Fine control method and control system for combustion state of boiler burner

Abstract

The invention relates to the technical field of thermal power generation, and provides a fine control method and system for the combustion state of a boiler burner, and the control method comprises the steps: S1, a monitoring step: employing a non-contact measurement mode, and obtaining the flow velocity parameters and concentration parameters of pulverized coal in a plurality of pulverized coal pipelines at the outlet of each coal mill of a boiler in real time; s2, an analysis step: comparing the flow velocity parameter and the concentration parameter with preset reference values, and analyzing pulverized coal distribution deviation among the pulverized coal pipelines; s3, an adjusting step: generating an adjusting instruction based on the pulverized coal distribution deviation, and controlling the opening degree of a pulverized coal flow balancing valve mounted on the pulverized coal pipeline so as to adjust the pulverized coal flow velocity and concentration among the pipelines; and S4, an early warning step: monitoring the opening degree of the pulverized coal flow balancing valve and the corresponding pulverized coal flow speed in real time, and generating and sending out an anti-blocking early warning signal when a preset blocking risk condition is identified to be met. Through cooperation of monitoring, analysis, adjustment and early warning steps, precise control over the combustion state is achieved.

Description

Technical Field

[0001] This application relates to the field of thermal power generation technology, and more specifically, to a method and control system for fine control of the combustion state of a boiler burner. Background Technology

[0002] Currently, existing coal-fired boilers, when operating at low loads for deep peak shaving, largely rely on traditional burners and manual adjustments based on experience. While this method can maintain basic operation, it suffers from significant technical bottlenecks. Due to inherent design differences in the various pipelines of the pulverizing system and the widespread use of contact measurement methods such as insertion Pitot tubes, the probes are easily worn and clogged by pulverized coal, leading to inaccurate measurements and an inability to obtain accurate air-coal parameters in real time. As a result, operators, operating in a "blind adjustment" state, struggle to accurately distribute pulverized coal and air to each burner, leading to significant deviations in pulverized coal concentration and flow rate within the furnace, and severely uneven combustion. This not only causes large deviations in superheater and reheater steam and wall temperatures, excessive desuperheating water flow, and decreased boiler efficiency, but also results in a significant increase in nitrogen oxide concentration at the furnace outlet, exacerbating the environmental burden. Simultaneously, frequent occurrences of flame instability, negative pressure fluctuations, and difficulties in maintaining dry-state operation under low loads directly threaten unit safety. Therefore, existing technologies urgently need a comprehensive control method that can achieve real-time and accurate monitoring and intelligent leveling of the air and pulverized coal parameters of each pulverized coal pipeline, so as to ensure the combustion stability, economy and environmental protection of the boiler under deep peak shaving conditions. Summary of the Invention

[0003] This application aims to at least solve the technical problems in the related technologies, such as the existing contact measurement methods using insertion Pitot tubes, whose probes are easily worn and clogged by coal powder, resulting in inaccurate measurements and the inability to obtain real-time air-coal parameters, and the difficulty of traditional control schemes in accurately distributing coal powder and air to each burner, resulting in huge deviations in coal powder concentration and flow rate in the furnace and severely uneven combustion.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: Firstly, this application provides a method for fine control of the combustion state of a boiler burner, applied to low-load conditions for deep peak shaving. The control method includes the following steps: S1, Monitoring step: Using a non-contact measurement method, the flow velocity and concentration parameters of pulverized coal in multiple pulverized coal pipes at the outlet of each coal mill of the boiler are acquired in real time; S2, Analysis step: The flow velocity and concentration parameters are compared with preset benchmark values ​​to analyze the pulverized coal distribution deviation between each pulverized coal pipe; S3, Adjustment step: Based on the pulverized coal distribution deviation, an adjustment command is generated, and the opening degree of the pulverized coal flow equalization valve installed on the pulverized coal pipe is controlled to adjust the pulverized coal flow velocity and concentration between each pipe; S4, Early warning step: The opening degree of the pulverized coal flow equalization valve and the corresponding pulverized coal flow velocity are monitored in real time. When a preset blockage risk condition is detected, an anti-blockage early warning signal is generated and issued.

[0005] This application provides a method for fine control of boiler burner combustion status. Through the coordinated operation of monitoring, analysis, adjustment, and early warning steps, it achieves a transformation from "coarse adjustment based on experience" to "fine adjustment based on data." In the precise sensing scenario, the monitoring step uses a non-contact array electrostatic induction sensor, connected in series with the pulverized coal pipe as a standard pipe section, to achieve real-time measurement of the pulverized coal flow rate and concentration across the entire cross-section without wear or turbulence, fundamentally solving the problems of wear and blockage and data inaccuracy in traditional measurement methods. In the intelligent decision-making scenario, the analysis step compares the monitored parameters with preset benchmarks. Through the signal processing center and the PLC automatic balancing control module, it accurately calculates the real-time deviation of pulverized coal distribution in each pipe, providing reliable data-driven precision adjustment. In the automatic balancing scenario, based on the analysis results, the adjustment step uses the PLC module to drive the pulverized coal flow balancing valve on the corresponding pulverized coal pipe, dynamically adjusting its opening to intelligently balance the pulverized coal concentration and flow rate at each burner inlet, ensuring a uniform distribution of the dynamic and temperature fields within the furnace, thereby effectively solving core problems such as low-load thermal deviation, steam temperature fluctuations, and excessive desuperheating water consumption. In the safety pre-control scenario, the early warning step monitors the correlation between the opening of the regulating valve and the pulverized coal flow rate in real time. Through preset logic, it intelligently judges the risk of pulverized coal pipe blockage and alarms in a timely manner, realizing a closed-loop control system that integrates process optimization and safety protection. This significantly improves the safety, economy and environmental protection of boiler operation under deep peak shaving conditions.

