basis for the comprehensive intelligent combustion closed-loop control of the boiler, the real-time online monitoring of the coal, powder and wind in the whole cycle is used to propose a fine and intelligent operation technical solution for balanced, stable combustion and high efficiency of the boiler, the predictive control technology based on online model identification is used to replace the traditional PID control, the steam temperature, steam pressure and NOx have large hysteresis, multi-variable and complex coupling control, the system control quality is improved, and closed-loop control is realized.

[0030] 2. The intelligent control method and system for boiler combustion based on online monitoring of coal powder and wind, the intelligent combustion closed-loop control system can realize intelligent operation control of the total amount of secondary air and the flow of secondary air small damper according to the real-time online monitoring data of the industrial composition of the coal quality, the primary air powder flow rate and concentration, the cross-section temperature field of the furnace, and the CO full cross-section measurement through intelligent modeling and advanced control technology, the indexes such as NOx emission in the furnace, the heat load at the outlet of the furnace and the combustion efficiency reach a comprehensive optimal balance, the intelligent steam-water control technology based on the temperature field feedforward signal in the furnace is researched, the coordination between the boiler and the steam-water control system, the steam temperature and the oxygen content closed-loop control system are optimized, the influence of combustion on the steam-water parameters can be more accurately expressed through the data fusion technology, and the quick prediction and adjustment of the desuperheating system to the change state of combustion in the furnace are realized. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present application;

[0032] Figure 2 It is a step schematic diagram of the secondary air intelligent air distribution control system in the structure of the present application;

[0033] Figure 3 It is a step schematic diagram of the CO online monitoring system in the structure of the present application;

[0034] Figure 4 It is a step schematic diagram of the information integration management system in the structure of the present application.

[0035] In the figure: 1, boiler combustion intelligent control system; 2, multi-variable field comprehensive monitoring system; 3, coal quality component monitoring system; 4, primary air powder flow velocity and concentration monitoring system; 5, acoustic wave temperature field monitoring system; 6, CO online monitoring system; 7, information integration management system; 8, J2EE multi-layer architecture system; 9, intelligent combustion closed-loop control system; 10, primary air regulation control system; 11, secondary air intelligent air distribution control system; 12, steam-water system optimization control system; 13, closed-loop air supply predictive control system; 14, intelligent SOFA air rate regulation system; 15, secondary air box air distribution control system. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] Please refer to Figures 1-4 The boiler combustion intelligent control system based on coal powder air online monitoring in the embodiment includes the boiler combustion intelligent control system 1, the multi-variable field comprehensive monitoring system 2, the coal quality component monitoring system 3, the primary air powder flow velocity and concentration monitoring system 4, the acoustic wave temperature field monitoring system 5, the CO online monitoring system 6, the information integration management system 7, the J2EE multi-layer architecture system 8, the intelligent combustion closed-loop control system 9, the primary air regulation control system 10, the secondary air intelligent air distribution control system 11, and the steam-water system optimization control system 12. The output end of the boiler combustion intelligent control system 1 is electrically connected with the input end of the multi-variable field comprehensive monitoring system 2. The output end of the multi-variable field comprehensive monitoring system 2 is electrically connected with the input end of the coal quality component monitoring system 3. The output end of the coal quality component monitoring system 3 is electrically connected with the input end of the primary air powder flow velocity and concentration monitoring system 4. The output end of the primary air powder flow velocity and concentration monitoring system 4 is electrically connected with the input end of the acoustic wave temperature field monitoring system 5. The output end of the acoustic wave temperature field monitoring system 5 is electrically connected with the input end of the CO online monitoring system 6. The output end of the CO online monitoring system 6 is electrically connected with the input end of the information integration management system 7. The output end of the information integration management system 7 is electrically connected with the input end of the J2EE multi-layer architecture system 8. The output end of the boiler combustion intelligent control system 1 is electrically connected with the input end of the intelligent combustion closed-loop control system 9. The output end of the intelligent combustion closed-loop control system 9 is electrically connected with the input end of the primary air regulation control system 10. The output end of the primary air regulation control system 10 is electrically connected with the input end of the secondary air intelligent air distribution control system 11. The output end of the secondary air intelligent air distribution control system 11 is electrically connected with the input end of the steam-water system optimization control system 12.

