A method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall

Abstract

This invention discloses a method for simultaneously detecting the three-dimensional temperature distribution of flames and water-cooled walls in a power plant boiler. S1 involves simultaneously acquiring visible light and infrared flame images of multiple cross-sections at different heights within the boiler furnace; S2 involves acquiring the monochromatic radiation intensity matrix I of the R and G values ​​of all pixels in the visible light flame image at the corresponding wavelengths. λ1 and I λ2 ; Obtain the monochromatic radiation intensity matrix I of the temperature of all pixels in the infrared flame image at the corresponding wavelength. λ3 S3 utilizes the monochromatic radiation intensity matrix I respectively λ1 and I λ2 The inverse solution of the full-band flame radiation intensity model is used to reconstruct the real three-dimensional temperature distribution of the flame and the absorption coefficient of the medium region; S4 is derived from the monochromatic radiation intensity matrix I λ3 The monochromatic radiation intensity of the flame under infrared wavelength is removed and substituted into the full-band flame radiation intensity model for inverse solution to reconstruct the three-dimensional temperature distribution of the water-cooled wall. This invention realizes the simultaneous detection of flame temperature and water-cooled wall temperature distribution.

Description

Technical Field

[0001] This invention belongs to the field of combustion detection technology, specifically a method for simultaneously detecting the three-dimensional temperature distribution of flames and water-cooled walls in a power plant boiler. Background Technology

[0002] In recent years, with the increasing share of new energy sources, power plant boilers have been operating at low loads and with large fluctuations for many years, posing a serious challenge to the safety of water-cooled walls. However, in actual production and operation, there is often a lack of effective monitoring and early warning methods to prevent potential risks such as uneven heat flux density, tube overheating, and severe ash and slag buildup in water-cooled walls. Once a serious accident such as water-cooled wall cracking or tube rupture occurs, the boiler must be shut down for repairs, which not only severely disrupts normal production and operation but also causes huge economic losses.

[0003] To prevent water-cooled wall overheating and temperature deviation, accurate online measurement of the temperature distribution of the entire furnace water-cooled wall is required. Contact temperature measurement methods, such as commonly used thermocouples and thermometers, are only used in laboratories or areas within the furnace where the temperature is not too high. Their disadvantages include slow response speed and large errors. More importantly, contact temperature measurement methods are generally difficult to implement for measuring the entire temperature field.

[0004] Three-dimensional temperature field visualization technology based on radiation image processing was first applied to combustion diagnosis of large power plant boilers, mainly to monitor flame center deviation and guide the adjustment of combustion uniformity within the furnace. Related research conclusions and field experimental results proved the feasibility of this technology in the field of power plant boiler combustion monitoring. Subsequent research reported experimental results of three-dimensional temperature field visualization technology on walking beam furnaces and tubular furnaces, mainly used to measure the surface temperature of heated workpieces and control the uniformity of workpiece heating. By achieving non-contact measurement of high-temperature solid surface temperatures, the application scope of three-dimensional temperature field visualization technology has expanded from power plant boilers to the entire field of high-temperature industrial furnaces. After more than ten years of development, three-dimensional temperature field visualization technology based on radiation image processing has become a method suitable for temperature measurement in various closed-cavity combustion systems. However, in power plant boilers, the water-cooled walls are covered by flames, and the flame temperature is much higher than the water-cooled wall temperature. The radiation energy information of the water-cooled walls is completely obscured by the flame radiation energy; therefore, it is difficult to simultaneously reconstruct the flame temperature and water-cooled wall temperature using radiation energy information from a single band. The surface temperature of water-cooled walls is generally in the range of 500-600℃. According to Wien's displacement law, the maximum radiation is located in the infrared wavelength region. However, flames also have strong radiation in this band. Flame radiation and wall radiation are coupled with each other. How to extract the radiation energy of water-cooled walls from radiation images is an important prerequisite for realizing the measurement of water-cooled wall temperature distribution. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for simultaneously detecting the three-dimensional temperature distribution of flames and water-cooled walls in a power plant boiler. The method simultaneously acquires visible light flame images and infrared flame images from multiple cross-sections at different heights within the boiler furnace, obtains the boundary radiation intensity of the flame in both the visible and infrared spectral bands, and establishes a matrix for inverse solving to obtain the true three-dimensional temperature distribution of the flame and the three-dimensional temperature distribution of the water-cooled wall, thereby achieving simultaneous detection of flame temperature and wall temperature distribution.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall, the specific steps of which are as follows:

