CN101907563A - Sulfur dioxide analyzer based on ultraviolet light-emitting diode and analysis method - Google Patents

Abstract

The invention discloses a sulfur dioxide analyzer based on an ultraviolet light-emitting diode, which comprises the ultraviolet light-emitting diode, an absorption cell, a spectrometer and a computer connected to the spectrometer, wherein an incident window and an emergent window which correspond to each other and are transparent to ultraviolet light are respectively arranged on two sides of the absorption cell, and an air inlet and an air outlet are also arranged on the absorption cell; an incident optical fiber is connected between the ultraviolet light-emitting diode and the incident window of the absorption cell, and two collimators are respectively arranged at two ends of the incident optical fiber; an emergent optical fiber is connected between the emergent window of the absorption cell and the spectrometer, and two collimators are respectively arranged at two ends of the emergent optical fiber; the included angle between the incident window and the ultraviolet light path and the included angle between the incident window and the ultraviolet light path are acute angles or obtuse angles close to right angles. The invention also discloses a sulfur dioxide analysis method based on the ultraviolet light-emitting diode. The invention has the advantages of accurate measurement, large measurement range and short measurement time.

Description

Flue gas analyser and analytical approach based on ultraviolet light-emitting diode

Technical field

The present invention relates to a kind of gas analyzing apparatus, especially relate to a kind of concentration that is used for measurement gas sulphuric dioxide based on the ultraviolet absorption method flue gas analyser, the invention still further relates to sulfur dioxide analyzing method based on ultraviolet light-emitting diode.

Background technology

Sulphuric dioxide is a kind of important environmental pollution gas, has been listed in the routine measurement project, and has declared one of content as environmental statistics.The concentration that detects sulphuric dioxide accurately and rapidly has vital role in environmental protection, environmental monitoring, environmental warning, pollution source control, evaluation of flue gas desulfurizer performance.

But because shortcoming such as current flue gas analyser commonly exists cross interference, Measuring Time is long and measuring accuracy is relatively poor, can not well satisfy the needs of on-line monitoring.It is low that the non-dispersion infrared absorption process is measured the sulphuric dioxide cost, but measuring accuracy is not high, only is fit to measure the sulphuric dioxide of high concentration; Ultraviolet fluorescence method measures that the sulphuric dioxide cost is very high, and measurement range is little, can not widespread use; And that the laboratory chemical method is measured the sulphuric dioxide time is long, can not be used for on-line monitoring, sulphuric dioxide situation that can not the current discharging of rapid reaction.

Summary of the invention

At problem set forth above, the sulphuric dioxide in-line analyzer that the object of the invention is to provide a kind of to be measured accurately, measurement range is big, Measuring Time is short.

The present invention realizes by following technical measures, a kind of flue gas analyser based on ultraviolet light-emitting diode, comprise ultraviolet light-emitting diode, absorption cell, spectrometer and be connected computing machine on the spectrometer, described absorption cell both sides are respectively arranged with injecting window and penetrating window of corresponding and penetrating ultraviolet light, also are provided with air intake opening and exhausr port on the absorption cell; The injecting of described ultraviolet light-emitting diode and absorption cell be connected with between the window one with the ultraviolet light of ultraviolet light-emitting diode emission from injecting the incident optical that window imports absorption cell, the two ends of this incident optical are respectively arranged with a collimating apparatus; Be connected with the outgoing optical fiber that will penetrate the ultraviolet photo-sensitive cell in the ultraviolet photoconduction directive spectrometer that window penetrates between the ejaculation window of described absorption cell and the spectrometer, the two ends of this outgoing optical fiber also are respectively arranged with a collimating apparatus; Wherein, inject window and penetrate angle between the ultraviolet light path of window and transmission to inject angle between the ultraviolet light path of window and ejaculation window and transmission be acute angle or obtuse angle near the right angle.

Ultraviolet light-emitting diode preferably can be sent the ultraviolet light-emitting diode that wavelength coverage is the connection ultraviolet light of 290-320nm.

As a kind of optimal way, the spectral range of described optical fiber is 200-1100nm, and core diameter is 900um.

As a kind of optimal way, the measurement range of described spectrometer is 200-340nm, and grating indentation density is 2400mm ^-1, resolution is 0.29nm.

As a kind of optimal way, described ultraviolet photo-sensitive cell is the linear CCD array, totally 3648 pixels, and each pixel is that 8um is wide, 200um is long.

As a kind of optimal way, injecting window and penetrating window of described absorption cell is quartz material, and absorption cell side diameter is 22mm, and length is 102.5mm, and logical optical range is 200-2700nm.