[0038] A boiler combustion intelligent control method based on coal powder wind online monitoring, comprising the following steps:

[0039] 1) The boiler combustion intelligent control system 1 can control the opening of the multivariate field comprehensive monitoring system 2 and the intelligent combustion closed-loop control system 9;

[0040] 2) The multivariate field comprehensive monitoring system 2 is installed on the newly designed boiler equipment, which can realize online monitoring of key field information of the boiler combustion process by measuring industrial components of the coal quality, primary air powder flow rate and concentration, furnace cross-section temperature field, and CO full cross-section measurement technology;

[0041] 3) According to the online monitoring requirements of the multivariate field comprehensive monitoring system 2 for the boiler, the coal quality component monitoring system 3, the primary air powder flow rate and concentration monitoring system 4, the acoustic temperature field monitoring system 5, the CO online monitoring system 6, and the information integration management system 7 can perform detailed online monitoring on each key field information of the boiler;

[0042] 4) The coal quality component monitoring system 3 can perform online and continuous analysis and diagnosis of industrial components and characteristics of the coal quality, the primary air powder flow rate and concentration monitoring system 4 can measure the full cross-section of the coal powder flowing through the pipeline, the acoustic temperature field monitoring system 5 can enable the operator to clearly observe the combustion state in the furnace, the CO online monitoring system 6 can measure the CO concentration of the large-scale flue cross-section, and the information integration management system 7 can enable the operator to better understand the changes in the combustion field;

[0043] 5) According to the combustion condition and online monitoring condition of the boiler, the J2EE multi-layer architecture system 8 can minimize the functional and technical coupling between the layers of the platform;

[0044] 6) The intelligent combustion closed-loop control system 9 is installed on the newly designed boiler equipment, which realizes intelligent operation control of the secondary air total amount and the secondary small air door flow through intelligent modeling and advanced control technology;

[0045] 7) According to the online monitoring condition of the intelligent combustion closed-loop control system 9 for the boiler, the primary air regulation control system 10, the secondary air intelligent air distribution control system 11, and the steam-water system optimization control system 12 can perform precise control on each key system of the boiler;

[0046] 8) The primary air regulation control system 10 can analyze and calculate the measured parameters and send control signals to the coal powder concentration and flow rate regulation devices to act on the electric actuators of each device;

[0047] 9) The secondary air intelligent distribution control system 11 can control the closed-loop air supply predictive control system 13, the intelligent SOFA air rate regulation system 14, and the secondary air box distribution control system 15;

[0048] 10) The closed-loop air supply predictive control system 13 uses model identification technology to establish an accurate dynamic model between the air supply fan dynamic blade opening, the primary air fan dynamic blade opening, and the boiler main control and oxygen content, the intelligent SOFA air rate regulation system 14 can control the SCR inlet NOx, the reheat steam temperature, the acoustic temperature field average, and the front screen outlet superheated steam temperature, and the secondary air box distribution control system 15 can adjust the total opening of the left and right large air boxes, and control the balance combustion in the furnace depth direction according to the front and rear large air box total opening ratio;

[0049] 11) According to the data obtained by online monitoring, the steam-water system optimization control system 12 constructs the in-furnace radiation intensity index through data fusion technology, which can more accurately express the influence of combustion on steam-water parameters.

[0050] The secondary air intelligent distribution control system 11 includes the closed-loop air supply predictive control system 13, the intelligent SOFA air rate regulation system 14, and the secondary air box distribution control system 15, the output end of the closed-loop air supply predictive control system 13 is electrically connected with the input end of the intelligent SOFA air rate regulation system 14, the output end of the intelligent SOFA air rate regulation system 14 is electrically connected with the input end of the secondary air box distribution control system 15, the CO online monitoring system 6 is composed of a CEMS sampling probe integrated system, a heater, a back flushing switching device, a sampling pipeline system, a negative pressure generator, a CO analyzer, a measuring cell, and a CO concentration monitoring instrument, the information integrated management system 7 is presented from the aspects of safety guarantee system, standard specification system, three-dimensional model library, three-dimensional platform engine, visualization display, data management subsystem, and operation and maintenance support subsystem, and the boiler combustion intelligent control system 1 can control the opening or closing of the multivariable field comprehensive monitoring system 2 and the intelligent combustion closed-loop control system 9.