[0006] Secondly, this application proposes a fine-grained control system for the combustion state of a boiler burner, used to optimize boiler combustion under deep peak-shaving and low-load conditions. The fine-grained control system includes: a monitoring module comprising several non-contact pulverized coal parameter sensors installed on multiple pulverized coal pipelines to acquire real-time pulverized coal flow rate and concentration signals in each pipeline; an execution module comprising several pulverized coal flow equalization valves correspondingly installed on the pulverized coal pipelines to regulate the pulverized coal flow rate in their respective pipelines; and a control module communicatively connected to the monitoring and execution modules. The control module is configured to: receive flow rate and concentration signals sent by the monitoring module; analyze the uniformity of pulverized coal distribution among the pipelines based on the flow rate and concentration signals; and generate control commands based on the analysis results to drive the pulverized coal flow equalization valves in the execution module to achieve dynamic balance in pulverized coal distribution among the pipelines.

[0007] The boiler burner combustion state fine control system provided in this application is used to achieve combustion optimization of the boiler under deep peak shaving and low load conditions. Therefore, it has all the beneficial effects of the boiler burner combustion state fine control method, which will not be elaborated here.

[0008] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0009] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of a method for fine control of the combustion state of a boiler burner according to an embodiment of this application; Figure 2 This is a schematic diagram of the flue gas temperature trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 3 This is a schematic diagram illustrating the flue gas temperature trend after employing a fine control method for boiler burner combustion status according to an embodiment of this application. Figure 4 This is a schematic diagram illustrating the trend of nitrogen oxide concentration at the inlet of a denitrification device before the adoption of a fine control method for boiler burner combustion status, according to an embodiment of this application. Figure 5 This is a schematic diagram showing the trend of nitrogen oxide concentration at the inlet of a denitrification device after adopting a fine control method for the combustion state of a boiler burner, according to an embodiment of this application. Figure 6 This is a schematic diagram illustrating the desuperheating water flow trend before the adoption of a fine control method for boiler burner combustion status, according to an embodiment of this application. Figure 7This is a schematic diagram illustrating the desuperheating water flow trend after adopting a fine control method for boiler burner combustion status according to an embodiment of this application. Figure 8 This is a schematic diagram of the inlet steam temperature trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 9 This is a schematic diagram illustrating the inlet steam temperature trend after employing a fine control method for boiler burner combustion status according to an embodiment of this application. Figure 10 This is a schematic diagram of the high-temperature reheater wall temperature distribution trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 11 This is a schematic diagram showing the high-temperature reheater wall temperature distribution trend after adopting a fine control method for boiler burner combustion state according to an embodiment of this application. Figure 12 This is a schematic diagram of the structure of a boiler coal-fired system according to an embodiment of this application; Figure 13 This is a structural block diagram of a boiler burner combustion state fine control system according to an embodiment of this application.

[0010] in, Figure 12 and Figure 13 The correspondence between the reference numerals and component names in the attached drawings is as follows: 200 Boiler burner combustion status fine control system, 210 monitoring module, 212 non-contact pulverized coal parameter sensor, 220 execution module, 222 pulverized coal flow equalization valve, 230 control module, 232 signal processing center, 234 PLC automatic balancing and adjustment control module, 236 anti-clogging early warning unit, 240 distributed control system (DCS), 300 coal mill. Detailed Implementation

[0011] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0012] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0013] The following reference Figures 1 to 13 This application describes a method for fine control of the combustion state of a boiler burner and a control system for fine control of the combustion state of a boiler burner, provided according to some embodiments of the present application.

[0014] According to the first aspect of this application, Figure 1 As shown, one embodiment of this application provides a method for fine control of the combustion state of a boiler burner, applied to low-load conditions for deep peak shaving. The control method includes the following steps: S1, Monitoring step: Using a non-contact measurement method, the flow velocity and concentration parameters of pulverized coal in multiple pulverized coal pipes at the outlet of each coal mill of the boiler are acquired in real time; S2, Analysis step: The flow velocity and concentration parameters are compared with preset benchmark values ​​to analyze the pulverized coal distribution deviation between each pulverized coal pipe; S3, Adjustment step: Based on the pulverized coal distribution deviation, an adjustment command is generated, and the opening degree of the pulverized coal flow equalization valve installed on the pulverized coal pipe is controlled to adjust the pulverized coal flow velocity and concentration between each pipe; S4, Early warning step: The opening degree of the pulverized coal flow equalization valve and the corresponding pulverized coal flow velocity are monitored in real time. When a preset blockage risk condition is identified, an anti-blockage early warning signal is generated and issued.

[0015] Specifically, such as Figure 1 As shown in the embodiments of this application, a method for fine control of boiler burner combustion state is also proposed, applied to low-load conditions for deep peak shaving. The control method includes: S1. Monitoring steps: Using a non-contact measurement method, the flow rate and concentration parameters of pulverized coal in multiple pulverized coal pipes at the outlet of each coal mill in the boiler are obtained in real time. S2. Analysis steps: Compare the flow rate parameters and concentration parameters with the preset benchmark values ​​to analyze the coal powder distribution deviation between each coal powder pipeline; S3. Adjustment steps: Based on the coal powder distribution deviation, an adjustment command is generated, and the opening of the coal powder flow equalization valve installed on the coal powder pipeline is controlled to adjust the coal powder flow rate and concentration between each pipeline. S4. Early warning procedure: Monitor the opening degree of the pulverized coal flow equalization valve and the corresponding pulverized coal flow rate in real time. When the preset blockage risk conditions are detected, generate and issue an anti-blockage early warning signal.

