System and method for scanning measurement of flame equivalence ratio based on fiber optic spectrometer

Abstract

The present application relates to the technical field of combustion diagnosis and spectrum measurement, and discloses a system and method for scanning measurement of flame equivalence ratio based on a fiber-optic spectrometer, which comprises directing a fiber-optic sensing end of the fiber-optic spectrometer towards a flame front produced by a burner, and driving the fiber-optic sensing end to move in a longitudinal plane parallel to the flame front according to a set path and step length by means of a displacement mechanism, so as to collect chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame; analyzing and processing the data collected by the fiber-optic sensing end based on a chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data, and then calculating a local or overall equivalence ratio distribution image information of the flame by means of a tomographic inversion algorithm. The fiber-optic spectrometer is driven by the displacement mechanism to collect chemiluminescence radiation spectrum of the flame at different positions of the flame front, and a data processing module is combined to realize high-resolution and two-dimensional distribution measurement of the equivalence ratio of the flame.

Description

Technical Field

[0001] This invention relates to the fields of combustion diagnostics and spectral measurement technology, specifically to a system and method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer. Background Technology

[0002] In the research of various novel engine technologies, combustion efficiency is the primary prerequisite for evaluating engine performance, and flame combustion efficiency is closely related to the local equivalence ratio. During engine operation, complex physical and chemical processes occur inside the combustion chamber, particularly the strong coupling between flow and combustion, and the interaction between shock waves and the boundary layer, making combustion parameters difficult to measure directly. Therefore, developing advanced non-contact equivalence ratio measurement methods has become a key research focus in the development of novel power systems.

[0003] Complex combustion environments are often accompanied by intense chemical reactions. The energy released by these chemical reactions causes a significant proportion of ground-state molecules to be excited to higher energy states. These high-energy particles then transition to lower energy levels and emit photons of specific frequencies. By using a spectral testing system, the wavelength information corresponding to these spontaneously emitted photons can be collected. This wavelength information is closely related to combustion parameters such as the local equivalence ratio during combustion.

[0004] Existing optical diagnostic technologies, which mainly rely on single-point measurements, cannot reflect the problem of flame non-uniformity. In combination with actual engineering needs, the required measurement system must have spatial scanning capabilities. Summary of the Invention

[0005] The purpose of this invention is to provide a system and method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, so as to solve the technical problem that existing optical diagnostic techniques, which are mainly based on single-point measurements, cannot reflect the non-uniformity of flames.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A method for scanning and measuring flame equivalence ratio based on a fiber optic spectrometer is characterized by including pointing the fiber optic sensing end of the fiber optic spectrometer toward the front of the flame generated by the burner, and driving the fiber optic sensing end to move along a set path and step size in a longitudinal plane parallel to the front of the flame through a displacement mechanism, thereby collecting the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame point by point. The data collected by the fiber optic sensing end is analyzed and processed based on the chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data. Then, the local or overall equivalence ratio distribution image information of the flame is calculated by the tomographic inversion algorithm.

[0007] As a preferred embodiment of the present invention, a digital delay generator is used to synchronize the data acquisition of the fiber optic sensing end of the fiber optic spectrometer with the movement of the fiber optic sensing end driven by the displacement mechanism within the flame front region.

[0008] As a preferred embodiment of the present invention, it further includes a method for correcting the wavelength response systematic error of the fiber optic spectrometer, specifically comprising: The fiber optic sensing end of the fiber optic spectrometer is oriented at a fixed distance toward a standard light source formed by a standard tungsten lamp. The fiber optic sensing end collects the radiation intensity of the standard light source. The radiation intensity of the standard light source obtained by the fiber optic spectrometer is compared with the factory radiation information of the standard light source. The wavelength response of the fiber optic spectrometer is corrected using the comparison results.

[0009] As a preferred embodiment of the present invention, the method for analyzing and processing the data collected by the fiber optic sensing end based on the chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data is as follows: Calibration was obtained using a premixed flame. The mapping model assigns the intensity of each sampling point. Substituting into the mapping model, we obtain the equivalent ratio line integral feature data of the corresponding sampling points. ,Will Arranged according to the set path, forming the line integral equivalent ratio vector.

