CN107941748A - A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS - Google Patents
A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS Download PDFInfo
- Publication number
- CN107941748A CN107941748A CN201711098726.3A CN201711098726A CN107941748A CN 107941748 A CN107941748 A CN 107941748A CN 201711098726 A CN201711098726 A CN 201711098726A CN 107941748 A CN107941748 A CN 107941748A
- Authority
- CN
- China
- Prior art keywords
- light
- laser
- gas
- tdlas
- das
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 36
- 238000000041 tunable diode laser absorption spectroscopy Methods 0.000 title abstract description 8
- 238000010521 absorption reaction Methods 0.000 claims abstract description 53
- RJCQBQGAPKAMLL-UHFFFAOYSA-N bromotrifluoromethane Chemical compound FC(F)(F)Br RJCQBQGAPKAMLL-UHFFFAOYSA-N 0.000 claims abstract description 17
- GTLACDSXYULKMZ-UHFFFAOYSA-N pentafluoroethane Chemical compound FC(F)C(F)(F)F GTLACDSXYULKMZ-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000012545 processing Methods 0.000 claims abstract description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 31
- 230000008859 change Effects 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 8
- 238000012360 testing method Methods 0.000 claims description 7
- 230000006641 stabilisation Effects 0.000 claims description 6
- 238000011105 stabilization Methods 0.000 claims description 6
- 230000008878 coupling Effects 0.000 claims description 5
- 238000010168 coupling process Methods 0.000 claims description 5
- 238000005859 coupling reaction Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 230000004044 response Effects 0.000 claims description 5
- OYLGJCQECKOTOL-UHFFFAOYSA-L barium fluoride Chemical compound [F-].[F-].[Ba+2] OYLGJCQECKOTOL-UHFFFAOYSA-L 0.000 claims description 3
- 229910001632 barium fluoride Inorganic materials 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 3
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 230000003321 amplification Effects 0.000 claims description 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 2
- 239000000126 substance Substances 0.000 abstract description 5
- 230000001629 suppression Effects 0.000 abstract description 2
- 238000012795 verification Methods 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 47
- 238000000034 method Methods 0.000 description 16
- 229910000661 Mercury cadmium telluride Inorganic materials 0.000 description 15
- 238000001157 Fourier transform infrared spectrum Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 229920004449 Halon® Polymers 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- PXBRQCKWGAHEHS-UHFFFAOYSA-N dichlorodifluoromethane Chemical compound FC(F)(Cl)Cl PXBRQCKWGAHEHS-UHFFFAOYSA-N 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 241000931526 Acer campestre Species 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- 206010037660 Pyrexia Diseases 0.000 description 1
- 238000004847 absorption spectroscopy Methods 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- MCMSPRNYOJJPIZ-UHFFFAOYSA-N cadmium;mercury;tellurium Chemical compound [Cd]=[Te]=[Hg] MCMSPRNYOJJPIZ-UHFFFAOYSA-N 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- UHCBBWUQDAVSMS-UHFFFAOYSA-N fluoroethane Chemical compound CCF UHCBBWUQDAVSMS-UHFFFAOYSA-N 0.000 description 1
- 239000008246 gaseous mixture Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000001285 laser absorption spectroscopy Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000001745 non-dispersive infrared spectroscopy Methods 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000011514 reflex Effects 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000009738 saturating Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- 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
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- 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
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Optics & Photonics (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS, the extinguishing chemical bromotrifluoromethane (Halon 1301) that can be used aircraft fire protection system, pentafluoroethane (HFC 125) carry out measurement of concetration.The system includes QCL Distributed Feedback Lasers, collimater, temperature controller, signal generator, current driver, He Ne lasers, gas absorption cell, MCT detectors, data collecting card and data acquisition processing system.The present invention can realize high-precision, the quick measurement to two kinds of bromotrifluoromethane (Halon 1301), pentafluoroethane (HFC 125) extinguishing chemicals using a laser, with good interference free performance, it can meet the measurement demand that aircraft fire suppression system performance verification is tested.Compared with prior art, the present invention can realize the measurement of higher precision, and the application range of the present invention is not limited to both gas extinguishing agents, can expand to the gas of other keys of F containing C.