[0016] Specifically, in the S1 monitoring step, a non-contact measurement method is adopted, which means that a non-contact array of electrostatic induction sensors is installed in series on each pulverized coal pipe at the outlet of each coal mill. Since pulverized coal naturally becomes charged due to friction during pneumatic conveying, the sensor can non-invasively acquire electrostatic signals characterizing its flow state by sensing the charge carried by the flowing pulverized coal throughout the entire cross-section of the pipe. These raw signals are then processed into precise flow velocity and concentration parameters using a specific algorithm model. This fundamentally solves the wear and clogging problems inherent in traditional insertion-type Pitot tubes, achieving long-term, stable, and high-precision real-time sensing of key parameters.

[0017] In the S2 analysis step, the flow rate and concentration parameters are compared with preset benchmark values, specifically in the signal processing center and the PLC automatic balancing control module. The preset benchmark values ​​can be target values ​​set by operators or dynamic benchmarks automatically calculated by the system based on the real-time average of all pipeline parameters under the same coal mill. By comparing the deviations of individual pipe values ​​with the benchmark values, the PLC automatic balancing control module can quantitatively calculate the relative deviation of pulverized coal distribution in each pipeline, thereby accurately pinpointing the macroscopic "uneven combustion" problem to specific pipelines and burners, providing a clear, data-driven decision-making basis for fine-tuning.

[0018] In the S3 adjustment step, adjustment commands are generated based on the pulverized coal distribution deviation, and the pulverized coal flow balancing valve is controlled, thus forming a closed-loop control circuit. Specifically, the PLC automatic balancing adjustment control module converts the calculated deviation into control commands for the opening of each valve, which drive the electric actuator on the valve to operate. For pipelines with low pulverized coal concentration, the valve opening is increased to increase the flow rate; for pipelines with high concentration, the opening is decreased to limit the flow rate. Through this dynamic, online feedback adjustment, the pulverized coal flow rate and concentration in all pipelines are ultimately made consistent, achieving a dynamic and balanced distribution of air and pulverized coal concentration at the inlet of each burner. Simultaneously, key data from the entire process is uploaded in real time to the distributed control system (DCS), enabling centralized monitoring and historical traceability of the process.

[0019] In the S4 early warning step, the opening degree of the pulverized coal flow balancing valve and the corresponding pulverized coal flow velocity are monitored in real time to establish an intelligent early warning model based on multi-parameter correlation logic. The preset blockage risk condition is specifically defined as follows: when the opening degree of any valve is lower than a set low opening threshold (first preset threshold), and simultaneously the pulverized coal flow velocity in the pipeline is also lower than a set low flow velocity threshold (second preset threshold), the system determines that the pipeline has a high risk of blockage. This is because excessively small valve opening and excessively low flow velocity are the two most direct and critical precursor characteristics of impending blockage in the pulverized coal pipeline. Through this step, the system can promptly issue anti-blockage warning signals to operators before actual blockage occurs, realizing a shift from passive handling to active protection and ensuring the safe and reliable operation of the main control system.

[0020] Thus, the boiler burner combustion state precision control method provided in this application constructs a precise sensing layer based on non-contact measurement through the monitoring step, fundamentally avoiding the data inaccuracy problems caused by wear and blockage in traditional contact measurement, and providing a reliable data foundation for subsequent control; the analysis step realizes the judgment of pulverized coal distribution deviation, transforming operating data into an executable control basis; the adjustment step forms a closed-loop control loop with the pulverized coal flow equalization valve as the execution core, which can dynamically and online balance the pulverized coal supply of each burner, thereby directly ensuring the uniformity and stability of the combustion field in the furnace from the source; and the early warning step effectively avoids the risk of pulverized coal pipe blockage that may be caused by the adjustment process. This method together constitutes a complete "monitoring, diagnosis, adjustment, and protection" automated control process, ultimately effectively improving the combustion stability of the boiler under deep peak shaving and low load conditions, improving the problems of steam temperature deviation and excessive use of desuperheating water, and reducing nitrogen oxide generation from the combustion source.

[0021] Specifically, existing coal-fired boilers, under low-load conditions participating in deep peak shaving, largely rely on traditional burners and manual adjustments based on experience. While this method can maintain basic operation, it suffers from significant technical bottlenecks. Due to inherent design differences in the various pipelines of the pulverizing system and the widespread use of contact measurement methods such as insertion Pitot tubes, the probes are easily worn and clogged by pulverized coal, leading to inaccurate measurements and an inability to obtain accurate air-coal parameters in real time. As a result, operators in a "blind adjustment" state find it difficult to accurately distribute pulverized coal and air to each burner, resulting in significant deviations in pulverized coal concentration and flow rate within the furnace, and severely uneven combustion. This not only causes large deviations in superheater and reheater steam and wall temperatures, excessive desuperheating water volume, and decreased boiler efficiency, but also leads to a significant increase in nitrogen oxide concentration at the furnace outlet, exacerbating the environmental burden. At the same time, frequent occurrences of flame instability, negative pressure fluctuations, and difficulties in maintaining dry-state operation under low loads directly threaten unit safety. Therefore, existing technologies urgently need a comprehensive control method that can achieve real-time and accurate monitoring and intelligent leveling of the air and pulverized coal parameters of each pulverized coal pipeline, so as to ensure the combustion stability, economy and environmental protection of the boiler under deep peak shaving conditions.

