A method and system for controlling the blowing of soot from a heating surface of a boiler of a thermal power plant
By segmenting infrared temperature images of the boiler's heating surface and analyzing operating parameters, the area to be blown out is accurately identified, solving the problem of untimely or excessive blowing in existing technologies and improving boiler efficiency and safety.
Patent Information
- Application Number
- CN202610155675.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-04
- Publication Date
- 2026-07-10
AI Technical Summary
In existing technologies, it is difficult to achieve scientific soot blowing on the heating surfaces of thermal power plant boilers, resulting in untimely or excessive soot blowing, which affects boiler efficiency and safety.
By acquiring infrared temperature images of the boiler's heating surface, dividing them into several temperature regions, and combining current operating parameters and temperature change trends, the area to be soot blown is accurately identified, and the soot blowing time is determined based on the contamination rate.
It enables precise identification of areas requiring soot blowing, avoiding over- or under-blowing and improving the soot blowing efficiency and safety of boiler heating surfaces.
Smart Images
Figure CN122359700A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of boiler technology, and more specifically, to a method and system for controlling soot blowing on the heating surface of a thermal power plant boiler. Background Technology
[0002] Ash and slag buildup on the heating surfaces of thermal power plant boilers can lead to decreased heat transfer efficiency, increased flue gas temperature, and reduced boiler efficiency, and in severe cases, even tube rupture accidents. Therefore, regularly blowing soot from the heating surfaces is an important measure to ensure the safe and economical operation of the boiler.
[0003] Currently, the soot blowing control methods commonly used in thermal power plants mainly include timed soot blowing, soot blowing based on operating parameters, and soot blowing based on experience. It is difficult to achieve scientific soot blowing, which leads to untimely soot blowing, a decrease in the convective heat transfer coefficient, an increase in boiler flue gas temperature, and a reduction in boiler efficiency. Alternatively, excessive soot blowing will damage the tube wall and increase the incidence of tube rupture accidents. Summary of the Invention
[0004] This invention provides a method for controlling soot blowing on the heating surface of a thermal power plant boiler, to solve the problem of the difficulty in achieving scientific soot blowing on the heating surface of a boiler in the prior art, including:
[0005] Acquire infrared temperature images of the boiler's heating surface and segment them into several temperature regions; acquire current boiler operating parameters and determine the ideal temperature threshold for each temperature region based on these parameters; acquire the actual temperature change trend of each temperature region and select areas to be cleaned based on the actual temperature change trend and the ideal temperature threshold; determine the contamination rate of each area to be cleaned based on the actual temperature change trend and the soot blowing time based on the contamination rate.
[0006] Further, the infrared temperature image of the boiler heating surface is segmented into several temperature regions, including: performing grayscale processing on the infrared temperature image of the boiler heating surface to obtain a grayscale image of the boiler heating surface; selecting an initial seed point of the grayscale image of the boiler heating surface, calculating the grayscale value difference of each pixel in the preset neighborhood of the initial seed point, and determining whether the grayscale value difference of each pixel in the preset neighborhood of the initial seed point is less than a preset merging threshold; merging the pixels with grayscale value differences less than the preset merging threshold with the initial seed point, selecting the pixel with the smallest grayscale value difference from the initial seed point among the pixels merged with the initial seed point as a new initial seed point to continue growing, until the grayscale value difference between the latest initial seed point and other pixels in its preset neighborhood is greater than or equal to the preset merging threshold, thus obtaining the temperature region.
[0007] Further, the initial seed points for the grayscale image of the boiler heating surface are selected, including: obtaining a preset grayscale threshold, counting the pixels in the grayscale image of the boiler heating surface whose grayscale values are greater than the preset grayscale threshold, and obtaining the initial seed points.
[0008] Furthermore, the ideal temperature threshold for each temperature zone is determined based on the current boiler operating condition parameters, including: obtaining the boiler operating condition parameters and temperature values at each monitoring point of the heating surface under different operating conditions of the power plant; constructing a threshold generation model based on the boiler operating condition parameters and temperature values at each monitoring point of the heating surface under different operating conditions of the power plant; and inputting the current boiler operating condition parameters into the threshold generation model to obtain the ideal temperature threshold for each temperature zone.