[0007] S1 simultaneously acquires visible light flame images and infrared flame images of multiple cross-sections at different heights inside the boiler furnace of the power plant;

[0008] S2 obtains the monochromatic radiation intensity matrix of all pixels in the visible light flame image at the corresponding wavelength, representing the R and G values. λ1 and I λ2 ; Obtain the monochromatic radiation intensity matrix I of the temperature of all pixels in the infrared flame image at the corresponding wavelength. λ3 ;

[0009] S3 uses the monochromatic radiation intensity matrix I respectively λ1 and I λ2 The inverse solution of the full-band flame radiation intensity model is used to reconstruct the real three-dimensional temperature distribution of the flame and the absorption coefficient of the medium region.

[0010] S4 from the monochromatic radiation intensity matrix I λ3 The monochromatic radiation intensity of the flame at the infrared wavelength is removed and substituted into the full-band flame radiation intensity model for inverse solution to reconstruct the three-dimensional temperature distribution of the water-cooled wall.

[0011] Furthermore, in S1, detectors are arranged at least on two height sections, with at least two visible light detectors and two infrared detectors arranged on the same height section; the visible light detectors are used to capture visible light flame images; the infrared detectors are used to capture infrared flame images and receive radiation from the flames and water-cooled walls inside the furnace.

[0012] Furthermore, in S2, under the corresponding wavelength and detector exposure time conditions, based on the R value of a single pixel in the visible light flame image and the monochromatic radiation intensity I... λ1 By fitting the relationship between them, we can construct the monochromatic radiation intensity matrix I of all pixels R values ​​in the visible light image at the corresponding wavelength. λ1 .

[0013] Furthermore, in S2, under the corresponding wavelength and detector exposure time conditions, based on the G value of a single pixel in the visible light flame image and the monochromatic radiation intensity I...λ2 By fitting the relationship between them, the monochromatic radiance matrix I of all pixels G values ​​in the visible light image at the corresponding wavelength is constructed. λ2 .

[0014] Furthermore, in S3, the inverse solution is specifically as follows:

[0015] 1) Divide the entire three-dimensional space of the furnace into m grids to obtain spatial elements; divide the wall into n grids to obtain wall elements; divide the detector into P imaging elements to obtain the full-band flame radiation intensity model:

[0016]

[0017] Among them, I λ (i) represents the monochromatic radiation intensity received by the i-th imaging unit, R d,gIλ (ji) represents the proportion of monochromatic radiation energy emitted by the j-th spatial unit that is received by the i-th imaging unit per unit area; k λ m is the absorption coefficient of the medium region. -1 T g ΔV represents the temperature of the space unit, i.e., the flame temperature. g C1 and C2 represent the volume of a spatial unit, and are Planck constants.

[0018] 2) Based on monochromatic radiation intensity matrix The full-band flame radiation intensity model is matrixed, and the uniformly distributed optical parameters are used as the absorption coefficient k of the medium region. λ The initial values ​​for the iteration are obtained as follows:

[0019]

[0020]

[0021]

[0022] In the formula, This is a monochromatic radiation temperature imaging matrix. For temperature T j Blackbody radiation energy matrix at wavelength λ1, W·m -3 σ is the Boltzmann constant, with a value of 1.380649 × 10⁻⁶. -23 J / K;

[0023] The initial flame temperature distribution matrix T is obtained by inverse solving. j The details are as follows:

[0024]

[0025]

[0026] In the formula, D is an identity matrix with diagonal elements of 1;

[0027] 3) Based on monochromatic radiation intensity I λ2 The full-band flame radiation intensity model is matrixed to obtain:

[0028]

[0029]

[0030]

[0031] Substituting the initial flame temperature into the above matrix and performing an inverse solution yields the medium region absorption coefficient matrix. Specifically as follows:

[0032]

[0033] In the formula, This is called the medium region absorption coefficient imaging matrix; Let be the absorption coefficient matrix of the medium region, representing the set of absorption coefficients of all medium regions, and σ be the Boltzmann constant;

[0034] (4) Perform cross-iteration on steps 2) and 3) to obtain the numerically determined absorption coefficient matrix of the medium region. and the actual flame temperature distribution matrix T g .