[0022] To address the shortcomings of existing technologies, such as Figure 1As shown, the boiler burner combustion state fine control method provided in this application achieves a transformation from "experience-based coarse adjustment" to "data-based fine adjustment" through the coordinated operation of monitoring, analysis, adjustment, and early warning steps. In the precise sensing scenario, the monitoring step employs a non-contact array electrostatic induction sensor, connected in series with the pulverized coal pipe as a standard pipe section, achieving real-time measurement of the pulverized coal flow rate and concentration across the entire cross-section without wear or turbulence, fundamentally solving the problems of wear, blockage, and data inaccuracy inherent in traditional measurement methods. In the intelligent decision-making scenario, the analysis step compares the monitored parameters with preset benchmarks, and through the signal processing center and PLC automatic balancing control module, accurately calculates the real-time deviation of pulverized coal distribution in each pipe, providing reliable data-driven fine adjustment. In the automatic balancing scenario, based on the analysis results, the adjustment step uses the PLC module to drive the pulverized coal flow balancing valve on the corresponding pulverized coal pipe, dynamically adjusting its opening to intelligently balance the pulverized coal concentration and flow rate at each burner inlet, ensuring a uniform distribution of the dynamic and temperature fields within the furnace, thereby effectively solving core problems such as low-load thermal deviation, steam temperature fluctuations, and excessive desuperheating water consumption. In the safety pre-control scenario, the early warning step monitors the correlation between the opening of the regulating valve and the pulverized coal flow rate in real time. Through preset logic, it intelligently judges the risk of pulverized coal pipe blockage and alarms in a timely manner, realizing a closed-loop control system that integrates process optimization and safety protection. This significantly improves the safety, economy and environmental protection of boiler operation under deep peak shaving conditions.

[0023] Compared with existing technologies, the advantages of the boiler burner combustion state fine control method provided in this application are as follows: First, a measuring device for detecting pulverized coal flow rate and concentration is installed on the pulverized coal outlet pipe to display the measured values ​​of pulverized coal flow rate and concentration in each pipe in real time, achieving high-precision measurement and visualization of pulverized coal in each pipe. Second, a pulverized coal flow regulator is installed on the pulverized coal outlet pipe to adjust the deviation of pulverized coal flow rate and concentration in each pipe, providing operators with a basis for hot online adjustment of pulverized coal flow rate in each conveying pipe, achieving fine adjustment. Third, based on the online real-time measurement data, the PLC automatic balancing control module sends a control signal to the flow balancer to adjust the pulverized coal flow rate and concentration online, ensuring that each pulverized coal pipeline is in a balanced state. At the same time, the system transmits the measurement data and balancing results to the DCS in real time, realizing closed-loop control.

[0024] In some embodiments, optionally, such as Figure 1As shown, in the monitoring step, a non-contact measurement method is adopted to acquire the flow velocity and concentration parameters of pulverized coal in multiple pulverized coal pipes at the outlet of each coal mill in the boiler in real time. Specifically, this includes: collecting the flow velocity and concentration signals of pulverized coal in each pipe through a non-contact array electrostatic induction sensor installed on multiple pulverized coal pipes at the outlet of each coal mill, and processing the flow velocity and concentration signals to obtain the flow velocity and concentration parameters of pulverized coal; wherein, the non-contact array electrostatic induction sensor is connected in series as a standard pipe section to the pulverized coal pipe, and the inner diameter of the non-contact array electrostatic induction sensor is the same as the inner diameter of the pulverized coal pipe to achieve undisturbed, full-section measurement.

[0025] Specifically, such as Figure 1 As shown, the non-contact array electrostatic induction sensor works by sensing the electrostatic charge naturally carried by the flowing coal powder. Its non-contact measurement principle fundamentally eliminates sensor wear caused by coal powder scouring and measurement point blockage caused by media adhesion. Connecting the non-contact array electrostatic induction sensor in series as a standard pipe section with the same inner diameter as the coal powder pipeline makes the sensor a seamless component of the pipeline. No additional throttling, eddies, or dead zones are generated when the coal powder flows through it, achieving a turbulent measurement environment. Simultaneously, the array-type electrostatic induction point distribution captures the charge signal across the entire cross-section of the pipeline, rather than data from a single point, thus achieving an accurate characterization of the average state of the coal powder flow across the entire cross-section within the pipeline, resulting in more representative and reliable measurement results.

[0026] In some embodiments, optionally, such as Figure 1 As shown, in the analysis step, the flow rate parameters and concentration parameters are compared with preset benchmark values ​​to analyze the coal powder distribution deviation between each coal powder pipeline. Specifically, this includes: sending the collected flow rate signals and concentration signals to the signal processing center for processing to obtain the real-time coal powder flow rate and concentration values ​​of each pipeline; and in the PLC automatic balance adjustment control module, comparing the real-time coal powder flow rate and concentration values ​​of each pipeline with the target threshold set for the operating conditions to calculate the deviation of each pipeline relative to the average value.

[0027] Specifically, such as Figure 1As shown, the signal processing center is responsible for filtering, amplifying, and digitizing the raw electrostatic signals collected by the sensors, processing them into standardized, physically meaningful real-time coal powder flow rate and concentration values. These precise values ​​are then sent to the PLC automatic balancing control module. The core function of this module is to execute an intelligent comparison algorithm: it uses the real-time arithmetic mean of all pipeline parameters corresponding to the same coal mill as a dynamic benchmark, or compares it with a target threshold preset based on the current load and coal quality, thereby quantitatively calculating the percentage or absolute deviation of each pipeline relative to this average value. This process transforms the ambiguous phenomenon of "uneven combustion" into precise, quantifiable data indicators.

