A boiler soot blowing method based on steam soot blowing and acoustic soot blowing collaborative control
Patent Information
- Application Number
- CN202510428039.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-10-16
AI Technical Summary
[0033]本发明的有益效果是，采用蒸汽吹灰和声波吹灰协同控制技术，综合两种吹灰系统的优点，显著地降低吹灰作业的成本、提高了管壁使用寿命。同时，引入积灰监测模块，实时追踪和记录锅炉受热面上非松散积灰的累积状态，实现了精确控制和优化操作。相比传统方法，本方法能够实现锅炉吹灰的闭环控制，并且极大程度的降低吹灰作业成本，在电场节能技术领域具有广泛的应用前景。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of energy-saving technology and intelligent control technology for coal-fired power plants, and in particular to an energy-saving technology method for a power plant boiler soot blowing system and a method for coordinated control of boiler steam soot blowing and acoustic soot blowing. Background Technology
[0002] With the rapid development of my country's economy, the demand for electricity in various sectors is constantly increasing, making the development of the power industry self-evident. Although the country is accelerating the optimization of its energy structure and developing clean energy, thermal power generation will still occupy an important position in my country's power generation sector due to the country's national conditions and the technological limitations of various power generation methods. Among these, coal is currently the main fuel source for thermal power generation because of my country's relatively abundant coal resources. The phenomenon of minerals in coal being deposited as ash on the heating surfaces of a boiler after combustion is called heating surface ash. Ash accumulation on the heating surfaces reduces the heat transfer capacity of the boiler unit, lowers boiler efficiency, and affects the normal operation of the unit. Due to the imperfect coal supply and blending system and poor coal quality in my country, the coal used by boiler units is mostly prone to ash accumulation and slagging. Furthermore, in recent years, many power companies have chosen to blend economical coal types to reduce power generation costs, resulting in the use of coal types deviating from the design coal types, which further exacerbates the ash accumulation problem on the heating surfaces at all levels. Power plants often use soot blowers to clean the heating surfaces based on a timed and quantitative strategy. This soot blowing method often ignores the actual ash accumulation on the heating surfaces, fails to achieve the ideal soot blowing effect, and also reduces the operating efficiency of the unit.
[0003] Steam soot blowing has drawbacks such as dead zones, inconvenient operation, and high maintenance costs. Furthermore, its frequent use of periodic soot blowing leads to indiscriminate blowing, severely impacting the safety and economy of heat exchange pipes. If the soot blowing frequency is set too low, ash accumulation becomes severe, reducing heat transfer efficiency. Conversely, a high frequency results in wasted steam and increased wear on the pipe walls from the high-temperature, high-pressure steam. Sonic soot blowing, on the other hand, offers advantages such as no dead zones, no impact on the lifespan of the heat exchange surface pipe walls, and flexible operation. However, sonic soot blowing itself has a lower intensity and is only suitable for removing loose ash. Most power plants switch back to steam soot blowing systems after about two months of operation with sonic soot blowers. This is mainly because the mechanism of sonic soot blowers relies on acoustic fatigue. The repeated action of acoustic oscillations applies cyclical tensile and compressive loads to the ash particles. After a certain number of cycles, the ash's bond gradually breaks down due to fatigue, and is further eroded by the flue gas flow and impacted by particles in the flue gas, causing it to detach. However, under the influence of sound waves, the ash layer on the heated surface gradually forms a non-loose ash layer with a cyclic stress-resistant structure. This ash accumulates over time and cannot be completely eliminated by sound waves, posing a significant challenge to the widespread application of sonic sootblowers. This is mainly because: practice and theory are disconnected; reliable theoretical guidance is lacking; sootblowing parameters such as the frequency, angle, arrangement, and blowing cycle of the sound source cannot be determined; there is insufficient theoretical analysis of ash on different heated surfaces; the most appropriate sootblowing method cannot be found; and corresponding feedback and adjustments cannot be made based on the sootblowing effect. All of these factors lead to unsatisfactory sootblowing results, uneven sootblowing, and easy damage to the sootblowing equipment. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing. This method achieves economic efficiency in boiler soot blowing by comprehensively utilizing data processing, deep learning, and optimization algorithms, meeting the economic operation requirements of modern power plants. In the early ash accumulation stage of boiler operation and management, acoustic soot blowing technology is employed to significantly reduce the cost of soot blowing operations. To achieve precise control and optimized operation, an ash accumulation monitoring module is introduced to track and record the accumulation status of non-loose ash on the boiler's heating surface in real time. Once the monitored ash accumulation level reaches a preset threshold, the system automatically activates the steam soot blower to thoroughly clean the boiler's heating surface, ensuring efficient boiler operation and extending its service life.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] According to a first aspect of the present invention, a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing is provided.