[0035] Furthermore, in S4, the numerically determined absorption coefficient matrix of the medium region is... The absorption coefficient of the medium region and the actual flame temperature distribution matrix T g The actual flame temperature and infrared wavelength are substituted into the full-band flame radiation intensity model to obtain the flame monochromatic radiation intensity at the infrared wavelength.

[0036] Furthermore, in S4, from the monochromatic radiation intensity matrix I λ3 After removing the monochromatic radiation intensity of the flame at infrared wavelengths, the flame radiation intensity model across the entire wavelength band is matrixed:

[0037]

[0038]

[0039]

[0040] The inverse solution of the above matrix yields the three-dimensional temperature distribution matrix of the water-cooled wall:

[0041]

[0042]

[0043] In the formula, I λ3 I represents the total monochromatic radiation intensity received by the infrared detector at wavelength λ3. λ3,v This represents the intensity of monochromatic radiation from the flame received by the infrared detector at wavelength λ3, expressed in W·m. -3 ·sr -1 , For temperature T j Blackbody radiation energy at wavelength λ3, W·m -3 .

[0044] This invention provides a system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall, comprising:

[0045] The image detection module is used to simultaneously acquire visible light flame images and infrared flame images of multiple cross-sections at different heights inside the furnace of a power plant boiler;

[0046] The radiation intensity calibration module is used to obtain the monochromatic radiation intensity matrix I of all pixels in a visible light image at the corresponding wavelength, based on the R and G values. λ1 and I λ2 ; Obtain the monochromatic radiation intensity matrix I of the temperature of all pixels in the infrared image at the corresponding wavelength. λ3 ;

[0047] The flame three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix I. λ1 and I λ2 Perform inverse solving to reconstruct the true three-dimensional temperature distribution of the flame;

[0048] The water-cooled wall three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix I after removing the monochromatic radiation intensity of the flame at infrared wavelengths. λ3 Perform inverse kinematics to reconstruct the three-dimensional temperature distribution of the water-cooled wall.

[0049] The present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and a water-cooled wall, or, when the processor executes the computer program, it implements the functions of each module in the above-described system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and a water-cooled wall.

[0050] The present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and a water-cooled wall.

[0051] Compared with the prior art, the present invention has at least the following beneficial effects:

[0052] This invention provides a method for simultaneously detecting the three-dimensional temperature distribution of flames and water-cooled walls in a power plant boiler. In a power plant boiler, the water-cooled walls are covered by flames, and the flame temperature is much higher than the water-cooled wall temperature. The radiative energy information of the water-cooled walls is completely obscured by the flame radiative energy, making it difficult to simultaneously reconstruct the flame temperature and water-cooled wall temperature using radiation energy information from a single band. This invention acquires the boundary radiative intensity information of flame cross-sections at different heights in both the visible and infrared spectral bands, considering the transfer of radiative energy along the height direction. The energy transfer process completely follows the physical processes within the actual furnace, and the measurement results represent the true temperature of each spatial grid, achieving higher accuracy. Furthermore, the flame temperature distribution is reconstructed using visible light radiative information, and the water-cooled wall temperature distribution is reconstructed using infrared information, decoupling flame radiation and water-cooled wall radiation, thus achieving simultaneous detection of the flame temperature and water-cooled wall temperature distribution.

[0053] Furthermore, this invention employs a radiation image-based temperature measurement method, which uses visible light detectors and infrared detectors to achieve non-contact image detection. This enables continuous online monitoring of the temperature distribution of the water-cooled wall towards the fire side, offering advantages such as high accuracy, reliable equipment, and the ability to perform field measurements. Moreover, image detection allows for intuitive and rapid monitoring of the rate of change and deviation of the heated surface wall temperature, preventing boiler tube rupture and leakage, and significantly improving the safety and economy of boiler operation.

