CN115452768A - Turbulent combustion field three-dimensional temperature, gas concentration and particle concentration distribution measuring system - Google Patents
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Abstract
The invention discloses a turbulent combustion field three-dimensional temperature, gas concentration and particle concentration distribution measuring system, which comprises: h 2 O laser, emitting two H beams 2 O molecule infrared absorption spectrum line; CO 2 2 Laser, emitting CO 2 Molecular infrared absorption lines; the beam splitter divides the absorption spectral line into a plurality of laser beams which are distributed in a grid manner in the combustion field to be measured; the photoelectric detector is arranged around the combustion field to be detected and used for receiving the laser beam; the moving platform drives the beam splitter and the photoelectric detector to move; the upper computer system obtains the temperature and CO of each grid in the two-dimensional plane in an algebraic iteration mode 2 Gas concentration and particle concentration; then, three-dimensional temperature and CO of the combustion field to be measured are obtained through reconstruction of a plurality of two-dimensional planes 2 Gas concentrationDegree and particle concentration. The invention is used for three-dimensional temperature and CO of turbulent combustion field 2 The gas concentration and the particle concentration are simultaneously reconstructed on line, and the method has the advantages of non-invasion, quick response, high sensitivity and the like.
Description
Technical Field
The invention relates to the field of combustion field measurement, in particular to a turbulent combustion field three-dimensional temperature, gas concentration and particle concentration distribution measuring system.
Background
The combustion of fossil fuels is the leading form of energy utilization in the world today, supporting both industrial operation and social development in human society. In practical combustion plants, turbulent combustion is the predominant form of combustion. Due to the complexity of turbulent combustion fields, the temperature, gas composition and soot concentration etc. in the combustion flame are not uniformly distributed in space, and the distribution of these key physical parameters, chemical product concentrations, etc. have an impact on the energy conversion efficiency and safety in the combustion process. Meanwhile, pollutants such as carbon smoke particles and the like generated by incomplete combustion can cause serious environmental problems and threaten the safety and health of human beings.
In order to control the emission of soot pollutants during turbulent combustion, a sufficient understanding of the mechanism of their generation is required. Temperature, CO in the flame 2 The concentration and the like have great influence on the generation of soot, but the specific action mechanism of the soot is still greatly controversial at present. In addition, the temperature of the turbulent combustion field, CO, which is one of the important products of the combustion process 2 The concentration is also of great importance for basic research on combustion reactions. These theoretical studies on turbulent combustion science all require the related art to accurately measure the temperature of the flame, the gas component concentration, and the three-dimensional distribution of soot concentration on-line.
Chinese patent CN 111141524A designs a combustion field gas parameter measuring device based on a tunable semiconductor laser absorption spectrum technology, arranges a fan-shaped light beam to cover a reconstruction area, and only realizes two-dimensional reconstruction of single gas in a combustion flow field.
Chinese patent CN 113310857A designs a system, which adopts chromatography laser to induce incandescent light method to measure the carbon smoke particle primary particle size spatial distribution of combustion field, and adopts emission spectrum chromatography colorimetric thermometry system to measure turbulent flame temperature field. However, when measuring particulate concentration using laser-induced incandescent light methods, a standard flame of known soot particulate concentration needs to be first measured and calibrated, adding complexity to the system and operation. In addition, the system does not enable measurement of the combustion gas product concentration field.
Therefore, how to realize the simultaneous temperature and CO of turbulent combustion field 2 Three-dimensional distribution measurement of multiple parameters such as gas concentration and particle concentrationThe method has important significance in the aspects of basic research of combustion science, improvement of combustion efficiency, control of pollutant emission and the like.
Disclosure of Invention
In order to solve at least one technical problem mentioned in the background, the invention aims to provide a system for measuring three-dimensional temperature, gas concentration and particle concentration distribution of a turbulent combustion field, which is used for measuring three-dimensional temperature, CO and CO of the turbulent combustion field 2 The gas concentration and the particle concentration are simultaneously reconstructed on line, and the method has the advantages of non-invasion, quick response, high sensitivity and the like.
