CN115523958A - Gas temperature and concentration synchronous measurement method based on spectrum fast-slow separation principle - Google Patents
Gas temperature and concentration synchronous measurement method based on spectrum fast-slow separation principle Download PDFInfo
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- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
Abstract
The invention discloses a gas temperature and concentration synchronous measurement method based on a spectrum fast-slow separation principle, which comprises the following steps of: acquiring differential absorption spectra of chlorobenzene with unknown concentrations and temperature information at different wavelength points and carrying out normalization treatment; calculating a differential absorption cross section corresponding to the differential absorption spectrum of chlorobenzene at each wavelength point; normalizing the differential absorption cross section of each wavelength point at different temperatures; determining coefficient R for the normalized differential absorption spectrum of unknown concentration and temperature information and each normalized differential absorption section 2 Comparing one by one, and finding out the decision coefficient R 2 The temperature corresponding to the differential absorption cross section corresponding to the maximum value of (a) is taken as the predicted temperature; calculating the differential absorption cross section corresponding to the predicted temperature according to the beer-Lambert lawAnd (4) obtaining the concentration of chlorobenzene corresponding to the differential absorption cross section. The invention realizes the simultaneous measurement of the temperature and the concentration of the p-chlorobenzene by considering the temperature specificity of the differential absorption section.
Description
Technical Field
The invention relates to the technical field of chlorobenzene gas measurement, in particular to a gas temperature and concentration synchronous measurement method based on a spectrum fast-slow separation principle.
Background
Chlorobenzene is a major raw material for the production of pesticides, and is also an organically synthesized intermediate for the manufacture of chemical raw materials such as phenol, nitrophenol, aniline, and the like. Chlorobenzene is frequently used as a rubber aid, a solvent for paints, coatings and varnishes, a quick-drying ink, a dry cleaner and the like, and is applied to various fields such as production fields of dyes, medicines, perfumes and the like. Chlorobenzene has wide application, but with the development of industry in China, chlorobenzene compounds in soil and underground water are more seriously polluted, chlorobenzene has strong volatility, gaseous chlorobenzene in industrial environment also greatly threatens the environment and human health, and the chlorobenzene has an anesthetic effect on the central nervous system, has a stimulating effect on human skin and mucous membrane, and can increase the morbidity and mortality of chronic diseases. Secondly, in the field of waste disposal, chlorobenzene is considered as a precursor for persistent organic pollutants such as dioxins. Therefore, the accurate measurement of the chlorobenzene concentration is of great significance to the prevention and control of pollutants and the recognition of the generation of persistent organic pollutants in the waste treatment process. Although methods such as mass spectrometry, gas chromatography, high performance liquid chromatography, and ion mobility spectrometry among existing methods have been used to measure the concentration of chlorobenzene, the accuracy is not high, and the measurement of the temperature of chlorobenzene cannot be realized while the concentration of chlorobenzene is measured.
Disclosure of Invention
The invention aims to realize synchronous and accurate measurement of chlorobenzene concentration and temperature, and provides a gas temperature and concentration synchronous measurement method based on a spectrum fast-slow separation principle.
In order to achieve the purpose, the invention adopts the following technical scheme:
the method for synchronously measuring the gas temperature and the concentration based on the spectrum fast-slow separation principle comprises the following steps:
l1, acquiring a differential absorption spectrum of chlorobenzene with unknown concentration and temperature information and performing normalization treatment;
l2, calculating a differential absorption cross section corresponding to the differential absorption spectrum of the chlorobenzene at each wavelength point with known concentration and temperature in the experiment;
l3, performing normalization treatment on the differential absorption cross sections at different temperatures in the experiment;
l4, the difference absorption spectrum of the normalized unknown concentration and temperature information and each difference after normalizationCoefficient of determination R for partial absorption cross section 2 Comparing one by one, and finding out the decision coefficient R 2 The temperature corresponding to the differential absorption cross section corresponding to the maximum value of (a) is taken as the predicted temperature of the chlorobenzene at the unknown temperature in the step L1;
and L5, calculating the chlorobenzene concentration corresponding to the differential absorption cross section for the differential absorption cross section corresponding to the predicted temperature according to the beer-Lambert law.
Preferably, in step L2, the method of calculating the differential absorption cross section corresponding to the differential absorption spectrum is expressed by the following formula (5):
in the formula (1), Δ σ (λ) represents a differential absorption cross section obtained by incidence of light having a wavelength λ into chlorobenzene gas;
n represents chlorobenzene number density;
l represents an absorption optical path length;
DOD represents the differential absorption spectrum.
Preferably, in step L3, the method of normalizing the differential absorption cross section for each wavelength point at the same temperature is expressed by the following formula (2):
in the formula (2), Δ σ Normalization Represents the result of normalization on Δ σ;
i represents a differential absorption cross section corresponding to the ith wavelength point at a specified temperature and a specified concentration;
n represents the number of wavelength points selected in the wavelength band range of 201-220nm at a specified concentration and a specified temperature.
Preferably, the method for normalizing the differential absorption spectrum of chlorobenzene comprises:
ΔDOD Normalization represents the normalized result for DOD;
DOD i and the differential absorption spectrum corresponding to the ith wavelength point at a specified concentration at a specified temperature is represented.
Preferably, in step L4, the method for obtaining the predicted temperature corresponding to the differential absorption cross section includes:
s1, constructing a fitting function of a differential absorption cross section with respect to temperature;
and S2, solving the temperature corresponding to the differential absorption cross section according to the fitting function to serve as the predicted temperature.
Preferably, the fitting function constructed in step S1 is a first fitting function characterizing a relationship between a chlorobenzene differential absorption cross-section and temperature for each wavelength point, and the first fitting function is expressed by the following formula (1):
in the formula (3), Δ σ represents the chlorobenzene differential absorption cross section;
t represents a temperature;
a. b and c represent term coefficients, and d is a constant;
λ 1 representing a particular said wavelength point;
f represents the first fitting function.