[0010] As a preferred embodiment of the present invention, the method for obtaining local or overall equivalence ratio distribution image information of a flame by utilizing equivalence ratio feature data and then calculating it through a tomographic inversion algorithm specifically includes: Step 100: Using the fiber optic sensing end's acquisition plane as a reference, expand it to a two-dimensional distribution of the flame, determine the inversion region, and divide the inversion region into... Each pixel is a square pixel, with the size of the pixel equal to the step distance, and it is assumed that the equivalent ratio within each pixel is uniform; then the intersection length between the optical path and the pixel is accurately calculated using coordinates to construct the projection matrix; Step 200: Set the initial equivalent ratio of all pixels to the stoichiometry, configure the relaxation factor, number of iterations, convergence threshold, and set the prior constraints of flame axisymmetry or boundary to complete the initial parameter and constraint settings of the tomographic inversion algorithm. Step 300: Based on the measured value of the full equivalent ratio line integral of one side of the flame, first calculate the residual of all scanning optical paths one by one, then simultaneously solve the correction amount of each pixel unit and update the pixel equivalent ratio value in combination with prior constraints, iterate repeatedly until the residual meets the convergence condition or reaches the set number of iterations, and finally obtain the equivalent ratio pixel distribution of the flame cross section. Step 400: Using pseudo-color mapping, superimpose equivalence ratio lines, acquisition points, and flame outlines to form equivalence ratio distribution image information.

[0011] This invention provides a system for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, and a method for implementing the aforementioned scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, comprising: A fiber optic spectrometer having at least one fiber optic sensing end facing the front of the flame generated by the burner. The displacement mechanism has an optical fiber sensing end disposed at the actuating end of the displacement mechanism. The displacement mechanism is used to drive the optical fiber sensing end to move along a set path and step size in a longitudinal plane parallel to the front of the flame. A digital delay generator, connected to the fiber optic spectrometer and the displacement mechanism, is used to generate a control signal that synchronizes the movement of the fiber optic sensing end driven by the displacement mechanism with the signal acquisition performed by the fiber optic sensing end. The data processing and output module integrates a chemiluminescence intensity ratio and equivalence ratio database and a tomographic inversion algorithm. It is connected to the fiber optic spectrometer and is used to compare the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame obtained by the fiber optic sensing end with the equivalence ratio database for analysis and processing. Then, it calculates and outputs the local or overall equivalence ratio distribution image information of the flame through the tomographic inversion algorithm.

[0012] In a preferred embodiment of the present invention, the displacement mechanism outputs a 5V TTL signal as an external trigger signal for the digital delay generator, and the digital delay generator controls the synchronous acquisition action of the fiber optic sensing end through the external trigger signal.

[0013] As a preferred embodiment of the present invention, it further includes a calibration device, which is used to provide a standard light source to the fiber optic sensing end of the fiber optic spectrometer; The calibration device includes a standard tungsten lamp light source and a baffle plate disposed between the standard tungsten lamp light source and the optical fiber sensing end. A through hole is provided on the baffle plate, and the light generated by the standard tungsten lamp light source enters the optical fiber sensing end through the through hole.

[0014] As a preferred embodiment of the present invention, it further includes a black plate, which is disposed on the other side of the standard tungsten lamp light source away from the baffle, and the black plate is perpendicular to the reverse extension line of the optical path received by the optical fiber sensing end. Furthermore, the distance between the black plate and the standard tungsten lamp light source is twice the distance between the standard tungsten lamp light source and the fiber optic sensing end.

[0015] Compared with the prior art, the present invention has the following advantages: This invention utilizes a displacement mechanism to drive a fiber optic spectrometer to collect the chemiluminescence radiation spectrum of the flame at different locations on the flame front, and combines this with a data processing module to achieve high-resolution, two-dimensional distribution measurement of the flame equivalence ratio. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall system structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the calibration device structure according to an embodiment of the present invention.

[0018] The labels in the diagram represent the following: 1-Fiber optic spectrometer; 2-Fiber optic sensing end; 3-Displacement mechanism; 4-Digital delay generator; 5-Data processing and output module; 6-Calibration device; 7-Burner; 61-Standard tungsten lamp light source; 62-Baffle; 63-Through hole; 64-Black plate. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the present invention provides a method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, including pointing the fiber optic sensing end of the fiber optic spectrometer toward the front of the flame generated by the burner 7, and driving the fiber optic sensing end to move in a longitudinal plane parallel to the front of the flame according to a set path and step size through a displacement mechanism, and collecting the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame. The data collected by the fiber optic sensing end is analyzed and processed based on the chemiluminescence intensity ratio-equivalence ratio database to obtain equivalence ratio characteristic data. Then, the local or overall equivalence ratio distribution image information of the flame is calculated by the tomographic inversion algorithm.