[0054] Furthermore, in two-dimensional cross-sectional temperature measurements, the two-dimensional cross-section is simplified to a two-dimensional infinitely large plate, ignoring the transfer of radiant energy in the height direction. Therefore, it deviates significantly from the actual energy transfer process inside the furnace, and the temperature measurement result approximates the cumulative effect along the entire height direction. In contrast, the three-dimensional temperature measurement of this invention completely follows the physical process inside the actual furnace, without approximation in the height direction. The measurement result represents the true temperature of each spatial grid, resulting in higher accuracy. Moreover, to achieve the measurement of three-dimensional temperature distribution, simply replicating the two-dimensional measurement technology in the height direction would drastically increase the number of detectors. This would require a more accurate algorithm for solving the radiation transfer process to stretch the two-dimensional target image in three-dimensional physical space, thereby achieving true three-dimensional distributed detection. This would inevitably increase the computational load, resulting in slower response speed and larger errors.

[0055] Furthermore, after obtaining the three-dimensional flame distribution results, the temperature distribution inside the furnace can be given in various dimensions such as cross-section and longitudinal section, which intuitively reflects the position of the flame in the horizontal and vertical directions inside the furnace. The flame height and flame center position can be quickly determined, thereby guiding combustion adjustment and optimizing the internal temperature distribution of the furnace. By monitoring the three-dimensional water-cooled wall temperature distribution, the specific three-dimensional coordinates of the water-cooled wall overheating point can be given, thereby quickly identifying the overheating location of the water-cooled wall tube and judging the ash slagging situation of the furnace heating area. Attached Figure Description

[0056] Figure 1 This is a system for simultaneously detecting the three-dimensional flame temperature and water-cooled wall temperature distribution of a power plant boiler, as described in a specific embodiment of the present invention.

[0057] Figure 2 The image is captured by a visible light detector in a specific embodiment of the present invention;

[0058] Figure 3 The image is captured by the infrared detector in a specific embodiment of the present invention;

[0059] Figure 4 This refers to the calibration data of the visible light detector in a specific embodiment of the present invention;

[0060] Figure 5 This refers to the calibration data of the infrared detector in a specific embodiment of the present invention;

[0061] Figure 6 The three-dimensional temperature distribution of the flame detected in a specific embodiment of the present invention;

[0062] Figure 7 The figure shows the three-dimensional temperature distribution of the water-cooled wall detected in a specific embodiment of the present invention. Specifically, it shows the temperature distribution of the fire-facing surface of the water-cooled wall on the front, back, left, and right walls.

[0063] Specific implementation party

[0064] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0065] like Figure 1 As shown, the walls surrounding the furnace of a power plant boiler are water-cooled walls, with a flowing working fluid inside to cool the water-cooled wall tubes. The center of the furnace contains a pulverized coal flame, the temperature of which is higher than that of the water-cooled walls. This invention provides a method for simultaneously detecting the three-dimensional temperature distribution of the flame and water-cooled walls in a power plant boiler. The specific steps are as follows:

[0066] S1 is equipped with multi-layer image detectors at several different height sections inside the boiler furnace of the power plant to capture images of the flame inside the furnace and receive radiation from the flame and water-cooled wall inside the furnace. The image detectors include visible light detectors and infrared detectors. Each pixel in the image captured by the visible light detector contains red, green and blue primary color signal values, while each pixel in the image captured by the infrared detector is a temperature signal.

[0067] One specific example involves arranging two layers of detectors inside the furnace, with four detectors in each layer. Two of the detectors in each layer are visible light detectors, sensing wavelengths of 380-780nm. A total of four visible light detectors are used. The images captured by these detectors are shown below. Figure 2 As shown; the other two image detectors in each layer are infrared detectors, with a photosensitive wavelength of 3-5μm, and a total of four infrared detectors are arranged. The images captured by the infrared detectors are as follows. Figure 3 As shown.

[0068] In order to restore the boundary radiation intensity received by the detector from the distorted image signal, S2 uses a blackbody furnace to calibrate the visible light detector and the infrared detector.

