N2O analysis device and analysis method

Patent metadata

Field	Value
Publication number	US-10156517-B2
Application number	US-201615561701-A
Country	US
Kind code	B2
Filing date	Mar 29, 2016
Priority date	Mar 31, 2015
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

This N 2 O analysis device is provided with: a light source ( 11 ) which radiates laser light onto an exhaust gas ( 5 ) containing N 2 O, H 2 O and CO 2 ; a light receiver ( 13 ) which receives the laser light that has been radiated onto the exhaust gas ( 5 ); a light source control unit ( 14 a ) of a control device ( 14 ), which controls the wavelength of the laser light radiated by the light source ( 11 ) to between 3.84 μm and 4.00 μm; and a signal analyzing unit ( 14 b ) of the control device ( 14 ), which calculates the N 2 O concentration by means of infrared spectroscopy, using the laser light received by the light receiver ( 13 ) and the laser light controlled by the light source control unit ( 14 a ) of the control device ( 14 ).

First claim

The invention claimed is:

1. An N 2 O analysis device comprising:
light emission means for emitting laser light to flue gas containing N 2 O, H 2 O, and CO 2 , the flue gas being at normal pressures and being not treated with any one of a dust removal and a dehumidification and a pressure reduction;
light reception means for receiving the laser light emitted to the flue gas;
wavelength control means for performing control such that a wavelength of the laser light emitted by the light emission means is in a 3.84 to 4.00 μm band; and
N 2 O concentration calculation means for calculating a concentration of N 2 O by means of infrared spectroscopy, using the laser light received by the light reception means and the laser light controlled by the wavelength control means.

2. The N 2 O analysis device according to claim 1 , wherein
the wavelength control means performs control such that the wavelength of the laser light is 3.9034 to 3.9060 μm, 3.9090 to 3.9116 μm, or 3.9122 to 3.9148 μm.

3. The N 2 O analysis device according to claim 1 , wherein
the wavelength control means performs control such that the wavelength of the laser light is 3.9047 μm, 3.9103 μm, or 3.9135 μm.

4. The N 2 O analysis device according to claim 1 , wherein
the light emission means includes a nonlinear optical crystal, generates, by means of difference frequency generation using inputs of laser light with a wavelength of λ 1 and laser light with a wavelength of λ 2 , laser light with a wavelength of λ 3 satisfying 1/λ 3 =1/λ 1 −1/λ 2 , and outputs the laser light with the wavelength of λ 3 .

5. The N 2 O analysis device according to claim 1 , further comprising
temperature measurement means for measuring a temperature of the flue gas, wherein
the N 2 O concentration calculation means calculates the concentration of N 2 O by means of the infrared spectroscopy, using also the temperature of the flue gas measured by the temperature measurement means.

6. The N 2 O analysis device according to claim 1 , further comprising
sampling means for sampling the flue gas, wherein
the light emission means emits the laser light to the flue gas sampled by the sampling means.

7. The N 2 O analysis device according to claim 6 , further comprising
heating means for heating the flue gas sampled by the sampling means.

8. An N 2 O analysis method comprising:
emitting, by light emission means, laser light with a wavelength of 3.84 to 4.00 μm to flue gas containing N 2 O, H 2 O, and CO 2 , the flue gas being at normal pressures and being not treated with any one of a dust removal and a dehumidification and a pressure reduction;
receiving the laser light emitted to the flue gas; and
calculating a concentration of N 2 O by means of infrared spectroscopy, using the received laser light and the laser light which is controlled to be 3.84 to 4.00 μm.

9. The N 2 O analysis method according to claim 8 , wherein
the wavelength of the laser light emitted by the light emission means is controlled to be 3.9034 to 3.9060 μm, 3.9090 to 3.9116 μm, or 3.9122 to 3.9148 μm.

10. The N 2 O analysis method according to claim 8 , wherein
the wavelength of the laser light emitted by the light emission means is controlled to be 3.9047 μm, 3.9103 μm, 3.9135 μm.

11. The N 2 O analysis method according to claim 8 , wherein
equipment including a nonlinear optical crystal is used for the light emission means, the equipment generating, by means of difference frequency generation using inputs of laser light with a wavelength of λ 1 and laser light with a wavelength of λ 2 , laser light with a wavelength of λ 3 satisfying 1/λ 3 =1/λ 1 −1/λ 2 , and outputting the laser light with the wavelength of λ 3 .

12. The N 2 O analysis method according to claim 8 , further comprising:
measuring a temperature of the flue gas; and
calculating the concentration of N 2 O by means of the infrared spectroscopy, using also the measured temperature of the flue gas.

13. The N 2 O analysis method according to claim 8 , wherein the flue gas to which the laser light is emitted is sampled.

14. The N 2 O analysis method according to claim 13 , wherein
the sampled flue gas is heated.

Assignees

• Nippon Telegraph & Telephone
• Mitsubishi Heavy Ind Ltd

Inventors

• Tadanaga Osamu
• Tokura Akio
• Muta Kenji
• Fujii Shuuji
• Tsumura Yoichiro
• Nishimiya Tatsuyuki

Classifications

• G01N21/3504 Primary

  for analysing gases, e.g. multi-gas analysis · CPC title

• G01N2021/8578

  Gaseous flow · CPC title

• G01N2021/3137

  with selection of wavelengths after the sample · CPC title

• G01N2021/3148

  using three or more wavelengths · CPC title

• G01N2021/399

  Diode laser · CPC title