Wherein, inject window and penetrate angle between the ultraviolet light path of window and transmission and inject window and penetrate preferred 75 degree of angle to 85 degree or 95 between the ultraviolet light path of window and transmission and spend to 105 and spend.

The invention also discloses a kind of sulfur dioxide analyzing method based on ultraviolet light-emitting diode, its analytical procedure is:

One, detects SO ₂The peak wavelength of gas and peak valley wavelength:

(1), elder generation charges into N from the air intake opening of absorption cell to absorption cell ₂Gas;

(2), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(3), the N of ultraviolet light in absorption cell ₂Aspiration receive the back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(4), ultraviolet light in spectrometer inside through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulate the ultraviolet light of the emission 290-320nm wavelength of ultraviolet light-emitting diode, and the absorption cross section that writes down each wavelength gives computing machine as blank correlation data, discharges N from the gas outlet of absorption cell ₂Gas;

(5), charge into the SO of 500ppm again to absorption cell from the air intake opening of absorption cell ₂Calibrating gas;

(6), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(7), the SO of ultraviolet light in absorption cell ₂Gas absorption decay back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(8), ultraviolet light through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulates the ultraviolet light of the emission 290-320nm wavelength of ultraviolet light-emitting diode in spectrometer inside, and writes down the absorption cross section of each wavelength, as SO ₂The data of calibrating gas are given computing machine, discharge SO from the gas outlet of absorption cell ₂Gas;

(9), computing machine passes through SO ₂The data of calibrating gas and blank correlation data calculate the peaked emission wavelength of absorption cross section and count λ ₁, this wavelength is called peak wavelength, and near the emission wavelength in minimal absorption cross section is counted λ ₂, this wavelength is called the peak valley wavelength;

Two, carry out SO ₂The detection of gas concentration:

(10), elder generation charges into SO to be measured from the air intake opening of absorption cell to absorption cell ₂Gas;

(11), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(12), the SO of ultraviolet light in absorption cell ₂Gas absorption decay back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(13), ultraviolet light through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulates the emission wavelength of ultraviolet light-emitting diode in spectrometer inside, and detection peak wavelength X ₁With the peak valley wavelength X ₂Ultraviolet light SO to be measured in absorption cell ₂The peak wavelength after the gas absorption decay and the absorption cross section at peak valley wavelength place are counted σ (λ ₁) and σ (λ ₂) and be transferred to computing machine;

(14), the computing machine that is connected with spectrometer calculates SO to be measured by following formula ₂The concentration of gas:

$c=-\frac{R\·T}{N_A\·p}\frac{\ln \left[\frac{P\left({\mathrm{\λ}}_1\right)}{P\left({\mathrm{\λ}}_2\right)}\right]}{[\mathrm{\σ}\left({\mathrm{\λ}}_1\right)-\mathrm{\σ}\left({\mathrm{\λ}}_2\right)]\·L}$

Wherein, C is a sulfur dioxide concentration; R is constant=8.314J/molK; T is a kelvin degree; P is a pressure, and unit is a handkerchief; N _ABe avogadros constant=6.022*10 ²³Mol ^-1λ ₁And λ ₂Be respectively peak wavelength and peak valley wavelength; σ (λ ₁) and σ (λ ₂) be respectively the absorption cross section at peak wavelength and peak valley wavelength place; L is a light path.

SO after testing ₂The peak wavelength λ of gas ₁Be 300.09nm, the peak valley wavelength X ₂Be 301.47nm.

In water treatment system, use the present invention, can open rapidly, to close and between different analytical approachs, change. it pumps into sampling valve with sample from sample pot by getting liquid pump, simultaneously reagent is pumped into system, sample enters the sample loop of one or more sampling valves, sampling valve is brought the sample of sample loop into pipe system by conversion with carrier fluid, sample and reagent meet in spiral reaction coil pipe, sample is mixed in narrow spiral reaction coil pipe under laminar flow condition, automatically finish the The whole analytical process of each sample by computer software control, eliminate the cross pollution of sample, also avoided artificial error.Thereby improve whole water quality monitoring system efficient and reduce cost.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 utilizes the present invention to detect the measurement data tabulation of variable concentrations sulphuric dioxide.

Embodiment

Below in conjunction with embodiment and contrast accompanying drawing the present invention is described in further detail.