[0007] In some alternative embodiments, a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing includes the following steps:
[0008] Step S1. Obtain historical operating data of the power plant boiler flue gas system and steam-water system, and preprocess the historical operating data to remove outliers;
[0009] Step S2. Establish a boiler heating surface ash monitoring model, wherein the boiler heating surface includes the economizer and the air preheater;
[0010] Step S3. Establish the objective function for maximizing the net profit of the steam soot blowing system per unit time, and solve for the decision point for switching between the steam soot blowing system and the acoustic soot blowing system;
[0011] Step S4. Develop the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system;
[0012] Furthermore, in step S1, historical operating data of the power plant boiler flue gas system and steam-water system are obtained, and the historical operating data is preprocessed to remove outliers, including:
[0013] Step S11. Collect boiler flue gas system operating data, including inlet and outlet flue gas temperature data of heating surfaces such as economizer and air preheater. Collect boiler steam-water system operating data, including inlet and outlet working fluid temperature data of heating surfaces such as economizer and air preheater;
[0014] Step S12. Perform deviation analysis on the collected data and remove outliers that significantly deviate from the data trend; perform interpolation calculations by combining the data before and after the outlier to complete the removal of outlier data.
[0015] Furthermore, in step S2, an ash monitoring model for the boiler heating surface is established. The boiler heating surface includes the economizer and the air preheater, comprising:
[0016] Step S21. By measuring the heat transfer area of the heat transfer surface to be monitored, the calculated fuel quantity of the boiler, the heat transferred to the working fluid by the complete combustion of each kilogram of fuel, and the logarithmic heat transfer temperature difference of the heat transfer surface, the actual heat transfer coefficient of the heat transfer surface is calculated using Newton's law of cooling.
[0017] Step S22. Calculate the theoretical heat transfer coefficient of the heating surface by measuring the boiler structure and using the boiler thermal calculation formula;
[0018] Step S23. Define the contamination rate as a characterizing the degree of ash on the boiler heating surface. The expression for the contamination rate is: "Contamination rate = 1 - actual heat transfer coefficient / theoretical heat transfer coefficient";
[0019] Step S24. Introduce the heat storage model of the tube wall metal and the heat storage model of the working fluid, and establish a boiler heat storage surface ash monitoring model under the unsteady heat transfer condition of the boiler heat storage surface under rapid load change.
[0020] Furthermore, in step S3, an objective function for maximizing the net profit of the steam soot blowing system per unit time is established. The decision point for switching between the steam soot blowing system and the acoustic soot blowing system is obtained by solving the objective function, including:
[0021] Step S31. Fit the expressions for ash removal and soot blowing during the operation of the boiler steam soot blowing system, such as... Figure 2 As shown, during the steam system soot blowing stage, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash on the heated surface; steam soot blowing is performed at time t1, and the contamination rate drops to its lowest point. Similarly, during the acoustic system soot blowing stage, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash on the heated surface; after the contamination rate reaches a certain value, the acoustic soot blower is activated. However, due to the poor cleaning effect of the acoustic soot blower, the contamination rate cannot be reduced to its lowest point after acoustic soot blowing.
[0022] Step S32. Establish a model for the maximum net benefit of steam soot blowing per unit time. The benefit is the heat absorbed due to the soot blowing operation, and the cost is the steam and electricity consumed by the soot blowing operation.
[0023] Step S33. Solve the model for the maximum net benefit of steam soot blowing per unit time to obtain the decision point for switching between the steam soot blowing system and the acoustic soot blowing system. For example... Figure 2 As shown, the upper critical contamination rate FF max, i.e. the switching point between steam soot blowing and sonic soot blowing, and the lower critical contamination rate FF min are obtained.
[0024] Furthermore, in step S4, the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system is formulated, including:
[0025] Step S41. After the steam soot blowing system is started, the heated surfaces are cleaned, and the acoustic soot blower is then put into operation. The boiler ash accumulation is monitored using an ash accumulation monitoring model. Whenever the contamination rate reaches FF max, the acoustic soot blower is activated. However, due to the poor cleaning effect of the acoustic soot blower, the contamination rate may not be reduced to FF min after acoustic soot blowing. Figure 2 As shown;
[0026] Step S42. After the first sonic soot blowing, the contamination rate is reduced to FF1; after the second sonic soot blowing, the contamination rate is reduced to FF2; and so on, until the contamination rate is reduced to FFn after the nth soot blowing; if after sonic soot blowing, FFn≥FF max-0.1, then start the steam soot blower to clean the heated surface.
