A CT detection system for boiler combustion temperature field based on thermal radiation imaging

Abstract

The invention discloses a boiler combustion temperature field CT detection system based on thermal radiation imaging, which belongs to the field of boiler combustion detection in thermal power plants. The system is composed of a furnace combustion flame image shooting module arranged on the furnace wall, a furnace three-dimensional temperature field calculation and display module arranged on the boiler site, and a furnace three-dimensional temperature field data storage and transmission module. The invention adopts a horizontally arranged furnace flame camera probe to shoot the furnace flame image, uses the information of a row of pixels in the horizontal direction of the image to reconstruct the corresponding cross-sectional temperature distribution in the furnace, and then calculates layer by layer along the vertical direction of the image. In this way, the number of vertical pixels of the image is directly associated with the number of grids along the height of the furnace three-dimensional temperature field. The obtained furnace three-dimensional temperature field is composed of hundreds or thousands of layers of cross-sectional temperature distribution along the height direction, and the spatial resolution of the three-dimensional temperature field can be improved by dozens or even hundreds of times.

Description

Technical Field

[0001] The invention belongs to the field of boiler combustion detection in thermal power plants, and in particular relates to a boiler combustion temperature field CT detection system based on thermal radiation imaging. Background Art

[0002] At present, thermal power generation still occupies a dominant position in my country's power supply. In the production process of thermal power plants, boilers are relatively the most prone to problems. Due to the complexity of its own composition and structure, the coal combustion process in the boiler furnace is a black box system. It is difficult for operators to directly observe the exact situation of the furnace combustion, and the rationality of the temperature field distribution in the furnace will affect the stable operation of the boiler. Therefore, carrying out the combustion temperature field detection in the boiler furnace is of great practical significance to ensure the safe and efficient operation of the boiler, and can also provide rich combustion information for the intelligent construction of thermal power plants.

[0003] The literature [Zhou Huaichun, Lou Xinsheng, Deng Yuankai. Principle and analysis of three-dimensional temperature distribution detection of furnace combustion based on radiation image processing [J]. Proceedings of the CSEE, 1997, 17(1):1-4.] proposed a furnace three-dimensional temperature field detection method based on radiation image processing, which uses a CCD camera to capture the combustion flame image in the furnace. By processing the flame radiation image, combining thermal radiation imaging and inverse problem solving, the three-dimensional temperature field in the furnace can be obtained. The patent [Zhou Huaichun, Lou Chun, Cheng Qiang, Luo Zixue, Jiang Zhiwei. Real-time monitoring device for three-dimensional temperature field in coal-fired boiler furnace, Chinese utility model patent, authorization number: ZL200420076978.8,] gives a system device established in the implementation process of this method. The device arranges camera probes in layers along the height direction of the boiler in the furnace area from the cold ash hopper to the flame deflection angle of the boiler, with at least two cameras arranged on each layer, and the center line of the viewing angle is inclined downward. The video signals of each camera probe are sent to the video splitter to be synthesized into one signal, and then sent to the computer for processing. The multiple camera probes arranged can fully receive the radiation information from the furnace and can accurately calculate the three-dimensional temperature field in the furnace.

[0004] However, in practical applications, although the three-dimensional temperature field of the furnace can be obtained according to the above method, the CCD two-dimensional target surface is divided into pixel units in the horizontal and vertical directions. This processing method does not fully utilize the information of each pixel in the high-resolution flame image taken by the CCD camera, so that the obtained three-dimensional temperature field has only more than ten layers in the height direction (the spatial resolution is only in thousands of grids); therefore, a boiler combustion temperature field CT detection system based on thermal radiation imaging is urgently needed to overcome the problems existing in the existing detection methods. Summary of the invention

[0005] The purpose of the present invention is to provide a boiler combustion temperature field CT detection system based on thermal radiation imaging, which adopts a horizontally arranged furnace flame camera probe to capture the flame image in the furnace, uses the information of a row of pixels in the horizontal direction of the image to reconstruct the corresponding cross-sectional temperature distribution in the furnace, and then calculates layer by layer along the vertical direction of the image. This method directly associates the number of vertical pixels of the image with the number of grids along the height of the three-dimensional temperature field of the furnace. The obtained three-dimensional temperature field of the furnace is composed of hundreds or thousands of layers of cross-sectional temperature distribution along the height direction, which can improve the spatial resolution of the three-dimensional temperature field by dozens or even hundreds of times.