In order to achieve the purpose, the invention provides the following technical scheme: turbulent combustion field three-dimensional temperature, gas concentration, granule concentration distribution measurement system includes:
H 2 o laser for emitting two H beams 2 O molecule infrared absorption spectrum line;
CO 2 laser for emitting CO 2 Molecular infrared absorption lines;
beam splitter, let H 2 O molecule infrared absorption spectrum line or CO 2 The molecular infrared absorption spectral lines are respectively divided into a plurality of laser beams which are distributed in a grid manner in a certain two-dimensional plane of a combustion field to be measured;
the photoelectric detector is arranged around the combustion field to be detected and used for receiving the laser beam;
the moving platform drives the beam splitter and the photoelectric detector to move along the direction vertical to the two-dimensional plane;
the upper computer system is used for solving the temperature and CO on each laser beam in a two-dimensional plane 2 The gas concentration and the particle concentration are obtained by means of algebraic iteration to obtain the temperature and CO of each grid in a two-dimensional plane 2 Gas concentration and particle concentration; then, three-dimensional temperature and CO of the combustion field to be measured are obtained through reconstruction of a plurality of two-dimensional planes 2 Gas concentration and particle concentration.
Further, the solving process of the temperature is as follows:
and (3) establishing a relation between the spectral line intensity and the temperature:
where k is Boltzmann 'S constant, h is Planckian' S constant, c is the speed of light, S (T) 0 ) Indicating the gas absorption line at a reference temperature T 0 Line intensity at E' represents transition frequency v 0 The transition energy of the low state, Q (T) represents the partition function of the absorption gas at the temperature T, Q (T) 0 ) Indicating the absorption gas at a reference temperature T 0 A lower partition function;
the partition function is:
Q(T)＝a+bT+cT 2 +dT 3
wherein a, b, c and d are third-order polynomial coefficients of a partition function;
scanning two lines H 2 O molecule infrared absorption line v 1 And v 2 Then, the temperature can be found:
wherein, S (T) v1 Is H 2 V of O 1 Line intensity of absorption lines at temperature T, S (T) v2 Is H 2 V of O 2 Line intensity of absorption line at temperature T, S (T) 0 ) v1 Is H 2 V of O 1 Absorption line at reference temperature T 0 Line intensity at, S (T) 0 ) v2 Is H 2 V of O 2 Absorption line at reference temperature T 0 The line intensity of (b).
Further, said CO 2 The solution process for the gas concentration is as follows:
constructing a ray projection intensity formula:
wherein, I 0 Denotes the incident laser intensity, I t Indicating the emitted laserIntensity, L denotes the optical path, α abs Denotes the gas absorption coefficient,. Kappa. ext Denotes the extinction coefficient of the particles, E flame Indicating flame radiation intensity, P air pressure, X abs Which is indicative of the concentration of the absorbing gas,
a linear function representing the gas absorption line, S (T) representing the line intensity of the gas absorption line at a temperature T; linear function
The integral value over the entire spectral range is 1.
Further, the solving process of the particle concentration is as follows:
wherein, f v Is the particle concentration; λ is the laser incident wavelength, and m is the negative refractive index; kappa abs Is the absorption coefficient of the particles.
Further, the algebraic iterative process of the gas absorption coefficient is as follows:
the optical path length of the jth beam through the ith grid is denoted as L i，j Solving equation A = ∑ α abs L, then the projection absorbance A of the jth light beam passing through the whole area to be measured vm，j Expressed as:
wherein the subscript vm denotes a wavelength v m A beam of (a) i Represents the absorbance per unit length within a single grid, and in the iterative algorithm, the absorbance per unit length within each grid of the kth iteration is represented as:
the iteration process passes through two adjacent iteration processes alpha vm，i Stops when the difference of (d) is less than epsilon, and is expressed as the following formula;
further, a time division multiplexer is arranged in front of the beam splitter, and the time division multiplexer alternately outputs the H in time sequence 2 Infrared absorption line of O molecule and CO 2 Molecular infrared absorption lines.