[0051] The multivariate field comprehensive monitoring system 2 is a boiler combustion multivariate field comprehensive monitoring technology. The multivariate field comprehensive monitoring system 2 can perform information fusion on the coal quality composition monitoring system 3, the primary air powder flow rate and concentration monitoring system 4, the acoustic wave temperature field monitoring system 5 and the CO online monitoring system 6. The high temperature and high dust environment in the furnace makes it difficult to monitor the combustion state information in real time. However, the high NOx emission, the heating surface coking and the high flue gas temperature are often affected by the key data such as the coal quality composition, the uniformity of the primary air powder flow rate and concentration, the flue gas temperature distribution at the furnace outlet and the furnace water wall thermal load. The multivariate field comprehensive monitoring system 2 realizes the online monitoring of the key field information of the boiler combustion process by using the industrial composition of the coal quality, the primary air powder flow rate and concentration, the furnace cross section temperature field and the CO full cross section measurement technology. The complex combustion field monitoring information in the furnace is fused through the combustion field information integration technology, thereby providing a basis for the boiler comprehensive intelligent combustion closed loop control.

[0052] The coal quality composition monitoring system 3 is an online monitoring technology of the industrial composition of the coal quality. The intelligent artificial ray method is used to realize the real-time online monitoring of the moisture, ash content and low calorific value of the coal quality. The intelligent artificial ray uses low energy rays, and the penetration energy is weak. A few millimeter steel plates can completely shield the artificial rays. There is no additional ray outside the equipment. The online monitoring technology of the industrial composition of the coal quality effectively solves the problem of the data lag in the laboratory. The coal quality composition monitoring system 3 can continuously analyze and diagnose the industrial composition and characteristics of the coal quality in real time, realizes the dynamic coupling of the coal quality and the boiler combustion, and improves the economy and safety of the boiler operation.

[0053] The primary air powder flow rate and concentration monitoring system 4 is an online monitoring technology of the primary air powder flow rate and concentration. The primary air powder flow rate and concentration monitoring system 4 uses the array type electrostatic induction technology to realize the real-time online measurement of the non-contact full cross section primary air powder flow rate and concentration. The measurement probe adopts a non-contact ring or arc structure design. The inner diameter of the sensor is consistent with the inner diameter of the primary air powder pipeline, which can replace part of the coal powder pipeline, maximally reduce the wear caused by the impact of coal powder and the influence of the probe on the coal powder flow, realize long-term reliable measurement, and accurately monitor the full cross section coal powder flow state of the primary air pipeline without being affected by the change of the coal powder flow mode. The array type sensor completely wraps the entire coal powder path. The accurate measurement is realized by combining the data fusion technology of the array type sensing electrode. The measurement sensor is installed on the primary air pipeline close to the outlet of the burner to perform full cross section sensing and measurement on the coal powder flowing through the pipeline, and accurately and reliably measure the flow rate and concentration of the coal powder in each pipeline.

[0054] The acoustic wave temperature field monitoring system 5 is an online monitoring technology for the acoustic wave temperature field of the furnace. The acoustic wave temperature field monitoring system 5 adopts a flue gas temperature measurement method based on acoustic waves to realize real-time online monitoring of high-temperature flue gas in the furnace. The technical principle is that the propagation speed of acoustic waves in a gas is a function of the temperature of the gas, and the acoustic wave speed calculation formula is as follows: c = (kRT / M) 1 / 2 wherein k is the ratio of the specific heat at constant pressure to the specific heat at constant volume of the gas medium, which is related to the composition and state of the gas; R is the molar gas constant, and its value is 8.314 J / mol.k; and M is the average kilomole mass of the gas. By combining computer control, acoustics, information processing and image processing technologies, acoustic wave gas temperature measurement of the temperature distribution of a certain cross section of the boiler is realized. Eight sets of acoustic wave generators and acoustic wave receivers are installed around the boiler. The speed of acoustic waves between each acoustic sensor is measured by measuring the acoustic wave flight time τ between the acoustic wave receivers on both sides of the furnace. The average temperature on these paths is calculated according to the formula. Then, the temperature distribution of a typical layer in the furnace is reconstructed by a temperature field image reconstruction algorithm. The acoustic wave measurement technology of the furnace temperature field enables the operating personnel to intuitively and clearly observe the combustion state in the furnace. On this basis, secondary air operation optimization control is realized, which is beneficial to improving the poor operation stability of the combustion system and the problem of flame deflection.