[0021] For each step distance, the chemiluminescence intensity is collected 10-20 times and averaged to obtain the line integral intensity value at that location. (The subscripts are the coordinates of the data collection points).

[0022] The data acquisition of the fiber optic sensing end of the fiber optic spectrometer is synchronized with the movement of the fiber optic sensing end within the flame front region by the displacement mechanism, achieved through a digital delay generator.

[0023] Outliers (such as sudden changes in intensity caused by stage jitter) are removed, and the intensity values ​​of empty backgrounds (areas without flames) are subtracted.

[0024] The method for analyzing and processing data collected by the fiber optic sensing end based on the chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data is as follows: Calibration was obtained using a premixed flame. The mapping model ensures that the fiber optic path length and detection wavelength during calibration are consistent with the actual scan, and sets the intensity at each acquisition point. Substituting into the mapping model, we obtain the equivalent ratio line integral feature data of the corresponding sampling points. ,Will Arranged according to the set path, they form a line integral equivalent ratio vector, which corresponds to the equivalent ratio integral value of a light path passing through the flame.

[0025] One of the fiber optic sensors collected the data. It is the line integral intensity along the optical axis at that location, therefore It is the integral value of the local equivalence ratio of the flame over that optical path, not the single-point equivalence ratio.

[0026] Data constraints are applied to the final obtained line integral equivalence ratio vector: equivalence ratio values ​​that exceed the fuel combustible range in the inversion results are removed and replaced with range boundary values; The method of obtaining local or global equivalence ratio distribution image information of a flame by using equivalence ratio feature data and then calculating it through a tomographic inversion algorithm specifically includes: Step 100: Using the acquisition plane of the fiber optic sensing end as a reference, expand it into a two-dimensional distribution of the flame (fix the Z-axis as zero), determine the inversion region, divide the inversion region into N×N square pixels, the size of each pixel is equal to the step distance, and assume that the equivalent ratio within each pixel is uniform; then, accurately solve the intersection length between the optical path and the pixel through coordinate calculation to construct the projection matrix. Projection matrix Build: For each acquisition point (corresponding to one optical path), calculate all pixel units traversed by that optical path and determine the optical path percentage of each pixel. ; Represented as the first optical path in the first Length within each pixel / the first The total length of the optical path (the portion passing through the flame); if the optical path does not pass through the first... 1 pixel, =0; Step 200: Set the initial equivalent ratio of all pixels to the stoichiometry, configure the relaxation factor, number of iterations, convergence threshold, and set the prior constraints of flame axisymmetry or boundary to complete the initial parameter and constraint settings of the tomographic inversion algorithm. Set the initial equivalence ratio distribution: =1.0; Iteration parameters: relaxation factor The value range is 0.6-0.8; the number of iterations The value range is 100-500; convergence threshold (Stop if the sum of squared residuals is less than this value); If the flame is axially symmetric (such as a Bunsen burner flame), add = Symmetric constraints; if the flame boundary is known, fix the pixels outside the boundary to 0; Step 300: Based on the measured value of the full equivalent ratio line integral of one side of the flame, first calculate the residual of all scanning optical paths one by one, then simultaneously solve the correction amount of each pixel unit and update the pixel equivalent ratio value in combination with prior constraints, iterate repeatedly until the residual meets the convergence condition or reaches the set number of iterations, and finally obtain the equivalent ratio pixel distribution of the flame cross section. Among them, the In the next iteration, calculate the residuals (actual measured value - calculated value) for all acquisition paths: ; Represented as the first The measured value of the equivalent ratio line integral for each path. For the first The calculated value of the next iteration; Then calculate the correction amount for each pixel (considering the residuals of all paths simultaneously). ; in, Represented as pixels The total weight traversed by all paths, avoiding over-correction of pixels covered by multiple paths; If pixels No path to pass through. Keep the initial value; Pixel value update (add prior constraints in this step): ; Axisymmetry constraint: If and For symmetrical pixels, the average value is taken after updating: ; If non-negative constraints: Then set it to 0; Step 400: Using pseudo-color mapping, superimpose equivalence ratio lines, acquisition points, and flame outlines to form equivalence ratio distribution image information.