[0006] To achieve the above-mentioned purpose, the present invention provides a boiler combustion temperature field CT detection system based on thermal radiation imaging, which is composed of a furnace combustion flame image shooting module arranged on the furnace wall, a furnace three-dimensional temperature field calculation and display module arranged on the boiler site, and a furnace three-dimensional temperature field data storage and transmission module;

[0007] The furnace combustion flame image shooting module includes a furnace flame camera probe and a router; wherein the furnace flame camera probe is composed of a high temperature resistant endoscope lens and a camera, and the furnace flame camera probe is installed on the furnace wall in a layered horizontal arrangement, with at least one layer arranged, and at least one furnace flame camera probe is installed on each furnace wall of each layer, and the center line of the field angle of the furnace flame camera probe is perpendicular to the wall on which it is installed, so as to ensure that the furnace combustion flame image is shot in a horizontal manner;

[0008] The three-dimensional temperature field calculation and display module in the furnace includes an embedded development board, a touch screen and a power supply; the flame image data taken by the furnace flame camera probe is received through the embedded development board, and each image taken by the furnace flame camera probe has M pixels in the horizontal direction and N pixels in the vertical direction. The corresponding cross-sectional temperature distribution in the furnace is reconstructed using the information of a row of pixels in the horizontal direction of all images, and then layer by layer calculation is performed along the vertical direction of the image, and finally the three-dimensional temperature field of the furnace composed of N layers of cross-sectional temperature distribution is obtained, and displayed in the form of a pseudo-color cloud map on the touch screen;

[0009] The three-dimensional temperature field data storage and transmission module in the furnace includes a data storage device and a communication interface; the embedded development board stores the temperature field data calculated from the current flame image data in the data storage device, and uses the industrial bus communication protocol in a client manner to send the temperature field data in a specific format to the designated data receiving end, and the data receiving end extracts the temperature field data after parsing the received information.

[0010] Preferably, the number of furnace flame camera probes to be installed on each furnace wall of each layer is determined according to the horizontal field angle α of the furnace flame camera probe and the rectangular cross-sectional size of the furnace, the length L of the front and rear walls, and the width W of the left and right walls; the specific determination method is as follows:

[0011] When the furnace flame camera probe is installed on the front wall or the rear wall, the visible dimension of its horizontal field angle α on the center normal of the left and right walls is S1=W×tg(α / 2); if S1 is not less than the length L of the front and rear walls, then one camera probe is installed on the wall of this layer; if S1 is less than the length L of the front and rear walls, then the number of furnace flame camera probes on this layer of the wall should be increased and arranged at equal intervals until the sum of the visible dimensions of the furnace flame camera probes on the center normal of the left and right walls is not less than the length of the front and rear walls. The number of furnace flame camera probes O1 installed on this wall is:

[0012]

[0013] In the formula, Indicates rounding up;

[0014] When the furnace flame camera probe is installed on the left wall or the right wall, the visible size of its horizontal field angle α on the center normal of the front and rear walls is S2=L×tg(α / 2); if S2 is not less than the width W of the left and right walls, a furnace flame camera probe is installed on the wall of this layer; if S2 is less than the width W of the left and right walls, the number of furnace flame camera probes on this layer and this wall should be increased and arranged at equal intervals until the sum of the visible sizes of the furnace flame camera probes on the center normal of the front and rear walls is not less than the width W of the left and right walls. The number of furnace flame camera probes O2 installed on this wall is:

[0015]

[0016] In the formula, Indicates rounding up;

[0017] Therefore, the number of furnace flame camera probes installed on each layer of the furnace wall is:

[0018] O=(O1+O2)×2.

[0019] Preferably, according to the vertical field angle β of the furnace flame camera probe and the furnace height size, the furnace height H below the boiler flame deflection angle and above the cold ash hopper, the number of layers P of the furnace flame camera probe arrangement is determined, specifically:

[0020] When the length of the front and rear walls L is not less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = W × tg (β / 2); when the length of the front and rear walls L is less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = L × tg (β / 2); if S3 is not less than the furnace height H, the furnace flame camera probe only needs to be arranged in one layer; if S3 is less than the furnace height H, the number of layers of the furnace flame camera probe should be increased until the sum of the visible dimensions of the furnace flame camera probe on the central axis along the furnace height is not less than the furnace height H, and the calculation expression of P is as follows:

[0021]

[0022] In the formula, Indicates rounding up.