[0028] In some embodiments, optionally, such as Figure 1 As shown, in the adjustment step, based on the coal powder distribution deviation, an adjustment command is generated, and the opening of the coal powder flow balancing valve installed on the coal powder pipeline is controlled to adjust the coal powder flow rate and concentration between each pipeline. Specifically, based on the deviation, the PLC automatic balancing adjustment control module generates a corresponding control command and sends it to the electric actuator of the coal powder flow balancing valve installed on the corresponding coal powder pipeline. The coal powder flow balancing valve adjusts its opening according to the control command to increase the flow rate of the pipeline with a low coal powder distribution or decrease the flow rate of the pipeline with a high coal powder distribution, so as to achieve dynamic balanced distribution of coal powder concentration at the inlet of each burner. The real-time coal powder flow rate value, concentration value, and opening status of the coal powder flow balancing valve are uploaded in real time and integrated into the distributed control system (DCS) for monitoring and recording.

[0029] Specifically, such as Figure 1 As shown, after receiving the deviation from the analysis step, the PLC automatic balancing control module generates a control command proportional to the deviation through its internal integrated control algorithm. This command is sent via the industrial communication network to the electric actuator of the pulverized coal flow equalization valve on the corresponding pulverized coal pipeline, driving the valve to precisely adjust its opening. For pipelines with low pulverized coal distribution, the control command increases the valve opening, increasing the pulverized coal flow in that pipeline; for pipelines with high pulverized coal distribution, the opening is decreased to limit the flow, ultimately achieving a dynamic and balanced distribution of pulverized coal concentration at the inlet of each burner. Simultaneously, the system uploads and integrates key process variables such as real-time pulverized coal flow rate, concentration, and valve opening into the distributed control system (DCS) via a standard industrial communication protocol.

[0030] In some embodiments, optionally, such as Figure 1As shown, in the early warning step, the opening degree of the pulverized coal flow equalization valve and the corresponding pulverized coal flow rate are monitored in real time. When the preset blockage risk conditions are identified, an anti-blockage early warning signal is generated and issued. Specifically, this includes: real-time monitoring of the opening degree of each pulverized coal flow equalization valve and the pulverized coal flow rate of the corresponding pipeline. When it is determined that the opening degree of any pulverized coal flow equalization valve is lower than the first preset threshold and the pulverized coal flow rate of its corresponding pipeline is lower than the second preset threshold, an anti-blockage early warning signal is generated and issued.

[0031] Specifically, such as Figure 1 As shown, the opening degree of the pulverized coal flow equalization valve directly determines the flow cross-sectional area, while the pulverized coal flow velocity reflects the actual conveying state. When the valve opening is too small (below the first preset threshold) and the flow velocity is too low (below the second preset threshold), it indicates that the pipeline is in a dangerous condition with severely insufficient flow capacity, and pulverized coal is very likely to accumulate in the pipeline and eventually develop into a complete blockage. This design effectively avoids the risk of pipe blockage caused by extreme adjustments during the automatic leveling process, ensuring the continuous and stable operation of the pulverizing system and the entire combustion control process.

[0032] In some embodiments, optionally, such as Figure 1 As shown, the first preset threshold is 10% to 20% of the opening range, and the second preset threshold is 40% to 50% of the normal design flow rate.

[0033] Specifically, such as Figure 1 As shown, when the valve opening of the pulverized coal flow equalization valve is 10% to 20% below its normal adjustment range, it indicates that it is approaching its mechanical adjustment limit and the flow cross-section is too small. Simultaneously, when the pulverized coal flow velocity is 40% to 50% below the normal design operating condition, the kinetic energy of the airflow is insufficient to maintain the suspension and transport of pulverized coal particles. The simultaneous fulfillment of these two conditions constitutes a clear critical criterion for impending deposition and blockage in the pulverized coal pipe. Precisely setting the threshold within this range achieves an optimal balance between adjustment accuracy and safety margin, allowing the control system to make sufficiently fine adjustments to eliminate deviations while ensuring adequate early warning time before the flow state deteriorates to an irreversible degree.

[0034] In a specific application, taking the No. 2 boiler of a thermal power plant as an example, the implementation process and results of the fine control method for the combustion state of the boiler burner of this application are illustrated: like Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of the flue gas temperature trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 3This is a schematic diagram illustrating the flue gas temperature trend after adopting a fine-grained combustion state control method for boiler burners, according to an embodiment of this application. It can be seen that the flue gas temperature is optimized and reduced after adopting the fine-grained combustion state control method compared to before.

[0035] like Figure 4 and Figure 5 As shown, Figure 4 This is a schematic diagram illustrating the trend of nitrogen oxide concentration at the inlet of a denitrification device before the adoption of a fine control method for boiler burner combustion status, according to an embodiment of this application. Figure 5 This diagram illustrates the trend of nitrogen oxide concentration at the inlet of the denitrification device after adopting a fine-grained boiler burner combustion state control method, according to an embodiment of this application. The comparison shows that the nitrogen oxide concentration at the inlet of the denitrification device is significantly lower after adopting the fine-grained boiler burner combustion state control method compared to before. Before adopting the fine-grained boiler burner combustion state control method, the average nitrogen oxide concentration at the inlet of the denitrification device was 280 mg / m³. 3 (Oxygen content) was around [value missing], and nitrogen oxide emissions were slightly high. After adopting a refined control method for boiler burner combustion status, the average nitrogen oxide concentration at the denitrification unit inlet was 250 mg / m³. 3 With an oxygen content of around [value missing], nitrogen oxide emissions are relatively low. With improved combustion uniformity and supplementary oxygen optimization measures, there is still room for further optimization of nitrogen oxide emissions.