Preferably, λ 1 =201.24nm, a =2.99 × 10 -25 ，b＝-3.70×10 -22 ，c＝1.43×10 -19 ，d＝-1.55×10 -17 。
Preferably, the fitting function constructed is a second fitting function characterizing the relationship between the chlorobenzene differential absorption cross section and the wavelength for each temperature point, and the second fitting function is expressed by the following formula (4):
in the formula (4), T 1 Represents a specific said temperature point;
λ represents a wavelength;
Δσ 298K the chlorobenzene differential absorption cross section representing the position of a lambda wavelength point at a temperature of 298K;
a represents the temperature T 1 Coefficients of the second fitting function fitted to the 298K differential absorption cross-section,
b represents the temperature T 1 The coefficients of the first order of the second fitting function in fitting relation to the 298K differential absorption cross-section,
c represents the temperature T 1 A constant term of the second fitting function fitted to the 298K differential absorption cross-section,
m Q 、m P 、m C respectively representing the corresponding parameters a, b and c and cubic term coefficients in the temperature fitting process;
n Q 、n P 、n C respectively representing the corresponding parameters a, b and c and quadratic term coefficients in the temperature fitting process;
P Q 、P P 、P C respectively representing the corresponding parameters a, b and c and the first-order coefficient in the temperature fitting process;
w Q 、w P 、w C respectively representing the constant terms in the fitting process of the corresponding parameters a, b and c and the temperature.
Preferably, the fitting function is constructed such that the light incident into the chlorobenzene gas is ultraviolet light having a wavelength in a wavelength band of 201nm to 220 nm.
The invention has the following beneficial effects:
1. in consideration of the temperature specificity of the differential absorption section, the invention creatively provides a method for simultaneously measuring the temperature and the concentration, and the measurement deviation of the method on the temperature is within 1.89%. Due to the spectral resolution of the instrument and other reasons, partial deviation of a concentration inversion result is large, but the method can basically realize synchronous measurement of temperature and concentration, and provides a new idea for popularizing the differential absorption spectrum to the field of simultaneous measurement of temperature and concentration. 2. With the change of temperature, the differential absorption spectrum of chlorobenzene not only shows the change of amplitude, but also shows the difference in the shape. In order to further understand the spectral absorption characteristics of chlorobenzene, the invention calculates important spectral parameters at different temperatures, namely differential absorption cross sections, constructs a binary function of the differential absorption cross sections with respect to temperature and wavelength, and performs dimension reduction fitting on the binary function under the conditions of fixed temperature and wavelength respectively, thereby obtaining the differential absorption cross sections of chlorobenzene at continuous temperature under a target detection waveband. The two fitting methods provided show that the error of the fitting method with a single wavelength point is relatively large, because the spectrum acquisition of the single point is easily influenced by the fluctuation of an instrument, but both the two fitting methods realize that the concentration inversion error is within 2.74 percent, and have high consistency with the shape of a differential absorption cross section obtained in an experiment.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic diagram of the structure of a fitting data generating apparatus;
FIG. 2 is a schematic representation of the differential absorption spectrum of 50ppm chlorobenzene at different temperatures;
a in fig. 3 is a differential absorption cross section of chlorobenzene recorded in an MPI-Mainz ultraviolet database at a specified waveband and at a temperature of 298K, b is a convolved database differential absorption cross section, c is an experimentally obtained differential absorption cross section;
FIG. 4 is a bar graph comparing chlorobenzene concentration with actual concentration obtained by inversion of standard absorption cross-section and a graph of the trend of calculated deviation along with temperature;
FIG. 5 is a graph of a fit of the relationship between the temperature compensation coefficient K (T) and the temperature T;
FIG. 6 is a schematic diagram of a fitted curve of temperature and differential absorption cross-section at a wavelength of 201.24 nm;
FIG. 7 is a schematic flow chart of the construction of temperature versus differential absorption cross-section for chlorobenzene at successive wavelengths;
FIG. 8 is a schematic diagram of the division of the differential absorption cross section of chlorobenzene into 8 monotonic intervals;
FIG. 9 is a graph of a fit relationship of differential absorption cross sections at different temperatures and 298K;
FIG. 10 is a graph of a fit relationship between the second fit function's quadratic coefficient, first order coefficient, constant term, and temperature;
FIG. 11 is a schematic flow chart of the construction of a fitting relationship of chlorobenzene differential absorption cross-sections at different temperatures and 298K;
FIG. 12 is a graph showing the results and deviations of the two fitting methods used in this example to invert chlorobenzene concentrations;
FIG. 13 is a graph showing the variation of the differential absorption cross-section at a continuous temperature of 288K to 473K in the 201-220nm wavelength band plotted according to the second fitting method;
FIG. 14 is a schematic of normalized chlorobenzene differential absorption cross-sections at different temperatures;
FIG. 15 is a flow chart for simultaneous measurement of chlorobenzene temperature and concentration;
FIG. 16 is a diagram illustrating an implementation step of a method for performing gas concentration inversion based on a fitted spectral fast-changing absorption cross-section according to an embodiment of the present invention;
fig. 17 is a diagram of implementation steps of a method for synchronous measurement of gas temperature and concentration based on the principle of spectrum fast-slow separation according to an embodiment of the present invention.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
Wherein the showings are for the purpose of illustration only and not for the purpose of limiting the same, the same is shown by way of illustration only and not in the form of limitation; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate an orientation or a positional relationship based on that shown in the drawings, it is only for convenience of description and simplification of description, but not to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limitations on the present patent, and specific meanings of the terms may be understood according to specific situations by those of ordinary skill in the art.
In the description of the present invention, unless otherwise explicitly specified or limited, the term "connected" or the like, if appearing to indicate a connection relationship between components, is to be understood broadly, for example, as being either fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be connected through any combination of two or more members or structures. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Since chlorobenzene has strong absorption characteristics in the ultraviolet wavelength range, differential absorption spectroscopy is suitable for the measurement of chlorobenzene concentrations. ChlorineThe benzene has a main absorption between 170-220nm and a characteristic absorption band between 240-280nm, but 2 orders of magnitude lower than the main absorption band. Considering the increase of Rayleigh scattering in the atmosphere and O in the air 2 Absorption makes the light intensity attenuation of short wave ultraviolet within 200nm faster, so the 201nm-220nm wave band is selected in the experiment to carry out the inversion analysis of chlorobenzene concentration. The absorption cross section of chlorobenzene can be calculated in absorption measurements using the Beer-Lambert law (Beer-Lambert law). When the beam passes through chlorobenzene, the ratio of the incident intensity to the transmitted intensity can be expressed as:
I(λ)/I 0 (λ)＝exp(-σ(λ)NL) (1)
wherein I 0 (λ) and I (λ) represent incident light intensity and transmitted light intensity, respectively;
λ represents the wavelength of the incident light;
σ(λ)(cm 2 /molecule) represents the absorption cross section; n (molar/cm) 3 ) Represents the chlorobenzene number density; l (cm) is the absorption optical path length.
