A high-precision flue gas measurement method

Abstract

The present invention relates to the field of data processing technology, and in particular to a method for high-precision measurement of flue gas, the method comprising: passing the flue gas to be measured into a sample pool of a differential optical absorption spectroscopy technology DOAS measurement system to obtain differential absorption spectral data of the flue gas to be measured; from the differential absorption spectral data of the flue gas to be measured, screening out the differential absorption spectral data corresponding to the area with the highest concentration of flue gas distribution in the sample pool as the spectral data to be processed; based on the difference in the influence of temperature on the absorption peaks of different gases, separating the overlapping absorption peaks in the spectral data to be processed to obtain the absorption peak curve corresponding to each gas in the flue gas to be measured; and obtaining the concentration of each gas according to the absorption peak curve corresponding to each gas. The present invention can improve the concentration detection accuracy of each gas in the flue gas.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a high-precision flue gas measurement method. Background Art

[0002] To determine the environmental impact of flue gas emitted during industrial production, the concentration of harmful gases (primarily sulfur dioxide and nitrogen oxides) must be detected. Currently, differential optical absorption spectroscopy (DOAS) is the primary method used to detect flue gas emitted during industrial production to determine the concentration of harmful gases. DOAS technology uses the selective absorption characteristics of gas molecules to specific wavelengths of light to quantitatively analyze gas concentrations. However, when the flue gas contains multiple gases, since different gases may have absorption peaks within similar wavelength ranges, the absorption peaks of different gases may overlap, making it difficult to distinguish from the spectral data which gas causes the absorption peak, resulting in low gas concentration detection accuracy. Summary of the Invention

[0003] In order to solve the technical problem of low gas concentration detection accuracy in existing flue gas measurement methods, the present invention aims to provide a high-precision flue gas measurement method. The technical solution adopted is as follows:

[0004] A high-precision flue gas measurement method, comprising:

[0005] Passing the flue gas to be tested into a sample cell of a differential optical absorption spectroscopy (DOAS) measurement system, and obtaining differential absorption spectrum data of the flue gas to be tested at room temperature using the DOAS measurement system; wherein the flue gas to be tested includes a plurality of different gases;

[0006] The differential absorption spectrum data of the smoke to be tested at room temperature is selected, and the differential absorption spectrum data corresponding to the area with the highest smoke concentration in the sample pool is selected as the spectrum data to be processed;

[0007] Based on the differences in the effects of temperature on the absorption peaks of different gases, the overlapping absorption peaks in the spectral data to be processed are separated to obtain the absorption peak curves corresponding to each gas in the flue gas to be measured;

[0008] According to the absorption peak curve corresponding to each gas, the concentration of each gas in the flue gas to be measured is obtained.

[0009] Furthermore, the differential absorption spectrum data corresponding to the area with the highest smoke concentration in the sample pool is selected from the differential absorption spectrum data of the smoke to be tested at room temperature as the spectrum data to be processed, including:

[0010] Passing air into a sample cell of a differential optical absorption spectroscopy (DOAS) measurement system, and obtaining differential absorption spectrum data of the air at room temperature using the DOAS measurement system;

[0011] Dividing the spectrometer scanning area in the sample cell of the DOAS measurement system into a plurality of sub-areas;

[0012] Based on the difference between the differential absorption spectrum data of the flue gas to be tested at room temperature corresponding to each sub-region and the differential absorption spectrum data of air at room temperature, the sub-region with the highest flue gas distribution concentration in the sample pool is determined, and the differential absorption spectrum data corresponding to the sub-region with the highest flue gas distribution concentration in the sample pool is used as the spectral data to be processed.

[0013] Furthermore, based on the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to each sub-region, determining the sub-region with the highest smoke distribution concentration in the sample pool includes:

[0014] The difference between the differential absorption spectrum data of the flue gas to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to each sub-region is calculated using the following formula:

[0015] ;

[0016] in, is the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to the k-th sub-region; is the peak value of the absorption peak of the smoke to be measured corresponding to the i-th wavelength in the differential absorption spectrum data of the smoke to be measured at room temperature corresponding to the k-th sub-region; is the peak value of the absorption peak of air corresponding to the i-th wavelength in the differential absorption spectrum data of air at room temperature corresponding to the k-th sub-region; is the number of wavelengths; Indicates taking the absolute value;

[0017] Calculate the flue gas density at room temperature corresponding to each sub-area using the following formula:

[0018] ;

[0019] in, represents the smoke density at room temperature corresponding to the kth sub-area; represents the difference between the differential absorption spectrum data of the flue gas to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to the j-th sub-region; m represents the number of sub-regions; represents the normalization function;

[0020] The sub-region with the largest smoke density at room temperature is taken as the sub-region with the highest smoke distribution concentration in the sample pool.

