CN201210140Y - Multi-parameter laser wavelength modulation spectrum detection apparatus used in fire field - Google Patents
Multi-parameter laser wavelength modulation spectrum detection apparatus used in fire field Download PDFInfo
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- CN201210140Y CN201210140Y CNU2008200379959U CN200820037995U CN201210140Y CN 201210140 Y CN201210140 Y CN 201210140Y CN U2008200379959 U CNU2008200379959 U CN U2008200379959U CN 200820037995 U CN200820037995 U CN 200820037995U CN 201210140 Y CN201210140 Y CN 201210140Y
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Abstract
A fire ground multi-parameter laser wavelength modulation spectrum detection device comprises lasers, a multi-path laser controller, a White cell, a photodetector, phase locking enlargement modules, a multi-path data collection card and a microcomputer; the utility model is characterized in that a plurality of lasers are arranged, each laser is externally connected with the multi-path laser controller so as to control the working current and temperature; the emitting laser of the lasers is respectively accessed to a combiner through optical fibers; an optical fiber collimator is connected between the output fiber of the combiner and the light inlet of the White cell; the air inlet of the White cell is provided with a flue-gas pre-treatment device, and the air outlet is provided with an air extracting pump; the air outlet of the White cell is provided with the photodetector; the output signal of the photodetector is divided into two paths to be accessed to two phase locking enlargement modules, and the output signal of the two phase locking enlargement modules is sent to the microcomputer through the multi-path data collection card; signal wires are arranged among the multi-path laser controller, the phase locking enlargement modules and the multi-path data collection card to realize signal transmission.
Description
Technical field:
The utility model belongs to the fire monitoring technical field, particularly relates to laser absorption gas analysis pick-up unit.
Background technology:
Scene of a fire many reference amounts comprise scene of a fire oxygen concentration, multiple poisonous gas concentration and smokescope, and being influences personnel escape and the key factor of implementing rescue in the fire.In the analyzing detecting method of gas, common detection method mainly contains following several at present: the electrochemical process of utilizing electrode and electrolytic solution that gas is detected; The electric approach of utilizing the semi-conductor gas device to detect; Utilize gas that characteristics such as the refractive index of light or light absorption are come optical method of detected gas etc.These methods respectively have suitable application area, but surveyed the limitation of mechanism, electrochemical process and electric approach exist sensor life-time short, easily " poisoning ", defective such as cross interference is serious, the response time is long, can't satisfy scene of a fire many reference amounts and detect that desired polycomponent detects simultaneously and strong gas-selectively.Advantages such as existing checkout equipment based on optical means has highly sensitive, and gas-selectively is strong, but still have following defective in actual use:
1. Fourier transform infrared spectrometry (FTIR), can be at very wide infrared band, gas concentration is carried out Measurement and analysis, though this method is highly sensitive, can analyze simultaneously, measure by the multiple poisonous gas of realization, but need to adopt beam splitter and scan mode, and need take a sample gas, can only carry out the gasmetry analysis in the laboratory, can't realize the gaseous product of scene of fire is carried out the online in real time measurement.
2. existing optical means gas detection equipment light path is comparatively fragile, is subject to the environmental interference influence, more is difficult to realize simultaneously the monitoring to smokescope.
3. existing gas-detecting device is difficult to all accomplish that the real-time online to multicomponent gas detects.
The utility model content:
The purpose of this utility model is to provide a kind of highly sensitive scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit that can carry out online detection simultaneously to scene of a fire many reference amounts, to overcome the above-mentioned defective of prior art, the online in real time that realizes multicomponent gas in the fire smoke detects, and the reference frame of science is provided for fire rescue work.
