Visual measurement system for slag bonding of platen superheater

Abstract

The utility model discloses a platen superheater slag-bonding visual measuring system which comprises a driving device fixed outside a water cooling wall and a lens cover capable of penetrating through the water cooling wall to extend into a hearth, and the driving device is connected with the lens cover through a connecting piece. A pinhole lens is arranged at the position, close to the front end, in the lens cover, a camera protection cover is fixed to the rear end of the lens cover, and a camera is arranged in the camera protection cover. The signal input end of the camera is connected with the pinhole lens, and the signal output end of the camera is connected with the signal processing module through the control module; a compressed air inlet is formed in the position, close to the rear end, of the camera protection cover, and a compressed air outlet is formed in the front end of the lens cover. According to the utility model, the slag-bonding image and the slag-bonding quantitative data of the platen superheater can be obtained, and a basis is provided for combustion adjustment and soot blowing as required for operators.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of coal-fired power plant boiler, especially relates to a screen type superheater slagging visual measurement system. BACKGROUND

[0002] The screen type superheater of the coal-fired power plant boiler is arranged on the upper part of the furnace, and simultaneously receives the radiation heat exchange of the flame in the furnace and the convection heat exchange of the flue gas, directly receives the scouring of the high-temperature flue gas, and is located at the position of trading ash deposition and slagging.

[0003] After the screen type superheater is slagged, it will cause heat transfer deterioration, flue gas temperature, pipe wall over-temperature, high-temperature corrosion, and even pipe explosion, large slag dropping and other accidents affecting the safe operation of the boiler.

[0004] At present, the monitoring research on the slagging of the screen type superheater of the coal-fired boiler mainly includes theoretical calculation method and actual measurement method.

[0005] The theoretical calculation method is based on the heat balance between the flue gas and the steam, however, the related data parameters are difficult to measure, and the accuracy of the theoretical calculation result is poor.

[0006] The actual measurement method mainly includes radar ranging method, the Chinese patent document with publication number CN116123550A discloses a method for obtaining the slagging state of the bottom of the screen type superheater of the boiler, a certain number of radar ranging devices are arranged at different heights from the bottom of the screen type superheater on the front wall and the rear wall, the distance to the opposite side is measured, and the distance when the bottom of the screen type superheater is not slagged is compared, so as to judge whether the bottom of the screen type superheater is slagged and the position and size of the slag block. The Chinese patent document with publication number CN217278920U discloses a system for obtaining the slagging state of the water-cooled wall of the boiler, the distance from each part of the water-cooled wall is accurately measured, and the distance when not slagged is compared, so as to judge whether each part of the water-cooled wall is slagged and the thickness of the slag layer.

[0007] However, the radar ranging method is greatly disturbed by the slagging morphology, which affects the accuracy of the measurement result, and the maintenance cost is high. UTILITY MODEL CONTENTS

[0008] A screen type superheater slagging visual measurement system can obtain the screen type superheater slagging image and slagging quantitative data, and provide a basis for the combustion adjustment of the operating personnel and the on-demand soot blowing.

[0009] A screen type superheater slagging visual measurement system comprises a driving device fixed on the outside of the water-cooled wall and a lens cover that can pass through the water-cooled wall and extend into the furnace, and the driving device is connected with the lens cover through a connecting piece.

[0010] The pinhole lens is arranged in the lens cover and close to the front end position, the rear end of the lens cover is fixed with a camera protection cover, and the camera protection cover is internally provided with a camera; the signal input end of the camera is connected with the pinhole lens, and the signal output end is connected with a signal processing module through a control module; the rear end of the camera protection cover is provided with a compressed air inlet, and the front end of the lens cover is provided with a compressed air outlet.

[0011] Preferably, the lens cover is arranged to penetrate into the furnace through the fire observation hole on the water cooling wall.

[0012] Further, the fire observation hole is provided with a baffle door, the baffle door is connected with the control module, and the opening and closing of the baffle door is controlled through the control module. When the lens cover needs to enter the furnace for shooting, the baffle door is automatically opened, and the lens cover is withdrawn, and the baffle door is automatically closed.

[0013] Preferably, the lens cover adopts a double-layer structure, and is used for forming two compressed air channels. The lens is cooled through the two air channels, and the cooling air is blown out from the front end of the protection cover, so that the fire is pressed and the dust is blown away, and the imaging clarity is ensured.

[0014] Preferably, the compressed air outlet arranged at the front end of the lens cover functions as an image taking hole of the pinhole lens, and the field angle of the pinhole lens is 90 degrees.

[0015] Preferably, the lens cover is internally provided with an air pressure monitoring module, and the air pressure monitoring module is connected with the control module. When the pressure is lower than the set value, the probe is automatically withdrawn.

[0016] Preferably, the pinhole lens is provided with a temperature monitoring module, and the temperature monitoring module is connected with the control module.