Furthermore, the output end of the beam splitter is provided with a laser collimator, and the laser collimator is used for collimating the split laser beam.
Further, a heat insulation sleeve is arranged outside the photoelectric detector and/or the laser collimator.
Furthermore, the upper computer system comprises a data acquisition card and a computer.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a new method for simultaneously measuring and separating the molecular absorption coefficient and the soot extinction coefficient when simultaneously considering the absorption effect of gas molecules, the soot extinction effect and the flame background radiation in a turbulent combustion field to jointly act on a laser signal based on the molecular absorption spectrum; then, an algebraic iterative reconstruction algorithm is adopted to finally obtain the temperature and CO 2 The three-dimensional distribution of the gas concentration and the particle concentration has the advantages of non-invasion, quick response, high sensitivity and the like.
Drawings
FIG. 1 is an overall schematic block diagram of an embodiment of the present invention.
Fig. 2 is a signal diagram of two signal generators of the present invention in one cycle.
Fig. 3 is a flow chart of an embodiment of the invention.
In the figure: 1. h 2 An O laser; 1a, a first signal generator; 2. CO 2 2 A laser; 2a, a second signal generator; 3. a beam combiner; 4. time division multiplexingA machine; 5. a beam splitter; 6. a laser collimator; 7. a first heat insulating sleeve; 8. a photodetector; 9. a second heat insulating sleeve; 10. a signal amplification integration device; 11. a data acquisition card; 12. and (4) a computer.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, the present embodiment provides a system for measuring three-dimensional temperature, gas concentration, and particle concentration distribution of a turbulent combustion field. The method comprises the following steps: the device comprises a laser system, a transmitting and receiving measurement system, a signal detection and acquisition system and a three-dimensional mobile platform.
Specifically, the laser system includes: first 1a and second 2a, H signal generators 2 O laser 1 (for H) 2 Distributed feedback type tunable semiconductor laser with O detection working at 1398.3 nm), CO 2 Laser 2 (for CO) 2 A distributed feedback type tunable semiconductor laser working at 2001.6nm for detection), a beam combiner 3, a time division multiplexer 4 and a beam splitter 5; the beam splitter 5 is H 2 O molecule infrared absorption spectrum line or CO 2 The molecule infrared absorption spectrum lines are respectively divided into a plurality of laser beams which are distributed in a grid manner in a certain two-dimensional plane of the combustion field to be measured.
The transmission-reception measurement system includes: the device comprises a laser collimator 6, a first heat insulation sleeve 7, a combustion field S to be measured, a photoelectric detector 8 and a second heat insulation sleeve 9. The first thermal insulation sleeve 7 and the second thermal insulation sleeve 9 are used for reducing the radiation influence of the turbulent combustion field to be measured.
The signal detection and acquisition system comprises: the device comprises a signal amplification integrated device 10 and an upper computer system; the upper computer system comprises a data acquisition card 11 and a computer 12.
The three-dimensional mobile platform includes: and the moving platform drives the beam splitter and the photoelectric detector to move along the direction vertical to the two-dimensional plane.
When the laser controller works, the first signal generator 1a generates a section of sawtooth wave signal and a section of square wave signal in one period, the signals are superposed on the laser controller A, and the superposition of the sawtooth wave signal enables H 2 The O laser 1 (1398.3 nm) continuously scans in a narrow band range, and the corresponding driving current is lower than the laser threshold current after the square wave signal is superimposed, so that the laser does not output a signal in this section, that is, the laser output signal is 0. Laser controller drive H of superimposed sawtooth wave signal 2 O laser (1398.3 nm) capable of scanning two H beams simultaneously 2 O molecule infrared absorption line.