As shown in Figure 1, a kind of flue gas analyser based on ultraviolet light-emitting diode, comprise ultraviolet light-emitting diode 1, absorption cell 3, spectrometer 5 and the computing machine 6 that is connected spectrometer 5 by USB, described absorption cell 3 both sides are respectively arranged with injecting window 304 and penetrating window 302 of corresponding and penetrating ultraviolet light, also are provided with air intake opening 301 and exhausr port 303 on the absorption cell 3; The injecting of described ultraviolet light-emitting diode 1 and absorption cell 3 be connected with between the window 304 one with the ultraviolet light of ultraviolet light-emitting diode 1 emission from injecting the incident optical 2 that window 304 imports absorption cells 3, the two ends of this incident optical 2 are respectively arranged with a collimating apparatus 201 and 202; Be connected with the outgoing optical fiber 4 that will penetrate the linear CCD array 501 in the ultraviolet photoconduction directive spectrometer 5 that window 302 penetrates between the ejaculation window 302 of described absorption cell 3 and the spectrometer 5, the two ends of this outgoing optical fiber 4 also are respectively arranged with a collimating apparatus 401 and 402; Wherein, inject window 304 and penetrate angle person between the ultraviolet light path of window 302 and transmission and 85 spend.

Wherein, the wavelength coverage that can send of ultraviolet light-emitting diode 1 is 290-320nm; The spectral range of incident optical 2 and outgoing optical fiber 4 is 200-1100nm, and core diameter is 900um; The measurement range of spectrometer 5 is 200-340nm, and grating indentation density is 2400mm ^-1, resolution is 0.29nm; Have 3648 pixels on the linear CCD array 501, each pixel is that 8um is wide, and 200um is long; Injecting window 304 and penetrating window 302 of absorption cell 3 is quartz materials, and the side diameter of absorption cell 3 is 22mm, and length is 102.5mm, and logical optical range is 200-2700nm.

Based on the sulfur dioxide analyzing method of ultraviolet light-emitting diode, its analytical procedure is:

One, detects SO ₂The peak wavelength of gas and peak valley wavelength:

(1), elder generation charges into N from the air intake opening 301 of absorption cell 3 to absorption cell 3 ₂Gas;

(2), then open ultraviolet light-emitting diode 1, by incident optical 2 guiding absorption cells 3, ultraviolet light enters absorption cell 3 by collimating apparatus 202 ejaculations of incident optical 2 other ends by injecting window 304 to ultraviolet light after collimating apparatus 201 becomes directional light at this moment;

(3), the N of ultraviolet light in absorption cell 3 ₂Aspiration receive the back by penetrate window 302 through collimating apparatus 401 by outgoing optical fiber 4 direct light spectrometers 5, ultraviolet light is injected spectrometer 5 by the collimating apparatus 402 of outgoing optical fiber 4 other ends;

(4), ultraviolet light in spectrometer 5 inside through shining behind collimation, focal length, the diffraction on the linear CCD array 501, regulate the ultraviolet light of ultraviolet light-emitting diode 1 emission 290-320nm wavelength, and the absorption cross section that writes down each wavelength gives computing machine 6 as blank correlation data, discharges N from the gas outlet 303 of absorption cell 3 ₂Gas;

(5), charge into the SO of 500ppm again to absorption cell 3 from the air intake opening 301 of absorption cell 3 ₂Calibrating gas;

(6), then open ultraviolet light-emitting diode 1, by incident optical 2 guiding absorption cells 3, ultraviolet light enters absorption cell 3 by collimating apparatus 202 ejaculations of incident optical 2 other ends by injecting window 304 to ultraviolet light after collimating apparatus 201 becomes directional light at this moment;

(7), the SO of ultraviolet light in absorption cell 3 ₂Aspiration receive the decay back by penetrate window 302 through collimating apparatus 401 by outgoing optical fiber 4 direct light spectrometers 5, ultraviolet light is injected spectrometer 5 by the collimating apparatus 402 of outgoing optical fiber 4 other ends;

(8), ultraviolet light through shining behind collimation, focal length, the diffraction on the linear CCD array 501, regulates the ultraviolet light of ultraviolet light-emitting diode 1 emission 290-320nm wavelength in spectrometer 5 inside, and the absorption cross section that writes down each wavelength is as SO ₂The data of calibrating gas are given computing machine 6, discharge SO from the gas outlet 303 of absorption cell 3 ₂Gas;

(9), computing machine 6 passes through SO ₂The data of calibrating gas and blank correlation data calculate the peaked emission wavelength 300.09nm of absorption cross section, and this wavelength is called peak wavelength, near the emission wavelength 301.47nm in minimal absorption cross section, and this wavelength is called the peak valley wavelength;