[0055] The CO online monitoring system 6 is a CO online monitoring technology based on full cross-section flue gas mixed sampling. The CO online monitoring system 6 adopts a full cross-section CO concentration mixed sampling technology to measure the CO concentration of a large-scale flue cross-section and obtain accurate measurement of the CO concentration distribution of the air preheater inlet flue, which is beneficial to guiding the boiler combustion adjustment and improving the boiler efficiency. The full cross-section CO concentration mixed sampling device is arranged in the vertical space between the denitration outlet flue and the air preheater outlet flue. All sampling pipeline systems are designed to be vertical or at a large inclination angle. The collected flue gas can flow from high pressure to low pressure in the sampling pipeline from top to bottom under the action of the differential pressure on the air preheater flue gas side without the need for an additional power source. This arrangement fully utilizes the characteristics of the equipment, is simple and reliable, and installs a CO analyzer on the full cross-section CO concentration mixed sampling device. The measurement pool can realize the integration of multiple CO concentration monitoring instruments such as infrared, ultraviolet, laser and in-situ types, and realize synchronous multi-point monitoring of the CO concentration of the denitration outlet cross-section.

[0056] The information integration management system 7 is a combustion field information integration technology. The combustion field data of the information integration management system 7 is presented to the user in a graphical manner, which helps the front-line operating personnel better understand the changes in the combustion field. The system's closed-loop control logic presents the effects of combustion adjustment in real time. The system is mainly presented by safety specifications and guarantee systems, data, model libraries, three-dimensional engines and visual displays.

[0057] The J2EE multi-layer architecture system 8 is a platform software architecture technology based on a J2EE multi-layer architecture system. The J2EE multi-layer architecture system 8 adopts an overall design of a platform software architecture based on a J2EE multi-layer architecture system. This design mode can reduce the coupling degree of functions and technologies between layers of the platform to the lowest level, and also reduces the influence of future technical upgrades on the overall structure to the lowest level. The platform is divided into three main parts, namely, a presentation layer, a business logic layer, and a data layer. The design of the presentation layer is based on web three-dimensional technology and can deeply display the change parameters of the combustion field through rotation and scaling. The business processing layer is mainly designed and implemented by using Java and Python, completes the construction of a three-dimensional engine, and uses a modularized mode to increase the expansibility of the system. The access to a relational database is uniformly designed and implemented based on the Hibernate technology, the database is operated in an object-oriented mode to simplify the access to the database, and the access to a real-time database is uniformly designed and implemented by using VC++, and the system is constructed based on the ACE technology system, which can improve the stability and expansibility of the interface layer.

[0058] The intelligent combustion closed-loop control system 9 is a comprehensive intelligent combustion closed-loop control technology for a boiler. The intelligent combustion closed-loop control system 9 can realize intelligent operation control of the total amount of secondary air and the flow of a secondary air damper according to the provided real-time online monitoring data of industrial components of the coal quality entering the furnace, the concentration of the primary air powder flow rate, the temperature field of the furnace cross section, and the CO full cross section measurement, so as to achieve comprehensive optimal balance of indexes such as NOx emission in the furnace, the heat load at the furnace outlet, and the combustion efficiency.

[0059] The primary air leveling control system 10 is a primary air leveling control technology based on wind powder monitoring. The primary air leveling control system 10 aims at the balance problem of air and coal powder fuel in multiple output pipelines from the coal powder separator of the coal mill. Based on the CFD two-phase flow simulation technology combined with field testing and experiments, according to the mode and principle of good adjustment performance, no jamming, no powder accumulation and no fixed resistance to the pipeline when the air and powder are not adjusted, a coal powder flow velocity balancing device is designed. The flow resistance of each pipeline is balanced by continuously changing the differential pressure at the outlet of the coal mill, so that the coal powder flow velocity at the outlet of each burner is kept balanced. The uniformity of the amount of coal powder entering each primary air pipeline is mainly affected by the distribution characteristics of the coal mill itself. The adjustment of the distribution of the coal powder before entering the pipeline is required. The uniformity of the flow field of the coal powder before entering the pipeline above the separator of the outlet of the coal mill is changed and the flow guiding technology is adopted. Based on the CFD simulation analysis of the coal powder, the coal powder concentration distribution adjustment device is designed to make the flow field distribution of the coal powder uniform before entering the pipeline, and the fine adjustment is performed through the flow guiding components to realize the adjustment and uniform distribution of the amount of coal powder. Based on the key parameters such as the accurate measurement of the coal powder flow velocity and the concentration distribution, the measurement parameters are analyzed and calculated through the automatic leveling control model, and the control signals are sent to the coal powder concentration and flow velocity adjustment device to act on each electric actuator, so that the coal powder flow velocity and flow at the outlet of each burner in the same layer are in a balanced state, thereby realizing the automatic adjustment under various working conditions.