[0027] Step S43. Real-time monitoring of ash accumulation status is achieved through the ash accumulation monitoring model, thereby visualizing the soot blowing effect and realizing closed-loop control of the soot blowing system.
[0028] A boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing, comprising the following processing units, including:
[0029] The data preprocessing unit is used to acquire historical operating data of the power plant boiler flue gas system and steam-water system, and to preprocess the historical operating data to remove outliers.
[0030] The ash accumulation monitoring unit is used to establish an ash accumulation monitoring model for the boiler heating surface, which includes the economizer and the air preheater.
[0031] The control switching unit establishes the objective function of maximizing the net benefit of the steam soot blowing system per unit time, and obtains the switching decision point between the steam soot blowing system and the acoustic soot blowing system by solving the objective function.
[0032] The control strategy unit is used to formulate the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system.
[0033] The beneficial effects of this invention are that by employing a combined control technology of steam soot blowing and acoustic soot blowing, the advantages of both soot blowing systems are integrated, significantly reducing the cost of soot blowing operations and increasing the service life of the tube walls. Simultaneously, the introduction of an ash accumulation monitoring module tracks and records the accumulation status of non-loose ash on the boiler heating surface in real time, achieving precise control and optimized operation. Compared with traditional methods, this method can achieve closed-loop control of boiler soot blowing and greatly reduce the cost of soot blowing operations, showing broad application prospects in the field of electric field energy-saving technology. Attached Figure Description
[0034] Figure 1 This is a flowchart illustrating a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing, as shown in an embodiment of the present invention.
[0035] Figure 2 Soot blowing effect diagrams for steam soot blowing system and sonic soot blowing system
[0036] Figure 3 This is a logic diagram illustrating the specific implementation steps of a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing, as shown in an embodiment of the present invention. Detailed Implementation
[0037] Example 1
[0038] A boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing, such as Figure 1 As shown.
[0039] Step S1: Obtain historical operating data of the power plant boiler flue gas system and steam-water system, and preprocess the historical operating data to remove outliers to prevent abnormal data from affecting the calculation results.
[0040] Specifically, this includes step S11: collecting boiler flue gas system operating data, including inlet and outlet flue gas temperature data for heating surfaces such as the economizer and air preheater. It also includes collecting boiler steam-water system operating data, including inlet and outlet working fluid temperature data for heating surfaces such as the economizer and air preheater.
[0041] Step S12. Perform deviation analysis on the collected data and remove outliers that significantly deviate from the data trend; perform interpolation calculations by combining the data before and after the outlier to complete the removed outlier data; Step S12 eliminates the influence of outliers on the subsequent monitoring model and prevents the ash accumulation monitoring curve from fluctuating greatly at individual outlier points, which could lead to malfunctions of the soot blowing system.
[0042] Step S2: Establish a boiler heating surface ash monitoring model, wherein the boiler heating surface includes the economizer and the air preheater.
[0043] Specifically, step S21 involves calculating the actual heat transfer coefficient of the heating surface by measuring the heat transfer area of the surface to be monitored, the calculated fuel quantity of the boiler, the heat transferred to the working fluid by the complete combustion of each kilogram of fuel, and the logarithmic heat transfer temperature difference of the heating surface, using Newton's law of cooling.
[0044] Step S22. Calculate the theoretical heat transfer coefficient of the heating surface by measuring the boiler structure and using the boiler thermal calculation formula, taking the ideal heat transfer coefficient of the economizer as an example.
[0045] Step S23. Define the contamination rate as a characterizing the degree of ash accumulation on the boiler's heating surface. The expression for the contamination rate is: "Contamination rate = 1 - actual heat transfer coefficient / theoretical heat transfer coefficient". The characteristics of the contamination rate are: the larger the contamination rate value, the more serious the ash accumulation on the heating surface; the smaller the contamination rate value, the less ash accumulation on the heating surface. Wherein: CF is the cleaning factor; K sj K is the actual heat transfer coefficient. lx Ideal heat transfer coefficient
[0046] Step S24. Introduce the metal heat storage model and working fluid heat storage model of the heated surface tube wall to establish a boiler ash accumulation monitoring model under unsteady heat transfer conditions of the boiler heated surface under rapid load changes. During rapid load changes, the heat balance equation is not satisfied, meaning the heat released by the flue gas is not equal to the heat absorbed by the working fluid, causing significant fluctuations in the ash accumulation monitoring curve. By introducing the metal heat storage model and working fluid heat storage model, the heat transfer inertia is increased, making the model closer to the actual heat transfer process, and the ash accumulation detection curve becomes more accurate. The heat storage capacity of the metal tube wall is: The heat storage capacity of steam is:
[0047] Step S3: Establish the objective function for maximizing the net profit of the steam soot blowing system per unit time, and obtain the decision point for switching between the steam soot blowing system and the acoustic soot blowing system by solving the objective function.