[0009] Furthermore, a threshold generation model is constructed based on the boiler operating parameters under different power plant operating conditions and the temperature values at each monitoring point of the heating surface. This includes: inputting the boiler operating parameters under different power plant operating conditions into the pre-constructed threshold generation model and outputting the predicted temperature values of the boiler heating surface under different operating conditions; adjusting the model parameters of the threshold generation model based on the difference between the predicted temperature values of the boiler heating surface under different operating conditions and the corresponding actual temperature values, until the difference between the predicted temperature values of the boiler heating surface output by the threshold generation model and the corresponding actual temperature values is less than a preset difference threshold, thus obtaining the threshold generation model.
[0010] Further, the areas to be blown out are selected based on the actual temperature change trend and the ideal temperature threshold of the temperature region, including: drawing a temperature change curve based on the actual temperature change trend of the temperature region, performing curve fitting on the temperature change curve to obtain a temperature fitting curve; determining the highest temperature value of the temperature region in a preset time period based on the temperature fitting curve, and calculating the absolute value of the difference between the highest temperature value of the temperature region in the preset time period and the ideal temperature threshold; if the absolute value of the difference between the highest temperature value and the ideal temperature threshold is greater than the allowable deviation threshold, then the corresponding temperature region is determined as the area to be blown out.
[0011] Furthermore, before calculating the absolute value of the difference between the highest temperature value of the temperature region during the preset time period and the ideal temperature threshold, the method further includes: determining the temperature change rate of the temperature region during the preset time period based on the temperature fitting curve, determining the thermal conductivity parameters of the temperature region based on the temperature change rate, and correcting the highest temperature value based on the thermal conductivity parameters to obtain the corrected highest temperature value.
[0012] Furthermore, the contamination rate of each area to be blown is determined based on the actual temperature change trend, including: determining the thermal conductivity parameters of the area to be blown based on the actual temperature change trend, and determining the contamination rate based on the thermal conductivity parameters of the area to be blown.
[0013] Furthermore, the soot blowing time is determined based on the contamination rate of the area to be soot blown, including: determining the required steam volume based on the contamination rate of the area to be soot blown, and determining the soot blowing time of the area to be soot blown based on the required steam volume.
[0014] To achieve the above objectives, the present invention also provides a soot blowing control system for the heating surface of a thermal power plant boiler, comprising: The segmentation module acquires infrared temperature images of the boiler's heating surface and divides these images into several temperature regions. The operating condition module acquires current boiler operating condition parameters and determines the ideal temperature threshold for each temperature region based on these parameters. The filtering module acquires the actual temperature change trend of each temperature region and filters out regions to be cleaned based on the actual temperature change trend and the ideal temperature threshold. The soot blowing module determines the contamination rate of each region to be cleaned based on its actual temperature change trend and determines the soot blowing time based on the contamination rate.
[0015] The beneficial effects of this invention are as follows: By applying the above technical solution, this invention acquires infrared temperature images of the boiler's heating surface, divides these images into several temperature regions, acquires current boiler operating parameters, and determines the ideal temperature threshold for each temperature region based on these parameters. It also acquires the actual temperature change trend of each temperature region, filters out areas to be cleaned based on the actual temperature change trend and the ideal temperature threshold, determines the contamination rate of each area based on the actual temperature change trend, and determines the cleaning time based on the contamination rate. This invention can accurately identify the heating surface areas requiring cleaning, preventing both over-cleaning and under-cleaning, thus improving the cleaning efficiency of the boiler's heating surface. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 The present invention provides an overall flowchart of a method for controlling soot blowing on the heating surface of a thermal power plant boiler, as proposed in an embodiment of the present invention. Figure 2 A schematic diagram of a soot blowing control system for the heating surface of a thermal power plant boiler, as proposed in an embodiment of the present invention, is shown. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] This application provides a method for controlling soot blowing on the heating surface of a thermal power plant boiler, such as... Figure 1 As shown, it includes: S101, acquire the infrared temperature image of the boiler heating surface, and divide the infrared temperature image of the boiler heating surface into several temperature regions. In some embodiments of this application, the infrared temperature image of the boiler heating surface is segmented into several temperature regions, including: performing grayscale processing on the infrared temperature image of the boiler heating surface to obtain a grayscale image of the boiler heating surface; selecting an initial seed point of the grayscale image of the boiler heating surface, calculating the grayscale value difference of each pixel in the preset neighborhood of the initial seed point, and determining whether the grayscale value difference of each pixel in the preset neighborhood of the initial seed point is less than a preset merging threshold; merging the pixels with grayscale value differences less than the preset merging threshold with the initial seed point, selecting the pixel with the smallest grayscale value difference from the initial seed point among the pixels merged with the initial seed point as a new initial seed point to continue growing, until the grayscale value difference between the latest initial seed point and other pixels in its preset neighborhood is greater than or equal to the preset merging threshold, thus obtaining a temperature region.
