Double-model blockage detection system and method applied to air preheater

Abstract

The invention provides a double-model blockage detection system and method applied to an air preheater, a camera module is provided with a visible light camera device, the visible light camera device is used for shooting and obtaining surface visible light image data of a plurality of heat transfer elements in real time, and a thermal imaging module is provided with an infrared thermal imaging device. The infrared thermal imaging device is used for shooting and obtaining surface thermal imaging data of a plurality of heat transfer elements in real time, and the blockage evaluation module establishes a visible light blockage model and a thermal imaging blockage model according to the surface visible light image data and the surface thermal imaging data of the heat transfer elements and is used for evaluating the blockage state of the air preheater based on the dual models. According to the invention, the automatic detection function of the blockage state of the air preheater can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of air preheaters, and in particular relates to a dual-model blockage detection system and method applied to air preheaters. Background Art

[0002] A rotary air preheater is a device used to improve energy efficiency. It is commonly found in thermal power plants, boiler systems, industrial furnaces, and other places. It can preheat the air entering the combustion system by recovering the heat in the high-temperature flue gas, thereby reducing fuel consumption and improving combustion efficiency. As thermal power generation and other systems have increasingly stringent production requirements for power generation efficiency, loss control, etc., how to achieve online monitoring, analysis, and diagnosis of air preheater operation and performance has become increasingly important. Among them, the blockage of the air preheater refers to the accumulation of a large amount of dust, ash, particulate matter or other impurities inside the air preheater, resulting in obstructed air flow or reduced heat exchange efficiency. Therefore, during the operation of the air preheater, detecting the blockage of the air preheater is an important task to ensure the efficient operation of the air preheater.

[0003] Under the existing technology, conventional air preheater detection means can collect image data in the internal heat exchange space of the air preheater in a visual manner. However, during the operation of the air preheater, a large amount of detection image data will be generated. Manual review and diagnosis by operators will consume huge human resources and time resources, and it is impossible to achieve timely feedback and accurate positioning of the blockage condition of the air preheater. At the same time, the air preheater detection device under the existing technology is limited by the operating temperature and cannot be extended into the internal heat exchange space of the air preheater, resulting in poor clarity and accuracy of the collected image data, which affects the diagnosis of the blockage condition of the air preheater. Summary of the invention

[0004] The present invention provides a dual-model blockage detection system and method for an air preheater to solve the technical problem that the conventional air preheater blockage diagnosis method cannot realize automatic detection of the air preheater blockage condition under the prior art.

[0005] In order to solve the above problems, the technical solution of the present invention is: a dual-model blockage detection system applied to an air preheater, comprising: A camera module, wherein the camera module is provided with a visible light camera device, the visible light camera device is fixedly mounted on the side wall of the cold source gas input end of the air preheater, and the field of view of the visible light camera device faces a plurality of heat transfer elements in the heat exchange space inside the air preheater, and the visible light camera device is used to capture and obtain surface visible light image data of the plurality of heat transfer elements in real time; A thermal imaging module, wherein the thermal imaging module is provided with an infrared thermal imaging device, which is fixedly mounted on the side wall of the cold source gas input end of the air preheater, and the field of view of the infrared thermal imaging device faces a plurality of heat transfer elements in the heat exchange space inside the air preheater, and the infrared thermal imaging device is used to capture and obtain surface thermal imaging data of the plurality of heat transfer elements in real time; A blockage assessment module is electrically connected to the camera module and the infrared thermal imaging device, respectively. The blockage assessment module establishes a visible light blockage model and a thermal imaging blockage model according to the visible light image data of the heat transfer element surface output by the camera module and the thermal imaging image data of the heat transfer element surface output by the thermal imaging module, respectively, and is used to assess the blockage state of the air preheater based on the dual model.

[0006] Preferably, the camera module is further provided with a first optical extension lens, the first optical extension lens is fixedly connected to the lens bayonet of the visible light camera device, and the first optical extension lens is used to extend into the heat exchange space inside the air preheater; The thermal imaging module is also provided with a second optical extension lens, which is fixedly connected to the lens mount of the infrared thermal imaging device, and is used to extend into the heat exchange space inside the air preheater.