[0060] The secondary air intelligent air distribution control system 11 can control the closed-loop air supply prediction control system 13, the intelligent SOFA air rate adjustment system 14 and the secondary air box air distribution control system 15. The steam-water system optimization control system 12 is a boiler steam-water system optimization control technology. The conventional DCS control system currently mainly uses the boiler main control and its differential acceleration form to represent the combustion feedforward. Each unit also uses the turning chamber smoke temperature as the combustion feedforward. The former is too simple to accurately express the influence range of the combustion system on the steam-water side parameters. The latter has obvious hysteresis and is extremely unfavorable for closed-loop control. The average value of the furnace outlet smoke temperature obtained by the sound wave temperature measurement reflects the radiation effect of the coal combustion after entering the furnace on the boiler water wall. Through data fusion technology, the in-furnace radiation intensity index is constructed, which can more accurately express the influence of combustion on the steam-water parameters. This index can be used as a feedforward parameter to optimize and transform the following several steam-water control systems:

[0061] (1) The water-coal ratio constitutes a coordinated control strategy to replace the feedwater control strategy, which can effectively avoid the water-coal control disorder caused by the fixed water-coal ratio function setting after the change of the calorific value of the coal, and greatly stabilize the separator outlet steam temperature and superheat degree, thereby providing stable boundary conditions for the supercritical unit superheat steam temperature control;

[0062] (2) As the feedforward of the main steam temperature control system, replace the original boiler main control feedforward, more accurate calculation of water injection desuperheating water flow and flue gas damper control, realize the stable control of main and reheat steam temperature under variable load conditions;

[0063] (3) As the feedforward of the reheat steam temperature control system, replace the original boiler main control feedforward, combined with the flue gas damper control system, control the reheat steam temperature and minimize the reheat steam temperature desuperheating water, improve the economic benefit of the unit.

[0064] The closed-loop air supply predictive control system 13 is a direct oxygen quantity optimization closed-loop air supply predictive control system. The closed-loop air supply predictive control system 13 directly closes the loop between the fan dynamic blade or variable frequency command and the oxygen quantity to control the air supply. An accurate dynamic model between the air supply fan dynamic blade opening, the primary air fan dynamic blade opening, the boiler main control and the oxygen quantity is established by using model identification technology. The system corrects the air-coal relationship in real time, no longer relies on the fixed air-coal relationship, ensures that the air quantity and the coal quantity are always in the proportion required by the actual oxygen quantity control, uses the predictive control technology to process the oxygen quantity large lag process, and the quality is obviously improved compared with the conventional PID control. The new oxygen quantity optimization strategy directly issues the air supply fan dynamic blade opening command according to the dynamic model and the oxygen quantity process value and the set value deviation. The measured total air quantity feedback measurement signal is only used as a dynamic protection intervention and does not participate in and affect the closed-loop control command under normal circumstances. In this way, the intermediate process is saved, the action of the air supply fan is faster and more accurate, and the problem of disturbance to the control system caused by the distortion of the air quantity measurement dynamic characteristics can be effectively avoided.

[0065] The intelligent SOFA air rate regulation system 14 is a low-nitrogen combustion intelligent SOFA air rate regulation system. The intelligent SOFA air rate regulation system 14 intelligently regulates the burnout air separation rate of the low-nitrogen burner secondary air system. Advanced predictive control technology is adopted. The SOFA zone and the main combustion zone air volume ratio is set by the multivariable predictive controller. The control targets are the SCR inlet NOx, the reheat steam temperature, the average value of the sound wave temperature field and the front screen outlet superheated steam temperature. The system solves the problem of obtaining the lowest SCR inlet NOx emission concentration under the condition of meeting the above index requirements according to the specific coal quality and efficiency index requirements of the boiler. The entire secondary air box height direction fine air distribution control strategy can be abstracted as a four-input four-output multivariable control system.

[0066] The secondary air box air distribution control system 15 is a fine air distribution control system in the width and depth directions of the secondary air box. The secondary air box air distribution control system 15 adjusts the air distribution in the two dimensions of the depth and width of the furnace according to the deviation of the flue gas temperature distribution reflected by the furnace acoustic temperature measurement system, adjusts the total opening of the left and right large air boxes, controls the balanced combustion in the width direction of the furnace, divides the air box opening into two groups of left and right according to the physical position, if the ratio is one, it means that the current combustion is balanced in the width direction and does not need to be changed, if the ratio is greater than or less than one, it means that the combustion is biased to the left wall or the right wall, and a bias needs to be added to one or several air box total openings in the burnout air and the main combustion zone according to the numerical value. The total opening ratio of the front and rear large air boxes controls the balanced combustion in the depth direction of the furnace, divides the air box opening into two groups of front and rear according to the physical position, if the ratio is one, it means that the current combustion is balanced in the depth direction and does not need to be changed, if the ratio is greater than or less than one, it means that the combustion is biased to the front wall or the back wall, and a bias needs to be added to one or several air box total openings in the burnout air and the main combustion zone according to the numerical value. Since it is not necessary to burn in the center with 100% accuracy, a dead zone needs to be set, and a bias needs to be added when the dead zone is exceeded.