The second signal generator 2a generates a sawtooth wave signal and a square wave signal in one cycle, and superimposes the signals on the laser controller B, and the superposition of the sawtooth wave signal causes CO 2 The laser 2 (2001.6 nm) scans continuously in a narrow band range, and the corresponding driving current is lower than the threshold current of the laser after the square wave signal is superposed, so that the laser does not output a signal in the narrow band range, namely the output signal of the laser is 0. Laser controller driving CO by overlapping sawtooth wave signals 2 Laser (2001.6 nm) capable of scanning a single CO line 2 Molecular infrared absorption line for CO 2 The concentration measurement, the signals of the two signal generators during one cycle are shown in fig. 2.
After the two laser beams are output through the tail fibers, the two laser beams are combined through the beam combiner 3, then pass through the time division multiplexer 4, and finally are equally divided into 18 paths through the beam splitter 5. Wherein, 9 paths of light beams are collimated by the laser collimator 6 on the right side of the combustion field S to be measured, and 9 paths of light beams are collimated by the laser collimator 6 on the lower side of the combustion field S to be measured. After passing through the flow field area together, 18 light beams are received by 18 photodetectors 8 respectively.
The signal detected by the photodetector 8 is further amplified by the signal amplification integrated device 10, the multi-signal amplification integrated device 10 comprises a first-stage trans-impedance amplifier and a second-stage signal amplifier, and the final signal amplification is realized by adjusting the resistance values of the two stages of amplifiers. The data acquisition card synchronously acquires the amplified signals and then transmits the signals to the computer for data processing of the acquired signals.
Before the combustion field S to be measured runs, the data acquisition card can obtain a laser background signal. After the burner to be tested is ignited, the data acquisition card can simultaneously acquire H in one period 2 O molecule absorption signal, CO 2 Molecular absorption signal, particle absorption signal, and flame background radiation signal. The data of the acquisition card is transmitted to a computer to separate the molecular absorption coefficient and the soot extinction coefficient, and H of each light path can be obtained simultaneously 2 Absorbance of O molecule, CO 2 Molecular absorbance and soot extinction.
Dividing the two-dimensional area of each layer of the combustor to be tested into 81 grids of 9 multiplied by 9, and according to the H of each light path 2 Absorbance of O molecule, CO 2 Molecular absorbance and soot extinction degree, and obtaining combustion field temperature distribution and CO by adopting an algebraic iteration method 2 Solving the two-dimensional distribution of gas concentration distribution and carbon smoke particle concentration, reconstructing 9 layers of two-dimensional areas by the movement of the moving platform along the third dimension direction, and establishing the temperature distribution and CO in a space coordinate system of 729 grids of 9 multiplied by 9 2 Gas concentration distribution and carbon smoke particle concentration distribution, thereby realizing three-dimensional temperature and CO of turbulent combustion field 2 The flow chart of the on-line measurement and multi-parameter three-dimensional measurement system for the gas concentration and the particle concentration is shown in figure 3.
Ray cast intensity formula:
in the formula I 0 Denotes the incident laser intensity, I t Denotes the intensity of the emitted laser light, L denotes the optical path length, α abs Denotes the gas absorption coefficient, κ ext Denotes the extinction coefficient of the particles, E flame Indicating flame radiation intensity, P pressure, X abs Which is indicative of the concentration of the absorbing gas,
represents a linear function of the gas absorption line, and S (T) represents the line intensity of the gas absorption line at temperature T. Wherein the line type letterNumber of
Integral value of 1 over the whole spectral range, line intensity S T Only with respect to temperature, line position, can be expressed as:
where k is Boltzmann 'S constant, h is Planckian' S constant, c is the speed of light, S (T) 0 ) Indicating the gas absorption line at a reference temperature T 0 Line intensity at, E' represents transition frequency v 0 At a low state transition energy, Q (T) representing the partition function of the absorption gas at a temperature T, Q (T) 0 ) Indicating that the absorption gas is at the reference temperature T 0 The following partition functions. The partition function can be reduced to a third order polynomial over temperature, expressed as:
Q(T)＝a+bT+cT 2 +dT 3
for H 2 O molecules and CO 2 The third-order polynomial coefficients of the partition functions of the molecules in the low temperature range of 70-500K, the medium temperature range of 500-1500K and the high temperature range of 1500-3005K are respectively shown in Table 1.1 and Table 2.2.