Description
Technical field
The present invention relates to a kind of measurement of concetration technology to aircraft gas extinguishing agent, and TDLAS- is based on more particularly to one kind
The gas extinguishing agent concentration measurement system of DAS.
Background technology
Bromotrifluoromethane, also known as Halon 1301, are a kind of high-efficiency fire-extinguishants of nontoxic residue-free, because of its superior fire extinguishing
Performance, is still aircraft fire protection system, the most important gas extinguishing agent of ground panzer explosion protection system at present.
Pentafluoroethane (HFC-125) is a kind of new Halon Replacement extinguishing chemical, its better heat stability, non-conductive, mesh
In the enging cabin of the preceding part military aircraft for being applied to the U.S..
Agent concentration measurement is an important experiment of aircraft fire protection System Performance Analysis, to assessment system design
Reasonability and the reliability of fire extinguishing.Therefore, measurement precisely, quick response, highly sensitive agent concentration measuring system for
The design of aircraft fire protection system, verification, improvement important in inhibiting.
According to FAA (Federal Aviation Administration) Advisory Circulars AC 20-100, bromotrifluoromethane is dynamic in aircraft engine nacelle and auxiliary
The fire extinguishing region planted agent in power cabin can maintain the concentration not less than 6% in 0.5s, to ensure reliability of putting out a fire.In addition, at FAA pairs
In four class fire scenario confirmatory experiments of aircraft hold Halon Replacement fire extinguishing system certification, it is also desirable to which the continuous analyzer of extinguishing chemical comes
The change of measurement record agent concentration；The extinguishing property test experiments of gas extinguishing agent are also required to such reliable apparatus.
At present, agent concentration measuring apparatus focuses primarily upon two class of pressure differential method and infrared absorption method.Wherein, pressure differential method is set
Standby advantage of lower cost, but easily it is subject to background gas to disturb；Non-dispersive infrared formula is developed based on infrared absorption method NIST
(NDIR) measuring apparatus, light source are globar, carry out machinery modulation using chopper, measurable bromotrifluoromethane is in 0-20% models
Enclose interior concentration value.Tunable diode laser absorption spectrometry technology (Tunable Diode Laser Absorption
Spectroscopy, TDLAS) it is a kind of detection method based on gas absorption spectra, semiconductor laser with tunable has this
The characteristic of sample：Under electric current excitation, launch the laser of specific wavelength, the change of Injection Current intensity can trigger wavelength in small model
Enclose interior linear change.Optical maser wavelength can be adjusted to a certain Absorption Line of testing molecule using the characteristic, and it is attached in Absorption Line
It is near to carry out periodic scan.Compared with the detecting devices of other principles, TDLAS have noninvasive, high sensitivity, high accuracy,
Equipment instrument is compact to wait many merits, has been widely used in atmospheric monitoring, industrial gasses on-line analysis, motor-vehicle tail-gas measurement
Etc. field of gas detection.At present, the measurement of aircraft fire protection system agent concentration, which relies primarily on, leases overseas equipment, rates
High, cycle length.Aircraft gas extinguishing agent TDLAS concentration measurement system of the research and development with independent intellectual property right is to breaking foreign technology
Block, the development for promoting Aircraft Security System design and basic scientific research research important in inhibiting.
According to measuring method and applicable elements, TDLAS mainly has two types：
1. direct absorption process
Direct absorption process (Direct Absorption Spectroscopy, DAS) uses triangular wave or sawtooch sweep
Current signal, realizes scanning of the wavelength near absworption peak, and the voltage curve that detector exports at Absorption Line will have substantially
Reduction, the inversion formula that can obtain concentration to be measured is fitted with corresponding gas concentration to voltage signal pad value, directly
Absorption process is connect to be suitable for absorbing strong measuring environment.
2. wavelength modulation method
Wavelength modulation method (Wavelength Modulation Spectroscopy, WMS) combines wavelength-modulation technique
With harmonic wave Detection Techniques, the test limits of ppm-ppt ranks can be realized with the use of long light path multiple reflections gas absorption cell.