[0007] Preferably, a first gas passage is provided in the lens body shell of the first optical extension lens, and the first gas passage is configured to be annularly wrapped around the circumferential side wall of the first optical extension lens along the length extension direction of the first optical extension lens, and the first gas passage is used to inject high-pressure cold source gas; A second gas passage is provided in the lens body shell of the second optical extension lens. The second gas passage is configured to be annularly wrapped around the circumferential side wall of the second optical extension lens along the length extension direction of the second optical extension lens. The second gas passage is used to inject high-pressure cold source gas.

[0008] Preferably, a first air curtain device is provided at the front end of the lens of the first optical extension lens, and the first air curtain device is used to inject high-pressure cold source gas and form an air curtain on the mirror surface of the first optical extension lens; A second air curtain device is provided at the front end of the lens of the second optical extension lens, and the second air curtain device is used to inject high-pressure cold source gas and form an air curtain on the mirror surface of the second optical extension lens.

[0009] Preferably, the camera module is further provided with an LED fill light device, and the LED fill light device is fixedly mounted on the front end of the lens of the first optical extension lens, and is used to provide a shooting light source for the visible light camera device.

[0010] Preferably, a dual-model blockage detection system applied to an air preheater is further provided with a positioning module, the positioning module is electrically connected to the blockage assessment module, the positioning module comprises a plurality of positioning parts and a sensor, one end of the positioning part is fixedly connected to the rotation center of the air preheater, the sensor is fixedly arranged in the horizontal radial direction of the rotation center of the air preheater, and is non-contacting with the rotation center of the air preheater; The number of the positioning parts is consistent with the number of the heat transfer elements in the air preheater, and the positioning parts are arranged in a circumferential ring along the vertical arrangement intervals of the heat transfer elements in the air preheater; The positioning module is configured such that when the air preheater drives the heat transfer element to rotate through the rotation center, the plurality of positioning parts and the corresponding plurality of heat transfer elements maintain the same rotation position, and when any of the positioning parts rotates to the sensing area of ​​the sensor, the sensor outputs a detection signal.

[0011] Preferably, a reset positioning portion is provided among the plurality of positioning portions, and the reset positioning portion is configured such that when the reset positioning portion rotates to a sensing area of ​​the sensor, the sensor outputs a reset signal.

[0012] Based on the same concept, the present invention also provides a dual-model blockage detection method applied to an air preheater, which is applied to a dual-model blockage detection system applied to an air preheater as described in any one of the above, comprising the following steps: S1: The camera module takes real-time visible light image data of the surfaces of several heat transfer elements and transmits the data to the blockage assessment module; the thermal imaging module takes real-time thermal imaging image data of the surfaces of several heat transfer elements and transmits the data to the blockage assessment module; S2: The blockage assessment module calculates and obtains the average grayscale value of several heat transfer elements With the average temperature , and during the operation of the air preheater, the grayscale values ​​of several heat transfer elements are obtained respectively , and the temperature values ​​of several heat transfer elements ; S3: The blocking assessment module establishes a visible light blocking model and a thermal imaging blocking model to respectively determine the grayscale values ​​of several heat transfer elements. With temperature value Is it reasonable if there is a set of gray values ​​of heat transfer elements Greater than , where A is the preset visible light blocking coefficient, and the temperature value of the heat transfer element Greater than , where B is a preset thermal imaging blockage coefficient, the blockage assessment module outputs an air preheater blockage alarm.

[0013] Preferably, in S2, the blockage assessment module calculates and obtains the average grayscale value of a plurality of heat transfer elements. With the average temperature , further comprising the steps of: S21: During the operation of the air preheater, when the positioning module outputs a reset signal for the first time, the blockage assessment module starts to record the grayscale values ​​and temperature values ​​of several heat transfer elements respectively. When the positioning module outputs a reset signal again, the blockage assessment module stops recording the grayscale values ​​and temperature values ​​of the heat transfer elements. Based on the number of heat transfer elements in the air preheater, the blockage assessment module calculates and obtains the average grayscale value of several heat transfer elements. With the average temperature .

