CN202735250U - Infrared analyzer for low-concentration smoke - Google Patents
Infrared analyzer for low-concentration smoke Download PDFInfo
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- CN202735250U CN202735250U CN 201220415137 CN201220415137U CN202735250U CN 202735250 U CN202735250 U CN 202735250U CN 201220415137 CN201220415137 CN 201220415137 CN 201220415137 U CN201220415137 U CN 201220415137U CN 202735250 U CN202735250 U CN 202735250U
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Abstract
The utility model relates to an infrared analyzer for low-concentration smoke. A gaseous pollutant detection unit (8) comprises an infrared source (10) and a chopper (11) disposed behind the infrared source (10). An absorption cell (12), a measuring gas chamber (13), a light filter (14) and a detection sensor (15) are sequentially disposed behind the chopper along an optical path. The absorption cell (12) is provided with an absorption cell sample gas inlet (16) and an absorption cell sample gas outlet (17). The measuring gas chamber (13) is divided into a sample cell (20) and a reference cell (21) along the optical path to allow for high-precision measurement of smoke. Sample gas to be measured is irradiated by a non-dispersive infrared monochromatic source to allow for quantitative accurate analysis. The infrared analyzer for low-concentration smoke is suitable for measuring low-concentration NO smoke and also applicable to detection of low-concentration CO and CO2.
Description
Technical field
The invention belongs to the flue gas monitoring apparatus field, especially a kind of low-concentration flue gas infrared spectrum analyser.
Background technology
Existing light concentration gas online test method adopts the non-dispersion infrared absorption spectrophotometry in the majority.Its ultimate principle is: after non-dispersion infrared monochromatic source irradiation sample gas, the molecule in the sample can absorb the light of some wavelength; There is not absorbed light to arrive detecting device.After detecting device detects this light intensity, produce ac voltage signal, signal by the Computing analysis, obtains absorbance corresponding to gas after amplifying processing.Because absorbance log is proportional to the concentration of this composition in the sample, utilizes size and the spectrum of the absorbance that obtains, and according to the comparison of absorption with the standard specimen of concentration known, can carry out quantitative Accurate Analysis to testing sample gas.For example: application number is that 201110043686.9 Chinese invention patent application discloses a kind of non-dispersion infrared polycomponent flue gas analyzer product, and wherein, sample cell adopts the Multi reflection pool structure, increases the gas absorption light path.
The core component of above-mentioned detection method is infrared detector; According to the difference of application characteristic, can be divided into twin-beam, miniflow, microphone etc. dissimilar.For example: Wuhan Sifang Photoelectric Science ﹠ Technology Co., Ltd. discloses the miniflow infrared sensor structure of the said firm's invention in " crucial difficult point and the calibration method of miniflow infrared gas analyzer device in CEMS uses inquired into " paper: detecting device is comprised of front air chamber, rear gas chamber, microfluidic sensor, forward and backward air chamber is disposed in order before and after optical path direction, and is full of the gas of component to be measured.Under the effect of infrared light, the gas in the forward and backward air chamber of detecting device expands; Owing to having differences in expansion, can cause producing between the forward and backward air chamber small flow; After microfluidic sensor detects this flow, produce ac voltage signal, signal obtains the concentration of gas after treatment.
Be summed up, there are the following problems for above-mentioned flue gas infrared spectrum analyser:
1) sample cell or absorption cell, as adopt the Multi reflection pool structure to increase the gas absorption light path, light path design is comparatively complicated, mirror surface structure and technological requirement are higher, easily produce interference fringe, optical aberration even memory effect (for the stronger gas of adsorbability), thereby cause the reduction of measuring accuracy;
2) infrared detector: forward and backward air chamber is disposed in order as adopting before and after optical path direction, so that after passing the infrared light of measuring chamber and entering the extinction chamber, then pass again another air chamber, easily disturb the measuring accuracy of releasing electric explorer, the difficult measurement that stably realizes light concentration gas.