[0023] Preferably, the specific process of reconstructing and displaying the corresponding cross-sectional temperature distribution in the furnace is as follows:

[0024] Step 1, when the furnace flame camera probe shoots the furnace combustion flame image in a horizontal manner, according to the CT principle, in the image shot by each furnace flame camera probe, the furnace combustion flame radiation information received by each row of pixels comes from the furnace combustion flame section with a layer thickness of S4. It is known that there are N pixels in the vertical direction of the image, then S4 = S3 / N; the number of furnace flame camera probes in each layer determined by the furnace combustion flame image shooting module is O, and each row in the image obtained by each furnace flame camera probe has M pixels, then according to the principle of thermal radiation imaging, a linear equation group model of the furnace combustion flame section temperature field and the corresponding O×M flame radiation information is established in the embedded development board;

[0025] Step 2. Call the optimization algorithm for solving the linear equations model in the embedded development board, and use each layer of furnace flame camera probes to detect the N-layer furnace section temperature field. The spatial size of each layer of the section temperature field is L×W×S4; the furnace combustion flame image shooting module determines the number of layers P of camera probes, and then performs the same calculation on the flame images taken by the furnace flame camera probes layer by layer to obtain the three-dimensional furnace temperature field composed of the H / S4 layer section temperature distribution, and displays the furnace section temperature distribution of each layer in layers in the form of pseudo-color cloud maps on the touch screen.

[0026] Preferably, the three-dimensional temperature field data of the furnace obtained in step 2 is stored in a data storage device according to a layered storage method, and then its physical coordinates in the furnace are determined according to the thickness S4 of each layer of the cross-sectional temperature field, and the cross-sectional temperature distribution data of each layer is stored in sequence using the physical coordinates of each layer of the cross-sectional temperature distribution as an index.

[0027] Preferably, the industrial bus communication protocols include CAN (Controller Area Network) bus, Profibus (Process Field Bus) bus, Modbus bus and Ethernet / IP (Industrial Protocol) bus.

[0028] Therefore, the present invention adopts the above-mentioned boiler combustion temperature field CT detection system based on thermal radiation imaging, which has the following beneficial effects:

[0029] (1) Combining thermal radiation imaging with CT principles, it is proposed to arrange camera probes in layers horizontally, determine the number of layers and the number of camera probes in each layer, establish a linear equation model of the thermal radiation information received by each row of pixels in the image and the furnace cross-section temperature field, and then calculate layer by layer along the vertical direction of the image, thereby constructing an online monitoring system of the furnace three-dimensional temperature field with high spatial resolution along the furnace height direction;

[0030] (2) The detection method and device proposed in the present invention are based on an embedded system and provide a data communication interface based on an industrial bus. Compared with the usual host computer system, the structure of the entire device is more compact and can be integrated into the distributed control system of a thermal power generator set as a primary sensor for boiler combustion detection, and is suitable for the intelligent construction of thermal power plants.

[0031] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a boiler combustion temperature field CT detection system based on thermal radiation imaging of the present invention;

[0033] Figure 2 This is a layout diagram of the furnace flame camera probe according to an embodiment of the present invention;

[0034] Reference numerals

[0035] 1. Furnace combustion flame image shooting module; 2. Furnace three-dimensional temperature field calculation and display module; 3. Furnace three-dimensional temperature field data storage and transmission module; 4. Camera; 5. High temperature resistant endoscope lens; 6. Furnace flame camera probe. DETAILED DESCRIPTION

[0036] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] See also Figure 1-2 A boiler combustion temperature field CT detection system based on thermal radiation imaging, which is composed of a furnace combustion flame image shooting module 1 arranged on the furnace wall, a furnace three-dimensional temperature field calculation and display module 2 arranged on the boiler site, and a furnace three-dimensional temperature field data storage and transmission module 3;

[0038] The furnace combustion flame image shooting module 1 includes a furnace flame camera probe 6 and a router; wherein the furnace flame camera probe 6 is composed of a high temperature resistant endoscope lens 5 and a camera 4, and the furnace flame camera probe 6 is installed on the furnace wall in a layered horizontal arrangement, with at least one layer arranged, and at least one furnace flame camera probe is installed on each furnace wall of each layer, and the center line of the field angle of the furnace flame camera probe 6 is perpendicular to the wall on which it is installed, so as to ensure that the furnace combustion flame image is shot in a horizontal manner;