[0014] Preferably, in S3, the blockage assessment module outputs an air preheater blockage alarm, further comprising the following steps: S31: During the operation of the air preheater, the blockage assessment module locates the rotation position of the currently detected heat transfer element in real time through the positioning module, and the gray value of the currently detected heat transfer element is With temperature value When all are unreasonable, the blockage assessment module outputs the real-time rotation position of the heat transfer element currently detected.

[0015] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: (1) The present invention provides a dual-model blockage detection system and method for an air preheater, which is provided with a visible light camera device and an infrared thermal imaging device, which are respectively used to obtain visible light image data and thermal imaging data of a heat transfer element in the heat exchange space inside the air preheater. The blockage assessment module establishes a visible light blockage model and a thermal imaging blockage model based on the visible light image data and the thermal imaging data, and automatically diagnoses and detects the blockage state of the heat transfer element through the dual model, thereby effectively improving the detection accuracy and speed of the blockage state of the air preheater.

[0016] (2) The present invention provides a dual-model blockage detection system and method for an air preheater, wherein an optical extension lens is provided in a visible light camera device and an infrared thermal imaging device, respectively, and a gas passage is provided in the lens body shell of the optical extension lens, and an air curtain device is provided at the front end of the lens of the optical extension lens. The gas passage can wrap the lens body of the optical extension lens with high-pressure cold source gas, and the air curtain device can form an air curtain on the mirror surface of the optical extension lens. Through the setting of the optical extension lens, the visible light camera device and the infrared thermal imaging device can be extended into the dusty and high-temperature heat exchange space inside the air preheater, thereby improving the clarity and accuracy of the visible light image data and the thermal imaging image data.

[0017] (3) The present invention provides a dual-model blockage detection system and method for an air preheater, which is provided with a positioning module. The positioning module includes a plurality of positioning parts and a sensor. The positioning parts correspond to the positions of heat transfer elements respectively. During the operation of the air preheater, the real-time position of the heat transfer element can be indirectly located through the positioning module. Therefore, when the blockage assessment module detects the presence of a blocked heat transfer element, the blocked heat transfer element can be located promptly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a dual-model blockage detection system for an air preheater provided by the present invention; Figure 2 A schematic structural diagram of a camera module provided by the present invention; Figure 3 A schematic diagram of the structure of a thermal imaging module provided by the present invention; Figure 4 A flow chart of a dual-model blockage detection method for an air preheater provided by the present invention; Figure 5 A schematic diagram of the preprocessing process of the visible light image of the heat transfer element provided by the present invention; Figure 6 A schematic diagram of a heat transfer element provided by the present invention after preprocessing of a visible light image and a thermal image.

[0019] Explanation of the reference numerals: 1: visible light camera device; 2: infrared thermal imaging device; 3: heat transfer element; 4: first optical extension lens; 5: second optical extension lens; 6: first gas through hole; 7: second gas through hole; 8: first air curtain device; 9: third gas through hole; 10: second air curtain device; 11: fourth gas through hole; 12: LED fill light device; 13: positioning part; 14: sensor; 15: rotation center of air preheater. DETAILED DESCRIPTION

[0020] The following is a further detailed description of a dual-model blockage detection system and method for an air preheater proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0021] First embodiment See also Figures 1 to 3 This embodiment provides a dual-model blockage detection system for an air preheater, which is used to realize an automatic detection function of the blockage state of the air preheater, including a camera module, a thermal imaging module and a blockage assessment module.

[0022] Among them, the camera module is provided with a visible light camera device 1, which is fixed on the side wall of the cold source gas input end of the air preheater, and through the adjustment of the lens angle of the visible light camera device 1, the field of view of the visible light camera device 1 faces a number of heat transfer elements 3 in the heat exchange space inside the air preheater. The visible light camera device 1 is used to capture and obtain surface visible light image data of the number of heat transfer elements 3 in real time.

[0023] The thermal imaging module is provided with an infrared thermal imaging device 2, which is fixed on the side wall of the cold source gas input end of the air preheater. By adjusting the lens angle of the infrared thermal imaging device 2, the field of view of the infrared thermal imaging device 2 faces the several heat transfer elements 3 in the heat exchange space inside the air preheater. The infrared thermal imaging device 2 is used to capture and obtain surface thermal imaging data of the several heat transfer elements 3 in real time.