Summary of the invention
For solving the problems of the technologies described above, the low-concentration flue gas analyser of a kind of high precision, high reliability is provided, the technical solution used in the present invention is as follows:
A kind of low-concentration flue gas infrared spectrum analyser comprises cabinet 1, adds thermal control units 2, output display unit 3, data acquisition process unit 4, power supply 5; The cabinet 1 interior flue gas pipeline that arranges, drainage filtration unit 6 is arranged on the flue gas pipeline import, difference set temperature sensor, pressure transducer, humidity sensor, lambda sensor 7, detection for gaseous contaminants unit 8 on the flue gas pipeline; Described detection for gaseous contaminants unit 8 comprises infrared light supply 10 and is arranged on thereafter chopper 11, is followed successively by absorption cell 12 behind chopper, measures air chamber 13, light filter 14, detecting sensor 15 along light path arrangement; Establish absorption cell sample gas import 16 and absorption cell sample gas outlet 17 at absorption cell 12, measure air chamber 13 and be respectively sample cell 20, reference cell 21 along optical path direction, reference cell 21 interior encapsulation calibrating gas, sample cell 20 is established sample cell sample gas import 18 and sample cell sample gas outlet 19, and absorption cell sample gas outlet 17 is connected with sample cell sample gas import 18.
In the technique scheme, detecting sensor 15 is the miniflow pneumatic detector preferably, structure comprises transmission window 22, extinction chamber 23, gas compensation chamber 24, gas filter 25, there is passage 26 to connect between extinction chamber 23 and the gas compensated chamber 24, be provided with platinum filament and pneumatic pyroelectric detector in the passage 26, extinction chamber 23 is arranged on over against transmission window 22 positions, and gas compensation chamber 24 is that cyclic rings is around 23 peripheries, extinction chamber.
The length of absorption cell 12 of the present invention is 100mm ~ 240mm, and length selects to depend on gas concentration size to be measured; General gas concentration to be measured is lower, and absorption cell length is just longer, in order to can allow monochromatic light fully be absorbed by the gas of certain wavelength, forms obvious absorption peak feature in spectrogram.
The calibrating gas of reference cell 21 interior encapsulation of the present invention is that concentration is 100mg/m
3NO; When gas concentration to be measured exceeded standard, analyser of the present invention judged that with automatic alarm gas is defective.If need the gas of compatible various concentration to detect, can encapsulate the gas to be measured of certain concentration in reference cell according to customer requirement.
Principle of the present invention is as follows: the non-dispersion infrared absorption spectrophotometry is a kind of novel gas concentration detection method: after non-dispersion infrared monochromatic source irradiation sample gas, the molecule in the sample can absorb the light of some wavelength; There is not absorbed light to arrive the miniflow detecting device.After the miniflow detecting device detects this light intensity, produce ac voltage signal, signal by the Computing analysis, obtains absorbance corresponding to gas after amplifying processing.Because absorbance log is proportional to the concentration of this composition in the sample, utilizes size and the spectrum of the absorbance that obtains, and according to the comparison of absorption with the standard specimen of concentration known, can carry out quantitative Accurate Analysis to testing sample gas.
The present invention is applicable to the measurement of light concentration gas, especially for the measurement of low concentration of NO gas, utilize the measurement sensitivity of NO gas lower concentration values and to the responsive absorption characteristics of infrared light, absorption cell of special increase, during measurement, allow infrared beam pass successively absorption cell, sample cell and arrive detecting sensor, in order to can allow the monochromatic light that passes through fully be absorbed by NO gas, make and pass that to enter the transmissivity T that detecting device obtains behind the sample cell larger, to solve gas concentration to be measured when very low, transmissivity T is lower, the accurate difficult problem of measurement gas lower concentration values has improved the mutually ability of mutual interference of analyser detection sensitivity and anti-polycomponent.
The present invention utilizes chopper so that the infrared beam that single light source sends becomes twin-beam, adopt the twin-beam metric measurement, compare other optical measuring techniques, has following obvious advantage: the effect of monitoring at any time that light intensity changes and the impact that changes is proofreaied and correct by reference light, can automatically eliminate the intensity of light source and change caused error, avoid because the measuring error that power-supply fluctuation or light source ages cause, simultaneously amplifier gain variation and optics and electronics components and parts have also been eliminated to two unbalanced impacts of light path, thereby so that drift reduces, the baseline straightening degree improves, and variation with temperature and changing not, improved the stability of instrument.