[0021] Furthermore, based on the differences in the effects of temperature on the absorption peaks of different gases, the overlapping absorption peaks in the spectral data to be processed are separated to obtain the absorption peak curves corresponding to the gases in the flue gas to be measured, including:

[0022] Obtain differential absorption spectrum data of the flue gas to be tested at different temperatures;

[0023] Based on the differential absorption spectrum data of the flue gas to be tested at different temperatures, the temperature difference index of each absorption peak is obtained;

[0024] Based on the temperature difference index of each absorption peak, a preset clustering algorithm is used to cluster the absorption peaks in the spectral data to be processed. The absorption peak in each cluster after clustering is regarded as the absorption peak of a gas, so as to separate the absorption peaks corresponding to different gases in the spectral data to be processed and obtain the absorption peak curve corresponding to each gas in the flue gas to be tested.

[0025] Furthermore, based on the differential absorption spectrum data of the flue gas to be tested at different temperatures, the temperature difference index of each absorption peak is obtained, including:

[0026] Based on the differential absorption spectrum data of the flue gas to be tested at different temperatures, the peak value of each absorption peak at different temperatures is obtained;

[0027] For each absorption peak, based on its peak value at different temperatures, a polynomial curve of its peak value changing with temperature is obtained;

[0028] For each absorption peak, its original temperature difference index is calculated based on the polynomial curve of its peak value changing with temperature and the maximum change value of its absorption peak width caused by temperature change;

[0029] According to the degree to which the smoke density in the sub-region with the highest smoke distribution concentration in the sample pool is affected by temperature, the original temperature difference index of each absorption peak is corrected to obtain the temperature difference index of each absorption peak.

[0030] Furthermore, the polynomial curve of the peak value of the absorption peak changing with temperature is expressed as:

[0031] ;

[0032] in, Indicates the The peak value of the absorption peak; Indicates temperature value; 、 、 、 are fitting coefficients.

[0033] Furthermore, for each absorption peak, its original temperature difference index is calculated based on the polynomial curve of its peak value changing with temperature and the maximum change value of its absorption peak width caused by temperature change, including:

[0034] For each absorption peak, its characteristic value is calculated based on the polynomial curve of its peak value changing with temperature;

[0035] For each absorption peak, its original temperature difference index is calculated based on its characteristic value and the maximum change value of its absorption peak width caused by temperature change; wherein, the calculation formula of the original temperature difference index is:

[0036] ;

[0037] in, Indicates the The original temperature difference index of each absorption peak; Indicates the Characteristic value of an absorption peak; Indicates the The maximum change in the width of an absorption peak due to temperature change.

[0038] Furthermore, the characteristic value of the absorption peak is expressed as:

[0039] ;

[0040] in, Indicates the The characteristic value of an absorption peak.

[0041] Furthermore, the temperature difference index of the absorption peak is expressed as:

[0042] ;

[0043] in, For the The temperature difference index of the absorption peak; For the The original temperature difference index of each absorption peak; is the smoke density of the sub-area with the highest smoke concentration in the sample pool at the tth temperature value; is the average value of the smoke density of the sub-area with the highest smoke density in the sample pool at c different temperature values; c is the number of temperature values; Indicates taking the absolute value.

[0044] Furthermore, the temperature value ranges from 20°C to 100°C.

[0045] The present invention has the following beneficial effects:

[0046] The high-precision flue gas measurement method provided by the present invention determines the area with the highest flue gas concentration in the sample pool based on the distribution of the flue gas to be measured in the sample pool, and uses the differential absorption spectrum data corresponding to the flue gas in this area as the spectral data to be processed; further, based on the different characteristics of the absorption peaks of different gases changing with temperature, the overlapping absorption peaks in the spectral data to be processed are separated to accurately obtain the absorption peak curve corresponding to each gas, thereby improving the concentration detection accuracy of different gases in the flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 This is a schematic diagram of the execution flow of the high-precision flue gas measurement method.

