A monitoring system for ash on the low-temperature heating surface of a boiler

Abstract

This application discloses a monitoring system for ash accumulation on the low-temperature heating surface of a boiler, belonging to the field of pulverized coal boiler combustion technology. It aims to solve the technical problems of inaccurate observation of ash accumulation on the low-temperature heating surface in existing boiler shafts and the lack of intuitive basis for soot blowing decisions. The system is installed at the corresponding location in the boiler shaft through an opening in the furnace wall. It includes a lens rod with a lens and matching supplementary lighting components, an imaging acquisition unit, and can be equipped with an intelligent control module and a grayscale analysis module to achieve online visual acquisition and automatic analysis of ash accumulation status. This system effectively improves the accuracy of ash accumulation monitoring and adaptability to complex operating conditions, significantly reduces deployment and maintenance costs, provides accurate decision-making basis for soot blowing operations, significantly reduces soot blowing energy consumption and heating surface loss, and improves the stability and intelligent management level of boiler operation.

Description

Technical Field

[0001] This application belongs to the field of pulverized coal boiler combustion technology, and specifically relates to a monitoring system for ash accumulation on the low-temperature heating surface of a boiler. Background Technology

[0002] Ash accumulation on the low-temperature heating surfaces in the boiler shaft area is a common phenomenon during boiler operation, especially in boilers burning low-ash-fusion-point coal, high-alkali coal, or high-ash-content coal. Due to the dense arrangement of tubes on the low-temperature heating surfaces within the shaft, fine ash particles and dust generated during boiler combustion easily deposit on the surface of these heating surfaces. This ash accumulation weakens the heat transfer efficiency of the low-temperature superheater and reheater within the shaft area, leading to an increase in flue gas temperature. Furthermore, excessive accumulation of ash and dust significantly reduces the flue gas flow cross-sectional area, causing an increase in flue gas velocity, thereby exacerbating wear on the low-temperature heating surfaces and, in severe cases, even causing tube rupture accidents.

[0003] Currently, soot blowing technology is commonly used in this area to remove the accumulation of ash and dust. However, the shaft area is a low-temperature heating surface with a lack of visible light illumination. Even with observation holes, it is difficult to directly observe the fine ash accumulation on the heating surface. Therefore, operators mainly rely on experience and changes in the pressure difference of the low-temperature heating surface to determine and start / stop the soot blowing device. To avoid the aggravation of ash accumulation due to untimely soot blowing, it is often necessary to increase the soot blowing frequency. This practice not only increases the consumption of soot blowing steam, but also accelerates the erosion and loss of the tube wall material of the low-temperature heating surface due to frequent purging. Summary of the Invention

[0004] This application provides a monitoring system for ash accumulation on the low-temperature heating surface of a boiler. By installing an optical probe assembly on the side wall of the boiler shaft, it enables online, non-contact, and visual monitoring of the ash accumulation status on the low-temperature heating surface, thereby solving the technical problems of invisible ash accumulation status and lack of intuitive basis for soot blowing decisions.

[0005] To achieve the above objectives, this application provides a monitoring system for ash accumulation on the low-temperature heating surface of a boiler. The system is installed on the low-temperature heating surface inside the boiler shaft through an opening in the furnace wall. It includes a mirror rod installed in the opening in the furnace wall. A lens is provided at one end of the mirror rod near the furnace, and a camera is provided at the other end. The camera is optically coupled to the lens to capture images of ash accumulation on the surface of the low-temperature heating surface. The lens is equipped with a fill light, which is used to provide uniform and high-brightness illumination to the low-temperature heated surface to be tested in front of the lens.

[0006] In one embodiment, the illumination angle of the fill light is the same as the shooting angle of the lens.

[0007] In one embodiment, the fill lights are evenly distributed in a ring around the lens.

[0008] In one embodiment, the fill light wavelength covers the response range of the camera imaging element.

[0009] In one embodiment, the telescopic rod is used.

[0010] In one embodiment, the camera is connected to the host computer of the video surveillance system in the control room via a signal cable.

[0011] In one embodiment, the position of the furnace wall opening on the side wall of the boiler shaft is such that the lens and the supplementary light can observe the surface of the low-temperature heated surface.

[0012] In one embodiment, a control module and a grayscale analysis module are also included.

[0013] In one embodiment, the control module is used to adjust the brightness of the fill light and the camera exposure parameters, and to control the camera to transmit the captured images to the host of the video monitoring system in the central control room.

[0014] In one embodiment, the grayscale analysis module is installed in the host of the video surveillance system in the central control room to analyze the grayscale distribution in the images captured by the camera.