[0069] 1) The calibration curve of the visible light detector is as follows: Figure 4 As shown, its physical meaning is the relationship between the red and green primary color signal values ​​of each pixel in a visible light image and the monochromatic radiation intensity I under the corresponding wavelength conditions. λ1 I λ2 The fitting relationship between them:

[0070] I λ1 =10422.8×(R / S);

[0071] I λ2 =6630.9×(G / S);

[0072] Where R represents the red primary color signal value, G represents the green primary color signal value, S represents the detector exposure time, and I represents the red primary color signal value. λ1 I represents the monochromatic radiation intensity at wavelength λ1. λ2 This represents the monochromatic radiation intensity at wavelength λ2.

[0073] 2) The calibration curve of the infrared detector is as follows: Figure 5 As shown, its physical meaning is the temperature signal of each pixel in the infrared image and the monochromatic radiation intensity I under the corresponding wavelength conditions. λ3 The fitting relationship between them:

[0074] I λ3 = -7.65 + 3.39 × T - 62143.76 × T 2 +54.97×T 3 -0.016×T 4

[0075] Among them, I λ3 This represents the monochromatic radiation intensity at an infrared wavelength of λ3.

[0076] S3 determines the monochromatic radiation intensity I of each pixel in the visible light image based on the red and green primary color signal values ​​and the corresponding wavelength conditions. λ1 I λ2 The fitting relationship between them was obtained by extracting the monochromatic radiation intensity of two bands from the visible light image and then reconstructing the three-dimensional temperature distribution of the flame. The results are as follows: Figure 6 As shown;

[0077] S4, based on the temperature signal of each pixel in the infrared image and the monochromatic radiation intensity I under the corresponding wavelength conditions. λ3 The fitting relationship between them was used to extract the monochromatic radiation intensity in the infrared band from the infrared image. Combined with the inverse problem solution method, the three-dimensional temperature distribution of the water-cooled wall was reconstructed. The results are as follows: Figure 7 As shown.

[0078] In a specific embodiment of the present invention, the number of detector layers can be three or more, and each layer can have four or more detectors. As the number of detector layers or the number of detectors per layer increases, the reconstruction errors of the flame temperature and water-cooled wall temperature will decrease.

[0079] Specifically, the inverse problem solving method in this invention is as follows:

[0080] 1) Divide the entire three-dimensional space of the furnace into m grids to obtain spatial elements; divide the wall into n grids to obtain wall elements; divide the detector into P imaging elements. Considering the response characteristics of the two detectors to the received radiation wavelength, the radiation intensity received by the two detectors in a certain line-of-sight direction mainly includes the radiation intensity from the flame and the radiation intensity from the water-cooled wall, expressed as:

[0081] I λ (i)=I λ，v (i)+I λ，s (i) (1)

[0082] In the formula, I λ (i) represents the monochromatic radiation intensity received by the two detectors in the i-th imaging unit, I λ，v (i) represents the intensity of monochromatic radiation received from the flame, I λ，s (i) represents the received monochromatic radiation intensity from the water-cooled wall, in W·m -3 ·sr -1 For the detailed derivation process, please refer to the reference "Principles and Technology of Visual Detection of Flames Inside Furnaces".

[0083]

[0084]

[0085] In the formula, R d,gIλ (ji), R d,wIλ (ji) represents the proportion of monochromatic radiation energy emitted by the j-th wall element and spatial element that is received by the i-th imaging element per unit area and unit angle; k λ m is the absorption coefficient of the medium region. -1 , ε w T is the wall emissivity; g T w ΔV represents the temperature of the space element (i.e., the flame temperature) and the temperature of the wall element, respectively. g ,,ΔS w Let C1 and C2 represent the volume of the spatial unit and the area of ​​the wall unit, respectively. C1 and C2 are Planck constants with values ​​of 3.742 × 10⁻⁶. -16 W / m 2 and 1.4388×10 -2 m·K.