[0049] Figure 2 Schematic diagram of the DOAS measurement system.

[0050] Figure 3 This is a schematic diagram of the change in the absorption peak value of SO2 gas at different temperature points. DETAILED DESCRIPTION

[0051] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail a high-precision flue gas measurement method proposed according to the present invention, its specific implementation method, structure, characteristics and effects. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0052] A high-precision flue gas measurement method provided by the present invention is described in detail below with reference to the accompanying drawings.

[0053] A high-precision flue gas measurement method, such as Figure 1 As shown, the execution steps of this method are as follows:

[0054] S1, passing the flue gas to be tested into a sample cell of a differential optical absorption spectroscopy (DOAS) measurement system, and obtaining differential absorption spectrum data of the flue gas to be tested at room temperature using the DOAS measurement system; wherein the flue gas to be tested includes a plurality of different gases;

[0055] The structure of the DOAS measurement system used in this embodiment is as follows: Figure 2 As shown, it uses an L6565 deuterium lamp as the light source, which can provide a continuous spectrum in the 200nm to 400nm band. The incident light from the light source is collimated and enters the sample cell, and the outgoing light enters the spectrometer using fiber coupling. The spectrometer has an entrance slit width of 25μm, a grating density of 1200 lines / mm, a spectral range of 200nm to 500nm, and a resolution of 0.65nm. During the experiment, the pressure in the sample cell must be maintained constant. The flue gas to be measured is emitted during industrial production processes and is mainly composed of harmful gases such as sulfur dioxide and nitrogen oxides.

[0056] S2, from the differential absorption spectrum data of the smoke to be tested at room temperature, selecting the differential absorption spectrum data corresponding to the area with the highest smoke concentration in the sample pool as the spectrum data to be processed;

[0057] It's important to note that flue gas may contain carbon particles, sulfur oxides, nitrogen oxides, and other substances, which are generally more dense than air. Therefore, after the flue gas is placed in the sample cell, it will be unevenly distributed throughout the cell, resulting in different absorption peaks in different areas. Therefore, to enable subsequent spectral data processing, it's first necessary to determine the distribution of the flue gas.

[0058] Specifically, in this embodiment, the implementation process of the above S2 is as follows:

[0059] S21, passing air into a sample cell of a differential optical absorption spectroscopy (DOAS) measurement system, and obtaining differential absorption spectrum data of the air at room temperature using the DOAS measurement system.

[0060] S22, dividing the spectrometer scanning area in the sample cell of the DOAS measurement system into a plurality of sub-areas.

[0061] S23, based on the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to each sub-region, determining the sub-region with the highest smoke distribution concentration in the sample cell, and using the differential absorption spectrum data corresponding to the sub-region with the highest smoke distribution concentration in the sample cell as the spectral data to be processed;

[0062] Furthermore, based on the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to each sub-region, determining the sub-region with the highest smoke distribution concentration in the sample pool includes:

[0063] S231, calculating the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to each sub-region, using the following formula:

[0064] ;

[0065] in, is the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to the kth sub-region. The larger the difference value, the greater the current smoke proportion; is the peak value of the absorption peak of the smoke to be measured corresponding to the i-th wavelength in the differential absorption spectrum data of the smoke to be measured at room temperature corresponding to the k-th sub-region; is the peak value of the absorption peak of air corresponding to the i-th wavelength in the differential absorption spectrum data of air at room temperature corresponding to the k-th sub-region; is the number of wavelengths; Indicates taking the absolute value;

[0066] S232, calculate the flue gas density at room temperature corresponding to each sub-area using the following formula:

[0067] ;

[0068] in, represents the smoke density at room temperature corresponding to the kth sub-area; represents the difference between the differential absorption spectrum data of the flue gas to be tested at room temperature and the differential absorption spectrum data of air at room temperature corresponding to the j-th sub-region; m represents the number of sub-regions; represents the normalization function; It is used to indicate whether the current sub-region is an area with a relatively high smoke concentration. The larger the value, the more likely the corresponding sub-region is to be an area with a relatively high smoke concentration.