[0027] like Figure 2 As shown, it also includes a method for correcting the wavelength response systematic error present in fiber optic spectrometers, specifically including: The fiber optic sensing end of the fiber optic spectrometer is oriented at a fixed distance toward a standard light source formed by a standard tungsten lamp. The fiber optic sensing end collects the radiation intensity of the standard light source. The radiation intensity of the standard light source obtained by the fiber optic spectrometer is compared with the factory radiation information of the standard light source. The wavelength response of the fiber optic spectrometer is corrected based on the comparison results.

[0028] Within the flame cross-section, in addition to parallel movement, the fiber optic sensing end can be rotated slightly around the acquisition point (e.g., ±10°) to supplement 2-3 sets of small-angle sector scan data, increasing the dimension of the projection matrix.

[0029] like Figure 1 and Figure 2 As shown, this embodiment further provides a system for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, and a method for implementing scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, including: The fiber optic spectrometer 1 has at least one fiber optic sensing end 2, which faces the front of the flame generated by the burner. The displacement mechanism 3 has an optical fiber sensing end 2 located at the actuating end of the displacement mechanism 3. The displacement mechanism 3 is used to drive the optical fiber sensing end 2 to move along a set path and step size in a longitudinal plane parallel to the flame front. It can control the optical fiber to move up and down / left and right in the same vertical plane of the flame (such as the XZ plane) with an accuracy ≤0.1mm. The optical fiber sensing end faces the side of the flame to ensure that the optical axis of the optical fiber still passes through the flame area after each movement. Define the scan area: cover the entire visible area of ​​the flame in the vertical plane; Set the step distance: Select according to the flame size (e.g., 1~2mm). The smaller the distance, the denser the sampling points, and the higher the inversion accuracy. Planning the scanning path: Parallel scanning is preferred, or it can be combined with fan-shaped scanning (when only one side is used, first translate the X-axis at equal intervals along the Y-axis (vertical) to obtain multiple sets of parallel optical path signals; then, with a certain point as the center, slightly rotate the fiber angle to supplement the fan-shaped optical path signal and improve the inversion dimension). The digital delay generator 4 is connected to the fiber optic spectrometer 1 and the displacement mechanism 3, and is used to generate a control signal that synchronizes the movement of the fiber optic sensing end 2 driven by the displacement mechanism 3 with the signal acquisition of the fiber optic sensing end 2. The data processing and output module 5 integrates a chemiluminescence intensity ratio-equivalence ratio database and a tomographic inversion algorithm. It is connected to the fiber optic spectrometer 1 and is used to analyze and process the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame obtained by the fiber optic sensing end 2 by comparing them with the database. Then, it calculates and outputs the local or overall equivalence ratio distribution image information of the flame through the tomographic inversion algorithm.

[0030] In this embodiment, a unique index ID is assigned to each step scanning point on one side of the flame. This ID is used throughout the entire process from light intensity acquisition to… From vector construction to projection matrix binding, to avoid data misalignment, a three-dimensional lookup table of X-coordinate-Z-index ID is commonly used in practice and stored in a local CSV file as the index benchmark for all data processing.

[0031] The displacement mechanism 3 outputs a 5V TTL signal as an external trigger signal for the digital delay generator 4. The digital delay generator 4 controls the synchronous acquisition action of the fiber optic sensing end 2 through the external trigger signal.

[0032] After each fiber movement, ensure that the fiber axis is aligned (e.g., perpendicular to the scanning plane) to avoid intensity deviations caused by changes in optical path length. Before data acquisition, calibrate the zero point of the displacement stage to eliminate mechanical errors.

[0033] It also includes a calibration device 6, which provides a standard light source to the fiber optic sensing end 2 of the fiber optic spectrometer 1.

[0034] The calibration device 6 includes a standard tungsten lamp light source 61 and a baffle 62 disposed between the standard tungsten lamp light source 61 and the fiber optic sensing end 2. A through hole 63 is provided on the baffle 62, through which light generated by the standard tungsten lamp light source 61 enters the fiber optic sensing end 2. By adjusting (replacing) different positions of the baffle and different diameters of the through holes 63, the luminous flux can be adjusted, thereby enabling more precise calibration of the fiber optic sensing end 2.