[0036] like Figure 6 and Figure 7 As shown, Figure 6 This is a schematic diagram illustrating the desuperheating water flow trend before the adoption of a fine control method for boiler burner combustion status, according to an embodiment of this application. Figure 7This diagram illustrates the desuperheating water flow trend after implementing a fine-grained combustion state control method for a specific embodiment of this application. The comparison shows that the flow rates of the primary and secondary desuperheating water decrease significantly after implementing the method compared to before. Before implementing the method, the desuperheating water flow rates on both sides of the boiler superheater fluctuated wildly, with the maximum value reaching 80 t / h, exceeding 10% of the boiler feedwater flow rate. This excessive desuperheating water flow also led to a certain degree of boiler efficiency reduction. After implementing the fine-grained combustion state control method, the desuperheating water flow rates on both sides of the boiler superheater are significantly reduced, with the maximum value on both sides reaching 20 t / h, approximately 2.5% of the feedwater flow rate. This substantial reduction in desuperheating water flow to the heating surfaces results in significant energy savings for the system. The smaller deviation in desuperheating water flow rates on both sides of the boiler demonstrates a substantial improvement in combustion uniformity and greatly ensures the safety of the heating surfaces.

[0037] like Figure 8 and Figure 9 As shown, Figure 8 This is a schematic diagram of the inlet steam temperature trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 9 This diagram illustrates the inlet steam temperature trend after implementing a fine-tuning method for boiler burner combustion status according to an embodiment of this application. The comparison shows that after implementing the fine-tuning method, the inlet steam temperatures on the left and right sides of the under-pressure zone are essentially without deviation, while the inlet steam temperatures on the left and right sides of the pressure zone show slight deviations, but these deviations are small over a long period. The deviations in the inlet steam temperatures of the under-pressure zone and pressure zone are significantly eliminated. This ensures balanced combustion, resulting in a significant reduction in desuperheating water consumption, more stable working fluid steam flow, and more stable steam parameters, thus guaranteeing the safe and stable operation of the unit. Furthermore, before implementing the fine-tuning method, the furnace negative pressure fluctuated significantly, and the superheat fluctuated considerably, operating below 15°C for extended periods, reaching as low as around 0°C. Maintaining dry operation was difficult, and there was a constant risk of transitioning to wet operation. After implementing the fine-tuning method, the furnace negative pressure curve is more stable, and combustion stability is better. The superheat is generally maintained above 20°C, and the boiler stably maintains dry operation.

[0038] like Figure 10 and Figure 11 As shown, Figure 10 This is a schematic diagram of the high-temperature reheater wall temperature distribution trend before the adoption of the fine control method for boiler burner combustion state in one embodiment of this application; Figure 11This is a schematic diagram illustrating the high-temperature reheater wall temperature distribution trend after adopting a fine-grained boiler burner combustion state control method according to an embodiment of this application. The comparison shows that the high-temperature reheater wall temperature distribution is more uniform after adopting the fine-grained boiler burner combustion state control method. The phenomenon of lower temperatures on both sides and higher temperatures in the middle is significantly improved, and the combustion conditions inside the furnace are stable and good.

[0039] As shown in Table 1, Table 1 presents a comparison of the boiler's deep peak-shaving operation, showing the parameter changes before and after adopting the refined control method for boiler burner combustion status under the two operating conditions:

[0040] Table 1 According to the second aspect of this application, such as Figure 12 and Figure 13 As shown, embodiments of this application also propose a fine control system 200 for the combustion state of a boiler burner, used to optimize boiler combustion under deep peak shaving and low load conditions. The fine control system 200 for the combustion state of a boiler burner includes: a monitoring module 210, including several non-contact pulverized coal parameter sensors 212 installed on multiple pulverized coal pipelines, used to acquire the flow rate and concentration signals of pulverized coal in each pulverized coal pipeline in real time; an execution module 220, including several pulverized coal flow equalization valves 222 correspondingly installed on the pulverized coal pipelines, used to adjust the pulverized coal flow in their respective pipelines; and a control module 230, communicatively connected to the monitoring module 210 and the execution module 220. The control module 230 is configured to: receive the flow rate and concentration signals sent by the monitoring module 210; analyze the uniformity of pulverized coal distribution among the pulverized coal pipelines based on the flow rate and concentration signals; and generate control commands according to the analysis results to drive the pulverized coal flow equalization valves 222 in the execution module 220 to achieve dynamic balance of pulverized coal distribution among the pulverized coal pipelines.

[0041] Specifically, such as Figure 12 and Figure 13 As shown, the boiler burner combustion state fine control system 200 includes a monitoring module 210, an execution module 220, and a control module 230. The monitoring module 210 includes several non-contact pulverized coal parameter sensors 212 installed on multiple pulverized coal pipelines. The execution module 220 includes several pulverized coal flow equalization valves 222 correspondingly installed on the pulverized coal pipelines. The control module 230 includes a signal processing center 232 and a PLC automatic balancing and adjustment control module 234.