[0069] S233, taking the sub-region with the largest smoke density at room temperature as the sub-region with the highest smoke distribution concentration in the sample pool.

[0070] S3, based on the difference in the effect of temperature on the absorption peaks of different gases, separating the overlapping absorption peaks in the spectral data to be processed to obtain an absorption peak curve corresponding to each gas in the flue gas to be measured;

[0071] It should be noted that when using DOAS technology to detect gas concentration, temperature will affect the absorption peak of the gas, such as Figure 3 The figure shows how the absorption peak of SO2 (sulfur dioxide) gas changes at three different temperatures (50°C, 70°C, and 90°C). The effect of temperature on the absorption peak of a gas can be roughly expressed as follows: within a certain temperature range, as the temperature increases, the peak value of the gas absorption spectrum decreases, and the absorption characteristics tend to be smoother. Furthermore, due to differences in molecular structure and energy levels, different gases respond differently to temperature changes. For example, gases with complex molecular structures or larger molecules may be more sensitive to temperature changes. Therefore, the absorption peaks of different gases can be distinguished by observing the changes in their absorption peaks under different temperature changes.

[0072] Specifically, in this embodiment, the implementation process of the above S3 is as follows:

[0073] S31, obtaining differential absorption spectrum data of the flue gas to be tested at different temperatures;

[0074] In this embodiment, the temperature range is 20°C to 100°C.

[0075] S32, obtaining a temperature difference index for each absorption peak based on the differential absorption spectrum data of the flue gas to be tested at different temperatures;

[0076] The calculation process of the temperature difference index of the absorption peak is as follows:

[0077] S321, based on the differential absorption spectrum data of the smoke to be tested at different temperatures, obtaining the peak value of each absorption peak at different temperatures;

[0078] S322, for each absorption peak, based on its peak value at different temperatures, obtaining a polynomial curve of its peak value varying with temperature;

[0079] It should be noted that, since the peak value of the absorption peak will decrease with increasing temperature, in order to obtain a polynomial curve of the change of the peak value of the absorption peak with temperature, it is first necessary to use temperature as the horizontal coordinate and the peak value of the absorption peak at each wavelength as the vertical coordinate to construct a data coordinate system, and represent the peak values ​​of multiple absorption peaks obtained at different temperatures in the coordinate system. Then, using the data coordinate system, a polynomial fitting method is adopted to fit the curve equation of temperature and the peak value of the absorption peak.

[0080] Specifically, in this embodiment, the polynomial curve of the peak value of the absorption peak varying with temperature is expressed as:

[0081] ;

[0082] in, Indicates the The peak value of the absorption peak; Indicates temperature value; 、 、 、 All are fitting coefficients;

[0083] S323, for each absorption peak, based on a polynomial curve showing the variation of its peak value with temperature and the maximum variation of the width of the absorption peak due to temperature variation, calculate its original temperature difference index; the calculation process is as follows:

[0084] S3231, for each absorption peak, calculate its characteristic value based on the polynomial curve of its peak value changing with temperature, the formula is:

[0085] ;

[0086] in, Indicates the Characteristic value of an absorption peak;

[0087] In addition, it should be noted that for the above polynomial curve, the coefficients of the higher-order terms represent the drastic degree of curve change, so the coefficients of the higher-order terms can be integrated to represent the characteristic value of each absorption peak;

[0088] S3232, for each absorption peak, calculating its original temperature difference index based on its characteristic value and the maximum change value of the width of its absorption peak caused by temperature change;

[0089] It should be noted that temperature changes not only cause changes in the peak value of the absorption peak, but also in the peak width of the absorption peak. Therefore, when calculating the original temperature difference index, in addition to considering the peak value of the absorption peak with temperature change curve, it is also necessary to consider the maximum change in the width of the absorption peak caused by the temperature change of the current absorption peak. Based on this, in this embodiment, the calculation formula of the original temperature difference index is:

[0090] ;

[0091] in, Indicates the The original temperature difference index of each absorption peak; Indicates the The maximum change in the width of an absorption peak due to temperature change.