Technical solution of the present utility model is:
A kind of scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit, include laser instrument, the multi-path laser controller, the White pond, photodetector, phase-locked amplification module, the multi-channel data acquisition card, microcomputer is characterized in that: described laser instrument has many, and all external multi-path laser controller of each laser instrument is to control its working current and temperature, the shoot laser of described laser instrument inserts wave multiplexer respectively by optical fiber, be connected to optical fiber collimator between the light inlet in the output optical fibre of wave multiplexer and White pond, the air intake opening in White pond is equipped with Flue Gas Pretreatment Device, and the gas outlet is equipped with aspiration pump; The light-emitting window place in described White pond is equipped with photodetector, and the output signal of photodetector is divided into two the road and inserts two phase-locked amplification modules, and the output signal of two phase-locked amplification modules is delivered to microcomputer through the multi-channel data acquisition card; Be connected with signal wire between described multi-path laser controller and phase-locked amplification module and the multi-channel data acquisition card and realize the signal transmission.
Described scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit is characterized in that described laser instrument has four, adopts the dfb semiconductor laser instrument, and its centre wavelength is corresponding CO respectively
2, CO, HCN and O
2The absorption line; Described photodetector is for selecting for use the InGaAs photodiode as receiving device, and its spectral response range is 900～1700nm.
The utility model adopts a multi-path laser controller, many laser instruments, wave multiplexer, optical fiber collimator, White pond, photodetector, two phase-locked amplification modules, multi-channel data acquisition card, microcomputer and Flue Gas Pretreatment Device, aspiration pump and White pond to import and export pipeline, constitutes optical maser wavelength modulated spectrum scene of a fire many reference amounts pick-up unit.
In the utility model, the multi-path laser controller is mainly realized following function: the low frequency sawtooth scan electric current of (1) generation amplitude and frequency adjustable, realize optical maser wavelength scanning; (2) produce the Sine Modulated electric current, realize the optical maser wavelength modulation, and provide fundamental frequency (f) reference signal and frequency multiplication (2f) reference signal to give phase-locked amplification module; (3) control the working temperature of each laser instrument; (4) work schedule of many laser instrument sense channels of control is realized the multi-laser time-sharing multiplex, and is provided timesharing sequential synchronizing signal to the multi-channel data acquisition card.Many laser instruments that use in the utility model, absorption lines of gases to be detected in its corresponding scene of a fire of centre wavelength difference many reference amounts; Laser instrument adopts the dfb semiconductor laser instrument, its outstanding advantage be that wavelength tuning speed is very fast and the output spectral line is very narrow (＜50MHz), monochromaticity is good.The laser that wave multiplexer is exported 4 laser instruments share a branch of optical fiber and exports successively, sends in the White pond behind the optical fiber collimator collimation through being installed in White pond light path front end.
The measuring principle of the utility model fire smoke:
According to the Lambert-Beer law, when a branch of light intensity is I
0Input directional light when inciding in the gas to be measured, light is decayed by gas, output intensity I (t) and input light intensity I
0(t) and the pass between the gas concentration be
I(t)＝I
0(t)exp[-α(v)CL] (1)
(v) be absorption coefficient, promptly gas is in the absorption line style at certain frequency v place for α in the formula; L is the length that absorbs the path; C is the concentration of gas to be measured.
An additional sawtooth period frequency sweep electric current and Sine Modulated electric current that amplitude is less that slowly changes on the direct drive electric current of system's noise spectra of semiconductor lasers, the frequency of light source and output intensity also are subjected to corresponding modulation:
v＝v
0+v
m?sin?ωt (2)
I
0(t)＝I
0[1+η?sin?ωt] (3)
In the formula, v
0Centre frequency during for the light source non-modulated; v
mModulation amplitude for frequency; η is the intensity modulation coefficient; ω=2 π f, f is the current-modulation frequency.With (2) formula and (3) formula substitution (1) formula, then have:
I(t)＝I
0(1+η?sin?ωt)exp[-α(v
0+v
m?sin?ωt)CL] (4)
At near-infrared band, absorption coefficient is very little, satisfy α (v) CL＜＜1, the modulation amplitude of light source is also very little, i.e. η＜＜1, (4) formula can be approximately like this:
I(t)＝I
0[1+η?sin?ωt-α(v
0+v
m?sin?ωt)CL] (5)
Because experiment is under atmospheric pressure to carry out, absorbing line style can describe with the Lorentz line style:
α in the formula
0The expression pure gas is at the absorption coefficient that absorbs the line center; v
gWith corresponding respectively centre frequency that absorbs of δ v and absorption line half-breadth.Accurately be locked on the gas absorption peak so work as the light source output center wavelength, i.e. v
0=v
gThe time, with (6) formula substitution (5) formula, and expanding into the fourier series sequence, the coefficient that obtains fundamental component and second harmonic component is respectively:
I
f＝I
0η I
2f＝-kα
0CLI
0 (7)
In the formula,
So have:
This shows that the ratio of second harmonic and first harmonic does not contain I
0, can eliminate the interference that factor such as light source fluctuation is brought like this with its output as system.(9) in the formula, remove gas concentration C to be measured, other parameters are constant, and system's output is proportional with gas concentration.Demarcate by standard gas, can obtain the concentration of gas to be measured.