[0015] Compared with the prior art, the beneficial effects of this application are: Firstly, it enables online, visual, and non-contact monitoring of the soot state of low-temperature heated surfaces, providing intuitive and accurate decision-making basis for soot blowing operations. This avoids the problem of excessive soot blowing caused by traditional reliance on experience-based judgment, significantly reduces soot blowing energy consumption, and reduces erosion damage to the heated surface tube wall caused by frequent purging, thereby greatly extending the service life of low-temperature heated surfaces.

[0016] Secondly, it is equipped with a supplementary lighting system that is highly adapted to the imaging angle. With a special light source layout and wavelength adaptation design, it effectively eliminates problems such as insufficient lighting and reflection interference in the monitoring area, greatly improving the imaging quality and detail recognition of the ash accumulation image. Even in the complex working conditions of flue gas and high humidity inside the furnace, it can still output high-quality monitoring data stably, significantly improving the accuracy of ash accumulation identification and the system's adaptability to working conditions.

[0017] Third, the system has a simple overall structure. The installation process only requires opening a small area in the furnace wall, without the need for large-scale modification of the original boiler structure. There are no components that come into direct contact with the high-temperature area inside the furnace, which reduces the deployment cost of the system. At the same time, there are no vulnerable parts or consumables consumed during operation, which significantly reduces long-term maintenance costs and effectively improves the system's application economy and promotion value.

[0018] Fourth, the system is equipped with an intelligent control module and a grayscale analysis module, which can adaptively adjust monitoring parameters and automatically analyze the development trend of ash accumulation, greatly improving the intelligent management and control level of boiler ash accumulation monitoring, reducing the workload of operators, predicting the risk of ash accumulation aggravation in advance, effectively preventing safety hazards such as poor flue gas circulation, wear of heating surfaces, and even tube rupture caused by excessive ash accumulation, and significantly improving the stability and safety of boiler operation.

[0019] Fifth, the retractable telescope rod design adapts to different installation scenarios and monitoring range requirements, effectively improving the system's scenario adaptability and installation flexibility, and can meet the low-temperature heating surface ash monitoring needs of boilers of different models and structures. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 An installation diagram of a monitoring system for ash accumulation on a boiler low-temperature heating surface, provided for this application; Figure 2 This is a schematic diagram of a monitoring system for ash accumulation on a boiler low-temperature heating surface, provided in this application.

[0022] Explanation of reference numerals in the attached diagram: 3. Low-temperature heating surface; 5. Furnace wall opening; 6. Boiler shaft; 7. Lens; 8. Fill light; 9. Lens rod; 10. Camera. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0024] See Figures 1 to 2 As shown, this application provides a monitoring system for ash accumulation on the low-temperature heating surface of a boiler. The system is installed on the low-temperature heating surface 3 inside the boiler shaft 6 through a furnace wall opening 5. It includes a mirror rod 9 installed in the furnace wall opening 5. A lens 7 is provided at one end of the mirror rod 9 near the furnace, and a camera 10 is provided at the other end. The camera 10 is optically coupled to the lens 7 and is used to capture images of ash accumulation on the surface of the low-temperature heating surface 3.

[0025] During installation and use, the lens rod 9 is inserted into the opening 5 in the furnace wall, the lens 7 is aimed at the low-temperature heating surface 3, the camera 10 is started to collect images through the lens 7, the images are analyzed, and the thickness and distribution characteristics of the ash accumulation are identified.

[0026] The lens 7 is equipped with a fill light 8, which is used to provide uniform and high-brightness illumination to the low-temperature heated surface 3 to be tested in front of the lens 7.

[0027] In this embodiment, the supplementary light 8 adopts an adjustable LED array or other light source, and can automatically adjust its brightness according to the ambient light intensity to ensure that a high-contrast image is obtained under different working conditions.

[0028] Optionally, the illumination angle of the supplementary light 8 is the same as the shooting angle of the lens 7 to ensure that the supplementary lighting area coincides with the imaging field of view, thus avoiding ineffective lighting and image overexposure.

[0029] Optionally, the supplementary lights 8 are evenly distributed in a ring around the lens 7. This ring layout not only improves the uniformity of illumination but also effectively suppresses the interference of reflections on the ash surface caused by strong light from one side, significantly enhancing the recognition accuracy of the ash layer outline and particle texture. In addition, the supplementary lights 8 are arranged on the outside of the boiler furnace wall, so they can easily obtain sufficient cooling capacity through air cooling or water cooling.

[0030] Optionally, the fill light 8 has a fill light wavelength that covers the response range of the imaging element of the camera 10, improving the image signal-to-noise ratio and grayscale resolution, and can still stably output high-quality original images, especially under harsh conditions such as low temperature and high humidity, and smoke.