[0092] S324, correcting the original temperature difference index of each absorption peak according to the degree to which the smoke density in the sub-region with the highest smoke concentration in the sample cell is affected by temperature, to obtain a temperature difference index for each absorption peak;

[0093] Among them, the temperature difference index of the absorption peak is expressed as:

[0094] ;

[0095] in, For the The temperature difference index of the absorption peak; For the The original temperature difference index of each absorption peak; is the smoke density of the sub-area with the highest smoke concentration in the sample pool at the tth temperature value; is the average value of the smoke density of the sub-area with the highest smoke density in the sample pool at c different temperature values; c is the number of temperature values;

[0096] It indicates the influence of temperature on the smoke density of the sub-area with the highest smoke distribution concentration in the sample pool.

[0097] S33, clustering the absorption peaks in the spectral data to be processed using a preset clustering algorithm based on the temperature difference index of each absorption peak, treating the absorption peak in each cluster after clustering as an absorption peak of a gas, thereby separating the absorption peaks corresponding to different gases in the spectral data to be processed, and obtaining an absorption peak curve corresponding to each gas in the flue gas to be tested;

[0098] The clustering algorithm used in this embodiment is the density-based noise application spatial clustering DBSCAN clustering algorithm.

[0099] S4, obtaining the concentration of each gas in the flue gas to be measured according to the absorption peak curve corresponding to each gas;

[0100] Among them, the method of obtaining gas concentration based on the absorption peak curve corresponding to the gas is an existing technology. The most widely used method is: based on the absorption peak of each gas, the multiple linear regression (MLR) method is used to distinguish and quantify the absorption contribution of different gases, and a model characterizing the relationship between the absorption peak and the gas concentration is established based on the standard gas of known concentration. The model is trained and the model parameters are optimized. The trained model is applied to the spectral data of the current gas to predict the gas concentration.

[0101] In summary, this embodiment first determines the area with the highest smoke concentration in the sample pool based on the distribution of the smoke to be tested in the sample pool, and uses the differential absorption spectrum data corresponding to the smoke in this area as the spectral data to be processed; then, based on the different characteristics of the absorption peaks of different gases changing with temperature, the overlapping absorption peaks in the spectral data to be processed are separated to accurately obtain the absorption peak curve corresponding to each gas, thereby effectively improving the concentration detection accuracy of different gases in the smoke.

[0102] Furthermore, it should be noted that the above are merely preferred embodiments of the present invention. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous. Furthermore, although preferred embodiments of the present invention have been described, it will be apparent to those skilled in the art that, once the basic inventive concepts of the present invention are understood, various improvements and modifications may be made without departing from the principles of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-precision flue gas measurement method, characterized in that: include: The smoke to be tested is passed into a sample cell of a differential optical absorption spectroscopy (DOAS) measurement system, and the differential absorption spectrum data of the smoke to be tested at room temperature is obtained by using the DOAS measurement system; wherein the smoke to be tested includes a variety of different gases; The differential absorption spectrum data corresponding to the area with the highest smoke distribution concentration in the sample pool are selected from the differential absorption spectrum data of the smoke to be tested at room temperature as the spectrum data to be processed; Based on the difference in the effect of temperature on the absorption peaks of different gases, the overlapping absorption peaks in the spectral data to be processed are separated to obtain the absorption peak curve corresponding to each gas in the flue gas to be tested; According to the absorption peak curve corresponding to each gas, the concentration of each gas in the flue gas to be tested is obtained; The method for acquiring the spectral data to be processed is as follows: passing air into a sample cell of a differential optical absorption spectroscopy technology DOAS measurement system, and using the DOAS measurement system to obtain differential absorption spectral data of air at room temperature; dividing the spectrometer scanning area in the sample cell of the DOAS measurement system into a plurality of sub-areas; based on the difference between the differential absorption spectral data of the flue gas to be measured at room temperature corresponding to each sub-area and the differential absorption spectral data of air at room temperature, determining the sub-area with the highest smoke distribution concentration in the sample cell, and using the differential absorption spectral data corresponding to the sub-area with the highest smoke distribution concentration in the sample cell as the spectral data to be processed; Among them, the method for obtaining the sub-area with the highest smoke distribution concentration in the sample pool is: The difference between the differential absorption spectrum data of the flue gas to be tested at room temperature and the differential absorption spectrum data of the air at room temperature corresponding to each sub-area is calculated, and the formula is as follows: ； in, is the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of the air at room temperature corresponding to the k-th sub-region; is the peak value of the absorption peak of the smoke to be tested corresponding to the ith wavelength in the differential absorption spectrum data of the smoke to be tested at room temperature corresponding to the kth sub-region; is the peak value of the absorption peak of air corresponding to the ith wavelength in the differential absorption spectrum data of air at room temperature corresponding to the kth sub-region; is the number of wavelengths; Indicates taking the absolute value; Calculate the smoke density at room temperature corresponding to each sub-area using the following formula: ； in, represents the smoke density at room temperature corresponding to the kth sub-area; represents the difference between the differential absorption spectrum data of the smoke to be tested at room temperature and the differential absorption spectrum data of the air at room temperature corresponding to the j-th sub-region; m represents the number of sub-regions; represents the normalization function; The sub-area with the largest smoke density at room temperature is taken as the sub-area with the highest smoke distribution concentration in the sample pool; Among them, the method for obtaining the absorption peak curve corresponding to each gas in the flue gas to be tested is: obtaining differential absorption spectrum data of the flue gas to be tested at different temperatures; based on the differential absorption spectrum data of the flue gas to be tested at different temperatures, obtaining the temperature difference index of each absorption peak; based on the temperature difference index of each absorption peak, using a preset clustering algorithm to cluster the absorption peaks in the spectral data to be processed, and taking the absorption peaks in each cluster after clustering as the absorption peak of a gas, so as to separate the absorption peaks corresponding to different gases in the spectral data to be processed, and obtain the absorption peak curve corresponding to each gas in the flue gas to be tested.