When laser is propagated in the White pond, except by the gas absorption to be measured, also be subjected to absorption or scattering process or the two common (delustring) effect of smoke particle, normally receiving the radiant flux that receives on the photelectric receiver of directional light will weaken.According to standard GB 4715 regulations, the utility model records obscuration coefficient, and with the expression smokescope, obscuration coefficient is represented with following formula:
In the formula, m is an obscuration coefficient, and unit is dB/m; D is the optical measurement length of test cigarette; P
0The radiation power that receives when smokeless; P is the radiation power that receives when cigarette is arranged.According to (7) formula result of calculation, measure the fundamental component I that receives when cigarette is arranged respectively
fThe fundamental component I that receives when smokeless
F0, with
Replace
Substitution (10) formula can obtain obscuration coefficient, to characterize smokescope.
Through discovering, the gas composition in the many reference amounts of the scene of a fire is very weak to the laser intensity decay, can ignore with respect to the light intensity attenuation that fire hazard aerosol fog causes, and is very little to the measurement influence of obscuration coefficient; And fire hazard aerosol fog can not produce high fdrequency component yet, influences the detection of gas component concentrations.Therefore this device can detect simultaneously to multiple gases component and fire hazard aerosol fog, and can not produce cross interference.
The centre wavelength of 4 dfb semiconductor laser instruments that the utility model uses is corresponding O respectively
2With other 3 kinds of absorption lines of gases to be detected, a need replacing different wavelength of laser device just can be realized the detection to gas with various in the enforcement, has good gas-selectively.
The utility model is owing to adopted 4 dfb semiconductor laser instruments, and its wavelength tuning speed is fast, and the output spectral line is very narrow, can output wavelength be tuned on the gas absorption to be measured peak exactly, and effectively eliminate interference between component; The multi-path laser controller drives 4 laser instruments according to the time-sharing multiplex mode, can realize 4 kinds of gas compositions are detected simultaneously; Adopt suitable algorithm and data processing method, utilize system light path that the extinction coefficient of smog is measured, realized detecting simultaneously in real time of scene of a fire many reference amounts.The utility model can fundamentally solve the defective that traditional detection method exists, advantage such as have real-time, polycomponent, high sensitivity, gas-selectively is strong, reliability is high, anti-environmental interference ability is strong is applicable to the online detection of scene of a fire many reference amounts in various environment place.
Of the present utility model applying promoting the development of China's fire detection technology realized the real time on-line monitoring to scene of a fire many reference amounts.
Description of drawings:
Accompanying drawing 1 is that the system of the utility model scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit constitutes synoptic diagram.
Accompanying drawing 2 is a multi-path laser controller architecture synoptic diagram.
Accompanying drawing 3 is a repeatedly principle of reflection synoptic diagram of White pond.
Accompanying drawing 4 is a data in real time analyzing and processing process flow diagram of the present utility model.