In order to avoid slow absorption influence on the measurement result caused by light intensity change due to scattering, unstable light source and the like, polynomial fitting is carried out on the detection spectrum to obtain a differential absorption spectrum. The whole absorption section of chlorobenzene can be decomposed into fast-changing absorption and slow-changing absorption:
σ(λ)＝σ 0 (λ)+Δσ(λ) (2)
in the formula (2), σ 0 (λ) represents slow absorption;
Δ σ (λ) represents a rapidly varying absorption;
from equation (2), equation (1) can be rewritten as:
I(λ)＝I 0 (λ)exp[-σ 0 (λ)NL]exp[-Δσ(λ)NL] (3)
except for slow changes, only the terms that change strongly with wavelength remain, and equation (3) can evolve as:
the DOD is defined as a differential absorption spectrum and can be obtained by polynomial fitting of a spectrum curve obtained by detection. The differential absorption cross section Δ σ of chlorobenzene can be calculated from DOD, the population density N, and the path length L in the experiment. However, the experimentally available spectral data are limited, and the differential absorption spectrum detection of chlorobenzene at all temperatures cannot be exhaustively performed, so that the differential absorption cross sections of chlorobenzene at various wavelengths at other temperatures are obtained by theoretically deriving and calculating from the existing absorption cross sections of chlorobenzene. It can be known from preliminary experiments and molecular absorption line theory that the change of temperature and wavelength can affect the intensity change of the differential absorption cross section, so that the differential absorption cross section of chlorobenzene is a binary function of temperature and wavelength, and can be expressed as:
Δσ＝f(T,λ) (5)
in the formula (5), f represents a mapping function of the differential absorption cross section along with the change of temperature and wavelength;
in order to accurately solve the differential absorption cross section Δ σ, the embodiment of the present invention provides two fitting methods to determine the differential absorption cross section of chlorobenzene at different temperatures:
the first is to fit the absorption cross section and the temperature of each wavelength point to obtain the function of the absorption cross section and the temperature of each wavelength point, in this embodiment, the specific wavelength λ 1 The lower unitary function of the differential absorption cross section and the temperature is as shown in equation (6). And arranging the unitary functions in the order of the wavelength lambda from small to large to finally obtain the binary functions of the absorption cross section with respect to temperature and wavelength.
Secondly, fitting the differential absorption cross section of each temperature point with the wavelength to obtain a function of the differential absorption cross section and the wavelength of each temperature point, and specifying the temperature T 1 And fitting parameters of the unitary functions with temperature to finally obtain a binary function of the differential absorption cross section with respect to the temperature and the wavelength.
However, since the shape of the chlorobenzene differential absorption cross section is complicated and difficult to express by a single functional expression, equation (7) is converted into a binary function of the differential absorption cross section and the differential absorption cross section at the λ wavelength point positions at the temperatures T and 298K by using the differential absorption cross section at 298K as a standard:
in the formula (8), Δ σ 298K A chlorobenzene differential absorption cross section representing a lambda wavelength point position at a temperature of 298K;
a represents the temperature T 1 Coefficients of a second order term of said second fitting function in fitting relation to the 298K differential absorption cross-section,
b represents the temperature T 1 The first order coefficient of the second fitting function fitted to the 298K differential absorption cross-section,
c represents the temperature T 1 A constant term of the second fitting function in fitting relation to the 298K differential absorption cross-section,
m Q 、m P 、m C respectively representing the corresponding parameters a, b and c and cubic term coefficients in the temperature fitting process;
n Q 、n P 、n C respectively representing the corresponding parameters a, b and c and quadratic term coefficients in the temperature fitting process;
P Q 、P P 、P C respectively representing the corresponding parameters a, b and c and a first term coefficient in the temperature fitting process;
w Q 、w P 、w c respectively representing the constant terms in the fitting process of the corresponding parameters a, b and c and the temperature.
As can be seen from the above equations (6) - (8), the difference absorption cross section of chlorobenzene is related to the wavelength and the temperature, and after the wavelength data of the ultraviolet light incident into chlorobenzene and the temperature data of chlorobenzene are obtained, the difference absorption cross section of chlorobenzene can be solved according to the above equation (6) or equation (8). After the differential absorption cross section is obtained, the chlorobenzene concentration corresponding to the differential absorption cross section can be solved according to the Beer-Lambert law (Beer-Lambert law). Whether the two fitting relations expressed by the formulas (6) and (8) can accurately represent the mapping relation of the differential absorption cross section with the temperature and the wavelength or not is characterized in that term coefficients a, b and c and a constant d in the formulas (6) and (8) are accurately solved, for example, in the formula (6), the specific wavelength lambda is 1 Next, the temperature T and the corresponding differential absorption cross section Δ σ are taken as fitting points to solve a, b, c, and d, and the more the number of the fitting points is, the smoother the curve represented by the formula (6) is, and the more accurate the values of a, b, c, and d obtained by inverse extrapolation are, so that in order to conveniently obtain a sufficient number of data fitting points, the invention specially provides a fitting data generating device as shown in fig. 1, and the experimental principle of the device is as follows:
as a light source, a high-pressure deuterium lamp (Hamamatsu, L9815) having a broadband emission spectrum was used, and light emitted from the deuterium lamp was converted into parallel light by a quartz lens 1 (Thorlab, LA 4545) having a focal length of 100 mm. The parallel light passes through a gas absorption cell 2 having a length of 50cm and a diameter of 2 cm. The light path passes through the gas absorption cell 2 and then enters the optical fiber 5 connected to the spectrometer through the focusing lens 3. In order to improve the coupling efficiency and reduce the dissipation of light beams, a quartz collimating mirror 6 (74-UV collimating lens) is arranged at the tail part of the optical fiber, and the transmission light wave band range is 200-2000nm. The gas mixing unit consists of a highly stable mass flow controller 7 (MFC, seven Stars) and a pre-heated mixing chamber 8, the chlorobenzene standard gas being nominally pre-mixed with 100ppm of chlorobenzene and nitrogen. Experiments were conducted with different chlorobenzene concentrations, preferably using two MFCs to achieve further dilution of the sample gas with nitrogen. The temperature outside the gas absorption cell 2 is preferably controlled by a glass fiber heating belt, and the temperature controller 9 can control the temperature within a range of 273K-673K. The detection range of the spectrometer 4 (Ocean Optics, maya pro) is 200nm-340nm, the resolution is 0.6nm, and the narrow-band absorption wave band of chlorobenzene at 200-220nm is covered. Reference numeral "10" in fig. 1 is a gas tank. FIG. 2 shows the differential absorption spectra of 50ppm chlorobenzene at different temperatures. As can be seen from fig. 2, the absorption peaks of chlorobenzene at different temperatures are the same, but the absorption peaks become smaller as the temperature increases, because at room temperature the molecule is mainly in its ground state vibrational level. As the temperature increases, the number of molecules in the ground state vibration level decreases, and the temperature affects the density of the gas, so that the temperature change affects the absorption of the gas molecules, and although the absorption peak positions are the same, as the temperature increases, the absorption peak amplitude decreases, the absorption tends to be smooth, and the differential structure is smoothed.