Further, detecting sensor of the present invention adopts the miniflow pneumatic detector, utilizes the miniflow pneumatic principle, is designed with inside and outside two air chambers; In the middle of the inside air chamber is positioned at, as the extinction chamber; Skin air chamber by way of compensation; Inside and outside be provided with platinum filament and pneumatic pyroelectric detector in the very thin passage between the air chamber; Owing to only being furnished with the extinction chamber along optical path direction, guaranteed that all light beams that pass absorption cell, sample cell are only obtained by the detection of extinction chamber, thereby guarantee accuracy of detection and the sensitivity of analyser, structure is more reasonable, is particularly suitable for the measurement of the low-concentration flue gas such as NO.And according to the existing miniflow detector arrangement of announcing in the world at present, before and after optical path direction, to be disposed in order this two air chambers, after the infrared light that causes passing measuring chamber enters the extinction chamber, pass respectively again another air chamber, easily disturb the measuring accuracy of releasing electric explorer, so that this structure obviously is not suitable for the gasmetry of low concentration.
The industry that the present invention can be benefited has: refining, petrochemical industry and chemical treatment, metallurgical production, hardening heat processing, gas production and distribution, the measurement of inflammable mixture of gas, biotechnology, garbage loading embeading processing, the analysis of boiler flue gas, power plant, process smelting furnace and incinerator, various places CEMS integrator and ring prison station etc.The present invention also can be applicable to low concentration CO, CO except being suitable for the measurement of NO low-concentration flue gas
2Detection Deng flue gas.
Description of drawings
Fig. 1 is the topology layout figure of embodiment of the invention flue gas analyzer.
Fig. 2 is detection for gaseous contaminants cellular construction schematic diagram of the present invention.
Fig. 3 is detection for gaseous contaminants of the present invention unit two-way arrangement schematic diagram.
Fig. 4 is miniflow pneumatic detector structural front view.
Fig. 5 is miniflow pneumatic detector structure right view.
Embodiment
Embodiment 1:
Fig. 1 is the topology layout figure of embodiment of the invention flue gas analyzer, as shown in the figure, comprises cabinet 1, adds thermal control units 2, output display unit 3, data acquisition process unit 4, power supply 5; The cabinet 1 interior flue gas pipeline that arranges, drainage filtration unit 6 is arranged on the flue gas pipeline import, difference set temperature sensor, pressure transducer, humidity sensor, lambda sensor 7, detection for gaseous contaminants unit 8 on the flue gas pipeline; Also comprise a flue gas measuring multiple parameters chamber 9 in the cabinet, temperature sensor, pressure transducer, humidity sensor all are arranged in the flue gas measuring multiple parameters chamber 9.
The detection for gaseous contaminants unit 8 of the present embodiment comprises infrared light supply 10 and is arranged on thereafter chopper 11, is followed successively by absorption cell 12 behind chopper, measures air chamber 13, light filter 14, detecting sensor 15 along light path arrangement; Establish absorption cell sample gas import 16 and absorption cell sample gas outlet 17 at absorption cell 12, measure air chamber 13 and be respectively sample cell 20, reference cell 21 along optical path direction; Reference cell 21 interior encapsulation calibrating gas, in the testing process, when gas concentration to be measured exceeded standard, analyser of the present invention judged that with automatic alarm gas is defective.Sample cell 20 is established sample cell sample gas import 18 and sample cell sample gas outlet 19, and absorption cell sample gas outlet 17 is connected with sample cell sample gas import 18.The light beam that send in chopper 11 modulated infrared light sources 10 forms two monochromic beams, and a branch of entering through absorption cell 12 measured air chamber 13, and another bundle enters the alternately irradiation of reference cell 21, two monochromic beams through absorption cell 12.
In the technique scheme, detecting sensor 15 is the miniflow pneumatic detector preferably, structure such as Fig. 4 are shown in Figure 5, comprise transmission window 22, extinction chamber 23, gas compensation chamber 24, gas filter 25, there is passage 26 to connect between extinction chamber 23 and the gas compensated chamber 24, is provided with platinum filament in the passage 26 and by TaLiO
3Be the pneumatic pyroelectric detector that main material is made, the pressure leakages rate of 2 air chambers requires less than 10
-11Mbar/s.Extinction chamber 23 is arranged on over against transmission window 22 positions, and gas compensation chamber 24 is that cyclic rings is around 23 peripheries, extinction chamber.When the infrared light that passes measuring chamber entered extinction chamber 23, the gas in the extinction chamber 23 expanded; Owing to having differences in expansion, can cause producing between extinction chamber 23 and the gas compensated chamber 24 small flow; After pneumatic pyroelectric detector detects this flow, can produce and measure needed ac voltage signal.