[0048] Specifically, this includes step S31. Fitting the ash removal expression and soot blowing expression for the heated surface area during the operation of the boiler steam soot blowing system, such as... Figure 2 As shown, during the steam system soot blowing stage, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash on the heated surface; steam soot blowing is performed at time t1, and the contamination rate drops to its lowest point. Similarly, during the acoustic system soot blowing stage, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash on the heated surface; after the contamination rate reaches a certain value, the acoustic soot blower is activated. However, due to the poor cleaning effect of the acoustic soot blower, the contamination rate cannot be reduced to its lowest point after acoustic soot blowing.
[0049] Step S32. Establish a model for the maximum net benefit of steam soot blowing per unit time. The benefit is the increased heat absorption due to the soot blowing operation, and the cost is the steam and electricity consumed in the soot blowing operation. In this model, the dependent variable is the heat absorption, and the independent variables are the ash accumulation time t1 and the soot blowing time t2.
[0050] Step S33. Solve the model for the maximum net benefit of steam soot blowing per unit time to obtain the decision point for switching between the steam soot blowing system and the acoustic soot blowing system. For example... Figure 2 As shown, the upper critical contamination rate FF max, i.e. the switching point between steam soot blowing and sonic soot blowing, and the lower critical contamination rate FF min are obtained.
[0051] Step S4: Develop collaborative control logic for the steam soot blowing system and the acoustic soot blowing system to ensure reasonable switching between them, and use the ash accumulation monitoring model to provide feedback on the soot blowing effect, thereby achieving closed-loop control of soot blowing.
[0052] Specifically, step S41 involves cleaning the heated surfaces after the steam soot blowing system is started, at which point the acoustic soot blower is put into operation. The boiler ash accumulation is monitored using an ash accumulation monitoring model, and the acoustic soot blower is activated whenever the contamination rate reaches FF max. However, due to the poor cleaning effect of the acoustic soot blower, the contamination rate may not be reduced to FF min after acoustic soot blowing. Figure 2 As shown.
[0053] Step S42. After the first sonic soot blowing, the contamination rate is reduced to FF1; after the second sonic soot blowing, the contamination rate is reduced to FF2; and so on, until the contamination rate is reduced to FFn after the nth soot blowing; if after sonic soot blowing, FFn≥FF max-0.1, then start the steam soot blower to clean the heated surface.
[0054] Step S43. Real-time monitoring of ash accumulation status is achieved through the ash accumulation monitoring model, thereby visualizing the soot blowing effect and realizing closed-loop control of the soot blowing system.
[0055] Application examples
[0056] Taking a power plant in Northwest China as an example, this invention discloses a boiler soot blowing method based on the coordinated control of steam soot blowing and acoustic soot blowing, comprising the following steps:
[0057] Step S1: Data processing is performed using MATLAB. First, the historical operating data of the power plant boiler flue gas system and steam-water system are read using the xlsread function, including the flue gas temperature and working fluid temperature data at the inlet and outlet of the economizer, air preheater and other heating surfaces.
[0058] Use the plot function to draw graphs of historical running data and observe obvious outliers in the data.
[0059] The collected data is subjected to deviation analysis to remove outliers that significantly deviate from the data trend; then, three interpolation calculations are performed using the data before and after the outlier to complete the replacement of the removed outlier data.
[0060] Step S2: Establish a boiler heating surface ash monitoring model, wherein the boiler heating surface includes the economizer and the air preheater.
[0061] By measuring the heat transfer area of the heating surface to be monitored, the calculated fuel quantity of the boiler, the heat transferred to the working fluid by the complete combustion of each kilogram of fuel, and the logarithmic heat transfer temperature difference of the heating surface, the actual heat transfer coefficient of the heating surface is calculated using Newton's law of cooling. The theoretical heat transfer coefficient of the heating surface is calculated by measuring the boiler structure and using the boiler thermodynamic calculation formula. Furthermore, a boiler heating surface ash monitoring model is established under the unsteady heat transfer conditions of the boiler heating surface under rapid load changes by introducing the heat storage model of the heating surface tube wall metal and the heat storage model of the working fluid.