TABLE 1.1H 2 Third-order polynomial coefficient of partition function of O molecule at different temperatures
TABLE 2.1 CO 2 Third order polynomial coefficients of partition functions at different temperatures of molecules
Measuring temperature according to a bilinear method, scanning H 2 V of O 1 、v 2 For both absorption lines, the temperature can be determined as:
S(T) v1 is H 2 V of O 1 Line intensity of absorption lines at temperature T, S (T) v2 Is H 2 V of O 2 Line intensity of absorption line at temperature T, S (T) 0 ) v1 Is H 2 V of O 1 Absorption line at reference temperature T 0 Line intensity at, S (T) 0 ) v2 Is H 2 V of O 2 Absorption line at reference temperature T 0 The line intensity of (b).
From the Rayleigh assumption, the extinction coefficient κ is calculated ext Only the absorption effect of the particles is considered, and the influence of scattering, reflection and the like on the laser intensity is ignored, namely, the extinction coefficient kappa of the particles is assumed ext ≈κ abs ，κ abs Is the absorption coefficient of the particles. Particle concentration f v Can be expressed as:
in the formula, λ is the laser incident wavelength, and m is the negative refractive index.
Due to the selectivity of gas absorption, it is only present in a narrow wavelength range within the laser wavelength scan range, whereas particle extinction is common throughout the entire laser wavelength scan range. In addition, the flame radiation signature is an inherent property of the flame, independent of whether there is laser output. Therefore, when the output signal of the laser is 0, the measured signal is the flame radiation intensity; when the laser outputs a signal normally and superposes a sawtooth wave signal, the gas absorption signal and the extinction signal of the particles are detected simultaneously and are effectively separated.
To implement the three-dimensional solution, the three-dimensional space is first divided into 9 two-dimensional spaces along the third dimension direction, and each two-dimensional space is separately solved. In each two-dimensional space, the space is divided into 9 multiplied by 9 grids, and each physical parameter in each grid is assumedThe numbers are the same. Solving equation A =sigmaalpha by algebraic iteration method abs L and K = ∑ κ abs L, obtaining alpha in each grid abs And kappa abs From α within each cell abs The temperature and gas concentration in each grid is then derived from the κ in each grid abs And then the particle concentration in each grid is obtained.
The two-dimensional area is divided into N × N grids, and it is assumed that physical parameters such as pressure, temperature, concentration, and the like of gas in each grid are the same. The optical path of the jth beam through the ith grid is denoted as L i，j Solving equation A = ∑ α abs L, then the projection absorbance A of the jth light beam passing through the whole area to be measured vm，j Can be expressed as:
wherein the subscript vm denotes a wavelength v m A light beam of i Represents the absorbance per unit length within a single grid. In the iterative algorithm, the absorbance per unit length within each grid of the kth iteration may be expressed as:
the iteration process passes through two adjacent iteration processes alpha vm，i Is less than epsilon < s > stop, expressed as the following formula, the iteration stop criterion chosen here is epsilon =1.0 × 10 -10 。
Solving for K = ∑ κ abs Process and solving equation a = ∑ α of L abs The L procedure is similar as follows: .