2. The high-precision flue gas measurement method according to claim 1, characterized in that: Based on the differential absorption spectrum data of the flue gas to be tested at different temperatures, the temperature difference index of each absorption peak is obtained, including: Based on the differential absorption spectrum data of the smoke to be tested at different temperatures, the peak value of each absorption peak at different temperatures is obtained; For each absorption peak, based on its peak value at different temperatures, a polynomial curve of its peak value changing with temperature is obtained; For each absorption peak, its original temperature difference index is calculated based on the polynomial curve of its peak value changing with temperature and the maximum change value of the width of its absorption peak caused by temperature change; According to the degree to which the smoke density in the sub-region with the highest smoke distribution concentration in the sample pool is affected by temperature, the original temperature difference index of each absorption peak is corrected to obtain the temperature difference index of each absorption peak.

3. The high-precision flue gas measurement method according to claim 2, characterized in that: The polynomial curve of the peak value of the absorption peak changing with temperature is expressed as: ； in, Indicates The peak value of the absorption peak; Indicates temperature value; , , , All are fitting coefficients.

4. The high-precision flue gas measurement method according to claim 3, characterized in that: For each absorption peak, based on the polynomial curve of its peak value changing with temperature and the maximum change value of its absorption peak width due to temperature change, its original temperature difference index is calculated, including: For each absorption peak, its characteristic value is calculated based on the polynomial curve of its peak value changing with temperature; For each absorption peak, its original temperature difference index is calculated based on its characteristic value and the maximum change value of the width of its absorption peak due to temperature change; wherein, the calculation formula of the original temperature difference index is: ； in, Indicates The original temperature difference index of each absorption peak; Indicates The characteristic value of an absorption peak; Indicates The maximum change in the width of an absorption peak due to temperature change.

5. The high-precision flue gas measurement method according to claim 4, characterized in that: The characteristic value of the absorption peak is expressed as: ； in, Indicates The characteristic value of an absorption peak.

6. The high-precision flue gas measurement method according to claim 2, characterized in that: The temperature difference index of the absorption peak is expressed as: ； in, For the The temperature difference index of the absorption peaks; For the The original temperature difference index of each absorption peak; is the smoke density of the sub-area with the highest smoke distribution concentration in the sample pool at the tth temperature value; is the average value of the smoke density of the sub-area with the highest smoke distribution density in the sample pool at c different temperature values; c is the number of temperature values; Indicates taking the absolute value.

7. The high-precision flue gas measurement method according to claim 6, characterized in that: The temperature value range is 20℃~100℃.

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