[0062] The contamination rate is defined as the degree of ash accumulation on the boiler's heating surface. The expression for the contamination rate is: "Contamination rate = 1 - actual heat transfer coefficient / theoretical heat transfer coefficient".
[0063] Step S3: Establish the objective function for maximizing the net benefit of the steam soot blowing system per unit time. Solve the objective function to obtain the decision point for switching between the steam and acoustic soot blowing systems. First, fit the expressions FF1 (heated surface area) and FF2 (steam soot blowing) during the operation of the boiler steam soot blowing system. Second, establish the model for maximizing the net benefit of steam soot blowing per unit time, where the soot blowing cost is the additional heat absorbed due to the soot blowing operation; the soot blowing cost is the steam and electricity consumed.
[0064] By solving the objective function, we obtain t1 and t2 when the net benefit is maximized. Substituting t1 into the FF1 expression, we obtain FFmax, which is the switching point between steam soot blowing and sonic soot blowing. Substituting t2 into the FF2 expression, we obtain the lower critical contamination rate FFmin.
[0065] Step S4: Establish the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system. First, after the steam soot blowing system is started, clean the heated surfaces. Then, the acoustic soot blower is put into operation. Monitor boiler ash accumulation using an ash accumulation monitoring model. Whenever the contamination rate reaches FF max, activate the acoustic soot blower. Because the cleaning effect of the acoustic soot blower is relatively poor, the contamination rate cannot be reduced to FF min after acoustic soot blowing. Record the contamination rate value after each acoustic soot blowing.
[0066] After the first sonic soot blowing, the contamination rate is reduced to FF1; after the second sonic soot blowing, the contamination rate is reduced to FF2; and so on, until the contamination rate is reduced to FFn after the nth soot blowing; if after sonic soot blowing, FFn≥FF max-0.1, then the steam soot blower is started to clean the heated surface.
[0067] The ash accumulation status is monitored in real time by using an ash accumulation monitoring model, thereby realizing closed-loop control of the soot blowing system and performing necessary supplementary blowing operations on some heated surfaces.
Claims
1. A boiler soot blowing method based on coordinated control of steam soot blowing and acoustic soot blowing, characterized in that... By coordinating and integrating steam sootblowers and acoustic sootblowers, a highly efficient and economical sootblowing system can be formed. This strategy not only leverages the advantages of steam sootblowing's superior performance but also combines the benefits of acoustic sootblowing technology, such as comprehensive coverage, no negative impact on pipe wall life, and lower operating costs. This method significantly improves the economy of sootblowing and extends the service life of heated surfaces. Step S1. Obtain historical operating data of the power plant boiler flue gas system and steam-water system, and preprocess the historical operating data to remove outliers; Step S2. Establish a boiler heating surface ash monitoring model, wherein the boiler heating surface includes the economizer and the air preheater; Step S3. Establish the objective function for maximizing the net profit of the steam soot blowing system per unit time, and solve for the decision point for switching between the steam soot blowing system and the acoustic soot blowing system; Step S4. Develop the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system.
2. The boiler soot blowing method based on coordinated control of steam soot blowing and acoustic soot blowing as described in claim 1, characterized in that, In step S1, historical operating data of the power plant boiler flue gas system and steam-water system are obtained, and the historical operating data is preprocessed to remove outliers, including: Step S11. Collect boiler flue gas system operating data, including inlet and outlet flue gas temperature data of heating surfaces such as economizer and air preheater. Collect boiler steam-water system operating data, including inlet and outlet working fluid temperature data of heating surfaces such as economizer and air preheater; Step S12. Perform deviation analysis on the collected data and remove outliers that significantly deviate from the data trend; perform interpolation calculations by combining the data before and after the outlier to complete the removal of outlier data.