[0039] According to the horizontal field angle α of the furnace flame camera probe and the rectangular cross-sectional dimensions of the furnace, the length of the front and rear walls L, and the width of the left and right walls W, determine the number of furnace flame camera probes to be installed on each furnace wall on each layer; the specific determination method is as follows:

[0040] When the furnace flame camera probe is installed on the front wall or the rear wall, the visible dimension of its horizontal field angle α on the center normal of the left and right walls is S1=W×tg(α / 2); if S1 is not less than the length L of the front and rear walls, then one camera probe is installed on the wall of this layer; if S1 is less than the length L of the front and rear walls, then the number of furnace flame camera probes on this layer of the wall should be increased and arranged at equal intervals until the sum of the visible dimensions of the furnace flame camera probes on the center normal of the left and right walls is not less than the length of the front and rear walls. The number of furnace flame camera probes O1 installed on this wall is:

[0041]

[0042] In the formula, Indicates rounding up;

[0043] When the furnace flame camera probe is installed on the left wall or the right wall, the visible size of its horizontal field angle α on the center normal of the front and rear walls is S2=L×tg(α / 2); if S2 is not less than the width W of the left and right walls, a furnace flame camera probe is installed on the wall of this layer; if S2 is less than the width W of the left and right walls, the number of furnace flame camera probes on this layer and this wall should be increased and arranged at equal intervals until the sum of the visible sizes of the furnace flame camera probes on the center normal of the front and rear walls is not less than the width W of the left and right walls. The number of furnace flame camera probes O2 installed on this wall is:

[0044]

[0045] In the formula, Indicates rounding up;

[0046] Therefore, the number of furnace flame camera probes installed on each layer of the furnace wall is:

[0047] O=(O1+O2)×2.

[0048] According to the vertical field angle β of the furnace flame camera probe and the furnace height size, the furnace height H below the boiler flame deflection angle and above the cold ash hopper is determined to determine the number of layers P of the furnace flame camera probe. The calculation content of the number of layers P of the furnace flame camera probe is as follows:

[0049] When the length of the front and rear walls L is not less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = W × tg (β / 2); when the length of the front and rear walls L is less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = L × tg (β / 2); if S3 is not less than the furnace height H, the furnace flame camera probe only needs to be arranged in one layer; if S3 is less than the furnace height H, the number of layers of the furnace flame camera probe should be increased until the sum of the visible dimensions of the furnace flame camera probe on the central axis along the furnace height is not less than the furnace height H, and the calculation expression of P is as follows:

[0050]

[0051] In the formula, Indicates rounding up.

[0052] The three-dimensional temperature field calculation and display module 2 in the furnace includes an embedded development board, a touch screen and a power supply; the flame image data taken by the furnace flame camera probe is received through the embedded development board, and each image taken by the furnace flame camera probe has M pixels in the horizontal direction and N pixels in the vertical direction. The corresponding cross-sectional temperature distribution in the furnace is reconstructed using the information of a row of pixels in the horizontal direction of all images, and then layer by layer calculation is performed along the vertical direction of the image, and finally the three-dimensional temperature field of the furnace composed of N layers of cross-sectional temperature distribution is obtained, and displayed in the form of a pseudo-color cloud map on the touch screen;

[0053] The three-dimensional temperature field data storage and transmission module 3 in the furnace includes a data storage device and a communication interface; the embedded development board stores the temperature field data calculated from the current flame image data in the data storage device, and uses the industrial bus communication protocol in the client mode to send the temperature field data in a specific format to the designated data receiving end, and the data receiving end extracts the temperature field data after parsing the received information. The industrial bus communication protocol includes CAN (Controller Area Network) bus, Profibus (Process Field Bus) bus, Modbus bus and Ethernet / IP (Industrial Protocol) bus. Among them, the specific process of reconstructing and displaying the corresponding cross-sectional temperature distribution in the furnace is as follows:

[0054] Step 1, when the furnace flame camera probe shoots the furnace combustion flame image in a horizontal manner, according to the CT principle, in the image shot by each furnace flame camera probe, the furnace combustion flame radiation information received by each row of pixels comes from the furnace combustion flame section with a layer thickness of S4. It is known that there are N pixels in the vertical direction of the image, then S4 = S3 / N; the number of furnace flame camera probes in each layer determined by the furnace combustion flame image shooting module is O, and each row in the image obtained by each furnace flame camera probe has M pixels, then according to the principle of thermal radiation imaging, a linear equation group model of the furnace combustion flame section temperature field and the corresponding O×M flame radiation information is established in the embedded development board;