[0024] The blockage assessment module is electrically connected to the camera module and the infrared thermal imaging device 2 respectively. The surface visible light image data of the heat transfer elements 3 obtained by the camera module and the surface thermal imaging data of the heat transfer elements 3 obtained by the thermal imaging module can be transmitted to the blockage assessment module by wire or wireless means. The blockage assessment module establishes a visible light blockage model and a thermal imaging blockage model based on the visible light image data and the thermal imaging data respectively, and then substitutes the surface visible light image data and the surface thermal imaging data of each individual heat transfer element 3 into the visible light blockage model and the thermal imaging blockage model to automatically assess and detect the blockage state of the air preheater.

[0025] The specific structure and function of the dual-model blockage detection system for an air preheater provided in this embodiment will be described in further detail below: Preferably, in this embodiment, the camera module is also provided with a first optical extension lens 4, the interface end of the first optical extension lens 4 is fixedly connected to the lens mount of the visible light camera device 1, and the mirror end of the first optical extension lens 4 extends into the high-temperature heat exchange space inside the air preheater, so that the visible light camera device 1 can shoot the visible light image of the surface of the heat transfer element 3 at a close distance, thereby improving the clarity and accuracy of the visible light image data.

[0026] Similarly, the thermal imaging module is also provided with a second optical extension lens 5, the interface end of the second optical extension lens 5 is fixedly connected to the lens mount of the infrared thermal imaging device 2, and the mirror end of the second optical extension lens 5 extends into the high-temperature heat exchange space inside the air preheater, so that the infrared thermal imaging device 2 can take a close-up thermal image of the surface of the heat transfer element 3, thereby improving the clarity and accuracy of the thermal imaging data.

[0027] Furthermore, in the present embodiment, a first gas passage is provided in the body shell of the first optical extension lens 4, and the first gas passage is configured to be annularly wrapped around the circumferential side wall of the first optical extension lens 4 along the length extension direction of the first optical extension lens 4, which can be understood as a sandwich layer is provided in the body shell of the first optical extension lens 4, and a first gas through hole 6 is also provided in the body shell of the first optical extension lens 4, the first gas through hole 6 is connected to the first gas passage, and the first gas through hole 6 can be externally connected to a high-pressure cold source gas storage container, so that high-pressure cold source gas can be continuously injected into the first gas passage, which is used to provide a cooling function for the body of the first optical extension lens 4, and prevent the first optical extension lens 4 from being damaged by the high temperature inside the air preheater.

[0028] Similarly, a second gas passage is provided in the body shell of the second optical extension lens 5, and the second gas passage is configured to be annularly wrapped around the circumferential side wall of the second optical extension lens 5 along the length extension direction of the second optical extension lens 5. It can be understood that the body shell of the second optical extension lens 5 has an interlayer, and a second gas through hole 7 is also opened in the body shell of the second optical extension lens 5. The second gas through hole 7 is connected to the second gas passage, and the second gas through hole 7 can be externally connected to a high-pressure cold source gas storage container, so that high-pressure cold source gas can be continuously injected into the second gas passage, which is used to provide a cooling function for the body of the second optical extension lens 5 to prevent the second optical extension lens 5 from being damaged by the high temperature inside the air preheater.

[0029] Furthermore, in the present embodiment, a first air curtain device 8 is provided at the front end of the lens of the first optical extension lens 4, and a third gas through hole 9 is also provided in the lens body shell of the first optical extension lens 4. The third gas through hole 9 can be externally connected to a high-pressure cold source gas storage container, and the third gas through hole 9 is connected to the air inlet end of the first air curtain device 8 through a gas passage, and the air outlet end of the first air curtain device 8 faces the front end mirror surface of the first optical extension lens 4. The first air curtain device 8 can output high-pressure cold source gas, and then form an air curtain on the front end mirror surface of the first optical extension lens 4, and continuously purge the front end mirror surface of the first optical extension lens 4 to prevent the high temperature inside the air preheater from damaging the first optical extension lens 4, and to prevent the dust inside the air preheater from accumulating on the mirror surface and affecting the shooting effect of the visible light camera device 1.