In order to understand the effect of temperature changes on chlorobenzene concentration measurements, the resulting differential absorption spectra were concentration-inverted according to Beer Lambert's law with the corresponding absorption cross-section at room temperature. The absorption cross section of chlorobenzene in a certain specified waveband at the temperature of 298K can be obtained from an MPI-Mainz ultraviolet database. In order to correct instrument errors, a system instrument function is convoluted with an absorption section in the database to obtain a standard absorption section after convolution, a diagram a in fig. 3 is an absorption section of chlorobenzene recorded in an MPI-Mainz ultraviolet database at a temperature of 298K and under the specified waveband, and a diagram b is a standard absorption section which is shown by a diagram a and is convoluted with the system instrument function, wherein it needs to be explained that the convolution process is used for correcting instrument errors, and a method for obtaining the standard absorption section through convolution is not within the protection scope of the present invention, and therefore is not specifically explained. The c diagram in fig. 3 is a schematic diagram of the differential absorption cross section of chlorobenzene obtained by experiment at the specified waveband and at the temperature of 298K, and the experimental result expressed by the c diagram is basically matched with the absorption cross section shown in the a diagram, which shows that the experimental method of the absorption cross section provided by the invention is effective. However, because the standard absorption cross section obtained after convolution still has an error due to a certain resolution with the original spectrum in the database, the principle that the absorption cross section is calculated by using a fitting method and the standard absorption cross section is obtained by convolution is completely different, and the influence of the error on the accuracy of the chlorobenzene concentration inversion result caused by the convolution is solved.
And performing concentration inversion on the obtained differential absorption spectrum by adopting a standard absorption section. After the differential absorption spectrum DOD, the standard differential absorption cross sections under the optical paths L and 298K are obtained by measurement, the differential absorption spectrum can be obtained according to the formula (4), i.e., beer Lambert Law:
wherein N (molar/cm) 3 ) Is the number density of chlorobenzene, the volume fraction C (ppm) and the number density N (moles/cm) 3 ) The conversion relationship between them can be expressed as:
wherein C is C Calculated concentration (ppm) for chlorobenzene; t is the gas temperature (K) at the time of measurement; v A A gas volume of 22.4L at 273K of 1 mol; n is a radical of A Is Avogastro constant 6.02 x 10 23 ；T 0 And 273K. The results are shown in table 1 below, and it can be seen from the comparative bar chart of the actual concentration and the calculated concentration shown in fig. 4 corresponding to table 1 and the curve of the variation trend of the deviation with temperature that the error (deviation) of the concentration inversion is larger as the temperature deviates from 298K. When the temperature rises to 473K, if the concentration inversion is carried out by adopting the standard absorption cross section, the deviation can reach more than 70%.
TABLE 1
According to the analysis, the influence of the temperature on the concentration inversion result is obvious, and in order to obtain a more accurate chlorobenzene concentration measurement result, the invention adoptsThe temperature compensation method is used for carrying out temperature compensation on the measurement result, the temperature compensation coefficient K (T) is obtained by fitting the ratio between the calculated concentration and the actual concentration of chlorobenzene at different temperatures, and the calculated concentration C of chlorobenzene is C And the actual concentration C A Is expressed by the following formula (9):
C C ＝C A xK (T) formula (9)
K (T) was measured using a standard chlorobenzene gas of known concentration, as shown in the following equation (10):
then measuring K (T) values at different temperatures, solving the term coefficient and constant of the fitting function of K (T) with respect to the temperature by taking the temperature and the corresponding K (T) value as fitting points, substituting the solved term coefficient and constant into the fitting function of K (T) with respect to the temperature to obtain the final fitting function of K (T) with respect to the temperature, and repeatedly carrying out experiments to obtain the fitting function of K (T) with respect to the temperature as expressed by the following formula (11):
K(T)＝exp(-0.000017527×T 2 +0.0073569×T-0.63957) (11)
in order to verify the applicability of the temperature compensation coefficient, the invention adopts 55ppm chlorobenzene standard gas to carry out research on concentration compensation under the four temperature conditions of 318K, 333K, 383K and 473K, and the verification result is shown in the following table 2:
TABLE 2
The temperature compensation coefficient K (T) can be obtained according to the measured temperature, after the temperature compensation is carried out on the calculated concentration, the detection error of the chlorobenzene concentration is reduced to be within 3.2%, the nonlinear influence of the temperature on the chlorobenzene detection is effectively eliminated, and the accuracy of the chlorobenzene concentration detection at different temperatures is improved.
The temperature compensation method described above considers only the influence of temperature on its amplitude, and considers the differential absorption spectrum shapes at different temperatures to be the same. It has been demonstrated in fig. 2, however, that the amplitude of the fluctuation of the differential absorption spectrum of chlorobenzene decreases with increasing temperature. In practice, therefore, temperature also has an effect on the shape of the differential absorption spectrum. By analyzing the influence, the error of predicting the chlorobenzene concentration by using the differential absorption spectrum at the known temperature can be further reduced, and more importantly, the gas temperature and the chlorobenzene concentration can be simultaneously obtained by spectrum under the condition of unknown concentration.
According to the molecular spectroscopy theory, the absorption spectrum is mainly influenced by the analytical absorption cross section. The following description will focus on how the present invention specifically uses the fitting method expressed by formula (6) or formula (8) to obtain the relationship between the differential absorption cross section and temperature in the interval 288-473K, and then obtains the concentration of the chlorobenzene gas to be measured by inversion.