The miniflow pneumatic detector is only surveyed the single component in the sample gas, and the extinction chamber 23 of each miniflow pneumatic detector and gas compensated chamber 24 encapsulate the component gas to be measured that needs detection in advance; For example measure NO and then encapsulate in advance NO gas, measure CO and then encapsulate in advance CO gas.
Embodiment 2:
As shown in Figure 3, for improving the utilization ratio of flue gas analyzer, detection for gaseous contaminants unit 8 be arranged two in parallel, other structures are with embodiment 1, can measure for different pollutants simultaneously, only need in reference cell 21, encapsulate different calibrating gas and select to think that corresponding detecting sensor gets final product, but preferred package NO and CO calibrating gas.
Embodiment 3:
Detecting sensor 15 is for measuring range at 0 ~ 100 ~ 3000 mg/m
3The NO sensor of (double-range); Reference cell 21 encapsulation NO calibrating gas.Data acquisition and processing unit comprise front-end control system, Circuits System, software analysis computing system; The output display unit comprises the compositions such as display screen, button, communication unit, communication serial ports.Drainage filtration unit 6 is water filtration membrane, can stop that the aqueous water in the flue gas passes through, the sensor in the protection cabinet.Add the flue gas pipeline heating of 2 pairs of cabinet insides of thermal control units, guarantee that system is under the temperature constant state.After flue gas enters cabinet, after measuring every context parameter, temperature sensor, pressure transducer, humidity sensor, lambda sensor can carry out the NO measurement of concetration.
The in advance calibrating gas preparation of encapsulation in the reference cell 21: with NO or CO gas respectively with nitrogen N
2(N
2Absorption peak is less or do not disturb eudiometry to be measured) be mixed with same concentrations C
The NO mark=C
The CO mark=100mg/m
3Calibrating gas; Then be encapsulated in respectively in the light path of corresponding gas in the reference cell 21.The identical calibrating gas of each reference cell encapsulation gas a kind of and to be measured.
The measurement concrete steps of light concentration gas are as follows:
Step 1, in the low-concentration flue gas infrared spectrum analyser, pass into nitrogen N
2, to nitrogen N
2Be full of absorption cell 12 and sample cell 20, generally select the nitrogen N of 99.99% purity
2
Step 2, infrared light supply 10 send monochromatic light, form two-beam after chopper 11 is cut light; Light beam arrives detecting sensor 15 by absorption cell 12, sample cell 20, light filter 14 successively, measures and obtains light intensity I
0Light beam arrives detecting sensor 15 by absorption cell 12, reference cell 21, light filter 14 successively in addition, measures and obtains light intensity I
Ginseng
Step 3, by formula T
Ginseng=I
Ginseng/ I
0, obtain to pass into nitrogen N
2Transmissivity T
Ginseng
Step 4, nitrogen N
2Discharge;
Step 5, gas to be measured is passed into the low-concentration flue gas infrared spectrum analyser, behind drainage filtration unit 6 filtration dryings, be full of absorption cell 12 and sample cell 20;
Step 6, infrared light supply 10 send monochromatic light, form two-beam after chopper 11 is cut light; Light beam arrives detecting sensor 15 by absorption cell 12, sample cell 20, light filter 14 successively, measures and obtains light intensity I;
Step 7, by formula T=I/ I
0, obtain to pass into gas transmissivity T to be measured;
Step 8, note reference cell 21 interior encapsulation calibrating gas concentration are C
Ginseng
Step 9, by formula C=(logT/logT
Ginseng) C
Ginseng, calculate gas concentration C to be measured.
Again by data acquisition process unit 4 and output display unit 3, the i.e. concentration value of exportable gas NO to be measured or CO.
When carrying out above-mentioned measuring process, by humidity sensor, temperature sensor and the pressure transducer in the flue gas measuring multiple parameters chamber 9, record in advance humidity, three parameters of temperature and pressure, obtain the ambient parameter data of gas to be measured, thereby obtain the standard state condition.