[0086] 2) For visible light detectors, since the flame temperature is much higher than the water-cooled wall temperature, the flame radiation in the visible light band is much greater than the water-cooled wall radiation. Therefore, the radiation share from the water-cooled wall can be ignored in the radiation intensity received by the detector, resulting in a full-band flame radiation intensity model, which simplifies formula (1) to the following:

[0087]

[0088] For infrared detectors, since the radiation from the wall and the flame are of the same magnitude in the infrared band, the radiation intensity received by the infrared detector includes both flame radiation and water-cooled wall radiation. The flame radiation portion is filtered out from the radiation intensity received by the infrared detector to obtain the radiation intensity of the water-cooled wall.

[0089] 3) Based on formula (4) and combined with the inverse solution method, the flame temperature distribution can be reconstructed. The specific steps are as follows:

[0090] (1) After capturing flame images using a visible light detector, the R and G values ​​of each pixel in the image are first extracted, and then converted into a monochromatic radiation intensity matrix I at the corresponding wavelength based on the calibration data. λ1 and I λ2 Specifically, the monochromatic radiance matrix I is calculated based on the R value and the fitted relationship. λ1 The monochromatic radiation intensity matrix I is calculated based on the G value and the fitted relationship. λ2 ;

[0091] (2) Given the uniformly distributed optical parameters across the entire field as the absorption coefficient k of the medium region. λThe initial values ​​for the iteration are obtained according to formulas (4-1) to (4-3), using the monochromatic radiation intensity matrix. Matrix reconstruction of formula (4) yields the initial flame temperature distribution matrix T. j ;

[0092]

[0093]

[0094]

[0095] In the formula, This is a monochromatic radiation temperature imaging matrix. For temperature T j Blackbody radiation energy matrix at wavelength λ1, W·m -3 σ is the Boltzmann constant, with a value of 1.380649 × 10⁻⁶. -23 J / K, k λ m is the absorption coefficient of the medium region. -1 .

[0096] The inverse solution of formula (4-1) is as follows:

[0097]

[0098]

[0099] In the formula, D is an identity matrix with diagonal elements of 1.

[0100] (3) Utilizing monochromatic radiation intensity I λ2 By reconstructing the matrix of formula (4), the absorption coefficient matrix of the medium region is obtained.

[0101]

[0102]

[0103]

[0104] The initial flame temperature distribution T j Substituting into formulas (4-4) to (4-6), the inverse solution of formula (4-4) is as follows:

[0105]

[0106] In the formula, This is called the medium region absorption coefficient imaging matrix; Let be the absorption coefficient matrix of the medium region, representing the set of absorption coefficients of all media, and σ be the Boltzmann constant.

[0107] (4) Iterate the calculations in steps (2) and (3) until the reconstructed value of the absorption coefficient in the medium region no longer changes, and the iteration converges. At this point, the true flame temperature distribution matrix T can be obtained. g The result is as follows Figure 6 As shown.

[0108] 4) After capturing images of the furnace interior using an infrared detector, the temperature value of each pixel is extracted from the image, and then converted into monochromatic radiation intensity I at the corresponding wavelength based on calibration data. λ3 Since the radiation from the wall and the flame are of equal magnitude in the infrared band, the radiation intensity received by the infrared detector includes both flame radiation and water-cooled wall radiation, thus satisfying the following condition:

[0109] I λ3 (i)=I λ3，v (i)+I λ3，s (i) (8)

[0110] (1) In the 3-5μm band, there is no gas emission and absorption. The radiation properties of the flame can be approximated as being consistent with those of the visible light band. Substituting the flame temperature and radiation parameters calculated in the previous steps into formula (4), the monochromatic radiation intensity of the flame at the infrared wavelength λ3 can be calculated.

[0111] (2) Then, the flame radiation component is filtered out from the radiation intensity received by the infrared detector, and the full-band flame radiation intensity model is matrixed:

[0112]

[0113]

[0114]

[0115] The temperature of each grid in the water-cooled wall is obtained by inversely solving equation (4-7), and the results are as follows: Figure 7 As shown, the water-cooled wall temperature matrix is ​​constructed as follows:

[0116]

[0117]

[0118] In the formula, I λ3 I represents the total monochromatic radiation intensity received by the infrared detector at wavelength λ3. λ3,v This represents the intensity of monochromatic radiation from the flame received by the infrared detector at wavelength λ3, expressed in W·m. -3 ·sr -1 , For temperature T j Blackbody radiation energy at wavelength λ3, W·m-3 .