[0030] Similarly, a second air curtain device 10 is provided at the front end of the lens of the second optical extension lens 5, and a fourth gas through hole 11 is also provided in the lens body shell of the second optical extension lens 5. The fourth gas through hole 11 can be externally connected to a high-pressure cold source gas storage container. The fourth gas through hole 11 is connected to the air inlet end of the second air curtain device 10 through a gas passage, and the air outlet end of the second air curtain device 10 faces the front end mirror surface of the second optical extension lens 5. The second air curtain device 10 can output high-pressure cold source gas, and then form an air curtain at the front end mirror surface of the second optical extension lens 5, and continuously purge the front end mirror surface of the second optical extension lens 5 to prevent the high temperature inside the air preheater from damaging the second optical extension lens 5, and to prevent the dust inside the air preheater from accumulating on the mirror surface and affecting the shooting effect of the infrared thermal imaging device 2.

[0031] Preferably, in this embodiment, since there is no lighting inside the air preheater, the camera module is also provided with an LED fill light device 12, which is fixed to the front end of the first optical extension lens 4 and is used to provide a shooting light source for the visible light camera device 1.

[0032] Preferably, in this embodiment, a positioning module is also provided, and the positioning module is electrically connected to the blockage assessment module. The positioning module includes a plurality of positioning parts 13 and a sensor 14. One end of the plurality of positioning parts 13 is fixedly connected to the air preheater rotation center 15, and the number of positioning parts 13 is consistent with the number of heat transfer elements 3 inside the air preheater. The plurality of positioning parts 13 are arranged in a circumferential ring along the vertical arrangement interval of the heat transfer elements 3 inside the air preheater. It can be understood that, with the air preheater rotation center 15 as the center, the horizontal cross-sectional distribution interval of the plurality of positioning parts 13 is completely consistent with the horizontal cross-sectional distribution interval of the plurality of heat transfer elements 3, that is, when the air preheater drives the heat transfer elements 3 to rotate through the rotation center 15, the positioning parts 13 and the corresponding heat transfer elements 3 maintain the same running speed and position. The sensor 14 is fixedly arranged in the horizontal radial direction of the air preheater rotation center 15, and is in a non-contact state with the air preheater rotation center 15.

[0033] In this embodiment, when the air preheater is in operation, the air preheater drives the heat transfer element 3 and the positioning part 13 to rotate through the rotation center 15. When only one set of the positioning part 13 rotates to the sensing area of ​​the sensor 14, the sensor 14 can output a detection signal to the blockage evaluation module. It can be understood that in this embodiment, the air preheater is provided with 48 sets of heat transfer elements 3. When the sensor 14 outputs 49 detection signals in total, it means that the air preheater drives the heat transfer element 3 to rotate completely.

[0034] Furthermore, in this embodiment, a reset positioning portion 13 is provided among the plurality of positioning portions 13. The reset positioning portion 13 is configured such that when the reset positioning portion 13 rotates to the sensing area of ​​the sensor 14, the sensor 14 can output a reset signal different from the detection signal to the blockage assessment module. In this embodiment, the blockage assessment module is provided with a counter. When the sensor 14 outputs the reset signal, the counter counts to zero. Subsequently, each time the sensor 14 outputs a detection signal, the counter counts by one until the sensor 14 outputs the reset signal again and the counter counts to zero again. It can be understood that, in the counting process of the counter, since the positions of the reset positioning portion 13 and the corresponding heat transfer element 3 are known, different counts of the counter correspond to different heat transfer elements 3, and the positions of the heat transfer elements 3 corresponding to different counts can also be inferred. For example, when the counter counts to 5, it represents the heat transfer element 3 corresponding to the reset positioning portion 13 after 5 groups of intervals in the rotation direction. Therefore, in this embodiment, when the blockage assessment module detects that the heat transfer element 3 is blocked, the actual position or number of the blocked heat transfer element 3 can be located and recorded according to the positioning module.