3. The boiler soot blowing method based on coordinated control of steam soot blowing and acoustic soot blowing as described in claim 1, characterized in that, In step S2, an ash monitoring model for the boiler heating surface is established. The boiler heating surface includes the economizer and the air preheater, comprising: Step S21. By measuring the heat transfer area of the heat transfer surface to be monitored, the calculated fuel quantity of the boiler, the heat transferred to the working fluid by the complete combustion of each kilogram of fuel, and the logarithmic heat transfer temperature difference of the heat transfer surface, the actual heat transfer coefficient of the heat transfer surface is calculated using Newton's law of cooling. Step S22. Calculate the theoretical heat transfer coefficient of the heating surface by measuring the boiler structure and using the boiler thermal calculation formula; Step S23. Define the contamination rate as a characterizing the degree of ash accumulation on the boiler's heating surface. The expression for the contamination rate is: "Contamination rate = 1 - actual heat transfer coefficient / theoretical heat transfer coefficient"; Step S24. Introduce the heat storage model of the heat-receiving surface tube wall metal and the heat storage model of the working fluid, and establish a boiler heat-receiving surface ash monitoring model under the unsteady heat transfer conditions of the boiler heat-receiving surface under rapid load change.
4. The boiler soot blowing method based on coordinated control of steam soot blowing and acoustic soot blowing as described in claim 1, characterized in that, In step S3, an objective function for maximizing the net profit of the steam soot blowing system per unit time is established. The decision point for switching between the steam soot blowing system and the acoustic soot blowing system is obtained by solving the objective function, including: Step S31. Fit the expressions for ash accumulation on the heated surface and the soot blowing during the operation of the boiler steam soot blowing system, as shown in Figure 2. During the steam soot blowing stage, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash accumulation on the heated surface. Steam soot blowing is performed at time t1, and the contamination rate drops to its lowest point. Similarly, during the soot blowing stage of the acoustic soot blowing system, the contamination rate gradually increases with the operation of the unit, indicating a gradual increase in ash accumulation on the heated surface. After the contamination rate reaches a certain value, the acoustic soot blower is activated. However, due to the poor cleaning effect of the acoustic soot blower, the contamination rate cannot be reduced to its lowest point after acoustic soot blowing. Step S32. Establish a model for the maximum net benefit of steam soot blowing per unit time. The benefit is the heat absorbed due to the soot blowing operation, and the cost is the steam and electricity consumed by the soot blowing operation. Step S33. Solve the model for the maximum net benefit of steam soot blowing per unit time to obtain the decision point for switching between the steam soot blowing system and the acoustic soot blowing system. As shown in Figure 2, the upper critical contamination rate FF max, i.e., the switching point between steam soot blowing and acoustic soot blowing, and the lower critical contamination rate FF min are obtained.
5. The boiler soot blowing method based on coordinated control of steam soot blowing and acoustic soot blowing as described in claim 1, characterized in that, In step S4, the collaborative control logic for the steam soot blowing system and the acoustic soot blowing system is formulated, including: Step S41. After the steam soot blowing system is started, the heated surfaces are cleaned, and the sonic soot blower is put into operation. The boiler ash accumulation is monitored using an ash accumulation monitoring model. Whenever the contamination rate reaches FF max, the sonic soot blower is activated. Due to the poor cleaning effect of the sonic soot blower, the contamination rate cannot be reduced to FF min after sonic soot blowing, as shown in Figure 2. Step S42. After the first sonic soot blowing, the contamination rate is reduced to FF1; after the second sonic soot blowing, the contamination rate is reduced to FF2; and so on, until the contamination rate is reduced to FFn after the nth soot blowing; if after sonic soot blowing, FFn≥FF max-0.1, then start the steam soot blower to clean the heated surface. Step S43. Real-time monitoring of ash accumulation status is achieved through the ash accumulation monitoring model, thereby visualizing the soot blowing effect and realizing closed-loop control of the soot blowing system. First, operating data of the boiler flue gas system and steam-water system are read from the power plant's DCS system, and the ideal and actual heat transfer coefficients of the economizer and air preheater are calculated to obtain the ash accumulation monitoring curve and monitor the pollution rate FF in real time. Second, the steam soot blowing system is analyzed using the maximum net benefit model for soot blowing per unit time to obtain the upper critical pollution rate FF max, which is the switching point between steam soot blowing and sonic soot blowing. After the steam soot blowing system is started, the heated surfaces are cleaned, and then the sonic soot blower is put into operation. The ash accumulation monitoring model monitors the ash condition on the heated surfaces, and the sonic soot blower is activated whenever the pollution rate reaches FF max. Due to the poor cleaning effect of the sonic soot blower, the pollution rate cannot be reduced to FF min after sonic soot blowing. After the nth soot blowing, the pollution rate is FFn; if FFn ≥ FF max - 0.1, it indicates that there is a large accumulation of non-loose ash on the heated surfaces, at which point the steam soot blower is activated to clean the heated surfaces again.