Two, carry out SO ₂The detection of gas concentration:

(10), elder generation charges into SO to be measured from the air intake opening 301 of absorption cell 3 to absorption cell 3 ₂Gas;

(11), then open ultraviolet light-emitting diode 1, by incident optical 2 guiding absorption cells 3, ultraviolet light enters absorption cell 3 by collimating apparatus 202 ejaculations of incident optical 2 other ends by injecting window 304 to ultraviolet light after collimating apparatus 201 becomes directional light at this moment;

(12), the SO of ultraviolet light in absorption cell 3 ₂Aspiration receive the decay back by penetrate window 302 through collimating apparatus 401 by outgoing optical fiber 4 direct light spectrometers 5, ultraviolet light is injected spectrometer 5 by the collimating apparatus 402 of outgoing optical fiber 4 other ends;

(13), ultraviolet light through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulates the emission wavelength of ultraviolet light-emitting diode in spectrometer inside, and ultraviolet light SO to be measured in absorption cell of detection peak wavelength 300.09nm and peak valley wavelength 301.47nm ₂The peak wavelength after the gas absorption decay and the absorption cross section at peak valley wavelength place are counted σ (λ ₁) and σ (λ ₂) and be transferred to computing machine;

(14), the computing machine that is connected with spectrometer calculates SO to be measured by following formula ₂The concentration of gas:

$c=-\frac{R\·T}{N_A\·p}\frac{\ln \left[\frac{P\left({\mathrm{\λ}}_1\right)}{P\left({\mathrm{\λ}}_2\right)}\right]}{[\mathrm{\σ}\left({\mathrm{\λ}}_1\right)-\mathrm{\σ}\left({\mathrm{\λ}}_2\right)]\·L}$

Wherein, C is a sulfur dioxide concentration; R is constant=8.314J/molK; T is a kelvin degree; P is a pressure, and unit is a handkerchief; N _ABe avogadros constant=6.022*10 ²³Mol ^-1λ ₁And λ ₂Be respectively peak wavelength 300.09nm and peak valley wavelength 301.47nm; σ (λ ₁) and σ (λ ₂) be respectively the absorption cross section at peak wavelength and peak valley wavelength place; L is a light path.

Fig. 2 utilizes the present invention to detect the measurement data tabulation of variable concentrations sulphuric dioxide, and the present invention has good rectilinearity as can be seen, and rectilinearity is 0.999.

More than be that flue gas analyser and its course of work of the present invention is based on ultraviolet light-emitting diode are set forth; be used for helping to understand the present invention; but embodiments of the present invention are not restricted to the described embodiments; any change that does not deviate under the principle of the invention to be done, modification, substitute, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (9)

1. flue gas analyser based on ultraviolet light-emitting diode, comprise ultraviolet light-emitting diode, absorption cell, spectrometer and be connected computing machine on the spectrometer, it is characterized in that: described absorption cell both sides are respectively arranged with injecting window and penetrating window of corresponding and penetrating ultraviolet light, also are provided with air intake opening and exhausr port on the absorption cell; The injecting of described ultraviolet light-emitting diode and absorption cell be connected with between the window one with the ultraviolet light of ultraviolet light-emitting diode emission from injecting the incident optical that window imports absorption cell, the two ends of this incident optical are respectively arranged with a collimating apparatus; Be connected with the outgoing optical fiber that will penetrate the ultraviolet photo-sensitive cell in the ultraviolet photoconduction directive spectrometer that window penetrates between the ejaculation window of described absorption cell and the spectrometer, the two ends of this outgoing optical fiber also are respectively arranged with a collimating apparatus; Wherein, inject window and penetrate window and the ultraviolet light path of transmission between angle be acute angle or obtuse angle near the right angle.

2. the flue gas analyser based on ultraviolet light-emitting diode according to claim 1 is characterized in that: described ultraviolet light-emitting diode is for can send the ultraviolet light-emitting diode that wavelength coverage is the connection ultraviolet light of 290-320nm.

3. the flue gas analyser based on ultraviolet light-emitting diode according to claim 1 is characterized in that: the spectral range of described optical fiber is 200-1100nm, and core diameter is 900um.

4. the flue gas analyser based on ultraviolet light-emitting diode according to claim 1 is characterized in that: the measurement range of described spectrometer is 200-340nm, and grating indentation density is 2400mm ^-1, resolution is 0.29nm.