Overlapped high-frequency sinusoidal signal realizes the modulation of signal on triangular wave or sawtooth waveforms low-frequency sweep signal, is detected using lock-in amplifier
Harmonic signal, obtained second harmonic signal is directly proportional to target gas levels, and such method can effectively inhibit noise,
Suitable for measuring Weak Absorption.
The present invention have selected basic detection of the direct absorption process (DAS) as system according to measurement purpose and use environment
Principle.
The content of the invention
In order to meet aircraft fire suppression system performance test demand, the present invention proposes that a kind of precision is high, response quickly goes out
Fiery agent concentration measuring device, based on TDLAS-DAS principles, with tunable distributed feedback quantum cascade laser (QCL-
DFB be) mid-infrared light source, from the global design of system, light channel structure, the selection of Absorption Line, the selection of component, light source tune
System and measuring method etc. are studied.
The technical solution adopted by the present invention is：A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS,
The system includes：QCL-DFB lasers, temperature controller, signal generator, current driver, collimater, bundling device, He-Ne
Laser, gas absorption cell, MCT detectors, data collecting card and data acquisition processing system, temperature controller is by QCL-DFB
Laser stabilization is in a constant working temperatures；Signal generator is connected with current driver, by low frequency sawtooth scanning signal
In input current driver；Current driver is connected with QCL-DFB lasers, to QCL-DFB laser input service electric currents；It is accurate
Straight device is connected with the light-emitting window of QCL-DFB lasers；The front light path of the collimater is equipped with bundling device, the outgoing with collimater
Light beam angle at 45 °；The exit portal of He-Ne lasers is realized through the infrared light after bundling device with reflection and closed towards bundling device
Beam；Gas absorption cell light inlet receives the combined beam light of infrared light and visible red towards bundling device；MCT detectors receive absorption
The emergent light in pond is simultaneously converted into voltage signal, is finally gathered by data collecting card and is transmitted to computer progress retrieving concentration meter
Calculate, wherein：
The QCL-DFB lasers, bromotrifluoromethane, pentafluoroethane two kinds of material absorbing peaks can be covered for providing
Laser of narrowband；
The temperature controller, for by laser control in constant operating temperature；
The signal generator, for producing triangular wave or sawtooth signal；
The current driver, for adjusting the operating current of laser, the wavelength of control output laser, and provides overload
Protection；
The collimater, for adjusting light path, collimated light beam is converted to by the diverging light of laser emitting；
The bundling device, for will be seen that feux rouges is coupled with infrared beam；
The He-Ne lasers, it is infrared with reflection after bundling device for sending visible red as instruction light beam
Light beam coupling, facilitates building and adjusting for light path；
The gas absorption cell, test sample gas is treated for being passed through, and laser beam is by absorption cell, since the absorption of gas is made
With light intensity decays, and open light path can also be used in the actual measurement in scene；
The MCT detectors, for measuring the laser intensity after absorbing, and are converted into defeated after the preposition amplification of voltage signal
Go out；
The data collecting card and data acquisition processing system, collection, processing for detector voltage signal, inverting meter
Calculation obtains under test gas concentration and change curve；
Temperature controller sweeps laser stabilization in a constant working temperatures, the low frequency sawtooth that signal generator produces
Retouch in signal input current driver and the operating current of laser is modulated, the wavelength for exporting laser is all near Absorption Line
Phase property scans；Become collimated light beam after laser emitting light collimator, since infrared light is invisible, the system utilizes bundling device
The red visible that the He-Ne lasers of 633nm are sent carries out light beam coupling with the light that QCL-DFB lasers are sent, convenient
Adjust light path and can intuitively be observed；After gas absorption cell is absorbed, emergent light is connect incident beam by MCT detectors
By and be converted into voltage signal, finally gathered by data collecting card and be transmitted to computer carry out retrieving concentration calculating.
Wherein, operating temperature, the electric current tuning scope of laser are adjusted, transmitting laser can be respectively in bromotrifluoromethane, five
The most strong Absorption Line 1207.729cm of fluoroethane-1、1209.158cm-1Nearby continuously scanned.