[0067] The working principle of the above embodiment is:

[0068] (1) The boiler intelligent combustion control system 1 can control the opening and closing of the multivariate field comprehensive monitoring system 2 and the intelligent combustion closed-loop control system 9. The in-furnace coal quality composition monitoring system 3, the primary air powder flow rate and concentration monitoring system 4, the acoustic temperature field monitoring system 5, the CO online monitoring system 6, the information integration management system 7, and the J2EE multi-layer architecture system 8 in the multivariate field comprehensive monitoring system 2 can realize online monitoring of key field information in the boiler combustion process through in-furnace coal quality industrial composition, primary air powder flow rate and concentration, furnace cross-section temperature field, and CO full cross-section measurement technology, and through combustion field information integration technology, the complex combustion field monitoring information in the furnace is fused to provide a basis for boiler comprehensive intelligent combustion closed-loop control.

[0069] (2) A boiler balanced, stable combustion and efficient fine and intelligent operation technical scheme based on real-time online monitoring of coal, powder and wind throughout the cycle is proposed. The predictive control technology based on online model identification is used to replace the traditional PID control, which is suitable for steam temperature, steam pressure and NOx with large lag, multivariable and complex coupling control, improves the system control quality, and realizes closed-loop control.

[0070] (3) Through the primary air leveling control system 10, the secondary air intelligent air distribution control system 11, the steam-water system optimization control system 12, the closed-loop air supply prediction control system 13, the intelligent SOFA air rate adjustment system 14 and the secondary air box air distribution control system 15 in the intelligent combustion closed-loop control system 9, the intelligent operation control of the total amount of secondary air and the flow of secondary air damper can be realized according to the provided real-time online monitoring data of industrial components of coal into the furnace, primary air powder flow concentration, cross-section temperature field of the furnace, CO full cross-section measurement, intelligent modeling and advanced control technology, so that the indexes such as NOx emission in the furnace, furnace outlet heat load and combustion efficiency reach the comprehensive optimal balance.

[0071] (4) The intelligent steam-water control technology based on the feedforward signal of the furnace temperature field is researched, the steam-water parameter optimization control system is optimized, through the data fusion technology, the influence of combustion on the steam-water parameter can be more accurately expressed, and the rapid prediction adjustment of the desuperheating system to the change state of the furnace combustion is realized.

[0072] Compared with the prior art:

[0073] (1) The pulverizing system optimization technology based on coal composition and air powder state monitoring: reasonable mill and primary air powder state parameters are the basis of combustion control, the mill air temperature and air pressure setting parameters should be adjusted according to the change of coal composition, the distribution of coal powder into the boiler can be measured and controlled, and adjustment is carried out at the same time, which plays an important role in preventing the phenomenon of primary air walling and coking and coal powder blockage.

[0074] (2) Furnace flue gas temperature and flue gas composition distributed measurement and secondary air distribution control strategy: the non-contact flue gas temperature measurement technology based on sound wave velocity measurement is realized, the real-time display of the temperature and isotherm of the furnace outlet temperature measurement cross-section is realized, the mixed sampling device of the tail flue is used to extract the flue gas, the accurate measurement of the average concentration of CO in the flue is realized through the CO online analyzer, the dynamic and static model relationship between the secondary air damper system and the above distributed parameters is researched according to the state of the furnace flue gas temperature and flue gas composition parameters, the multivariable predictive control technology is adopted, and the intelligent control strategy of secondary air distribution is formed.

[0075] (3) Boiler steam-water system optimization technology based on furnace temperature field monitoring: through the data fusion technology, the furnace radiation intensity index is constructed, which can more accurately express the influence of combustion on the steam-water parameter, the index can be used as a feedforward parameter to optimize the main and reheat steam temperature control system, and the rapid prediction adjustment of the desuperheating system to the change state of the furnace combustion is realized.