[0055] Step 2, calling the optimization algorithm for solving the linear equations model in the embedded development board, using each layer of furnace flame camera probes to detect N layers of furnace cross-section temperature field, and the spatial size of each layer of cross-section temperature field is L×W×S4; the number of layers P of camera probes arranged is determined by the furnace combustion flame image shooting module, and then the flame images shot by the furnace flame camera probes are calculated in the same way layer by layer to obtain the furnace three-dimensional temperature field composed of H / S4 layer cross-section temperature distribution, and the furnace cross-section temperature distribution of each layer is displayed in layers on the touch display screen in a pseudo-color cloud map; wherein the obtained furnace three-dimensional temperature field data is stored in the data storage device according to the layered storage method, and then the physical coordinates of each layer of cross-section temperature field are determined in the furnace according to the thickness S4 of each layer of cross-section temperature field, and the cross-section temperature distribution data of each layer is stored in sequence with the physical coordinates of each layer of cross-section temperature distribution as the index.

[0056] Example

[0057] In this specific embodiment, the embedded development board is Raspberry Pi 5, the camera of the furnace flame camera probe is Hikvision BC-18S40, the touch screen is DH10114A2 embedded capacitive screen, the power supply is DELIXI CDKU-S50, the data storage device is SanDisk 256GB MicroSD card, the communication interface is Gigabit Ethernet, etc. Figure 2 This is a furnace flame camera probe arrangement diagram provided for an embodiment of the present invention. The object of this embodiment is a 300MW supercritical boiler; the method of the present invention is described below with respect to the set object.

[0058] (1) Furnace combustion flame image shooting module;

[0059] This embodiment takes a four-corner cut-circle boiler as an example, with a rated power of 300MW. The boiler is a square boiler, and the length of the front and rear walls L is equal to the length of the left and right walls W, which is 14m; the furnace height H below the boiler flame deflection angle and above the cold ash hopper is 30m. The furnace flame camera probe used in the present invention has a horizontal field of view angle α=90° and a vertical field of view angle β=72°. The resolution of the image of the combustion flame in the furnace obtained is 2560 (width) × 1440 (height). For the furnace flame camera probe installed on the front and rear walls, the visible dimension S1 of its horizontal field of view on the normal line of the center of the left and right walls is S1=14m, which is equal to the length L of the front and rear walls. Therefore, one furnace flame camera probe can be installed on the front and rear walls of this layer; for the furnace flame camera probe installed on the left and right walls, the visible dimension S2 of its horizontal field of view on the normal line of the center of the front and rear walls is S2=14m, which is equal to the width W of the left and right walls. Therefore, one furnace flame camera probe can be installed on the left and right walls of this layer.

[0060] The length L of the front and rear walls of the boiler is equal to the width W of the left and right walls. The visible dimension S3 of the vertical field angle of the camera probe along the central axis in the direction of the furnace height is 10.17m. In order to ensure that the sum of the visible dimensions of the furnace flame camera probe on the central axis along the direction of the furnace height is greater than or equal to the furnace height H, a total of 3 layers of camera probes are arranged on the boiler.

[0061] (2) 3D temperature field calculation and display module in the furnace:

[0062] The furnace flame camera probe extends horizontally into the boiler to capture the combustion flame image. Each furnace flame camera probe captures 1440 pixels in the vertical direction. The furnace combustion flame radiation information received by each row of pixels comes from the furnace combustion flame section with a layer thickness of 0.00706m, and each layer of the combustion flame section is divided into 20×20 temperature field grids. There are 4 furnace flame camera probes on each layer of the boiler, and each furnace flame camera probe obtains a combustion flame image with 2560 pixels in the horizontal direction. According to the principle of thermal radiation imaging, a linear equation group model of 400 temperature field grids and corresponding 10240 flame radiation information is established in the embedded development board.