Wherein, the practical range of the measuring system is not limited to both gas extinguishing agents, can expand to other and contain
The gas of C-F keys.
Wherein, the collimater is installed on the light-emitting window of laser, has used ZnSe to increase broadband anti-reflection film for substrate
Planoconvex spotlight collimated.
Wherein, the bundling device is totally reflected 633nm visible reds, saturating to the mid-infrared light of 8270-8280nm wave bands
Rate is penetrated as 80% or so.
Wherein, gas absorption cell both sides window selects barium fluoride material.
Wherein, absorption cell is dismountable structure, can remove absorption cell in actual use using open light path, realize
Faster response time, more preferable real-time performance.
Wherein, the diaphragm that the emergent light of the gas absorption cell passes through carries out dim light.
Wherein, the emergent light after the dim light, the off-axis parabolic mirror through being coated with golden film are reflected, focused on, focus position
In the detection window of MCT detectors.
Wherein, the MCT detectors carry out low temperature denoising using thermoelectric-cooled mode, and investigative range is 2-12 μm.
The workflow of the present invention：The gaseous mixture of extinguishing chemical to be measured and nitrogen, temperature control are passed through into gas absorption cell
Laser stabilization is produced low frequency sawtooth scanning signal, is input to electricity by device processed in a constant working temperatures, signal generator
The operating current of laser is modulated in stream driver so that export the wavelength of laser near selected Absorption Line periodically
Scanning；Become collimated light beam after laser emitting light collimator, since infrared light is invisible, the system will using bundling device
The He-Ne lasers (red visible) of 633nm carry out light beam coupling with QCL, convenient to adjust light path and intuitively be seen
Examine；Incident beam by diaphragm, is received by MCT detectors after dim light after gas absorption cell is absorbed and is converted into voltage letter
Number, finally gathered by data collecting card and be transmitted to computer progress retrieving concentration calculating.
The present invention compared with prior art the advantages of be：
(1) present invention is based on TDLAS-DAS Diode Laser Absorption Spectroscopies, infrared band during use can cover
Quantum cascade laser, the scanning of wall scroll Absorption Line is realized by temperature, current-modulation, with using the infrared of traditional blackbody source
Absorption apparatus is compared, and has high certainty of measurement, good selective；
(2) gas extinguishing agent (bromotrifluoromethane and pentafluoroethane) that the present invention can be used with survey aircraft fire extinguishing system is dense
Degree；
(3) application range of the invention can be extended to the gas concentration detection of other keys containing C-F；
(4) present invention only needs to change other band lasers, it is possible to realizes the high-acruracy survey of other species.
Brief description of the drawings
Fig. 1 is that (fine line represents the aircraft gas extinguishing agent concentration measurement system theory structure block diagram based on TDLAS-DAS
Infrared light path, actual situation line represent the instruction light path of visible red, and thick line and arrow represent equipment control and signal transmission direction)；
Fig. 2 is the FTIR spectrum figure of bromotrifluoromethane；
Fig. 3 is the FTIR spectrum figure of pentafluoroethane；
Fig. 4 is the FTIR spectrum figure of background gas, wherein, Fig. 4 (a) is the FTIR spectrum of vapor
Figure, Fig. 4 (b) are the FTIR spectrum figure of carbon dioxide；
Fig. 5 is laser optical spectrogram, wherein, Fig. 5 (a) for 15 DEG C of operating temperature when laser under different current conditions
Light distribution, light distribution of the laser under condition of different temperatures when Fig. 5 (b) is operating current 0.41A；
Fig. 6 is light path schematic diagram, wherein, 1 is QCL-DFB lasers, and 2 be collimater, and 3 be bundling device, and 4 swash for He-Ne
Light device, 5 be gas absorption cell, and 6 be diaphragm, and 7 be off-axis parabolic mirror, and 8 be MCT detectors.
Embodiment
Below by embodiment combination attached drawing, the invention will be further described, but the practical range not office of the present invention
It is limited to both gas extinguishing agents, the gas of other keys containing C-F can be expanded to.