[0042] Specifically, the monitoring module 210, execution module 220, and control module 230 are connected via an industrial network to form a complete closed-loop control system. The non-contact pulverized coal parameter sensor 212 in the monitoring module 210 is responsible for real-time acquisition of the raw flow signals within each pulverized coal pipeline of the coal mill 300; the pulverized coal flow equalization valve 222 in the execution module 220 precisely adjusts the pulverized coal flow according to control commands; and the control module 230 analyzes and processes the monitoring data using its built-in control algorithm and generates corresponding adjustment commands. The collaborative work of these three modules forms a closed-loop control process of "perception, decision-making, and execution." The monitoring module 210 continuously provides the actual status of pulverized coal distribution in each pipeline; the control module 230 compares and analyzes to determine distribution deviations and generates control schemes; and the execution module 220 executes the adjustment commands, correcting deviations by changing the opening of the pulverized coal flow equalization valve 222, ultimately achieving dynamic balance in pulverized coal distribution among the pipelines. This system replaces the traditional extensive control relying on manual experience with automated closed-loop regulation, improving the combustion stability and economy of the boiler under deep peak-shaving conditions. In some embodiments, optionally, the control module 230 includes a signal processing center 232 and a PLC automatic balancing control module 234. The signal processing center 232 is communicatively connected to the monitoring module 210 and is used to receive and process the raw signals from the non-contact coal powder parameter sensor 212 to obtain usable coal powder flow rate and concentration values. The PLC automatic balancing control module 234 is communicatively connected to the signal processing center 232 and the execution module 220 and is configured to: receive coal powder flow rate and concentration values, calculate coal powder distribution deviation, and generate control commands to drive the coal powder flow equalization valve 222 to achieve dynamic balance in coal powder distribution. The control module 230 is also communicatively connected to the distributed control system DCS 240 to upload system status data to the DCS.

[0043] Specifically, the signal processing center 232 uses dedicated signal conditioning circuits and algorithms to filter, reduce noise, and extract features from the raw electrostatic signals collected by the sensors, converting them into standardized coal powder flow rate and concentration values ​​with clear engineering significance. The PLC automatic balancing control module 234 receives this processed, precise data and uses its built-in balancing algorithm to calculate the deviation in coal powder distribution across each pipeline in real time, generating corresponding control commands. Simultaneously, the control module 230 establishes a communication connection with the distributed control system DCS240 via industrial Ethernet or fieldbus, enabling the integration of all key parameters into the power plant's main control system, achieving single-point monitoring and centralized management.

[0044] In some embodiments, the control module 230 may optionally include an anti-blocking warning unit 236, which is configured to: monitor the opening degree of each pulverized coal flow equalization valve 222 and the pulverized coal flow rate of the corresponding pipeline; generate an anti-blocking warning signal when it is determined that the opening degree of any pulverized coal flow equalization valve 222 is lower than a first preset threshold and the pulverized coal flow rate of its corresponding pipeline is simultaneously lower than a second preset threshold; wherein, the first preset threshold is 10% to 20% of the opening degree range and the second preset threshold is 40% to 50% of the normal design flow rate.

[0045] Specifically, the anti-blockage early warning unit 236 can accurately identify risks before the flow conditions deteriorate to an irreversible level by monitoring these two key parameters in real time and performing logical AND operations, effectively avoiding false alarms that may be caused by fluctuations in a single parameter and ensuring the accuracy of the early warning.

[0046] In some embodiments, the non-contact coal powder parameter sensor 212 is optionally an electrostatic induction sensor, whose measuring pipe section is connected in series with the coal powder pipeline as part of the pipeline, and the inner diameter of the measuring pipe section is consistent with the inner diameter of the coal powder pipeline and is smoothly connected.

[0047] Specifically, the measuring section of the non-contact pulverized coal parameter sensor 212 is made of transparent material, manufactured using the same process as the pulverized coal pipeline. It is physically connected to the preceding and following pipelines via flanges or welding, forming a continuous conveying path. Its inner diameter is precisely machined to ensure a completely consistent size and smooth transition with the inner wall of adjacent pipelines. This structural design prevents throttling effects, eddies, or flow separation when pulverized coal flows through the measuring section, achieving truly undisturbed flow measurement. Furthermore, the transparent material of the non-contact pulverized coal parameter sensor 212 enables visual detection. This eliminates the interference with the flow field and wear problems inherent in traditional insertion-type measuring devices, while ensuring that the measurement results accurately reflect the overall conveying status of the pipeline, providing a reliable data foundation for precise pulverized coal distribution.

[0048] In the description of this application, the term "multiple" refers to two or more. Unless otherwise expressly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0049] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of fine control of the combustion state of a boiler burner, characterized by, The control method applied to low-load conditions of deep peak regulation comprises the following steps: S1, monitoring step: using a non-contact measurement method, real-time acquisition of the flow rate parameters and concentration parameters of the coal powder in the multiple coal powder pipelines at the outlet of each coal mill of the boiler; S2, analysis step: comparing the flow rate parameters and concentration parameters with the preset reference values, and analyzing the coal powder distribution deviation between the pipelines; S3, adjustment step: based on the coal powder distribution deviation, generating an adjustment instruction, and controlling the opening of the coal powder flow equalization valve installed on the coal powder pipeline to adjust the coal powder flow rate and concentration between the pipelines; S4, early warning step: real-time monitoring of the opening of the coal powder flow equalization valve and the corresponding coal powder flow rate, and generating and issuing a anti-clogging early warning signal when the preset clogging risk condition is identified.

2. The method of claim 1, wherein In the monitoring step, the non-contact measurement method is used to real-time acquisition of the flow rate parameters and concentration parameters of the coal powder in the multiple coal powder pipelines at the outlet of each coal mill of the boiler, specifically including: Through the non-contact array electrostatic induction sensor installed on the multiple coal powder pipelines at the outlet of each coal mill, the flow rate signal and concentration signal of the coal powder in each pipeline are collected, and the flow rate signal and concentration signal are processed to obtain the flow rate parameters and concentration parameters of the coal powder; wherein the non-contact array electrostatic induction sensor is connected in series as a standard pipe section to the coal powder pipeline, and the inner diameter of the non-contact array electrostatic induction sensor is the same as the inner diameter of the coal powder pipeline to realize non-disturbance flow and full-section measurement.