[0063] By calling the optimization algorithm for solving the linear equations model in the embedded development board, the temperature field of 1440 furnace sections can be detected by each layer of furnace flame camera probes. The spatial size of each layer of the temperature field is 14m×14m×0.00706m. By arranging three layers of furnace flame camera probes on the boiler, the flame images taken by the furnace flame camera probes are calculated layer by layer to obtain the furnace three-dimensional temperature field composed of 4249 layers of cross-sectional temperature distribution. The three-dimensional temperature field grid is divided into 400×4249, with a total of 1699600 temperature data, and the temperature distribution of each layer of the furnace section is displayed in layers on the touch screen in the form of a pseudo-color cloud map.

[0064] (3) Furnace three-dimensional temperature field data storage and transmission module:

[0065] The embedded development board stores the 400×4249 furnace three-dimensional temperature field data calculated from the current flame image data in layers in the data storage, and the thickness of each layer of cross-sectional temperature field is 0.00706m. The physical coordinates of each layer of cross-sectional temperature field in the furnace can be determined according to its thickness, and these physical coordinates are used as indexes to store the cross-sectional temperature distribution data of each layer in sequence.

[0066] This embodiment uses Ethernet / IP (Industrial Protocol) bus communication, which is an industrial automation communication protocol based on Ethernet. It can realize real-time communication on Ethernet and provides support for TCP / IP network. Data transmission adopts the format of JSON string. JSON is a lightweight data exchange format independent of programming language. After the temperature field data is calculated, it is organized into a JSON string, which contains temperature data, physical coordinates, grid number, calculation time and other contents. The embedded device can send JSON data to the server through TCP / IP connection for parsing, extraction, storage, display, etc.

[0067] Therefore, the present invention adopts the above-mentioned boiler combustion temperature field CT detection system based on thermal radiation imaging, adopts a horizontally arranged furnace flame camera probe to capture the flame image in the furnace, and uses the information of a row of pixels in the horizontal direction of the image to reconstruct the corresponding cross-sectional temperature distribution in the furnace, and then calculates layer by layer along the vertical direction of the image. This method directly associates the number of vertical pixels of the image with the number of grids along the height of the three-dimensional temperature field of the furnace. The obtained three-dimensional temperature field of the furnace is composed of hundreds or thousands of layers of cross-sectional temperature distribution along the height direction, which can increase the spatial resolution of the three-dimensional temperature field by dozens or even hundreds of times.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A boiler combustion temperature field CT detection system based on thermal radiation imaging, characterized in that: It consists of a furnace combustion flame image shooting module arranged on the furnace wall, a furnace three-dimensional temperature field calculation and display module arranged on the boiler site, and a furnace three-dimensional temperature field data storage and transmission module; The furnace combustion flame image shooting module includes a furnace flame camera probe and a router; wherein the furnace flame camera probe is composed of a high temperature resistant endoscope lens and a camera, and the furnace flame camera probe is installed on the furnace wall in a layered horizontal arrangement, with at least one layer arranged, and at least one furnace flame camera probe is installed on each furnace wall of each layer, and the center line of the field angle of the furnace flame camera probe is perpendicular to the wall on which it is installed; The three-dimensional temperature field calculation and display module in the furnace includes an embedded development board, a touch screen and a power supply; the flame image data taken by the furnace flame camera probe is received through the embedded development board, and each image taken by the furnace flame camera probe has M pixels in the horizontal direction and N pixels in the vertical direction. The corresponding cross-sectional temperature distribution in the furnace is reconstructed using the information of a row of pixels in the horizontal direction of all images, and then layer by layer calculation is performed along the vertical direction of the image, and finally the three-dimensional temperature field of the furnace composed of N layers of cross-sectional temperature distribution is obtained, and displayed in the form of a pseudo-color cloud map on the touch screen; The three-dimensional temperature field data storage and transmission module in the furnace includes a data storage device and a communication interface; the embedded development board stores the temperature field data calculated from the current flame image data in the data storage device, and uses the industrial bus communication protocol in a client manner to send the temperature field data in a specific format to the designated data receiving end, and the data receiving end extracts the temperature field data after parsing the received information.