Embodiment:
Embodiment 1
Present embodiment scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit is by 1,4 Distributed Feedback Lasers of a multi-path laser controller 12, wave multiplexer 2, optical fiber collimator 3, White pond 4, photodetector 5, two phase-locked amplification modules 6, multi-channel data acquisition card 7, microcomputer 8 and Flue Gas Pretreatment Device 9, an aspiration pump 10 with import and export pipeline 11 etc. and form.Flue Gas Pretreatment Device 9 will be monitored the air intake opening that on-the-spot flue gas is sent into White pond 4, and the gas outlet of the other end is connected with aspiration pump 10; Optical fiber collimator 3 is installed in light path porch, White pond, and photodetector 5 is installed in light path exit, White pond, and its output signal is divided into two-way, sends into two phase-locked amplification modules 6 simultaneously; Multi-channel data acquisition card 7 is inserted on the mainboard of microcomputer 8, and the signal of two phase-locked amplification modules links to each other with the analog input mouth of data collecting card.
For improving the sensitivity of photodetection, adopt the White pond to improve light path.Employed White pond 4 utilizes the spherical reflector image-forming principle to make in the present embodiment, White pond 4 mainly is made up of a primary mirror and two secondary mirrors, the radius-of-curvature of primary mirror and secondary mirror is consistent, Center Gap between primary mirror and the secondary mirror and radius-of-curvature equate, just formed confocal resonator like this between the primary and secondary mirror, light beam comes back reflective between the primary and secondary mirror.Repeatedly principle of reflection figure is as shown in Figure 3 in the White pond.
Adopt 4 Distributed Feedback Lasers in the present embodiment, centre wavelength is respectively 1609.0nm, 1567.133nm, 1537.965nm and 1273.0nm, respectively corresponding CO
2, CO, HCN and O
2The absorption line; The multi-path laser controller is pressed the time-sharing multiplex working method and is driven 4 Distributed Feedback Lasers 12, it is carried out length scanning and wavelength-modulated, and be responsible for: (1) provides the timesharing sequential synchronizing signal 13 of length scanning to multi-channel data acquisition card 7, guarantee the synchronous of data acquisition, (2) provide the fundamental frequency f and the frequency multiplication 2f reference signal 14 of sinusoidal wavelength-modulated to phase-locked amplification module 6.The laser that wave multiplexer is exported 4 road laser instruments 12 is combined into a branch of, adopts Optical Fiber Transmission, sends in the White pond behind optical fiber collimator 3 collimations through being installed in White pond 4 light path front ends.Photodetector 5 selects for use the InGaAs photodiode as receiving device, and its spectral response range is 900～1700nm.
During work, the flue gas at monitoring scene is sucked in the White pond 4 by air intake opening by aspiration pump 10 after Flue Gas Pretreatment Device 9 is handled; It is luminous to drive 4 Distributed Feedback Lasers by multi-path laser controller 1, send into the White pond through wave multiplexer 2 and optical fiber collimator 3, laser in White pond 4 through repeatedly the reflection and attenuation by absorption after, shine on the photodetector 5, be converted to electric signal by photodetector 5 again, divide two-way to send into and carry out the frequency-selecting amplification in two phase-locked amplification modules 6, obtain fundamental frequency (f) component and second harmonic (2f) component, carry out the A/D conversion by multi-channel data acquisition card 7 then, the digital quantity after the conversion is sent into microcomputer 8 and is carried out the real time data analyzing and processing.When carrying out the data analysis processing, with reference to formula (9), only need demarcate gas concentration to be measured in advance, obtain the concentration-I of 4 kinds of gases to be measured
2f/ I
fCurve, the data substitution calibration curve that data collecting card 7 is collected can obtain multiple gas concentration to be measured; With reference to formula (10), only need to gather in advance the fundamental component when smokeless, with what data collecting card 7 collected cigarette fundamental component substitution formula (10) arranged, can obtain to characterize the obscuration coefficient of smokescope.So just obtained to comprise the scene of a fire many reference amounts information of scene of a fire oxygen concentration, multiple poisonous gas concentration and smokescope simultaneously.