[0076] (4) Based on the coal quality online monitoring, the primary air powder concentration and flow rate online monitoring, the in-furnace temperature field distribution online monitoring and the flue gas CO concentration total amount online monitoring, the boiler combustion multivariable field comprehensive monitoring is realized, at the same time, the model identification and prediction control technology is adopted, the boiler combustion air distribution, oxygen content and steam water system closed loop control on the in-furnace combustion field is realized, the balanced and stable combustion field is maintained, the boiler combustion efficiency is improved, the main and reheat steam temperature fluctuation range under the variable load is controlled, the flue gas temperature at the furnace outlet is controlled to relieve the heating surface coking, the SCR inlet NOx emission concentration and fluctuation range are reduced.

[0077] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying that there is any such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... a" does not, without more limitations, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0078] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, alternatives, and variations can be made in the embodiments without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents.

Claims

1. A boiler combustion intelligent control system based on coal powder wind online monitoring, comprising a boiler combustion intelligent control system (1), a multivariate field comprehensive monitoring system (2), a coal quality component monitoring system (3), a primary air powder flow velocity and concentration monitoring system (4), a sound wave temperature field monitoring system (5), a CO online monitoring system (6), an information integration management system (7), a J2EE multi-layer architecture system (8), an intelligent combustion closed-loop control system (9), a primary air regulation control system (10), a secondary air intelligent air distribution control system (11), and a steam-water system optimization control system (12), characterized in that: The output end of the boiler combustion intelligent control system (1) is electrically connected with the input end of the multivariate field comprehensive monitoring system (2), the output end of the multivariate field comprehensive monitoring system (2) is electrically connected with the input end of the coal quality component monitoring system (3) entering the furnace, the output end of the coal quality component monitoring system (3) entering the furnace is electrically connected with the input end of the primary air powder flow velocity concentration monitoring system (4), the output end of the primary air powder flow velocity concentration monitoring system (4) is electrically connected with the input end of the acoustic temperature field monitoring system (5), the output end of the acoustic temperature field monitoring system (5) is electrically connected with the input end of the CO online monitoring system (6), the output end of the CO online monitoring system (6) is electrically connected with the input end of the information integrated management system (7), and the output end of the information integrated management system (7) is electrically connected with the input end of the J2EE multilayer architecture system (8). ​ The output end of the boiler combustion intelligent control system (1) is electrically connected with the input end of the intelligent combustion closed-loop control system (9), the output end of the intelligent combustion closed-loop control system (9) is electrically connected with the input end of the primary air regulation control system (10), the output end of the primary air regulation control system (10) is electrically connected with the input end of the secondary air intelligent air distribution control system (11), and the output end of the secondary air intelligent air distribution control system (11) is electrically connected with the input end of the steam-water system optimization control system (12).

2. The intelligent control system for boiler combustion based on online monitoring of coal powder wind according to claim 1, characterized in that: The secondary air intelligent air distribution control system (11) comprises a closed-loop air supply predictive control system (13), an intelligent SOFA air rate regulation system (14) and a secondary air box air distribution control system (15), the output end of the closed-loop air supply predictive control system (13) is electrically connected with the input end of the intelligent SOFA air rate regulation system (14), and the output end of the intelligent SOFA air rate regulation system (14) is electrically connected with the input end of the secondary air box air distribution control system (15).

3. The intelligent control system for boiler combustion based on online monitoring of coal powder wind according to claim 1, characterized in that: The CO online monitoring system (6) is composed of a CEMS sampling probe integrated system, a heater, a back-blowing switching device, a sampling pipeline system, a negative pressure generator, a CO analyzer, a measuring pool and a CO concentration monitoring instrument.

4. The intelligent control system for boiler combustion based on online monitoring of coal powder wind according to claim 1, characterized in that: The information integrated management system (7) is presented from the aspects of a safety guarantee system, a standard specification system, a three-dimensional model library, a three-dimensional platform engine, visualization display, a data management subsystem and an operation and maintenance support subsystem.

5. The intelligent control system for boiler combustion based on online monitoring of pulverized coal wind according to claim 1, characterized in that: The multivariate field comprehensive monitoring system (2) performs information fusion on the coal quality component monitoring system (3) entering the furnace, the primary air powder flow velocity concentration monitoring system (4), the acoustic temperature field monitoring system (5) and the CO online monitoring system (6), and performs online monitoring on key field information in the boiler combustion process.

6. The intelligent control system for boiler combustion based on online monitoring of pulverized coal wind according to claim 1, characterized in that: The furnace coal quality component monitoring system (3) continuously analyzes and diagnoses the industrial components and characteristics of the furnace coal quality in the whole process. The primary air powder flow rate concentration monitoring system (4) realizes real-time online measurement of the non-contact full-section primary air coal powder flow rate concentration by using an array-type electrostatic induction technology. The acoustic wave temperature field monitoring system (5) realizes real-time online monitoring of the high-temperature flue gas in the furnace by using a flue gas temperature measurement method based on acoustic waves. The CO online monitoring system (6) measures the CO concentration of a large-scale flue section by using a full-section CO concentration mixed sampling technology, thereby obtaining accurate measurement of the CO concentration distribution of the air preheater inlet flue.