The iteration process passes through two adjacent iteration processes alpha vm，i Is less than epsilon stop, expressed as the following equation, the iteration stop criterion chosen here is epsilon =1.0 × 10 -10 。
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (9)
1. Turbulent combustion field three-dimensional temperature, gas concentration, granule concentration distribution measurement system, its characterized in that includes:
H 2 o laser for emitting two H beams 2 O molecule infrared absorption spectrum line;
CO 2 laser for emitting CO 2 Molecular infrared absorption lines;
beam splitter, let H 2 O molecule infrared absorption spectrum line or CO 2 The molecular infrared absorption spectral lines are respectively divided into a plurality of paths of laser beams which are distributed in a grid manner in a certain two-dimensional plane of a combustion field to be measured;
the photoelectric detector is arranged around the combustion field to be detected and used for receiving the laser beam;
the moving platform drives the beam splitter and the photoelectric detector to move along the direction vertical to the two-dimensional plane;
the upper computer system is used for solving the temperature and CO on each laser beam in a two-dimensional plane 2 The gas concentration and the particle concentration are obtained by means of algebraic iteration to obtain the temperature and CO of each grid in a two-dimensional plane 2 Gas concentration and particle concentration; then, three-dimensional temperature and CO of the combustion field to be measured are obtained through reconstruction of a plurality of two-dimensional planes 2 Gas concentration and particle concentration.
2. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 1, wherein the temperature solution is as follows:
and (3) establishing a relation between the spectral line intensity and the temperature:
where k is Boltzmann 'S constant, h is Planckian' S constant, c is the speed of light, S (T) 0 ) Indicating the gas absorption line at a reference temperature T 0 Line intensity at E' represents transition frequency v 0 The transition energy of the low state, Q (T) represents the partition function of the absorption gas at the temperature T, Q (T) 0 ) Indicating the absorption gas at a reference temperature T 0 A lower partition function;
the partition function is:
Q(T)＝a+bT+cT 2 +dT 3
wherein a, b, c and d are third-order polynomial coefficients of a partition function;
scanning two lines H 2 O molecule infrared absorption line v 1 And v 2 Then, the temperature can be found:
wherein, S (T) v1 Is H 2 V of O 1 Line intensity of absorption lines at temperature T, S (T) v2 Is H 2 V of O 2 Line intensity of absorption line at temperature T, S (T) 0 ) v1 Is H 2 V of O 1 Absorption line at reference temperature T 0 Line intensity at, S (T) 0 ) v2 Is H 2 V of O 2 Absorption line at reference temperature T 0 The line intensity below.
3. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 2, wherein the CO 2 The solution process for the gas concentration is as follows:
constructing a ray projection intensity formula:
wherein, I 0 Denotes the incident laser intensity, I t Indicating the intensity of the emitted laser light, L the optical path, alpha abs Denotes the gas absorption coefficient,. Kappa. ext Denotes the extinction coefficient of the particles, E f1ame Indicating flame radiation intensity, P air pressure, X abs Which is indicative of the concentration of the absorbing gas,
a linear function representing the gas absorption line, S (T) representing the line intensity of the gas absorption line at a temperature T; linear function of
The integral value over the entire spectral range is 1.
4. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 3, wherein the particle concentration is solved as follows:
wherein f is v Is the particle concentration; λ is the laser incident wavelength, and m is the negative refractive index; kappa abs Is the absorption coefficient of the particles.
5. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 3, wherein the algebraic iterative process of gas absorption coefficients is as follows:
the optical path length of the jth beam through the ith grid is denoted as L i,j Solving equation A = ∑ α abs L, then the projection absorbance A of the jth light beam passing through the whole area to be measured vm,j Expressed as:
wherein the subscript vm denotes a wavelength v m A beam of (a) i Represents the absorbance per unit length within a single grid, and in the iterative algorithm, the absorbance per unit length within each grid of the kth iteration is represented as:
the iterative process passes through two adjacent iterative processes alpha vm,i Stops when the difference of (d) is less than epsilon, and is expressed as the following formula;
6. the turbulent combustion field three-dimensional temperature, gas concentration and particle concentration distribution measuring system according to claim 1, wherein a time division multiplexer is arranged in front of the beam splitter and alternately outputs the H in time sequence 2 Infrared absorption line of O molecule and CO 2 Molecular infrared absorption lines.
7. The turbulent combustion field three-dimensional temperature, gas concentration and particle concentration distribution measuring system as recited in claim 1, wherein the output end of the beam splitter is provided with a laser collimator for collimating the split laser beam.
8. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 7, wherein the photodetector and/or laser collimator is externally provided with a thermal insulating sleeve.
9. The turbulent combustion field three-dimensional temperature, gas concentration, particle concentration distribution measurement system of claim 1, wherein the upper computer system comprises a data acquisition card and a computer.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117091637A (en) * | 2023-10-16 | 2023-11-21 | 西北工业大学 | Gas detection system and method based on dual-optical frequency comb |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103557886A (en) * | 2013-10-29 | 2014-02-05 | 东南大学 | Method for simultaneously measuring distribution of high-temperature gas two-dimensional transient temperature field and concentration field based on hyper spectrum |
| CN109270013A (en) * | 2018-11-28 | 2019-01-25 | 润电能源科学技术有限公司 | Multidimensional burning gas temperature and multicomponent concentration measuring method and system in a kind of furnace |
| CN111175049A (en) * | 2020-01-20 | 2020-05-19 | 中国科学院力学研究所 | Diagnosis system and method for multidimensional temperature and concentration field of engine combustion chamber |
| CN111239075A (en) * | 2020-02-18 | 2020-06-05 | 华东师范大学重庆研究院 | Combustion field gas temperature and multi-component concentration measuring system based on self-adaptive optical fiber optical comb |
| CN113217942A (en) * | 2021-05-06 | 2021-08-06 | 浙江大学 | Hyperspectral image-based dynamic flame measurement method and device |
| CN114166515A (en) * | 2021-12-02 | 2022-03-11 | 哈尔滨工业大学 | Device and method for realizing SLIPI-3DLIF measurement of engine combustion chamber |
-
2022
- 2022-09-19 CN CN202211139162.4A patent/CN115452768A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103557886A (en) * | 2013-10-29 | 2014-02-05 | 东南大学 | Method for simultaneously measuring distribution of high-temperature gas two-dimensional transient temperature field and concentration field based on hyper spectrum |
| CN109270013A (en) * | 2018-11-28 | 2019-01-25 | 润电能源科学技术有限公司 | Multidimensional burning gas temperature and multicomponent concentration measuring method and system in a kind of furnace |
| CN111175049A (en) * | 2020-01-20 | 2020-05-19 | 中国科学院力学研究所 | Diagnosis system and method for multidimensional temperature and concentration field of engine combustion chamber |
| CN111239075A (en) * | 2020-02-18 | 2020-06-05 | 华东师范大学重庆研究院 | Combustion field gas temperature and multi-component concentration measuring system based on self-adaptive optical fiber optical comb |
| CN113217942A (en) * | 2021-05-06 | 2021-08-06 | 浙江大学 | Hyperspectral image-based dynamic flame measurement method and device |
| CN114166515A (en) * | 2021-12-02 | 2022-03-11 | 哈尔滨工业大学 | Device and method for realizing SLIPI-3DLIF measurement of engine combustion chamber |
Non-Patent Citations (4)
| Title |
|---|
| 姜建国 等: "用于TDLAS甲烷检测的激光器电流驱动与温控系统", 重庆大学学报, vol. 41, no. 02, pages 53 - 57 * |
| 张可可 等: "基于TDLAS一次谐波的二氧化碳温度测量", 光电子技术, vol. 34, no. 04, pages 301 * |
| 殷可为;胥;张龙;杨富荣;: "TDLAS技术用于燃烧场气体温度和浓度重建研究", 光电工程, vol. 43, no. 12, pages 21 - 27 * |
| 齐汝宾 等: "准连续激光调制吸收谱的多谐波分析", 光谱学与光谱分析, vol. 32, no. 03, pages 586 - 589 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117091637A (en) * | 2023-10-16 | 2023-11-21 | 西北工业大学 | Gas detection system and method based on dual-optical frequency comb |
| CN117091637B (en) * | 2023-10-16 | 2024-02-20 | 西北工业大学 | Gas detection system and method based on dual-optical frequency comb |
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