Claims (2)
1, a kind of scene of a fire many reference amounts optical maser wavelength modulated spectrum pick-up unit, include laser instrument, the multi-path laser controller, the White pond, photodetector, phase-locked amplification module, the multi-channel data acquisition card, microcomputer is characterized in that: described laser instrument has many, and all external multi-path laser controller of each laser instrument is to control its working current and temperature, the shoot laser of described laser instrument inserts wave multiplexer respectively by optical fiber, be connected to optical fiber collimator between the light inlet in the output optical fibre of wave multiplexer and White pond, the air intake opening in White pond is equipped with Flue Gas Pretreatment Device, and the gas outlet is equipped with aspiration pump; The light-emitting window place in described White pond is equipped with photodetector, and the output signal of photodetector is divided into two the road and inserts two phase-locked amplification modules, and the output signal of two phase-locked amplification modules is delivered to microcomputer through the multi-channel data acquisition card; Be connected with signal wire between described multi-path laser controller and phase-locked amplification module and the multi-channel data acquisition card and realize the signal transmission.
2, the scene of a fire according to claim 1 many reference amounts optical maser wavelength modulated spectrum pick-up unit is characterized in that described laser instrument has four, adopts the dfb semiconductor laser instrument, and its centre wavelength is corresponding CO respectively
2, CO, HCN and O
2The absorption line; Described photodetector is for selecting for use the InGaAs photodiode as receiving device, and its spectral response range is 900～1700nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200379959U CN201210140Y (en) | 2008-06-09 | 2008-06-09 | Multi-parameter laser wavelength modulation spectrum detection apparatus used in fire field |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008200379959U CN201210140Y (en) | 2008-06-09 | 2008-06-09 | Multi-parameter laser wavelength modulation spectrum detection apparatus used in fire field |
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| CN201210140Y true CN201210140Y (en) | 2009-03-18 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102183316A (en) * | 2010-12-10 | 2011-09-14 | 中国科学院安徽光学精密机械研究所 | Real-time temperature monitoring instrument for tunable semiconductor laser absorption spectrum |
| CN102004283B (en) * | 2009-09-02 | 2012-05-23 | 中国科学院半导体研究所 | Optical fiber coupling White cavity |
| CN101308090B (en) * | 2008-06-09 | 2013-11-06 | 中国科学技术大学 | Fire field multi- parameter laser wavelength modulated spectrum detection method and apparatus |
| CN104083841A (en) * | 2014-07-25 | 2014-10-08 | 电子科技大学 | Fire prevention and control system and method for mine and underground pipe network |
| CN104282110A (en) * | 2013-07-02 | 2015-01-14 | 李昇铁 | Apparatus of monitoring electrical fire for power distribution pannels |
| CN106404694A (en) * | 2016-11-14 | 2017-02-15 | 中国科学院合肥物质科学研究院 | Device for dynamically monitoring concentration of components in smoke gas in cigarette smoking procedures |
-
2008
- 2008-06-09 CN CNU2008200379959U patent/CN201210140Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101308090B (en) * | 2008-06-09 | 2013-11-06 | 中国科学技术大学 | Fire field multi- parameter laser wavelength modulated spectrum detection method and apparatus |
| CN102004283B (en) * | 2009-09-02 | 2012-05-23 | 中国科学院半导体研究所 | Optical fiber coupling White cavity |
| CN102183316A (en) * | 2010-12-10 | 2011-09-14 | 中国科学院安徽光学精密机械研究所 | Real-time temperature monitoring instrument for tunable semiconductor laser absorption spectrum |
| CN104282110A (en) * | 2013-07-02 | 2015-01-14 | 李昇铁 | Apparatus of monitoring electrical fire for power distribution pannels |
| CN104083841A (en) * | 2014-07-25 | 2014-10-08 | 电子科技大学 | Fire prevention and control system and method for mine and underground pipe network |
| CN104083841B (en) * | 2014-07-25 | 2017-06-16 | 电子科技大学 | It is a kind of for mine and the fire prevention and control system and method for underground pipe network |
| CN106404694A (en) * | 2016-11-14 | 2017-02-15 | 中国科学院合肥物质科学研究院 | Device for dynamically monitoring concentration of components in smoke gas in cigarette smoking procedures |
| CN106404694B (en) * | 2016-11-14 | 2023-04-07 | 中国科学院合肥物质科学研究院 | Device for dynamically monitoring smoke component concentration in cigarette smoking process |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090318 |