[0035] It also includes a black plate 64, which is located on the other side of the standard tungsten lamp light source 61 away from the baffle 62, and the black plate 64 is perpendicular to the reverse extension line of the light path received by the optical fiber sensing end 2.

[0036] Furthermore, the distance between the black plate 64 and the standard tungsten lamp light source 61 is twice the distance between the standard tungsten lamp light source 61 and the fiber optic sensing end 2, in order to eliminate the influence of ambient light diffuse reflection.

[0037] In this embodiment, the theoretical radiation intensity of the standard tungsten lamp source collected by the fiber optic sensing end (quartz fiber) can be calculated using a fitted polynomial formula. In the experiment, the operating current of the standard tungsten lamp source 61 was 6.3A, and the wavelength range was 180-1100nm. The formula for the radiation intensity at a reference point 0.5m away from the tungsten lamp can be obtained by fitting the reference intensity at a given wavelength in the reference manual. = + ,in: =1.23460581534230e-05; =-2.63556916460505e-07; =2.34999518386550e-09; =-1.13996186009223e-11; = 3.29460480639860e-14; = -5.88551739463419e-17; =6.57980398553153e-20; =-4.49667353945587e-23; =1.72183694547381e-26; =-2.83513126833773e-30.

[0038] This embodiment utilizes optical measurement equipment such as fiber optic spectrometers, which can be quickly deployed in various testing environments and calibrated. The system has high mobility, greatly improving its applicability.

[0039] The fiber optic spectrometer 1 used in this embodiment is model BIM-6002A, with a wavelength detection range of 180-1100nm.

[0040] The digital delay generator 4 in this embodiment is a DG645 manufactured by Stanford Research Systems (SRS) in the United States, with a trigger rate of up to 10MHz.

[0041] In this embodiment, the fiber optic sensing end 2 includes a lens barrel and an aperture, a positive meniscus lens, and a biconvex lens arranged sequentially in the lens barrel. The light path generated by the standard tungsten lamp light source 61 passes through the aperture, the positive meniscus lens, and the biconvex lens sequentially along the axis of the lens barrel, and is finally coupled into the fiber optic spectrometer through an optical fiber connection.

[0042] In this embodiment, the displacement mechanism 3 can be a two-dimensional electric stepper displacement stage (XZ axis, with vertical movement as the Z axis), and an optical fiber clamping device is set on the displacement stage to clamp the optical fiber sensing end.

[0043] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer, characterized in that, The method involves pointing the fiber optic sensing end of the fiber optic spectrometer toward the front of the flame generated by the burner, and driving the fiber optic sensing end to move along a set path and step size in a longitudinal plane parallel to the front of the flame through a displacement mechanism, thereby collecting the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame point by point. The data collected by the fiber optic sensing end is analyzed and processed based on the chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data. Then, the local or overall equivalence ratio distribution image information of the flame is calculated by the tomographic inversion algorithm.

2. The method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer according to claim 1, characterized in that, The data acquisition of the fiber optic sensing end of the fiber optic spectrometer is synchronized with the movement of the fiber optic sensing end within the flame front region by the displacement mechanism via a digital delay generator.

3. The method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer according to claim 1, characterized in that, It also includes a method for correcting the wavelength response systematic error present in the fiber optic spectrometer, specifically including: The fiber optic sensing end of the fiber optic spectrometer is oriented at a fixed distance toward a standard light source formed by a standard tungsten lamp. The fiber optic sensing end collects the radiation intensity of the standard light source. The radiation intensity of the standard light source obtained by the fiber optic spectrometer is compared with the factory radiation information of the standard light source. The wavelength response of the fiber optic spectrometer is corrected using the comparison results.

4. The method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer according to claim 1, characterized in that, The method for analyzing and processing data collected by the fiber optic sensing end based on the chemiluminescence intensity ratio and equivalence ratio database to obtain equivalence ratio characteristic data is as follows: Calibration was obtained using a premixed flame. The mapping model assigns the intensity of each sampling point. Substituting into the mapping model, we obtain the equivalent ratio line integral feature data of the corresponding sampling points. ,Will Arranged according to the set path, forming the line integral equivalent ratio vector.