7. The intelligent control system for boiler combustion based on online monitoring of pulverized coal wind according to claim 1, characterized in that: The information integration management system (7) is a graphical way to present to the user.

8. The intelligent boiler combustion control system based on online monitoring of pulverized coal air according to claim 1, characterized in that: The J2EE multi-layer architecture system (8) is divided into three parts, namely, a presentation layer, a business logic layer, and a data layer, so as to minimize the coupling degree of the functions and technologies between the layers of the platform.

9. The intelligent control system for boiler combustion based on online monitoring of pulverized coal wind according to claim 1, characterized in that: The intelligent combustion closed-loop control system (9) realizes intelligent operation control of the secondary air total amount and the secondary small air damper flow by using intelligent modeling and control technology.

10. A method for intelligent control of boiler combustion based on online monitoring of pulverized coal air, based on the intelligent control system for boiler combustion based on online monitoring of pulverized coal air according to any one of claims 1-9, characterized in that, The method comprises the following steps: 1) The multi-variable field comprehensive monitoring system (2) and the intelligent combustion closed-loop control system (9) are controlled to be turned on by the boiler combustion intelligent control system (1). 2) The multi-variable field comprehensive monitoring system (2) is installed on the boiler equipment to realize online monitoring of the key field information of the boiler combustion process by using the industrial components of the furnace coal quality, the primary air powder flow rate concentration, the furnace cross-section temperature field, and the CO full-section measurement technology. 3) According to the online monitoring requirements of the multi-variable field comprehensive monitoring system (2) for the boiler, the furnace coal quality component monitoring system (3), the primary air powder flow rate concentration monitoring system (4), the acoustic wave temperature field monitoring system (5), the CO online monitoring system (6), and the information integration management system (7) are fused to carefully monitor the key field information of the boiler. 4) The furnace coal quality component monitoring system (3) continuously analyzes and diagnoses the industrial components and characteristics of the furnace coal quality. The primary air powder flow rate concentration monitoring system (4) senses and measures the coal powder flowing through the pipeline in the full section. The acoustic wave temperature field monitoring system (5) enables the operating personnel to intuitively and clearly observe the combustion state in the furnace. The CO online monitoring system (6) measures the CO concentration of a large-scale flue section to obtain accurate measurement of the CO concentration distribution of the air preheater inlet flue. The information integration management system (7) enables the operating personnel to better understand the changes in the combustion field. 5) According to the combustion condition and the online monitoring condition of the boiler, the J2EE multi-layer architecture system (8) minimizes the coupling degree of the functions and technologies between the layers of the platform. 6) The intelligent combustion closed-loop control system (9) is installed on the boiler equipment to realize intelligent operation control of the secondary air total amount and the secondary small air damper flow by using intelligent modeling and control technology. 7) According to the online monitoring of the intelligent combustion closed-loop control system (9), the primary air leveling control system (10), the secondary air intelligent distribution control system (11), and the steam-water system optimization control system (12) precisely control the key systems of the boiler; 8) The primary air leveling control system (10) analyzes and calculates the measured parameters and sends control signals to the coal powder concentration and flow rate regulating devices to act on the electric actuators of the devices; 9) The secondary air intelligent distribution control system (11) controls the closed-loop air supply prediction control system (13), the intelligent SOFA air rate regulating system (14), and the secondary air box distribution control system (15); 10) The closed-loop air supply prediction control system (13) uses model identification technology to establish an accurate dynamic model between the air supply fan dynamic blade opening, the primary air fan dynamic blade opening, the boiler main control, and the oxygen content, the intelligent SOFA air rate regulating system (14) controls the SCR inlet NOx, the reheated steam temperature, the average sound wave temperature field, and the front screen outlet superheated steam temperature, and the secondary air box distribution control system (15) adjusts the total opening of the left and right large air boxes and adjusts the ratio of the total opening of the front and rear large air boxes to control the balanced combustion in the depth direction of the furnace; 11) According to the data obtained from online monitoring, the steam-water system optimization control system (12) constructs the in-furnace radiation intensity index through data fusion technology, which can more accurately express the influence of combustion on steam-water parameters.

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