[0020] In some embodiments of this application, the initial seed points of the grayscale image of the boiler heating surface are selected, including: Obtain a preset grayscale threshold, count the pixels in the grayscale image of the boiler heating surface whose grayscale value is greater than the preset grayscale threshold, and obtain the initial seed points.
[0021] In this embodiment, infrared temperature images of the boiler heating surface are acquired by an infrared imaging device. High-temperature points in the grayscale images of the boiler heating surface are selected by setting a preset grayscale threshold. Then, multiple temperature regions to be analyzed are grown from the high-temperature points based on the region growth rule.
[0022] S102, Obtain the current boiler operating condition parameters, and determine the ideal temperature threshold for each temperature zone based on the current boiler operating condition parameters; In some embodiments of this application, determining the ideal temperature threshold for each temperature zone based on the current boiler operating condition parameters includes: obtaining boiler operating condition parameters for different power plant operating conditions and temperature values at each monitoring point on the heating surface; constructing a threshold generation model based on the boiler operating condition parameters for different power plant operating conditions and temperature values at each monitoring point on the heating surface; and inputting the current boiler operating condition parameters into the threshold generation model to obtain the ideal temperature threshold for each temperature zone.
[0023] In some embodiments of this application, a threshold generation model is constructed based on boiler operating parameters under different power plant operating conditions and temperature values at various monitoring points on the heating surface. This includes: inputting boiler operating parameters under different power plant operating conditions into a pre-constructed threshold generation model, and outputting predicted temperature values of the boiler heating surface under different operating conditions; adjusting the model parameters of the threshold generation model based on the difference between the predicted temperature values of the boiler heating surface under different operating conditions and the corresponding actual temperature values, until the difference between the predicted temperature values of the boiler heating surface output by the threshold generation model and the corresponding actual temperature values is less than a preset difference threshold, thereby obtaining the threshold generation model.
[0024] In this embodiment, the boiler operating condition parameters include unit load, main steam flow rate, main steam pressure, and fuel quantity. Boiler operating condition parameters under different operating conditions during the power plant's historical operation are collected to establish a training sample set. A deep neural network model is pre-constructed, and the predicted temperature values of the boiler heating surface in the training sample set are output through the deep neural network model. The mean square error between the predicted temperature value and the actual temperature value is calculated. The model parameters are adjusted using a backpropagation optimization algorithm. Through iterative training, the prediction error of the model on the validation set is made less than a preset difference threshold, thus completing the training of the threshold generation model.
[0025] S103, obtain the actual temperature change trend of each temperature zone, and select the area to be blown out based on the actual temperature change trend of the temperature zone and the ideal temperature threshold. In some embodiments of this application, the area to be blown out is selected based on the actual temperature change trend of the temperature region and the ideal temperature threshold, including: drawing a temperature change curve based on the actual temperature change trend of the temperature region, performing curve fitting on the temperature change curve to obtain a temperature fitting curve; determining the highest temperature value of the temperature region in a preset time period based on the temperature fitting curve, calculating the absolute value of the difference between the highest temperature value of the temperature region in the preset time period and the ideal temperature threshold; if the absolute value of the difference between the highest temperature value and the ideal temperature threshold is greater than the deviation tolerance threshold, then the corresponding temperature region is determined as the area to be blown out.