As shown in Figure 1, the aerial extinguishing agent concentration measuring system based on TDLAS-DAS of the present invention, including QCL-DFB swash
Light device, temperature controller, signal generator, current driver, collimater, He-Ne lasers, gas absorption cell, MCT detections
Device, data collecting card and data acquisition processing system, each part mentioned above are connected composition one by Electric Wires ＆ Cables with technique gas circuit
Measuring system.
Temperature controller control laser works under a steady temperature, and the low frequency sawtooth that signal generator produces is swept
Retouch in signal input current driver and the operating current of laser is modulated so that the wavelength for exporting laser is attached in Absorption Line
Nearly periodic scan.Laser beam is photosensitive to MCT detectors by diaphragm aperture dim light, refocusing after gas absorption cell
Face, optical signal are received and are converted into voltage signal, are gathered by data collecting card and are transmitted to computer and carry out calculating processing.
Before actual measurement, the calibrating gas that various concentrations need to be passed through in gas absorption cell demarcates system (object gas and height
The normal mixture of pure nitrogen gas), the change of light intensity, the Fitting Calculation go out the relation with concentration before and after measurement absorbs.
As shown in Figure 2 and Figure 3, the most strong Absorption Line of bromotrifluoromethane is located at 1207.729cm-1Locate (≈ 8280nm), five fluorine
The most strong Absorption Line of ethane is located at 1209.158cm-1Locate (≈ 8270nm)；As shown in figure 4, in atmospheric environment, vapor, CO2
Substantially do not absorbed in this wave band Deng background gas, be advantageously implemented high-acruracy survey, therefore the system have selected respectively
8280nm, 8270nm are as length scanning center.
The laser is used to provide the continuous laser that can scan covering 8270nm, 8280nm, according to measurement demand,
The system have selected the feedback distribution quantum cascade laser of AdTech optics productions, have the sweep length of 8-10nm,
By adjusting operating temperature, thus it is possible to vary wavelength scanning range；When object gas is bromotrifluoromethane, operating temperature is set to 25
DEG C, current scanning scope 0.29-0.53A, it is possible to achieve the scanning of Absorption Line 8280nm most strong to bromotrifluoromethane；Object gas
For pentafluoroethane when, operating temperature is set to 15 DEG C, current scanning scope 0.29-0.41A, it is possible to achieve pentafluoroethane is most inhaled by force
The scanning of take-up 8270nm, the laser disclosure satisfy that the demand of the system.
The temperature controller is used for the operating temperature (15-45 DEG C) that stabilization is provided for laser, what the system used
It is the TC10LAB temperature control devices of wavelength productions.
The current driver, for adjusting the operating current (0.29-0.53A) of laser, control output laser
Wavelength, and overload protection is provided, ensure the trouble free service of laser and the accuracy of measurement, the system is given birth to using wavelength
The special driving equipment QCL 1000LAB of quantum cascade laser of production.
Temperature controller acts synergistically with current driver, and control laser stablizes output.In addition, it is contemplated that laser
Fever, system is also equipped with radiating module, ensures normal operation.
The MCT detectors are used to convert optical signal into voltage signal, are selected according to demands such as wave band, response times
The mercury cadmium telluride photodetector of Vigo productions, and it is built-in with preamplifier and TEC refrigeration modules.
The data acquisition uses the PXIe-6341 voltage acquisition boards of NI, it is possible to achieve high speed, high-precision voltage
Signal acquisition, input voltage range are ± 5V.Control and data sampling and processing program are programmed using LabVIEW, can be shown in real time
Show, record output voltage and inverting concentration value.
In order to meet systematic survey demand, while simplify light path, reduction system volume, reduce cost, light path part design
As shown in fig. 6, including QCL-DFB lasers 1, collimater 2, bundling device 3, He-Ne lasers 4, diaphragm 6, gas absorption cell 5,
Off-axis parabolic mirror 7, MCT detectors 8.The emergent light of QCL-DFB lasers 1 has the collimated infrared light of certain angle
The red instruction laser beam that beam and He-Ne lasers 4 are sent is coupled after the projection of bundling device 3 and reflex as a branch of
Red light beam, is conveniently adjusted, observes；Incident light passes through gas absorption cell, and the laser after gas absorbs is by 6 dim light of diaphragm；
Collimated light beam is turned to by off-axis parabolic mirror 7 and focuses on the photosurface of MCT detectors 8.