2. The boiler combustion temperature field CT detection system based on thermal radiation imaging according to claim 1 is characterized in that: According to the horizontal field angle α of the furnace flame camera probe and the rectangular cross-sectional dimensions of the furnace, the length of the front and rear walls L, and the width of the left and right walls W, determine the number of furnace flame camera probes to be installed on each furnace wall on each layer; the specific determination method is as follows: When the furnace flame camera probe is installed on the front wall or the rear wall, the visible dimension of its horizontal field angle α on the center normal of the left and right walls is S1=W×tg(α / 2); if S1 is not less than the length L of the front and rear walls, then one camera probe is installed on the wall of this layer; if S1 is less than the length L of the front and rear walls, then the number of furnace flame camera probes on this layer of the wall should be increased and arranged at equal intervals until the sum of the visible dimensions of the furnace flame camera probes on the center normal of the left and right walls is not less than the length of the front and rear walls. The number of furnace flame camera probes O1 installed on this wall is: In the formula, Indicates rounding up; When the furnace flame camera probe is installed on the left wall or the right wall, the visible size of its horizontal field angle α on the center normal of the front and rear walls is S2 = L × tg (α / 2); if S2 is not less than the width W of the left and right walls, a furnace flame camera probe is installed on the wall of the layer; If S2 is smaller than the width W of the left and right walls, the number of furnace flame camera probes on the wall of this layer should be increased and arranged at equal intervals until the sum of the visible dimensions of the furnace flame camera probes on the center normal of the front and rear walls is not less than the width W of the left and right walls. The number of furnace flame camera probes O2 installed on this wall is: In the formula, Indicates rounding up; Therefore, the number of furnace flame camera probes installed on each layer of the furnace wall is: O=(O1+O2)×2.

3. The boiler combustion temperature field CT detection system based on thermal radiation imaging according to claim 2 is characterized in that: According to the vertical field angle β of the furnace flame camera probe and the furnace height, the furnace height H below the boiler flame deflection angle and above the cold ash hopper is determined to determine the number of layers P of the furnace flame camera probe arrangement, specifically: When the length of the front and rear walls L is not less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = W × tg (β / 2); when the length of the front and rear walls L is less than the width of the left and right walls W, the visible dimension of the vertical field angle of the furnace flame camera probe along the central axis in the direction of the furnace height is S3 = L × tg (β / 2); if S3 is not less than the furnace height H, the furnace flame camera probe only needs to be arranged in one layer; if S3 is less than the furnace height H, the number of layers of the furnace flame camera probe should be increased until the sum of the visible dimensions of the furnace flame camera probe on the central axis along the furnace height is not less than the furnace height H, and the calculation expression of P is as follows: In the formula, Indicates rounding up.

4. The boiler combustion temperature field CT detection system based on thermal radiation imaging according to claim 3 is characterized in that: The specific process of reconstructing and displaying the corresponding cross-sectional temperature distribution in the furnace is as follows: Step 1, when the furnace flame camera probe shoots the furnace combustion flame image in a horizontal manner, according to the CT principle, in the image shot by each furnace flame camera probe, the furnace combustion flame radiation information received by each row of pixels comes from the furnace combustion flame section with a layer thickness of S4. It is known that there are N pixels in the vertical direction of the image, then S4 = S3 / N; the number of furnace flame camera probes in each layer determined by the furnace combustion flame image shooting module is O, and each row in the image obtained by each furnace flame camera probe has M pixels, then according to the principle of thermal radiation imaging, a linear equation group model of the furnace combustion flame section temperature field and the corresponding O×M flame radiation information is established in the embedded development board; Step 2. Call the optimization algorithm for solving the linear equations model in the embedded development board, and use each layer of furnace flame camera probes to detect the N-layer furnace section temperature field. The spatial size of each layer of the section temperature field is L×W×S4; the furnace combustion flame image shooting module determines the number of layers P of camera probes, and then performs the same calculation on the flame images taken by the furnace flame camera probes layer by layer to obtain the three-dimensional furnace temperature field composed of the H / S4 layer section temperature distribution, and displays the furnace section temperature distribution of each layer in layers in the form of pseudo-color cloud maps on the touch screen.

5. The boiler combustion temperature field CT detection system based on thermal radiation imaging according to claim 4 is characterized in that: The three-dimensional temperature field data of the furnace obtained in step 2 is stored in the data storage device according to the layered storage method, and then the physical coordinates of each layer of the cross-sectional temperature field are determined in the furnace according to the thickness S4 of each layer of the cross-sectional temperature field. The cross-sectional temperature distribution data of each layer is stored in sequence with the physical coordinates of each layer of the cross-sectional temperature distribution as the index.

6. The boiler combustion temperature field CT detection system based on thermal radiation imaging according to claim 5 is characterized in that: Industrial bus communication protocols include CAN bus, Profibus bus, Modbus bus and Ethernet / IP bus.

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