[0026] In this embodiment, the temperature change curve is fitted using an exponential smoothing method. The absolute value of the difference between the highest temperature value within a preset time period in the temperature fitting curve and the ideal temperature threshold of the corresponding temperature region is used to filter out the areas to be blown away that deviate significantly from the ideal temperature threshold.
[0027] In some embodiments of this application, before calculating the absolute value of the difference between the highest temperature value of the temperature region during a preset time period and the ideal temperature threshold, the method further includes: determining the temperature change rate of the temperature region during the preset time period based on the temperature fitting curve; determining the thermal conductivity parameter of the temperature region based on the temperature change rate; and correcting the highest temperature value based on the thermal conductivity parameter to obtain the corrected highest temperature value.
[0028] In this embodiment, since dust accumulation can deteriorate the heat transfer process of the heated surface, the temperature change rate of the temperature region is calculated by fitting the temperature curve. The temperature change rate is negatively correlated and then normalized to limit its range to [0, 2], thereby determining the thermal conductivity parameters of the temperature region. The thermal conductivity parameters are multiplied by the highest temperature value to correct the highest temperature value, further improving the accuracy of temperature region positioning.
[0029] S104, determine the contamination rate of each area to be blown based on the actual temperature change trend, and determine the blowing time based on the contamination rate of the area to be blown.
[0030] In some embodiments of this application, the contamination rate of the area to be blown is determined based on the actual temperature change trend of each area to be blown, including: determining the thermal conductivity parameters of the area to be blown based on the actual temperature change trend, and determining the contamination rate based on the thermal conductivity parameters of the area to be blown.
[0031] In this embodiment, the degree of ash accumulation, i.e., the contamination rate, in the area to be ashed is determined by the thermal conductivity parameters of the area to be ashed.
[0032] In some embodiments of this application, determining the soot blowing time based on the contamination rate of the area to be soot blown includes: determining the required amount of steam based on the contamination rate of the area to be soot blown, and determining the soot blowing time of the area to be soot blown based on the required amount of steam.
[0033] In this embodiment, the contamination rate of the area to be soot blown is directly proportional to the required amount of steam. The higher the contamination rate, the more steam is required, and the longer the soot blowing time, thus achieving scientific soot blowing of the boiler heating surface.
[0034] Based on the same technological concept, such as Figure 2 As shown, the present invention also provides a soot blowing control system for the heating surface of a thermal power plant boiler, comprising: The segmentation module acquires infrared temperature images of the boiler's heating surface and divides these images into several temperature regions. The operating condition module acquires current boiler operating condition parameters and determines the ideal temperature threshold for each temperature region based on these parameters. The filtering module acquires the actual temperature change trend of each temperature region and filters out regions to be cleaned based on the actual temperature change trend and the ideal temperature threshold. The soot blowing module determines the contamination rate of each region to be cleaned based on its actual temperature change trend and determines the soot blowing time based on the contamination rate.
[0035] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.
[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for controlling soot blowing on the heating surface of a thermal power plant boiler, characterized in that, include: Acquire infrared temperature images of the boiler heating surface and divide the images into several temperature regions. Obtain the current boiler operating condition parameters, and determine the ideal temperature threshold for each temperature zone based on the current boiler operating condition parameters; Obtain the actual temperature change trend of each temperature zone, and select the area to be blown out based on the actual temperature change trend of the temperature zone and the ideal temperature threshold. The contamination rate of each area to be blown is determined based on the actual temperature change trend, and the blowing time is determined based on the contamination rate of the area to be blown.
2. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 1, characterized in that, The infrared temperature image of the boiler's heating surface is divided into several temperature regions, including: The infrared temperature image of the boiler heating surface is converted to grayscale to obtain a grayscale image of the boiler heating surface. Select an initial seed point from the grayscale image of the boiler heating surface, calculate the difference in grayscale values of each pixel in the preset neighborhood of the initial seed point, and determine whether the difference in grayscale values of each pixel in the preset neighborhood of the initial seed point is less than a preset merging threshold. Pixels with grayscale differences less than a preset merging threshold are merged with the initial seed point. The pixel with the smallest grayscale difference from the initial seed point among the merged pixels is selected as the new initial seed point and the growth continues until the grayscale difference between the latest initial seed point and other pixels in its preset neighborhood is greater than or equal to the preset merging threshold, thus obtaining the temperature region.
3. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 2, characterized in that, The initial seed points for selecting the grayscale image of the boiler heating surface include: Obtain a preset grayscale threshold, count the pixels in the grayscale image of the boiler heating surface whose grayscale value is greater than the preset grayscale threshold, and obtain the initial seed points.
4. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 1, characterized in that, Determine the ideal temperature thresholds for each temperature zone based on the current boiler operating parameters, including: Obtain boiler operating parameters and temperature values at various monitoring points on the heating surface under different operating conditions of the power plant. Construct a threshold generation model based on the boiler operating parameters and temperature values at various monitoring points on the heating surface under different operating conditions of the power plant. Input the current boiler operating parameters into the threshold generation model to obtain the ideal temperature threshold for each temperature zone.
5. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 4, characterized in that, A threshold generation model is constructed based on boiler operating parameters under different power plant conditions and temperature values at various monitoring points on the heating surface, including: Input the boiler operating parameters under different operating conditions of the power plant into the pre-built threshold generation model, and output the predicted temperature values of the boiler heating surface under different operating conditions. The model parameters of the threshold generation model are adjusted according to the difference between the predicted temperature value of the boiler heating surface and the corresponding actual temperature value under different operating conditions, until the difference between the predicted temperature value of the boiler heating surface output by the threshold generation model and the corresponding actual temperature value is less than the preset difference threshold, thus obtaining the threshold generation model.
6. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 1, characterized in that, Based on the actual temperature change trend and ideal temperature threshold of the temperature range, the areas to be blown out are selected, including: Based on the actual temperature change trend of the temperature region, a temperature change curve is plotted, and curve fitting is performed on the temperature change curve to obtain the temperature fitting curve. The highest temperature value of the temperature region during the preset time period is determined based on the temperature fitting curve, and the absolute value of the difference between the highest temperature value of the temperature region during the preset time period and the ideal temperature threshold is calculated. If the absolute value of the difference between the highest temperature and the ideal temperature threshold is greater than the allowable deviation threshold, then the corresponding temperature region is determined as the region to be blown soot.
7. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 6, characterized in that, Before calculating the absolute value of the difference between the highest temperature value in the temperature range over a preset time period and the ideal temperature threshold, the following steps are also included: The rate of temperature change in the temperature region during the preset time period is determined based on the temperature fitting curve, and the thermal conductivity parameters of the temperature region are determined based on the rate of temperature change. The maximum temperature value is corrected based on the thermal conductivity parameters to obtain the corrected maximum temperature value.
8. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 7, characterized in that, The contamination rate of each area to be cleaned is determined based on the actual temperature change trend, including: The thermal conductivity parameters of the area to be blown are determined based on the actual temperature change trend, and the contamination rate is determined based on the thermal conductivity parameters of the area to be blown.
9. The method for controlling soot blowing on the heating surface of a thermal power plant boiler according to claim 8, characterized in that, The soot blowing time is determined based on the contamination rate of the area to be soot blown, including: The required steam volume is determined based on the contamination rate of the area to be cleaned, and the cleaning time for the area to be cleaned is determined based on the required steam volume.
10. A soot blowing control system for the heating surface of a thermal power plant boiler, characterized in that, include: The segmentation module is used to acquire infrared temperature images of the boiler heating surface and segment the infrared temperature images of the boiler heating surface into several temperature regions. The operating condition module is used to obtain the current boiler operating condition parameters and determine the ideal temperature threshold for each temperature zone based on the current boiler operating condition parameters. The filtering module is used to obtain the actual temperature change trend of each temperature zone and filter out the areas to be blown out based on the actual temperature change trend and the ideal temperature threshold. The soot blowing module is used to determine the contamination rate of each area to be soot blown based on the actual temperature change trend, and to determine the soot blowing time based on the contamination rate of the area to be soot blown.