3. The method of claim 2, wherein the step of determining the combustion state of the boiler burner comprises the steps of: determining a first combustion state of the boiler burner; determining a second combustion state of the boiler burner; and determining a third combustion state of the boiler burner. In the analysis step, the flow rate parameters and concentration parameters are compared with the preset reference values to analyze the coal powder distribution deviation between the pipelines, specifically including: The collected flow rate signal and concentration signal are sent to the signal processing center for processing to obtain the real-time coal powder flow rate value and concentration value of each pipeline, and in the PLC automatic balance adjustment control module, the real-time coal powder flow rate value and concentration value of each pipeline are compared with the target threshold set for the operating condition respectively to calculate the deviation amount of each pipeline relative to the average value.

4. The method of claim 3, wherein In the adjustment step, based on the coal powder distribution deviation, an adjustment instruction is generated, and the opening of the coal powder flow equalization valve installed on the coal powder pipeline is controlled to adjust the coal powder flow rate and concentration between the pipelines, specifically including: Based on the deviation amount, the PLC automatic balance adjustment control module generates a corresponding control instruction and sends it to the electric actuator of the coal powder flow equalization valve installed on the corresponding coal powder pipeline, and the coal powder flow equalization valve adjusts its opening according to the control instruction to increase the flow of the coal powder distribution low pipeline or reduce the flow of the coal powder distribution high pipeline to realize dynamic equalization distribution of the coal powder concentration at the inlet of each burner, and the real-time coal powder flow rate value, concentration value and opening state of the coal powder flow equalization valve are uploaded and integrated into the distributed control system DCS for monitoring and recording.

5. The method of claim 1, wherein In the pre-warning step, the opening degree of the pulverized coal flow equalization valve and the corresponding pulverized coal flow rate are monitored in real time, and when it is identified that the preset blockage risk condition is met, a blockage prevention pre-warning signal is generated and sent, specifically including: Real-time monitoring of the opening degree of each pulverized coal flow equalization valve and the pulverized coal flow rate of the corresponding pipeline, and when it is determined that the opening degree of any pulverized coal flow equalization valve is lower than the first preset threshold value and the pulverized coal flow rate of the corresponding pipeline is simultaneously lower than the second preset threshold value, a blockage prevention pre-warning signal is generated and sent.

6. The method of claim 5, wherein the step of determining the combustion state of the boiler burner comprises the steps of: The first preset threshold value is 10% to 20% of the opening range, and the second preset threshold value is 40% to 50% of the normal design flow rate.

7. A boiler burner combustion state fine control system characterized by, A boiler burner combustion state fine control system is used to realize the combustion optimization of the boiler under deep peak shaving low load conditions, and the system comprises: A monitoring module comprising a plurality of non-contact pulverized coal parameter sensors arranged on a plurality of pulverized coal pipelines for real-time acquisition of flow rate signals and concentration signals of pulverized coal in each of the pulverized coal pipelines; An execution module comprising a plurality of pulverized coal flow equalization valves arranged corresponding to the pulverized coal pipelines for adjusting the pulverized coal flow of the pipeline where each valve is located; A control module in communication connection with the monitoring module and the execution module, the control module being configured to: Receive the flow rate signals and concentration signals sent by the monitoring module; Analyze the uniformity of pulverized coal distribution among the pulverized coal pipelines based on the flow rate signals and concentration signals; Generate control instructions according to the analysis results to drive the pulverized coal flow equalization valves in the execution module to act, so as to realize the dynamic balance of the pulverized coal distribution among the pulverized coal pipelines.

8. The boiler burner firing condition fine control system in accordance with claim 7, characterized by, The control module comprises a signal processing center and a PLC automatic balance adjustment control module, the signal processing center is in communication connection with the monitoring module for receiving and processing the original signals of the non-contact pulverized coal parameter sensors to obtain available pulverized coal flow rate values and concentration values, and the PLC automatic balance adjustment control module is in communication connection with the signal processing center and the execution module and is configured to receive the pulverized coal flow rate values and concentration values, calculate the pulverized coal distribution deviation, and generate control instructions to drive the pulverized coal flow equalization valves to act, so as to realize the dynamic balance of the pulverized coal distribution; The control module is also in communication connection with a distributed control system DCS for uploading system state data to the distributed control system DCS.

9. The boiler burner firing condition fine control system in accordance with claim 7, wherein, The control module further comprises a blockage prevention pre-warning unit, the blockage prevention pre-warning unit being configured to: Monitor the opening degree of each pulverized coal flow equalization valve and the pulverized coal flow rate of the corresponding pipeline; When it is determined that the opening degree of any pulverized coal flow equalization valve is lower than the first preset threshold value and the pulverized coal flow rate of the corresponding pipeline is simultaneously lower than the second preset threshold value, a blockage prevention pre-warning signal is generated; wherein the first preset threshold value is 10% to 20% of the opening range, and the second preset threshold value is 40% to 50% of the normal design flow rate.

10. The boiler burner firing condition fine control system in accordance with claim 7, wherein, The non-contact pulverized coal parameter sensor is an electrostatic induction sensor, the measurement pipe section as a part of the pipeline is connected in series to the pulverized coal pipeline, and the inner diameter of the measurement pipe section is consistent with and smoothly connected to the inner diameter of the pulverized coal pipeline.

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