The fitting method expressed by the formula (6) is used for inverting the chlorobenzene concentration, and the steps are as follows:
1. fitting the temperature to a single wavelength (e.g., a specific wavelength λ) based on experimentally obtained data 1 ) And obtaining a functional relation of the differential absorption cross section intensity with the temperature change under the single wavelength according to the relation between the lower differential absorption cross section intensities. Taking a wavelength point 201.24nm in the range of 201nm to 220nm as an example, the differential absorption cross-section corresponding to 288K to 473K at the wavelength point is shown in the following Table 3. Fitting the functional relation of the temperature and the differential absorption cross section under the wavelength, if the fitting times are too low, the accuracy of the solving result of the relation is influenced, and if the fitting times are too high, a fitting curve can oscillate, so that the optimal fitting times are selected to be 3 times through repeated experimental summary.
TABLE 3
2. From the fitted curve of the temperature and the differential absorption cross section at the wavelength of 201.24nm shown in fig. 6, a fitted relation of the temperature and the differential absorption cross section at the wavelength point can be obtained, and the relation is expressed as follows:
Δσ＝2.99×10 -25 ×T 3 -3.70×10 -22 ×T 2 +1.43×10 -19 ×T-1.55×10 -17 formula (12)
According to the cubic function relation expressed by the formula (12), the chlorobenzene differential absorption cross section corresponding to the temperature at the wavelength of 201.24nm can be obtained by inputting any temperature in the range of 288-473K.
3. And sequentially fitting the differential absorption cross section intensity and the temperature at each wavelength point between 201nm and 220nm by using MATLAB programming, so that the single wavelength is widened to a target detection waveband, and the chlorobenzene differential absorption cross section which continuously changes along with the wavelength can be obtained.
The fitting method-steps 1-3 for inverting the chlorobenzene concentration is the flow for constructing the relationship between the temperature under continuous wavelengths and the chlorobenzene differential absorption cross section shown in fig. 7.
The fitting method expressed by the formula (8) is used for performing two-way inversion on the chlorobenzene concentration, and comprises the following steps:
1. the observation of the absorption spectrum of 201nm-220nm shows that the differential absorption cross section of chlorobenzene shows obvious periodicity-like and the relation between chlorobenzene and temperature is difficult to be characterized by a single function. Thus, as shown in FIG. 8, the present invention divides the differential absorption cross section of chlorobenzene into 8 monotonic segments, so that each segment can be characterized by a monotonic function.
2. The change of each section of the differential absorption cross section is complex, and the characteristics of the absorption cross section cannot be accurately described by a simple function. Therefore, in order to more accurately describe the characteristics of the absorption cross section at different temperatures, the absorption at different temperatures is compared with the absorption at 298K to obtain a fitting relation between the absorption at different temperatures and the absorption at 298K, and the absorption cross section at different temperatures is expressed by the same type of functional expression. Taking the spectrum of the sixth section (section VI) in fig. 8 as an example, fitting the differential absorption cross sections at 298K and different experimental temperatures, finding that the relationship between the two can be expressed by a quadratic function in the section, and the other sections can also be represented by a quadratic function relationship with the differential absorption cross section at 298K, so that each section of the absorption cross section at different temperatures can be solved by using the absorption cross section solving relational expression at 298K.
3. Because the differential absorption cross section shows obvious regular change along with the temperature, parameters (term coefficients and constants) in the function expression and the temperature also show certain regular change. The parameters are extracted and fitted with the temperature, a differential absorption section expression at the temperature can be constructed by inputting any temperature, the sixth section in fig. 8 is taken as an example, fitting points in the following table 3 are fitted to obtain quadratic function relational expressions (namely, second fitting functions) of the differential absorption sections at the temperatures and 298K, and quadratic coefficient, first order coefficient and constant term in the relational expressions are obtained through arrangement. Then, fitting the temperature with a quadratic term coefficient and a primary term coefficient, namely a constant term, wherein in order to keep consistency and simple and convenient operation, each parameter and the temperature are fitted into a cubic function relationship, and a function expression is written as follows:
wherein a, b and c respectively represent a quadratic term coefficient, a first order term coefficient and a constant term of a second fitting function of fitting relations of different temperatures and 298K differential absorption sections;
m Q 、m P 、m C respectively representing the corresponding parameters a, b and c and cubic term coefficients in the temperature fitting process;
n Q 、n P 、n C respectively representing the corresponding parameters a, b and c and the quadratic term coefficient in the temperature fitting process;
P Q 、P P 、P C respectively representing the corresponding parameters a, b and c and the first-order coefficient in the temperature fitting process;
w Q 、w P 、w C respectively representing the constant terms in the fitting process of the corresponding parameters a, b and c and the temperature.
TABLE 3
4. According to the formulas (13) - (15), specific values of a, b and c at any temperature in the range of 288-473K can be obtained by inputting the specific values, and the differential absorption cross section at the temperature can be obtained by substituting the specific values into a second fitting function of the differential absorption cross sections at different temperatures and 298K.
In summary, steps 1 to 4 of the fitting method for bi-inverting chlorobenzene concentration are a flow chart for constructing a fitting relationship between differential absorption cross sections at different temperatures and 298K shown in fig. 11.
The invention also compares and analyzes the experimental results of the two fitting methods, and the chlorobenzene concentration measurement results of the two fitting methods are compared by adopting 55ppm chlorobenzene under the temperature conditions of 318, 333, 383 and 473K in the experiment, and the specific comparison mode comprises two steps: first using a decision coefficient R 2 The correlation between the differential absorption cross section obtained by the experiment and the differential absorption cross sections of the two fitting methods at the corresponding temperature is measured, and then the accuracy of the chlorobenzene concentration obtained by inverting the differential absorption cross sections obtained by the two fitting methods is compared.
Coefficient of determination R for two fitting methods 2 For comparison, see table 4 below:
TABLE 4
As can be seen from Table 4, the differential absorption cross sections obtained by the two fitting methods are well consistent with experimental data, and the correlation coefficients are both above 0.99. The correlation coefficient of the fitting method II is slightly higher than that of the fitting method I, and the shape and the strength of the differential absorption cross section obtained by fitting of the fitting method II are more accurate.