Wherein：
Collimater straight 2 connects to be exported installed in QCL-DFB lasers 1, and it is that substrate increases broadband anti-reflection film to have used ZnSe
Planoconvex spotlight is collimated.
According to the specific wave band of agent concentration measurement demand combination QCL-DFB lasers 1,5 liang of side windows of gas absorption cell
Piece has selected barium fluoride material.
System has used diaphragm 6 to carry out confine optical beam by area ratio, and then realizes dim light, compared to infrared attenuating piece,
Greatly reduce cost.
The receiving area very little of MCT detectors 8, so needing light beam focusing to photosurface, system, which employs, is coated with guarantor
90 ° of off-axis parabolic mirrors 7 for protecting golden film turn to realize focusing and reflect.
What the present invention was not disclosed in detail partly belongs to techniques known.
Although the illustrative embodiment of the present invention is described above, in order to the technology of the art
Personnel understand the present invention, it should be apparent that the invention is not restricted to the scope of embodiment, to the common skill of the art
For art personnel, if various change appended claim limit and definite the spirit and scope of the present invention in, these
Change is it will be apparent that all utilize the innovation and creation of present inventive concept in the row of protection.
Claims (10)
1. a kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS, it is characterised in that the system includes：
QCL-DFB lasers, temperature controller, signal generator, current driver, collimater, bundling device, He-Ne lasers, gas
Absorption cell, MCT detectors, data collecting card and data acquisition processing system, temperature controller exist QCL-DFB laser stabilizations
One constant working temperatures；Signal generator is connected with current driver, and low frequency sawtooth scanning signal input current is driven
In device；Current driver is connected with QCL-DFB lasers, to QCL-DFB laser input service electric currents；Collimater and QCL-
The light-emitting window connection of Distributed Feedback Laser；The front light path of the collimater is equipped with bundling device, at 45 ° with the outgoing beam of collimater
Angle；The exit portal of He-Ne lasers is realized through the infrared light after bundling device with reflection towards bundling device and closes beam；Gas is inhaled
Receives pond light inlet receives the combined beam light of infrared light and visible red towards bundling device；MCT detectors receive the emergent light of absorption cell
And voltage signal is converted into, finally gathered by data collecting card and be transmitted to computer progress retrieving concentration calculating, wherein：
The QCL-DFB lasers, the arrowband at two kinds of bromotrifluoromethane, pentafluoroethane material absorbing peaks can be covered for providing
Laser；
The temperature controller, for by laser control in constant operating temperature；
The signal generator, for producing triangular wave or sawtooth signal；
The current driver, for adjusting the operating current of laser, the wavelength of control output laser, and provides overload and protects
Shield；
The collimater, for adjusting light path, collimated light beam is converted to by the diverging light of laser emitting；
The bundling device, for will be seen that feux rouges is coupled with infrared beam；
The He-Ne lasers, for send visible red as instruction light beam, after bundling device with the infrared beam of reflection
Coupling, facilitates building and adjusting for light path；
The gas absorption cell, treats test sample gas, laser beam is by absorption cell, due to the absorption of gas, light for being passed through
Decay by force, open light path can also be used in the actual measurement in scene；
The MCT detectors, for measuring the laser intensity after absorbing, and export after being converted into the preposition amplification of voltage signal；
The data collecting card and data acquisition processing system, collection, processing for detector voltage signal, Inversion Calculation obtain
To under test gas concentration and change curve；
Temperature controller is by laser stabilization in a constant working temperatures, the low frequency sawtooth scanning letter that signal generator produces
The operating current of laser is modulated in number input current driver, exports the wavelength of laser near Absorption Line periodically
Scanning；Become collimated light beam after laser emitting light collimator, since infrared light is invisible, the system will using bundling device
The red visible that the He-Ne lasers of 633nm are sent carries out light beam coupling with the light that QCL-DFB lasers are sent, convenient to adjust
Save light path and can intuitively be observed；After gas absorption cell is absorbed, emergent light is received incident beam by MCT detectors
And voltage signal is converted into, finally gathered by data collecting card and be transmitted to computer progress retrieving concentration calculating.
2. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
Operating temperature, the electric current tuning scope of laser are adjusted, transmitting laser can be inhaled in bromotrifluoromethane, the most strong of pentafluoroethane respectively
Take-up 1207.729cm-1、1209.158cm-1Nearby continuously scanned.
3. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
The practical range of the measuring system is not limited to both gas extinguishing agents, can expand to the gas of other keys containing C-F.
4. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
The collimater is installed on the light-emitting window of laser, and it is the planoconvex spotlight progress that substrate increases broadband anti-reflection film to have used ZnSe
Collimation.
5. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
The bundling device is totally reflected 633nm visible reds, left for 80% to the mid-infrared light transmissivity of 8270-8280nm wave bands
It is right.
6. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
Gas absorption cell both sides window selects barium fluoride material.
7. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
Absorption cell is dismountable structure, absorption cell can be removed in actual use using light path is opened, when realizing response faster
Between, more preferable real-time performance.
8. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
The diaphragm that the emergent light of the gas absorption cell passes through carries out dim light.
9. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
Emergent light after the dim light, the off-axis parabolic mirror through being coated with golden film are reflected, focused on, and focus is located at MCT detectors
Detection window.
10. the aircraft gas extinguishing agent concentration measurement system based on TDLAS-DAS as claimed in claim 1, it is characterised in that
The MCT detectors carry out low temperature denoising using thermoelectric-cooled mode, and investigative range is 2-12 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711098726.3A CN107941748A (en) | 2017-11-09 | 2017-11-09 | A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711098726.3A CN107941748A (en) | 2017-11-09 | 2017-11-09 | A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107941748A true CN107941748A (en) | 2018-04-20 |
Family
ID=61933652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711098726.3A Pending CN107941748A (en) | 2017-11-09 | 2017-11-09 | A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107941748A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109455311A (en) * | 2018-10-30 | 2019-03-12 | 中国科学技术大学 | A kind of aircraft engine nacelle simulator for agent concentration measurement experiment |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101644673A (en) * | 2009-09-09 | 2010-02-10 | 中国科学院光电技术研究所 | Infrared cavity ring-down spectroscopy trace gas detection method based on quantum cascade laser |
| CN102175641A (en) * | 2010-12-10 | 2011-09-07 | 中国科学院安徽光学精密机械研究所 | Trace gas detection device and method based on intermediate infrared quantum cascade laser direct absorption spectrum method |
| WO2012109030A1 (en) * | 2011-02-11 | 2012-08-16 | Adelphi University | Method and apparatus for trace gas detection using integrated wavelength modulated spectra across multiple lines |
| CN102706832A (en) * | 2012-06-01 | 2012-10-03 | 吉林大学 | Laser infrared gas analyzer based on TDLAS-WMS (tunable diode laser absorption spectroscopy-wavelength modulation spectroscopy) |
| CN104596987A (en) * | 2015-02-03 | 2015-05-06 | 中国科学院合肥物质科学研究院 | Mid-infrared spectroscopy-based trace gas detection method and device combining long-optical-path open light path with wavelength modulation technique |
| CN105277503A (en) * | 2015-08-20 | 2016-01-27 | 安徽大学 | Multi-component gas simultaneous detection device and method based on two quantum cascade laser spectrums |
-
2017
- 2017-11-09 CN CN201711098726.3A patent/CN107941748A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101644673A (en) * | 2009-09-09 | 2010-02-10 | 中国科学院光电技术研究所 | Infrared cavity ring-down spectroscopy trace gas detection method based on quantum cascade laser |