5. according to claim 1 or 4 described flue gas analysers based on ultraviolet light-emitting diode, it is characterized in that: described ultraviolet photo-sensitive cell is the linear CCD array, totally 3648 pixels, and each pixel is that 8um is wide, 200um is long.

6. the flue gas analyser based on ultraviolet light-emitting diode according to claim 1, it is characterized in that: injecting window and penetrating window of described absorption cell is quartz material, absorption cell side diameter is 22mm, and length is 102.5mm, and logical optical range is 200-2700nm.

7. the flue gas analyser based on ultraviolet light-emitting diode according to claim 1 is characterized in that: describedly inject window and penetrate angle between the ultraviolet light path of window and transmission that all to be 75 degree spend to 105 to 85 degree or 95 degree.

8. sulfur dioxide analyzing method based on ultraviolet light-emitting diode is characterized in that analytical procedure is:

One, detects SO ₂The peak wavelength of gas and peak valley wavelength:

(1), elder generation charges into N from the air intake opening of absorption cell to absorption cell ₂Gas;

(2), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(3), the N of ultraviolet light in absorption cell ₂Aspiration receive the back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(4), ultraviolet light in spectrometer inside through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulate the ultraviolet light of the emission 290-320nm wavelength of ultraviolet light-emitting diode, and the absorption cross section that writes down each wavelength gives computing machine as blank correlation data, discharges N from the gas outlet of absorption cell ₂Gas;

(5), charge into the SO of 500ppm again to absorption cell from the air intake opening of absorption cell ₂Calibrating gas;

(6), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(7), the SO of ultraviolet light in absorption cell ₂Gas absorption decay back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(8), ultraviolet light through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulates the ultraviolet light of the emission 290-320nm wavelength of ultraviolet light-emitting diode in spectrometer inside, and writes down the absorption cross section of each wavelength, as SO ₂The data of calibrating gas are given computing machine, discharge SO from the gas outlet of absorption cell ₂Gas;

(9), computing machine passes through SO ₂The data of calibrating gas and blank correlation data calculate the peaked emission wavelength of absorption cross section and count λ ₁, this wavelength is called peak wavelength, and near the emission wavelength in minimal absorption cross section is counted λ ₂, this wavelength is called the peak valley wavelength;

Two, carry out SO ₂The detection of gas concentration:

(10), elder generation charges into SO to be measured from the air intake opening of absorption cell to absorption cell ₂Gas;

(11), then open ultraviolet light-emitting diode, by incident optical guiding absorption cell, ultraviolet light enters absorption cell by the collimating apparatus ejaculation of the incident optical other end by injecting window to ultraviolet light after collimating apparatus becomes directional light at this moment;

(12), the SO of ultraviolet light in absorption cell ₂Gas absorption decay back by penetrate window through collimating apparatus by outgoing optical fiber direct light spectrometer, ultraviolet light is injected spectrometer by the collimating apparatus of the outgoing optical fiber other end;

(13), ultraviolet light through shining behind collimation, focal length, the diffraction on the ultraviolet photo-sensitive cell, regulates the emission wavelength of ultraviolet light-emitting diode in spectrometer inside, and detection peak wavelength X ₁With the peak valley wavelength X ₂Ultraviolet light SO to be measured in absorption cell ₂The peak wavelength after the gas absorption decay and the absorption cross section at peak valley wavelength place are counted σ (λ ₁) and σ (λ ₂) and be transferred to computing machine;

(14), the computing machine that is connected with spectrometer calculates SO to be measured by following formula ₂The concentration of gas:

$c=-\frac{R\·T}{N_A\·p}\frac{\ln \left[\frac{P\left({\mathrm{\λ}}_1\right)}{P\left({\mathrm{\λ}}_1\right)}\right]}{[\mathrm{\σ}\left({\mathrm{\λ}}_1\right)-\mathrm{\σ}\left({\mathrm{\λ}}_2\right)]\·L}$

Wherein, C is a sulfur dioxide concentration; R is constant=8.314J/molK; T is a kelvin degree; P is a pressure, and unit is a handkerchief; N _ABe avogadros constant=6.022*10 ²³Mol ^-1λ ₁And λ ₂Be respectively peak wavelength and peak valley wavelength; σ (λ ₁) and σ (λ ₂) be respectively the absorption cross section at peak wavelength and peak valley wavelength place; L is a light path.

9. the sulfur dioxide analyzing method based on ultraviolet light-emitting diode according to claim 8 is characterized in that: described peak wavelength λ ₁Be 300.09nm, the peak valley wavelength X ₂Be 301.47nm.

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