The results and deviations from the inversion of chlorobenzene concentrations for both fitting methods are given in table 5 below and in fig. 12:
TABLE 5
As can be seen from table 5, the chlorobenzene concentration deviation obtained by applying the fitting method one for inversion is within 2.74%, and the concentration deviation obtained by applying the fitting method two is within 2.7%, which indicates that both further improve the accuracy of concentration inversion compared with the temperature compensation method. And the concentration calculation deviation of the two methods proves that the fitting method II is slightly superior to the fitting method I, the minimum deviation reaches 0.13 percent, and the effectiveness of the fitting method provided by the invention is proved.
In summary, the fitting method is to construct a fitting relationship (i.e., a first fitting function) according to the differential absorption cross sections of wavelength single points at different temperatures, since single-point measurement is susceptible to environmental interference and the like, and the fitting method is to construct a fitting relationship (i.e., a second fitting function) according to multiple wavelength points, so that uncertainty in measurement results can be effectively reduced, and signal-to-noise ratio can be improved. According to the second fitting method, the differential absorption cross section of the 201-220nm wave band at the continuous temperature of 288K-473K is drawn, and the drawing result is shown in FIG. 13.
In summary, the method for performing gas concentration inversion based on the fitted spectrum fast-changing absorption cross section provided by this embodiment is shown in fig. 16, and includes the steps of:
s1, constructing a fitting function of a differential absorption cross section with respect to temperature;
and S2, solving the temperature corresponding to the differential absorption cross section according to the fitting function to serve as the predicted temperature.
In the above scheme, the fitting method one or two is used to solve the differential absorption cross section of chlorobenzene, and then the chlorobenzene concentration corresponding to the differential absorption cross section is inverted based on beer-lambert law, and the measurement of the chlorobenzene temperature is still realized by the temperature controller or the additional temperature sensor shown in fig. 1. In order to realize the simultaneous measurement of the chlorobenzene concentration and the temperature, the invention also provides a chlorobenzene concentration and temperature synchronous measurement method based on the ultraviolet differential absorption spectrum.
In an experiment, after differential absorption cross sections at different temperatures are observed, the most obvious change characteristic of the differential absorption cross sections is that a differential absorption peak becomes lower along with the increase of the temperature, and after the differential absorption cross sections are normalized, the shapes of the cross sections at different temperatures are observed to be different, which shows that the temperature not only can change the size of the absorption cross sections, but also can cause the shapes of the absorption cross sections to generate characteristic difference. Based on the observed phenomenon, the method for synchronously measuring chlorobenzene concentration and temperature based on the ultraviolet differential absorption spectrum provided by the embodiment comprises the following steps:
1. the chlorobenzene differential absorption spectrum with unknown concentration and temperature information is obtained through experiments, and at the moment, because the temperature of the chlorobenzene differential absorption spectrum is unknown, the concentration cannot be calculated by adopting a differential absorption cross section corresponding to the temperature according to the Beer-Lambert law (the concentration calculation process refers to the formula (4) above).
2. The chlorobenzene differential absorption cross section at each wavelength point at the same temperature is normalized (please refer to fig. 14 for schematic diagram of normalized differential absorption cross section at different temperatures), and assuming that the differential absorption cross section at a certain wavelength is represented by Δ σ, the normalization method is as follows:
in the formula (22), Δ σ Normalization Represents the result of normalization on Δ σ;
i represents a differential absorption cross section corresponding to the ith wavelength point at a specified temperature and a specified concentration;
n represents the number of wavelength points selected in the wavelength band range of 201-220nm at a specified concentration and a specified temperature.
The chlorobenzene differential absorption spectrum of unknown concentration and temperature information obtained by experiments is normalized, and the normalization method comprises the following steps:
in the formula (17), Δ DOD Normalization Represents the normalized result for DOD;
i represents a differential absorption spectrum corresponding to the ith wavelength point under a specified temperature and a specified concentration;
n represents the number of wavelength points selected in the wavelength band range of 201-220nm at a specified concentration and a specified temperature. 3. The chlorobenzene differential absorption spectrum of the unknown concentration and temperature information after the experiment normalization is one by one connected with the chlorobenzene differential absorption cross section after the normalization by a decision coefficient R through a pre-programmed programming language 2 In contrast, the decision coefficient is a variable describing the correlation between the two, and if the decision coefficient is larger, the shape of the two is closer, and the specific calculation formula is shown in formula (18). Searching a standard differential absorption section with the maximum coefficient determined by experimental data, wherein the temperature corresponding to the standard differential absorption section is the predicted temperature;
determining the coefficient R 2 The calculation method of (c) is shown in the following formula (18):
in the formula (18), the first and second groups,
representing a fitted differential absorption cross section of the ith wavelength point of the 201-220nm wave band;
y i the experimental differential absorption cross section of the ith wavelength point of the 201-220nm wave band is shown;
4. And (3) synchronously measuring the corresponding chlorobenzene concentration of the differential absorption cross section corresponding to the predicted temperature according to the Beer-Lambert law.
In short, the data processing flow of synchronous measurement of chlorobenzene temperature and concentration is shown in fig. 15 and 17, and comprises the steps of:
l1, acquiring a differential absorption spectrum of chlorobenzene with unknown concentration and temperature information;
l2, calculating a differential absorption cross section corresponding to the differential absorption spectrum of chlorobenzene at each wavelength point in an experiment with known concentration and temperature;
l3, normalizing the experimental differential absorption cross section at the same temperature;
l4, determining coefficient R for the difference absorption spectrum of the normalized unknown concentration and temperature information and each difference absorption section after normalization 2 Comparing one by one, and finding out the decision coefficient R 2 The temperature corresponding to the differential absorption cross section corresponding to the maximum value of (a) is taken as the predicted temperature of chlorobenzene with unknown temperature in the step L1;
and L5, calculating the chlorobenzene concentration corresponding to the differential absorption cross section according to the beer-Lambert law for the differential absorption cross section corresponding to the predicted temperature.