[0035] In summary, this embodiment provides a dual-model blockage detection system for air preheaters, which is provided with a visible light camera device 1 and an infrared thermal imaging device 2 with an extended and cooling protection structure, which can be extended into the high-temperature heat exchange space inside the air preheater, and then obtain the surface visible light image data and surface thermal imaging map data of the heat transfer element 3 by close-range photography. The blockage assessment module can establish a visible light blockage model and a thermal imaging blockage model for detecting the blockage status of the heat transfer element 3 based on the visible light image data and the thermal imaging map data. Subsequently, during the operation of the air preheater, the surface visible light image data and the surface thermal imaging map data of each individual heat transfer element 3 are substituted into the visible light blockage model and the thermal imaging blockage model, so as to realize the automatic assessment function of the blockage status of the heat transfer element 3. At the same time, based on the positioning module, when the blockage assessment module detects that there is a blockage status of the heat transfer element 3, the actual position or number of the blocked heat transfer element 3 can be accurately located in time, so as to facilitate the rapid execution of the subsequent blockage cleaning operation. In this embodiment, an artificial intelligence algorithm is used and based on a dual model, the blockage characteristics in the heat transfer element 3 are automatically processed and detected, which can effectively reduce labor costs and improve the timeliness and accuracy of monitoring the blockage status of the air preheater, thereby improving the operating efficiency and safety of the air preheater.

[0036] Second embodiment Based on the same concept, this embodiment provides a dual-model blockage detection method for an air preheater, which is applied to the dual-model blockage detection system for an air preheater described in any one of the first embodiments, see Figure 4 , including the following steps: S1: During the operation of the air preheater, the camera module captures and obtains the surface visible light image data of several heat transfer elements 3 in real time, and transmits it to the blockage assessment module. The thermal imaging module captures and obtains the surface thermal imaging data of several heat transfer elements 3 in real time, and transmits it to the blockage assessment module.

[0037] S21: The blockage assessment module obtains surface visible light image data and surface thermal imaging data of a plurality of heat transfer elements 3, and pre-processes the visible light image data and the surface thermal imaging data.

[0038] During the operation of the air preheater, a rotation cycle of the heat transfer element 3 is selected. When the positioning module outputs a reset signal for the first time, the blockage assessment module starts to record the grayscale values ​​and temperature values ​​of several heat transfer elements 3 respectively. When the positioning module outputs a reset signal again, it means that the heat transfer element 3 has completely rotated one circle. The blockage assessment module stops recording the grayscale value and temperature value of the heat transfer element 3. Based on the number of heat transfer elements 3 in the air preheater and the grayscale values ​​and temperature values ​​corresponding to all the heat transfer elements 3 in a single rotation cycle obtained by the blockage assessment module, the blockage assessment module can calculate and obtain the average grayscale value of several heat transfer elements 3. With the average temperature .

[0039] S22: In the subsequent rotation cycle of the heat transfer element 3, the blockage assessment module obtains the grayscale values ​​of several heat transfer elements 3 respectively. , and the temperature values ​​of several heat transfer elements 3 .

[0040] Preferably, in this embodiment, the blockage assessment module pre-processes the visible light image data and the thermal imaging image data of the heat transfer element 3, see Figure 5 , including: Mean filtering is performed on the visible light image and the thermal image through a filter to remove noise from the visible light image and the thermal image; histogram equalization is performed on the visible light image and the thermal image to enhance the contrast of the visible light image and the thermal image; the visible light image and the thermal image are sharpened based on the first-order differential operator to enhance the edge details of the visible light image and the thermal image; the visible light image and the thermal image are cropped and geometrically transformed to obtain the visible light image and the thermal image of the target size, see Figure 6 .

[0041] It is worth noting that the preprocessing process also includes screening of the visible light image and thermal imaging image of the heat transfer element 3. That is, in this embodiment, since the rotation speed of the heat transfer element 3 is adjustable and not fixed, the camera module and the thermal imaging module are set to a high-speed continuous shooting mode. Among all the visible light images and thermal imaging images taken, only a unique set of visible light images and thermal imaging images corresponding to a single heat transfer element 3 and having the best shooting angle, clarity, etc. will be screened out as the subsequent use image data of the visible light image and thermal imaging image of the single heat transfer element 3.