[0031] Optionally, the telescopic rod 9 can be adjusted in length according to actual usage needs, making it suitable for different scenarios and installation conditions, thus improving its flexibility and adaptability. Simultaneously, the supplementary light 8 emits light waves that meet the wavelength response range of the imaging element of the camera 10 and illuminates the surface under test. The camera 10 then captures the accumulation of slag and dust on the surface, overcoming the disadvantages of lack of illumination and difficulty in manual observation in this area, and achieving real-time monitoring of slag and dust accumulation on the low-temperature heated surface.

[0032] In this embodiment, when it is necessary to monitor the dust accumulation on the low-temperature heated surface 3, the supplementary light from the supplementary light lamp 8 is used to illuminate the low-temperature heated surface 3 to be tested. The dust accumulation on the low-temperature heated surface 3 to be tested can be received by the camera 10 through the lens 7 and the lens rod 9, and the imaging signal is sent to a distance.

[0033] Optionally, the camera 10 is connected to the host computer of the video monitoring system in the central control room via a signal cable. The signal is transmitted back to the host computer of the video monitoring system in the central control room in real time via a high-speed transmission channel. The host computer of the video monitoring system in the central control room analyzes the transmitted images and automatically identifies the thickness of the dust accumulation, the coverage density, and the development trend.

[0034] Optionally, the position of the furnace wall opening 5 on the side wall of the boiler shaft 6 is such that the lens 7 and the supplementary light 8 can observe the surface of the low-temperature heated surface 3, ensuring that the lens 7 can completely cover the area to be monitored under the illumination of the supplementary light 8, and avoiding the direct path of high-temperature flue gas, thus extending the service life of the optical components.

[0035] Optionally, a control module and a grayscale analysis module are also included. The control module is used to adjust the brightness of the supplementary light 8 and the exposure parameters of the camera 10, and to control the camera 10 to transmit the acquired images to the host of the video monitoring system in the central control room. The control module can also coordinate the start and stop of the supplementary light 8 and the camera 10 and link their parameters to improve the adaptive response capability to the dust accumulation state of the low-temperature heated surface 3 under different operating conditions, and ensure that the acquired images have optimal contrast and detail resolution.

[0036] Optionally, the grayscale analysis module is installed in the host of the video monitoring system in the central control room to analyze the grayscale distribution in the images captured by the camera 10, and identify the boundary of the grayscale area based on the preset grayscale threshold, calculate the mean and variance of grayscale per unit area, and then deduce the grayscale thickness gradient and the non-uniformity index of the accumulation.

[0037] 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A system for monitoring the fouling of low-temperature heating surfaces in a boiler, which is arranged in the boiler shaft (6) on the low-temperature heating surfaces (3) through a furnace wall opening (5), characterised in that, Includes a mirror rod (9) installed in the furnace wall opening (5), with a lens (7) at one end of the mirror rod (9) near the furnace and a camera (10) at the other end. The camera (10) is optically coupled to the lens (7) to capture images of ash accumulation on the surface of the low-temperature heating surface (3). The lens (7) is equipped with a fill light (8), which is used to provide uniform and high-brightness illumination to the low-temperature heated surface (3) to be tested in front of the lens (7).

2. A system for monitoring the fouling of low temperature heating surfaces of a boiler according to claim 1, characterized in that The illumination angle of the fill light (8) is the same as the shooting angle of the lens (7).

3. The monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 1, characterized in that: The fill lights (8) are evenly distributed in a ring around the lens (7).

4. The monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 1, characterized in that: The fill light wavelength of the fill light (8) covers the response range of the imaging element of the camera (10).

5. The monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 1, characterized in that: The mirror rod (9) is a telescopic rod.

6. The monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 1, characterized in that: The camera (10) is connected to the host of the video monitoring system in the central control room via a signal line.

7. The monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 1, characterized in that: The position of the furnace wall opening (5) on the side wall of the boiler shaft (6) is such that the lens (7) and the supplementary light (8) can observe the surface of the low-temperature heating surface (3).

8. A monitoring system for ash accumulation on a boiler low-temperature heating surface according to any one of claims 1-7, characterized in that: It also includes a control module and a grayscale analysis module.

9. A monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 8, characterized in that: The control module is used to adjust the brightness of the fill light (8) and the exposure parameters of the camera (10), and to control the camera (10) to transmit the acquired images to the host of the video monitoring system in the central control room.

10. A monitoring system for ash accumulation on a boiler low-temperature heating surface according to claim 8, characterized in that: The grayscale analysis module is installed in the host of the video monitoring system in the central control room to analyze the grayscale distribution in the images captured by the camera (10).

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