[0017] Optionally, the driving module adopts a metal guide rail transmission, and simultaneously adopts a motor with a self-locking function as power.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. The system structure is compact, the land occupation is small, the installation is convenient, the maintenance cost is low, the lens cover is arranged to penetrate into the furnace through the modified fire observation hole, the pinhole camera in the lens cover can obtain the screen type superheater area slagging image on line, the slagging position and the severity quantization data are directly displayed, the boiler operation adjustment is guided, the tube explosion and the large slag falling accidents of the heating surface are avoided, and the safety and the economy of the boiler are improved.

[0020] 2. The utility model adopts compressed air cooling, and the exhaust hole is arranged at the front end of the lens cover, so that the pinhole lens and the camera can be normally used in the high-temperature and dusty environment in the furnace. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic view of the screen type superheater slagging visual measurement system.

[0022] Figure 2 For Figure 1 It is a local enlarged view of the area A.

[0023] Figure 3 It is a principle view of adding the multi-frame image matrix in the embodiment of the utility model.

[0024] Figure 4 It is the area slagging image and quantitative processing result of a large coal-fired boiler screen type superheater taken in the embodiment of the utility model. CONCRETE EMBODIMENT

[0025] The utility model will be described in further detail below in combination with the drawings and embodiments, and it should be pointed out that the following described embodiments are intended to facilitate the understanding of the utility model and do not have any limiting effect on it.

[0026] As Figures 1-2 Shown, the hearth is equipped with the screen type superheater 1 and water cooled wall 3 for absorbing heat, the slag block 2 will be produced under the screen type superheater 1 when the boiler runs, after the modification of the fire hole, the baffle door 4 with automatic opening and closing function is added.

[0027] The screen type superheater slagging visual measurement system 5 in the embodiment of the utility model includes signal processing module 501, control module 502, camera protection cover 503, compressed air inlet 504, camera 505, driving device 506, connecting piece 507, lens cover 508, pinhole lens 509, compressed air outlet 510.

[0028] Specifically, the pinhole lens 509 is arranged in the lens cover 508 and is close to the front end position, the pinhole lens 509 transmits the video signal to the camera 505, the camera 505 is connected with the control module 502, and the control module 502 is connected with the signal processing module 501.The camera 505 is fixed in the camera protection cover 503, the camera protection cover 503 is communicated with the lens cover 508, the compressed air inlet 504 is arranged on the shell close to the rear end of the camera protection cover 503, the lens cover front end is equipped with the compressed air outlet 510, the compressed air outlet 510 is simultaneously used as the lens shooting hole, and the shooting range is determined by the field of view angle 511.The driving device 506 is fixed outside the water cooled wall 3 and is connected with the lens cover 508 through the connecting piece 507.

[0029] In order to obtain the morphology image of the screen superheater area slagging, on the one hand, compressed air is used to cool the camera and lens, and the control module 502 sets the compressed air pressure alarm value, the compressed air pressure should not be lower than 0.3MPa, when the pressure is lower than the set value, the driving device 506 drives the lens cover 508 to automatically exit to the outside of the furnace; on the other hand, the compressed air can blow away the dust in the field of view of the lens, prevent contamination, and obtain clearer images.

[0030] In order to reduce the influence of high temperature flame in the furnace on the image clarity as much as possible, the obtained picture is affected by the high temperature in the furnace, and a 1mm pinhole lens is used to effectively reduce the radiation area.

[0031] In order to improve the image effect of the system recording the target object, and at the same time improve the compactness of the device, a temperature monitoring module is arranged on the pinhole lens 509 to monitor the temperature of the lens, and the control module 502 sets the lens temperature alarm value, when the lens temperature exceeds the set value, the driving device 506 drives the lens cover 508 to automatically exit the furnace.

[0032] In order to facilitate the installation of the baffle door 4 of the automatic switch after the on-site observation hole is modified, the outer diameter of the lens cover 508 is 60mm.

[0033] In the embodiment, the method for monitoring the screen superheater slagging state and quantitative data by using the screen superheater slagging visual measurement system is as follows:

[0034] S1, check to ensure that the air pressure monitoring module and the temperature monitoring module in the lens cover 508 are not alarmed;

[0035] S2, start the system, after the baffle door 4 is automatically opened, the driving device 506 drives the front end of the lens cover 508 to automatically extend into the furnace, and the camera 505 shoots the screen superheater slagging and hanging slag through the pinhole lens 509;

[0036] S3, the shot video is transmitted to the signal processing module 501, and a deep learning network algorithm is used for original picture display and quantitative processing to obtain the slagging amount image and quantitative data in the field of view, and the shooting time in the furnace is 3 minutes each time under normal condition.

[0037] S4, the driving device 506 drives the lens cover 508 to exit, and the baffle door 4 is automatically closed.

[0038] During the video shooting process, if any of the compressed air pressure is lower than the set value or the lens temperature is higher than the set value, the lens cover 508 automatically exits the boiler for protection, and the baffle door 4 is automatically closed after the lens cover 508 exits each time.