[0042] S3: Blockage assessment module based on the average gray value of heat transfer element 3 With the average temperature , establish a visible light blocking model and a thermal imaging blocking model to respectively determine the grayscale values ​​of several heat transfer elements 3 With temperature value Is it reasonable, that is, if there is a set of gray values ​​of the heat transfer element 3 Greater than , where A is the preset visible light blocking coefficient, and the temperature value of the heat transfer element 3 is Greater than , where B is the preset thermal imaging blockage coefficient, it proves that the heat transfer element 3 is blocked, and the blockage assessment module outputs an air preheater blockage alarm.

[0043] Preferably, during the operation of the air preheater, the blockage assessment module locates the rotation position or number of the currently detected heat transfer element 3 in real time through the positioning module, and the gray value of the currently detected heat transfer element 3 is With temperature value When both are unreasonable, the air preheater blockage alarm output by the blockage assessment module includes the real-time rotation position or number of the heat transfer element 3 currently detected.

[0044] In summary, this embodiment provides a dual-model blockage detection method for an air preheater. First, the camera module and the thermal imaging module are used to obtain the surface visible light image data and the surface thermal imaging image data of the heat transfer element 3. The blockage assessment module calculates the average gray value of the heat transfer element 3 inside the air preheater. With the average temperature , establish a visible light blocking model and a thermal imaging blocking model, and continuously obtain the gray value of each independent heat transfer element 3 during the subsequent rotation of the heat transfer element 3 With temperature value , the gray value of each independent heat transfer element 3 With temperature value Substitute them into the visible light blockage model and the thermal imaging blockage model respectively, evaluate whether the heat transfer element 3 is blocked and record the number or position of the blocked heat transfer element 3. Through the dual-model blockage detection method applied to the air preheater provided in this embodiment, the accuracy of identifying the blockage state of the air preheater can be significantly improved.

[0045] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A dual-mode blockage detection system for air preheater, characterized in that: include: A camera module, wherein the camera module is provided with a visible light camera device, the visible light camera device is fixedly mounted on the side wall of the cold source gas input end of the air preheater, and the field of view of the visible light camera device faces a plurality of heat transfer elements in the heat exchange space inside the air preheater, and the visible light camera device is used to capture and obtain surface visible light image data of the plurality of heat transfer elements in real time; A thermal imaging module, wherein the thermal imaging module is provided with an infrared thermal imaging device, which is fixedly mounted on the side wall of the cold source gas input end of the air preheater, and the field of view of the infrared thermal imaging device faces a plurality of heat transfer elements in the heat exchange space inside the air preheater, and the infrared thermal imaging device is used to capture and obtain surface thermal imaging data of the plurality of heat transfer elements in real time; A blockage assessment module is electrically connected to the camera module and the infrared thermal imaging device, respectively. The blockage assessment module establishes a visible light blockage model and a thermal imaging blockage model according to the visible light image data of the heat transfer element surface output by the camera module and the thermal imaging image data of the heat transfer element surface output by the thermal imaging module, respectively, and is used to assess the blockage state of the air preheater based on the dual model.

2. The dual-mode blockage detection system for air preheater according to claim 1, characterized in that: The camera module is further provided with a first optical extension lens, the first optical extension lens is fixedly connected to the lens bayonet of the visible light camera device, and the first optical extension lens is used to extend into the heat exchange space inside the air preheater; The thermal imaging module is also provided with a second optical extension lens, which is fixedly connected to the lens mount of the infrared thermal imaging device, and is used to extend into the heat exchange space inside the air preheater.

3. The dual-mode blockage detection system for air preheater according to claim 2, characterized in that: A first gas passage is provided in the lens body shell of the first optical extension lens, and the first gas passage is configured to be annularly wrapped around the circumferential side wall of the first optical extension lens along the length extension direction of the first optical extension lens, and the first gas passage is used to inject high-pressure cold source gas; A second gas passage is provided in the lens body shell of the second optical extension lens. The second gas passage is configured to be annularly wrapped around the circumferential side wall of the second optical extension lens along the length extension direction of the second optical extension lens. The second gas passage is used to inject high-pressure cold source gas.