| CN102175641A (en) * | 2010-12-10 | 2011-09-07 | 中国科学院安徽光学精密机械研究所 | Trace gas detection device and method based on intermediate infrared quantum cascade laser direct absorption spectrum method |
| WO2012109030A1 (en) * | 2011-02-11 | 2012-08-16 | Adelphi University | Method and apparatus for trace gas detection using integrated wavelength modulated spectra across multiple lines |
| CN102706832A (en) * | 2012-06-01 | 2012-10-03 | 吉林大学 | Laser infrared gas analyzer based on TDLAS-WMS (tunable diode laser absorption spectroscopy-wavelength modulation spectroscopy) |
| CN104596987A (en) * | 2015-02-03 | 2015-05-06 | 中国科学院合肥物质科学研究院 | Mid-infrared spectroscopy-based trace gas detection method and device combining long-optical-path open light path with wavelength modulation technique |
| CN105277503A (en) * | 2015-08-20 | 2016-01-27 | 安徽大学 | Multi-component gas simultaneous detection device and method based on two quantum cascade laser spectrums |
Non-Patent Citations (2)
| Title |
|---|
| 汤媛媛等: "基于室温脉冲量子级联激光器的大气N2O监测仪研制", 《大气与环境光学学报》 * |
| 袁伟等: "基于红外吸收法的哈龙替代灭火剂HFC-125的浓度监测技术", 《火灾科学》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109455311A (en) * | 2018-10-30 | 2019-03-12 | 中国科学技术大学 | A kind of aircraft engine nacelle simulator for agent concentration measurement experiment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106802288B (en) | Gas-detecting device and method based on tunable laser and super continuous spectrums laser | |
| CN101308090B (en) | Fire field multi- parameter laser wavelength modulated spectrum detection method and apparatus | |
| CN104280362B (en) | A kind of superheated vapor laser spectrum on-line detecting system | |
| CN108007901B (en) | A kind of method and apparatus detecting multicomponent trace gas concentration | |
| CN104903704B (en) | Carry out the tunable diode laser absorption spectroscopy of steam measure | |
| RU2679455C1 (en) | Gases in the atmosphere concentration remote measurement method | |
| CN104596987A (en) | Mid-infrared spectroscopy-based trace gas detection method and device combining long-optical-path open light path with wavelength modulation technique | |
| CN107037003A (en) | A kind of system that moisture content in high-purity gas is detected based on cavity ring down spectroscopy technology | |
| US9212990B1 (en) | System and methods for molecular detection using intracavity laser absorption spectroscopy | |
| CN103499545B (en) | Adopt the semiconductor laser gas detecting system of gas reference chamber feedback compensation | |
| CN109406438A (en) | The system of light-source encapsulation body and the concentration for detection gas | |
| CN106872402A (en) | Gas-detecting device and method based on super continuous spectrums laser | |
| CN207379917U (en) | Aero-engine gas component and density monitoring system | |
| CN108195796A (en) | Aircraft gas extinguishing agent concentration measurement system and method based on TDLAS | |
| CN108061722A (en) | The detection device and detection method of a kind of carbonomonoxide concentration | |
| Wei et al. | Demonstration of non-absorbing interference rejection using wavelength modulation spectroscopy in high-pressure shock tubes | |
| Song et al. | Interband cascade laser-based ppbv-level mid-infrared methane detection using two digital lock-in amplifier schemes | |
| CN105911022A (en) | Hazardous chemical substance remote sensing detection method and device based on wide-tuning external cavity quantum cascade laser | |
| Li et al. | Mid-infrared telemetry sensor based calibration gas cell for CO detection using a laser wavelength locking technique | |
| CN201210140Y (en) | Multi-parameter laser wavelength modulation spectrum detection apparatus used in fire field | |
| CN107941748A (en) | A kind of aircraft gas extinguishing agent concentration measurement system based on TDLAS DAS | |
| CN110231307A (en) | Open light path gas concentration detection apparatus and method based on TDLAS technology | |
| US8445850B2 (en) | Optical remote sensing of fugitive releases | |
| CN107860749A (en) | Based on CO2The portable SF of laser6Leak remote sensing instrument | |
| Reid et al. | High sensitivity detection of trace gases at atmospheric pressure using tunable diode lasers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20180420 |