In order to verify the feasibility of synchronous measurement of chlorobenzene temperature and concentration provided by the invention, two groups of experiments are respectively carried out: 1. measuring the temperature and the concentration of chlorobenzene with different concentrations at the same temperature; 2. chlorobenzene with different temperatures was measured simultaneously for temperature and concentration at the same concentration. The following tables 6 and 7 show the predicted results and deviations of the method for synchronously measuring chlorobenzene concentration and temperature based on differential absorption spectroscopy provided in this example at the same temperature and the same concentration, respectively:
TABLE 6
TABLE 7
Through two sets of experimental data in tables 6 and 7, the deviation of the temperature prediction is found to be within 1.89%, but part of the data of the concentration prediction is far from the actual concentration, and the deviation reaches 12.27%. The chlorobenzene concentration and temperature synchronous measurement method based on the differential absorption spectrum, provided by the invention, predicts the temperature according to the shape of the differential absorption structure, then solves the concentration through the temperature and the differential absorption spectrum, and has the advantages that the temperature prediction result deviation is lower and the corresponding concentration prediction result deviation is also lower according to the influence rule of the temperature on the differential absorption spectrum. In the experiment, because of external factors such as instrument resolution and the like, certain instrument errors exist, so that large errors may occur in the concentration prediction process, but generally, the method realizes the simultaneous measurement of the temperature and the concentration of the chlorobenzene.
In conclusion, aiming at the problem that the temperature influences the gas absorption spectrum, so that the measured concentration is inaccurate, the invention takes the differential absorption characteristic of chlorobenzene with the waveband of ultraviolet 201-220nm as an object, and researches the condition that the differential absorption cross section of the chlorobenzene changes along with the temperature within the temperature range of 288K-473K. A calculation method of chlorobenzene differential absorption cross section under continuous temperature is established, a temperature and concentration synchronous inversion method based on differential absorption spectrum is obtained, and the following beneficial effects are mainly achieved:
1. with the change of temperature, the differential absorption spectrum of chlorobenzene not only shows the change of amplitude, but also shows the difference in the shape. In order to further understand the spectral absorption characteristics of chlorobenzene, the invention calculates important spectral parameters, namely differential absorption cross sections, at different temperatures, constructs a binary function of the differential absorption cross sections with respect to temperature and wavelength, and performs dimension reduction fitting on the binary function under the condition of fixed temperature and wavelength respectively, thereby obtaining the differential absorption cross sections of chlorobenzene at continuous temperature under a target detection waveband. The two fitting methods provided show that the error of the fitting method with a single wavelength point is relatively large, because the spectrum acquisition of the single point is easily influenced by the fluctuation of an instrument, but both the two fitting methods realize that the concentration inversion error is within 2.74 percent, and have high consistency with the shape of a differential absorption cross section obtained in an experiment.
1. In consideration of the temperature specificity of the differential absorption section, the invention creatively provides a method for simultaneously measuring the temperature and the concentration, and the measurement deviation of the method on the temperature is within 1.89%. Due to the spectral resolution of the instrument and other reasons, partial deviation of a concentration inversion result is large, but the method can basically realize synchronous measurement of temperature and concentration, and provides a new idea for the field of simultaneous measurement of temperature and concentration by using differential absorption spectroscopy.
It should be understood that the above-described embodiments are merely preferred embodiments of the invention and the technical principles applied thereto. Various modifications, equivalent substitutions, changes, etc., will also be apparent to those skilled in the art. However, such variations are within the scope of the invention as long as they do not depart from the spirit of the invention. In addition, certain terms used in the specification and claims of the present application are not limiting, but are used merely for convenience of description.
Claims (9)
1. A gas temperature and concentration synchronous measurement method based on a spectrum fast-slow separation principle is characterized by comprising the following steps:
l1, acquiring a differential absorption spectrum of chlorobenzene with unknown concentration and temperature information and performing normalization treatment;
l2, calculating a differential absorption cross section corresponding to the differential absorption spectrum of the chlorobenzene at each wavelength point with known concentration and temperature in the experiment;
l3, normalizing the differential absorption cross sections at different temperatures in the experiment;
l4, determining coefficient R for the differential absorption spectrum of the normalized unknown concentration and temperature information and each normalized differential absorption section 2 Comparing one by one, and finding out the decision coefficient R 2 The temperature corresponding to the differential absorption cross section corresponding to the maximum value of (a) is taken as the predicted temperature of the chlorobenzene at the unknown temperature in the step L1;
and L5, calculating the chlorobenzene concentration corresponding to the differential absorption cross section for the differential absorption cross section corresponding to the predicted temperature according to the beer-Lambert law.
2. The method for synchronously measuring the temperature and the concentration of the gas based on the spectrum fast-slow separation principle according to claim 1, wherein in the step L2, the method for calculating the differential absorption cross section corresponding to the differential absorption spectrum is expressed by the following formula (5):
in the formula (1), Δ σ (λ) represents a differential absorption cross section obtained by incidence of light having a wavelength λ into chlorobenzene gas;
n represents chlorobenzene number density;
l represents an absorption optical path length;
DOD represents the differential absorption spectrum.
3. The method for synchronously measuring the temperature and the concentration of a gas based on the spectrum fast-slow separation principle in claim 1, wherein in the step L3, the method for normalizing the differential absorption cross section of each wavelength point at the same temperature is expressed by the following formula (2):
in the formula (2), Δ σ Normalization Represents the result of normalization on Δ σ;
i represents a differential absorption cross section corresponding to the ith wavelength point at a specified temperature and a specified concentration;
n represents the number of wavelength points selected in the wavelength band range of 201-220nm at a specified concentration and a specified temperature.
4. The method for synchronously measuring the gas temperature and the concentration based on the spectrum fast-slow separation principle of claim 2, wherein the method for normalizing the differential absorption spectrum of chlorobenzene comprises the following steps:
ΔDOD Normalization represents the normalized result for DOD;
DOD i and the differential absorption spectrum corresponding to the ith wavelength point at the specified concentration at the specified temperature is represented.
5. The method for synchronously measuring chlorobenzene concentration and temperature based on differential absorption spectrum according to claim 1, wherein in step L4, the method for obtaining the predicted temperature corresponding to the differential absorption cross section comprises the steps of:
s1, constructing a fitting function of a differential absorption cross section with respect to temperature;
and S2, solving the temperature corresponding to the differential absorption cross section according to the fitting function to serve as the predicted temperature.
6. The method for synchronously measuring gas temperature and concentration based on the spectrum fast-slow separation principle according to claim 5, characterized in that the fitting function constructed in step S1 is a first fitting function representing the relationship between the chlorobenzene differential absorption cross section and the temperature at each wavelength point, and the first fitting function is expressed by the following formula (1):
in the formula (3), Δ σ represents the chlorobenzene differential absorption cross section;
t represents a temperature;
a. b and c represent term coefficients, and d is a constant;
λ 1 representing a particular said wavelength point;
f represents the first fitting function.