[0119] This invention provides a system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall, comprising:

[0120] The image detection module is used to simultaneously acquire visible light flame images and infrared flame images of multiple cross-sections at different heights inside the furnace of a power plant boiler;

[0121] The radiation intensity calibration module is used to obtain the monochromatic radiation intensity matrix I of all pixels in a visible light image at the corresponding wavelength, based on the R and G values. λ1 and I λ2 ; Obtain the monochromatic radiation intensity matrix I of the temperature of all pixels in the infrared image at the corresponding wavelength. λ3 ;

[0122] The flame three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix I. λ1 and I λ2 Perform inverse solving to reconstruct the true three-dimensional temperature distribution of the flame;

[0123] The water-cooled wall three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix I after removing the monochromatic radiation intensity of the flame at infrared wavelengths. λ3 Perform inverse kinematics to reconstruct the three-dimensional temperature distribution of the water-cooled wall.

[0124] The present invention also provides a terminal device, which includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps in the above-described method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall; or, when the processor executes the computer program, it implements the functions of each module in the above-described system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall.

[0125] The computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention.

[0126] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0127] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0128] The memory can be used to store the computer program and / or module. The processor implements various functions of the terminal device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0129] If the modules / units integrated in the terminal device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0130] Based on this understanding, all or part of the processes in the above-described embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms.

[0131] The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium may be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media may not include electrical carrier signals and telecommunication signals.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method of simultaneously detecting the flame and the three-dimensional temperature distribution of the water-cooled walls of a power plant boiler, characterized in that, The specific steps are as follows: S1 uses a visible light detector and an infrared detector to simultaneously acquire visible light flame images and infrared flame images of multiple cross-sections at different heights inside the furnace of a power plant boiler. S2 obtains a monochromatic radiation intensity matrix of all pixel points R value and G value in the visible light flame image under the corresponding wavelength I λ1 and I λ2 ; Obtaining monochromatic radiation intensity matrix of all pixel points in infrared flame image under corresponding wavelength I λ3 ; S3 uses monochromatic radiation intensity matrix respectively I λ1 and I λ2 Inverse solution of full-band flame radiation intensity model is carried out to reconstruct real flame three-dimensional temperature distribution and medium area absorption coefficient. S4 from the monochromatic radiation intensity matrix I λ3 The monochromatic radiation intensity of the flame under infrared wavelength is removed and substituted into the full-band flame radiation intensity model for inverse solution to reconstruct the three-dimensional temperature distribution of the water-cooled wall. In S3, the inverse solution is specifically as follows: 1) Divide the entire three-dimensional space of the furnace into m Divide the wall into n grids to obtain spatial elements; divide the wall into n grids to obtain wall elements; divide the detector into P imaging elements to obtain the full-band flame radiation intensity model: (4) in, I λ ( i ) indicates the first i The monochromatic radiation intensity received by each imaging unit, R d,gIλ ( ji ) indicates the first j The monochromatic radiation emitted by the first space unit is... i The share of each imaging unit received per unit area; The absorption coefficient of the medium region; T g This indicates the temperature of the space unit, i.e., the flame temperature. ΔV g C1 and C2 represent the volume of a spatial unit, and are Planck constants. 2) Based on monochromatic radiation intensity matrix The full-band flame radiation intensity model is matrixed, and the uniformly distributed optical parameters are used as the absorption coefficients of the medium region. The initial values ​​for the iteration are obtained as follows: (4-1) (4-2) (4-3) In the formula, This is a monochromatic radiation temperature imaging matrix. For temperature wavelength λ Blackbody radiation energy matrix at 1, W·m -3 , σ Here, is the Boltzmann constant, with a value of 1.380649 × 10⁻⁶. -23 J / K; The initial flame temperature distribution matrix is ​​obtained by inverse solving. The details are as follows: (5) (6) In the formula, D It is an identity matrix with diagonal elements all equal to 1. 3) Based on monochromatic radiation intensity I λ2 The full-band flame radiation intensity model is matrixed to obtain: (4-4) (4-5) (4-6) Substituting the initial flame temperature into the above matrix and performing an inverse solution yields the medium region absorption coefficient matrix. The details are as follows: (7) In the formula, This is called the medium region absorption coefficient imaging matrix; Let be the absorption coefficient matrix of the medium region, representing the set of absorption coefficients for all medium regions. σ Boltzmann's constant; (4) Perform cross-iteration on steps 2) and 3) to obtain the numerically determined absorption coefficient matrix of the medium region. and the actual flame temperature distribution matrix T g ; In S4, from the monochromatic radiation intensity matrix I λ3 After removing the monochromatic radiation intensity of the flame at infrared wavelengths, the flame radiation intensity model across the entire wavelength band is matrixed: (4-7) (4-8) (4-9) Inversely solving matrix (4-7) yields the three-dimensional temperature distribution matrix of the water-cooled wall: (9) (10) In the formula, I λ3 Indicates the infrared detector at wavelength λ The total monochromatic radiation intensity received under condition 3 I λ3,v Indicates the infrared detector at wavelength λ The intensity of monochromatic radiation received from the flame at point 3, W·m -3 ·sr -1 , For temperature wavelength λ Blackbody radiation energy at 3 W·m -3 .