[0039] As an implementation, in S3, a deep learning network algorithm based on YOLO-SOP video image shadow overlap model is adopted, including the following steps:

[0040] The method is based on YOLO-SOP network video image shadow overlap vector extraction + coupling of multiple parameters of the furnace (furnace flue gas temperature, flame center height, coal quality parameters, steam temperature, etc. affecting the screen superheater slagging parameters), and quantifies the screen superheater slagging state by using a single local perspective video, including the following steps:

[0041] (a) After taking N key frames, the frame images are first cropped, denoised, and black and white processed;

[0042] (b) The YOLO basic network bounding box prediction is used to extract the inspectable target position (X0, Y0, W, H) of each key frame, X0 and Y0 are the starting positions of the inspectable target, W is the width, and H is the height.

[0043] (c) The bounding box obtained in step (b) is divided into (M x M) target boxes, and the feature vector graph is extracted as a matrix with dimensions m x n, and multiple image matrices are added (multiple shadow overlap calculation) to obtain a multi-layer image. The principle is shown in Figure 3 , where the numbers represent the number of occurrences of each current target box. The higher the number, the higher the credibility, and the higher the weight. The formula is as follows:

[0044]

[0045] (d) The backbone network of YOLO v8 is used to establish a YOLO architecture containing 64 convolutional layers and pooling layers, and the image processed in step (c) is subjected to convolution operation to obtain a feature vector graph F img in the middle. img The calculation formula is as follows:

[0046]

[0047] where w is the convolution and weight parameter, (x, y) is the position coordinate, C in and C out are the input and output channels. The dimension of F img is (N, C, W, H), where N is the batch size, C is the number of channels, W and H are the height and width of the feature map respectively.

[0048] (e) The furnace sensor parameter processing is a feature vector graph. The sensor parameter is a vector P = [P1, P2, …, P n ], and the data is mapped to F sensorIn the middle, making F img F sensor Both have the same dimensions (i.e., number of channels, height, and width). The formula is as follows: F sensor =W fc +b.

[0049] Among them: W fc is the weight matrix of the fully connected layer, and b is the bias.

[0050] (f) Perform a weighted summation on the vector feature maps obtained in steps (d) and (e), using the following formula: F fusion =[F img ,F sensor ].

[0051] (g) Calculate the loss function, which includes classification loss, localization loss, and confidence loss. The formula is: L = aL cls +bL cls +cL cls Adjust the weight coefficients of loss terms a, b, and c appropriately based on actual operational data.

[0052] (h) Obtain the final trained algorithm model and calculate the slagging quantification data of the screen-type superheater.

[0053] like Figure 4 As shown, this is an image of slagging in the superheater area of ​​a large coal-fired boiler taken in an embodiment of this utility model, along with the quantitative processing results. The number "5" in the green box in the image represents the severity of slagging within the selected field of view (the severity of slagging ranges from 0 to 100), and the number "0.96" represents the confidence interval for image recognition and quantitative processing.

[0054] The embodiments described above provide a detailed explanation of the technical solution and beneficial effects of this utility model. It should be understood that the above descriptions are only specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, additions, and equivalent substitutions made within the scope of the principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A screen-type superheater slagging visualization measurement system, characterized by, The driving device (506) is fixed outside the water cooling wall (3) and the lens cover (508) can extend into the furnace through the water cooling wall (3), the driving device (506) is connected with the lens cover (508) through the connecting piece (507); The pinhole lens (509) is arranged in the lens cover (508) near the front end, the rear end of the lens cover (508) is fixed with the camera protection cover (503), the camera protection cover (503) is provided with the camera (505), the signal input end of the camera (505) is connected with the pinhole lens (509), the signal output end is connected with the signal processing module (501) through the control module (502), the compressed air inlet (504) is arranged on the camera protection cover (503) near the rear end, and the front end of the lens cover (508) is provided with the compressed air outlet (510).

2. The screen superheater bank slag visualization measurement system of claim 1, wherein, The lens cover (508) extends into the furnace through the fire observation hole on the water cooling wall (3).

3. The screen superheater coking visualization measurement system of claim 2, wherein, The baffle door (4) is arranged at the fire observation hole, and the baffle door (4) is connected with the control module (502).

4. The screen superheater bank slag visualization measurement system of claim 1, wherein, The lens cover (508) adopts a double-layer structure to form two compressed air channels.

5. The screen superheater clinkering visualization measurement system according to claim 1, characterized by, The compressed air outlet (510) arranged at the front end of the lens cover (508) is used as the imaging hole of the pinhole lens (509), and the field angle is 90 degrees.

6. The screen superheater bank slag visualization measurement system of claim 1, wherein, The lens cover (508) is provided with an air pressure monitoring module, and the air pressure monitoring module is connected with the control module (502).

7. The screen superheater bank slag visualization measurement system of claim 1, wherein, The pinhole lens (509) is provided with a temperature monitoring module, and the temperature monitoring module is connected with the control module (502).

8. The screen superheater clinkering visualization measurement system according to claim 1, characterized by, The driving device (506) adopts a metal guide rail transmission and a motor with a self-locking function as power.

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