Embodiment 4:
The flue gas analyzer structure is with embodiment 1, and in the low-concentration flue gas infrared spectrum analyser, the calibrating gas of reference cell 21 interior encapsulation is that concentration is 100mg/m
3NO(GB13223-2003 " fossil-fuel power plant atmospheric pollutant emission standard " in the NO standard limited value); This moment is by the measuring process of embodiment 3 and formula C wherein=(logT/logT
Ginseng) C
Ginseng, can judge fast then whether the NO concentration in the gas to be measured exceeds standard.
When gas concentration to be measured exceeded standard, analyser of the present invention judged that with automatic alarm gas is defective.If need the gas of compatible other concentration or kind to detect, can change according to customer requirement the gas of the certain concentration of reference cell 21 interior encapsulation, flexible, can adjust at any time according to market demand.
Claims (4)
1. low-concentration flue gas infrared spectrum analyser, comprise cabinet (1), add thermal control units (2), output display unit (3), data acquisition process unit (4), power supply (5), cabinet arranges flue gas pipeline in (1), drainage filtration unit (6) is arranged on the flue gas pipeline import, difference set temperature sensor on the flue gas pipeline, pressure transducer, humidity sensor, lambda sensor (7), detection for gaseous contaminants unit (8), it is characterized in that: described detection for gaseous contaminants unit (8) comprises infrared light supply (10) and is arranged on thereafter chopper (11), behind chopper, be followed successively by absorption cell (12) along light path arrangement, measure air chamber (13), light filter (14), detecting sensor (15), establish absorption cell sample gas import (16) and absorption cell sample gas outlet (17) at absorption cell (12), measure air chamber (13) and be respectively sample cell (20) along optical path direction, reference cell (21), encapsulation calibrating gas in the reference cell (21), sample cell (20) is established sample cell sample gas import (18) and sample cell sample gas outlet (19), and absorption cell sample gas outlet (17) is connected with sample cell sample gas import (18).
2. low-concentration flue gas infrared spectrum analyser according to claim 1, it is characterized in that: described detecting sensor (15) is the miniflow pneumatic detector, comprise transmission window (22), extinction chamber (23), gas compensation chamber (24), gas filter (25), there is passage (26) to connect between extinction chamber (23) and gas compensated chamber (24), be provided with platinum filament and pneumatic pyroelectric detector in the passage (26), extinction chamber (23) is arranged on over against transmission window (22) position, and gas compensation chamber (24) are that cyclic rings is around periphery, extinction chamber (23).
3. low-concentration flue gas infrared spectrum analyser according to claim 1, it is characterized in that: the length of absorption cell (12) is 100mm ~ 240mm.
4. low-concentration flue gas infrared spectrum analyser according to claim 1 is characterized in that: the calibrating gas of encapsulation is that concentration is 100mg/m in the reference cell (21)
3NO.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220415137 CN202735250U (en) | 2012-08-21 | 2012-08-21 | Infrared analyzer for low-concentration smoke |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220415137 CN202735250U (en) | 2012-08-21 | 2012-08-21 | Infrared analyzer for low-concentration smoke |
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| CN 201220415137 Withdrawn - After Issue CN202735250U (en) | 2012-08-21 | 2012-08-21 | Infrared analyzer for low-concentration smoke |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102809546A (en) * | 2012-08-21 | 2012-12-05 | 南京埃森环境技术有限公司 | Low-concentration flue gas infra-red analyzer and detection method |
| CN104122224A (en) * | 2014-08-13 | 2014-10-29 | 成都君凌科创科技有限公司 | High-precision non-dispersion infrared ray gas sensor |
| CN109839472A (en) * | 2019-02-01 | 2019-06-04 | 北京雪迪龙科技股份有限公司 | A kind of portable gas mercury monitoring system and monitoring method |
-
2012
- 2012-08-21 CN CN 201220415137 patent/CN202735250U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102809546A (en) * | 2012-08-21 | 2012-12-05 | 南京埃森环境技术有限公司 | Low-concentration flue gas infra-red analyzer and detection method |
| CN104122224A (en) * | 2014-08-13 | 2014-10-29 | 成都君凌科创科技有限公司 | High-precision non-dispersion infrared ray gas sensor |
| CN109839472A (en) * | 2019-02-01 | 2019-06-04 | 北京雪迪龙科技股份有限公司 | A kind of portable gas mercury monitoring system and monitoring method |
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20130213 Effective date of abandoning: 20150422 |