2. The method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall according to claim 1, characterized in that, In S1, detectors are arranged at least on two height sections, and at least two visible light detectors and two infrared detectors are arranged on the same height section; the visible light detectors are used to capture visible light flame images; the infrared detectors are used to capture infrared flame images and receive radiation from the flames and water-cooled walls inside the furnace.

3. The method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall according to claim 1, characterized in that, In S2, under the corresponding wavelength and detector exposure time conditions, the R value of a single pixel in the visible light flame image and the monochromatic radiation intensity are used as the basis for... I λ1 By fitting the relationship between them, a monochromatic radiation intensity matrix of the R values ​​of all pixels in the visible light image at the corresponding wavelength is constructed. I λ1 .

4. The method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall according to claim 1, characterized in that, In S2, under the corresponding wavelength and detector exposure time conditions, the G value of a single pixel in the visible light flame image and the monochromatic radiation intensity are used as the basis. I λ2 By fitting the relationship between them, a monochromatic radiation intensity matrix of the G values ​​of all pixels in the visible light image at the corresponding wavelength is constructed. I λ2 .

5. The method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall according to claim 1, characterized in that, In S4, the absorption coefficient matrix of the medium region is determined numerically. The absorption coefficient of the medium region and the actual flame temperature distribution matrix T g The actual flame temperature and infrared wavelength are substituted into the full-band flame radiation intensity model to obtain the flame monochromatic radiation intensity at the infrared wavelength.

6. A system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall, characterized in that, The method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall according to any one of claims 1 to 5, the system comprising: The image detection module is used to simultaneously acquire visible light flame images and infrared flame images of multiple cross-sections at different heights inside the furnace of a power plant boiler; The radiation intensity calibration module is used to obtain the monochromatic radiation intensity matrix of all pixels in a visible light image at the corresponding wavelength, based on their R and G values. I λ1 and I λ2 Obtain the monochromatic radiation intensity matrix of the temperature of all pixels in the infrared image at the corresponding wavelength. I λ3 ; The flame three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix. I λ1 and I λ2 Perform inverse solving to reconstruct the true three-dimensional temperature distribution of the flame; The water-cooled wall three-dimensional temperature distribution acquisition module is used to obtain the monochromatic radiation intensity matrix after removing the monochromatic radiation intensity of the flame at infrared wavelengths. I λ3 Perform inverse kinematics to reconstruct the three-dimensional temperature distribution of the water-cooled wall.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall as described in any one of claims 1-5; or, when the processor executes the computer program, it implements the functions of each module in the system for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall as described in claim 6.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of a method for simultaneously detecting the three-dimensional temperature distribution of a power plant boiler flame and water-cooled wall as described in any one of claims 1-5.

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