4. The dual-mode blockage detection system for air preheater according to claim 2, characterized in that: A first air curtain device is provided at the front end of the lens of the first optical extension lens, and the first air curtain device is used to inject high-pressure cold source gas and form an air curtain on the mirror surface of the first optical extension lens; A second air curtain device is provided at the front end of the lens of the second optical extension lens, and the second air curtain device is used to inject high-pressure cold source gas and form an air curtain on the mirror surface of the second optical extension lens.

5. The dual-mode blockage detection system for air preheater according to claim 2, characterized in that: The camera module is also provided with an LED fill light device, which is fixed to the front end of the lens of the first optical extension lens and is used to provide a shooting light source for the visible light camera device.

6. The dual-mode blockage detection system for air preheater according to claim 1, characterized in that: A positioning module is also provided, the positioning module is electrically connected to the blockage assessment module, the positioning module includes a plurality of positioning parts and a sensor, one end of the positioning part is fixedly connected to the rotation center of the air preheater, and the sensor is fixedly arranged in the horizontal radial direction of the rotation center of the air preheater and is non-contacting with the rotation center of the air preheater; The number of the positioning parts is consistent with the number of the heat transfer elements in the air preheater, and the positioning parts are arranged in a circumferential ring along the vertical arrangement intervals of the heat transfer elements in the air preheater; The positioning module is configured such that when the air preheater drives the heat transfer element to rotate through the rotation center, the plurality of positioning parts and the corresponding plurality of heat transfer elements maintain the same rotation position, and when any of the positioning parts rotates to the sensing area of ​​the sensor, the sensor outputs a detection signal.

7. The dual-mode blockage detection system for air preheater according to claim 6, characterized in that: A reset positioning portion is provided among the plurality of positioning portions, and the reset positioning portion is configured such that when the reset positioning portion rotates to the sensing area of ​​the sensor, the sensor outputs a reset signal.

8. A dual-model blockage detection method for an air preheater, characterized in that: A dual-model blockage detection system for an air preheater as claimed in any one of claims 1 to 7 comprises the following steps: S1: The camera module takes real-time visible light image data of the surfaces of several heat transfer elements and transmits the data to the blockage assessment module; the thermal imaging module takes real-time thermal imaging image data of the surfaces of several heat transfer elements and transmits the data to the blockage assessment module; S2: The blockage assessment module calculates and obtains the average grayscale value of several heat transfer elements With the average temperature , and during the operation of the air preheater, the grayscale values ​​of several heat transfer elements are obtained respectively , and the temperature values ​​of several heat transfer elements ; S3: The blocking assessment module establishes a visible light blocking model and a thermal imaging blocking model to respectively determine the grayscale values ​​of several heat transfer elements. With temperature value Is it reasonable if there is a set of gray values ​​of heat transfer elements Greater than , where A is the preset visible light blocking coefficient, and the temperature value of the heat transfer element Greater than , where B is a preset thermal imaging blockage coefficient, the blockage assessment module outputs an air preheater blockage alarm.

9. The dual-mode blockage detection system for air preheater according to claim 8, characterized in that: In S2, the blockage assessment module calculates and obtains the average grayscale value of several heat transfer elements. With the average temperature , further comprising the steps of: S21: During the operation of the air preheater, when the positioning module outputs a reset signal for the first time, the blockage assessment module starts to record the grayscale values ​​and temperature values ​​of several heat transfer elements respectively. When the positioning module outputs a reset signal again, the blockage assessment module stops recording the grayscale values ​​and temperature values ​​of the heat transfer elements. Based on the number of heat transfer elements in the air preheater, the blockage assessment module calculates and obtains the average grayscale value of several heat transfer elements. With the average temperature .

10. The dual-mode blockage detection system for air preheater according to claim 8, characterized in that: In S3, the blockage assessment module outputs an air preheater blockage alarm, further comprising the following steps: S31: During the operation of the air preheater, the blockage assessment module locates the rotation position of the currently detected heat transfer element in real time through the positioning module, and the gray value of the currently detected heat transfer element is With temperature value When all are unreasonable, the blockage assessment module outputs the real-time rotation position of the heat transfer element currently detected.

Images