5. The method for scanning and measuring the flame equivalence ratio based on a fiber optic spectrometer according to claim 4, characterized in that, The method of obtaining local or global equivalence ratio distribution image information of a flame by using equivalence ratio feature data and then calculating it through a tomographic inversion algorithm specifically includes: Step 100: Using the fiber optic sensing end's acquisition plane as a reference, expand it to a two-dimensional distribution of the flame, determine the inversion region, and divide the inversion region into... Each pixel is a square pixel, with the size of the pixel equal to the step distance, and it is assumed that the equivalent ratio within each pixel is uniform; then the intersection length between the optical path and the pixel is accurately calculated using coordinates to construct the projection matrix; Step 200: Set the initial equivalent ratio of all pixels to the stoichiometry, configure the relaxation factor, number of iterations, convergence threshold, and set the prior constraints of flame axisymmetry or boundary to complete the initial parameter and constraint settings of the tomographic inversion algorithm. Step 300: Based on the measured value of the full equivalent ratio line integral of one side of the flame, first calculate the residual of all scanning optical paths one by one, then simultaneously solve the correction amount of each pixel unit and update the pixel equivalent ratio value in combination with prior constraints, iterate repeatedly until the residual meets the convergence condition or reaches the set number of iterations, and finally obtain the equivalent ratio pixel distribution of the flame cross section. Step 400: Using pseudo-color mapping, superimpose equivalence ratio lines, acquisition points, and flame outlines to form equivalence ratio distribution image information.

6. A system for scanning measurement of flame equivalence ratio based on a fiber optic spectrometer, used to implement the method for scanning measurement of flame equivalence ratio based on a fiber optic spectrometer as described in any one of claims 1-3, characterized in that, include: The fiber optic spectrometer (1) has at least one fiber optic sensing end (2) facing the front of the flame generated by the burner. The displacement mechanism (3) has an optical fiber sensing end (2) located at the action end of the displacement mechanism (3). The displacement mechanism (3) is used to drive the optical fiber sensing end (2) to move along a set path and step size in a longitudinal plane parallel to the front of the flame. A digital delay generator (4) is connected to the fiber optic spectrometer (1) and the displacement mechanism (3) to generate a control signal that synchronizes the movement of the fiber optic sensing end (2) driven by the displacement mechanism (3) with the signal acquisition performed by the fiber optic sensing end (2). The data processing and output module (5) integrates a chemiluminescence intensity ratio and equivalence ratio database and a tomographic inversion algorithm. It is connected to the fiber optic spectrometer (1) and is used to compare the chemiluminescence radiation spectrum and chemiluminescence intensity data of the flame obtained by the fiber optic sensing end (2) with the equivalence ratio database for analysis and processing. Then, it calculates and outputs the local or overall equivalence ratio distribution image information of the flame through the tomographic inversion algorithm.

7. The system for scanning and measuring flame equivalence ratio based on a fiber optic spectrometer according to claim 6, characterized in that, The displacement mechanism (3) outputs a 5V TTL signal as an external trigger signal for the digital delay generator (4), and the digital delay generator (4) controls the synchronous acquisition action of the fiber optic sensing end (2) through the external trigger signal.

8. The system for scanning and measuring flame equivalence ratio based on a fiber optic spectrometer according to claim 6, characterized in that, It also includes a calibration device (6) for providing a standard light source to the fiber optic sensing end (2) of the fiber optic spectrometer (1); The calibration device (6) includes a standard tungsten lamp light source (61) and a baffle (62) disposed between the standard tungsten lamp light source (61) and the fiber optic sensing end (2). A through hole (63) is provided on the baffle (62), and the light generated by the standard tungsten lamp light source (61) enters the fiber optic sensing end (2) through the through hole (63).

9. A system for scanning and measuring flame equivalence ratio based on a fiber optic spectrometer according to claim 8, characterized in that, It also includes a black plate (64), which is disposed on the other side of the standard tungsten lamp light source (61) away from the baffle (62), and the black plate (64) is perpendicular to the reverse extension line of the optical path received by the optical fiber sensing end (2); Furthermore, the distance between the black plate (64) and the standard tungsten lamp light source (61) is twice the distance between the standard tungsten lamp light source (61) and the fiber optic sensing end (2).

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