7. The method for synchronously measuring the temperature and the concentration of the gas based on the spectrum fast-slow separation principle of claim 6, characterized in that λ 1 A =2.99 × 10 when =201.24nm -25 ，b＝-3.70×10 -22 ，c＝1.43×10 -19 ，d＝-1.55×10 -17 。
8. The method for synchronously measuring the temperature and the concentration of the gas based on the spectrum fast-slow separation principle according to claim 5, wherein the constructed fitting function is a second fitting function which characterizes the relationship between the chlorobenzene differential absorption cross section and the wavelength of each temperature point, and the second fitting function is expressed by the following formula (4):
in the formula (4), T 1 Represents a specific said temperature point;
λ represents a wavelength;
Δσ 298K the chlorobenzene differential absorption cross section representing the position of a lambda wavelength point at a temperature of 298K;
a represents the temperature T 1 Coefficients of the second fitting function fitted to the 298K differential absorption cross-section,
b represents the temperature T 1 The first order coefficient of the second fitting function fitted to the 298K differential absorption cross-section,
c represents the temperature T 1 A constant term of the second fitting function fitted to the 298K differential absorption cross-section,
m Q 、m P 、m C respectively representing the corresponding parameters a, b and c and cubic term coefficients in the temperature fitting process;
n Q 、n P 、n C respectively representing the corresponding parameters a, b and c and quadratic term coefficients in the temperature fitting process;
P Q 、P P 、P C respectively representing the corresponding parameters a, b and c and the first-order coefficient in the temperature fitting process;
w Q 、w P 、w C respectively representing the constant terms in the fitting process of the corresponding parameters a, b and c and the temperature.
9. The method for synchronously measuring the gas temperature and the concentration based on the spectrum fast-slow separation principle of claim 5, wherein when the fitting function is constructed, the light incident into the chlorobenzene gas is ultraviolet light with the wavelength of 201nm-220 nm.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116663433A (en) * | 2023-07-31 | 2023-08-29 | 山东科技大学 | Differential optimization algorithm based on differential absorption spectrometer |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009243968A (en) * | 2008-03-28 | 2009-10-22 | Toyota Motor Corp | Exhaust gas analyzer and analyzing method |
| JP2011122886A (en) * | 2009-12-09 | 2011-06-23 | Mitsubishi Heavy Ind Ltd | Temperature measuring device and temperature measuring method |
| CN102435567A (en) * | 2011-11-22 | 2012-05-02 | 杭州微兰科技有限公司 | Method for measuring gas component concentration in inverse calculation mode based on differential optical absorption spectrum |
| CN105548057A (en) * | 2016-01-12 | 2016-05-04 | 中绿环保科技股份有限公司 | Flue gas analysis and measurement method implemented through ultraviolet spectrum |
| CN106969800A (en) * | 2017-05-03 | 2017-07-21 | 东南大学 | The apparatus and method that a kind of utilization single spectral line measures gas temperature and concentration simultaneously |
| CN107271392A (en) * | 2017-06-12 | 2017-10-20 | 重庆大学 | One kind is based on gas differential absorption cross-section pattern measurement low concentration SO2Method |
| CN107796777A (en) * | 2017-10-20 | 2018-03-13 | 西安思坦科技有限公司 | A kind of data processing method of low concentration ultraviolet difference gas analyzer |
| US20200240910A1 (en) * | 2018-09-03 | 2020-07-30 | Shimadzu Corporation | Gas absorption spectroscopic device and gas absorption spectroscopic method |
| CN112666104A (en) * | 2020-12-29 | 2021-04-16 | 西安鼎研科技股份有限公司 | DOAS-based gas concentration inversion method |
| CN113310922A (en) * | 2020-02-27 | 2021-08-27 | 大唐环境产业集团股份有限公司 | NO concentration measuring system based on ultraviolet differential absorption spectrum and concentration calculating method |
-
2022
- 2022-10-15 CN CN202211262862.2A patent/CN115523958A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009243968A (en) * | 2008-03-28 | 2009-10-22 | Toyota Motor Corp | Exhaust gas analyzer and analyzing method |
| JP2011122886A (en) * | 2009-12-09 | 2011-06-23 | Mitsubishi Heavy Ind Ltd | Temperature measuring device and temperature measuring method |
| CN102435567A (en) * | 2011-11-22 | 2012-05-02 | 杭州微兰科技有限公司 | Method for measuring gas component concentration in inverse calculation mode based on differential optical absorption spectrum |
| CN105548057A (en) * | 2016-01-12 | 2016-05-04 | 中绿环保科技股份有限公司 | Flue gas analysis and measurement method implemented through ultraviolet spectrum |
| CN106969800A (en) * | 2017-05-03 | 2017-07-21 | 东南大学 | The apparatus and method that a kind of utilization single spectral line measures gas temperature and concentration simultaneously |
| CN107271392A (en) * | 2017-06-12 | 2017-10-20 | 重庆大学 | One kind is based on gas differential absorption cross-section pattern measurement low concentration SO2Method |
| CN107796777A (en) * | 2017-10-20 | 2018-03-13 | 西安思坦科技有限公司 | A kind of data processing method of low concentration ultraviolet difference gas analyzer |
| US20200240910A1 (en) * | 2018-09-03 | 2020-07-30 | Shimadzu Corporation | Gas absorption spectroscopic device and gas absorption spectroscopic method |
| CN113310922A (en) * | 2020-02-27 | 2021-08-27 | 大唐环境产业集团股份有限公司 | NO concentration measuring system based on ultraviolet differential absorption spectrum and concentration calculating method |
| CN112666104A (en) * | 2020-12-29 | 2021-04-16 | 西安鼎研科技股份有限公司 | DOAS-based gas concentration inversion method |
Non-Patent Citations (2)
| Title |
|---|
| 吕传明等: "DOAS烟气测量系统的温度非线性补偿方法", 光谱实验室, vol. 30, no. 5, pages 2572 - 2576 * |
| 张学典: "差分吸收光谱技术在环境监测中的理论和应用研究", 中国博士学位论文全文数据库工程科技I 辑, no. 04, pages 44 - 47 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116663433A (en) * | 2023-07-31 | 2023-08-29 | 山东科技大学 | Differential optimization algorithm based on differential absorption spectrometer |
| CN116663433B (en) * | 2023-07-31 | 2023-10-24 | 山东科技大学 | Differential optimization method based on differential absorption spectrometer |
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