WO2001027596A1 - Capteur de co - Google Patents

Capteur de co Download PDF

Info

Publication number
WO2001027596A1
WO2001027596A1 PCT/JP2000/007055 JP0007055W WO0127596A1 WO 2001027596 A1 WO2001027596 A1 WO 2001027596A1 JP 0007055 W JP0007055 W JP 0007055W WO 0127596 A1 WO0127596 A1 WO 0127596A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter
carbon monoxide
infrared
band
detector
Prior art date
Application number
PCT/JP2000/007055
Other languages
English (en)
Japanese (ja)
Inventor
Hiroshi Shirakawa
Kazuo Yamashita
Original Assignee
Nok Corporation
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nok Corporation filed Critical Nok Corporation
Priority to AU76837/00A priority Critical patent/AU7683700A/en
Publication of WO2001027596A1 publication Critical patent/WO2001027596A1/fr

Links

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
    • G01N21/35—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

Definitions

  • the present invention relates to a carbon monoxide (c ⁇ ) sensor using infrared spectroscopy. More specifically, the present invention relates to a C ⁇ sensor suitable for detecting the concentration of carbon monoxide in a fuel reformed gas supplied to a fuel cell.
  • c ⁇ carbon monoxide
  • Fuel cells have been proposed as power sources for electric vehicles and the like. Fuel cells produce continuous current directly from the chemical reaction of hydrogen and oxygen without burning. Several types of fuel cells are under development, but proton exchange membrane (PEM) type fuel cells are considered desirable for automotive applications due to their high power density.
  • PEM proton exchange membrane
  • a PEM fuel cell is composed of a membrane electrode assembly (MEA) formed by sandwiching a proton-conductive solid polymer electrolyte membrane between an anode plate and a cathode plate, and multiple MEAs are connected to each other. By doing so, a fuel cell stack is configured. Both sides of each MEA electrolyte membrane are coated with a thin platinum catalyst. Flow channels are formed on the surfaces of the anode plate and the cathode plate. Hydrogen gas flows through the flow path of the anode plate, and oxygen gas (or air) flows through the flow path of the cathode plate.
  • MEA membrane electrode assembly
  • hydrogen gas used in fuel cells is methanol or other hydrocarbon water. It can be obtained by a steam reforming process. For example, in a methanol steam reforming process, methanol and steam produce hydrogen and carbon dioxide according to the following reaction. CH 3 ⁇ H + H 2 ⁇ ⁇ C ⁇ 2 + 3H 2 (1) This reaction decomposes methanol to form carbon monoxide and hydrogen.
  • methanol reformed gas consists of hydrogen and carbon dioxide.
  • C ⁇ carbon monoxide
  • the concentration of carbon monoxide in the reformed gas sent to the fuel cell stack must be sufficiently reduced (for example, to about 20 ppm or less). Then, the reformed gas coming out of the methanol reformer is sent to the shift reactor, and carbon monoxide is converted to carbon dioxide according to the shift reaction of the above equation (3).
  • the shift reaction is not enough to reduce the concentration of carbon monoxide in the reformed gas to, for example, about 20 ppm or less, and some carbon monoxide (about 100 ppm or less) survives even in the shift reaction. Therefore, as disclosed in JP-A-8-329969 and US-A-6,001,499, carbon monoxide remaining without reacting even in the shift reaction is oxidized by the Prox reaction (preferred oxidation reaction). It is known to cause.
  • the Prox reaction is as follows.
  • the concentration of carbon monoxide in the reformed gas flowing out from the shift reaction unit is detected by the CO sensor, PROX reaction in accordance with the detected CO concentration
  • the concentration of carbon monoxide in the reformed gas is reduced to, for example, about 20 ppm or less, which is necessary to prevent platinum catalyst poisoning.
  • JP-A-8-329969, JP-A-8-138710 and US-A-6,001,499 include a C ⁇ sensor for detecting the CO concentration in reformed gas in controlling the reforming gas proxies. It is disclosed.
  • This CO sensor has an electrolyte membrane with an anode and a cathode, and measures the C ⁇ concentration based on the potential difference between the electrodes generated when the CO adsorbed on the anode catalyst is electrochemically oxidized. ing.
  • This electrochemical CO sensor has a drawback that the responsiveness is not enough to control the fuel cell system's proxy reaction section in real time because the rate at which CO gas passes through the electrolyte membrane is rate-limiting.
  • a metal oxide semiconductor type CO sensor represented by tin oxide is known.
  • the gas to be detected is adsorbed to the heated element, and the c ⁇ concentration is detected based on the resulting change in the electric resistance of the element.
  • C ⁇ sensors using infrared spectroscopy are also known (eg, US-A-5, 502,308, US-A-5,340,986, US-A-5,341,214).
  • This infrared spectroscopy type C ⁇ sensor has an infrared light source and an infrared detector installed in a waveguide, and a bandpass filter that transmits infrared in the infrared absorption wavelength band of CO before the detector. There is an evening.
  • This infrared spectroscopy type C0 sensor has the advantage of excellent responsiveness.
  • C_ ⁇ 2 infrared detector of the sensor identifies an absorption that by the C_ ⁇ from absorption by C_ ⁇ 2 Can not do.
  • C ⁇ 2 is called an interfering gas for C ⁇ to be detected.
  • the fuel reformed gas contains up to about 25 mol% of CO 2 , and the C ⁇ 2 concentration in the reformed gas is about 15 It can vary from mole% to about 25 mole%.
  • the reformed gas contains a large amount of C 0 2, since C_ ⁇ 2 concentration in the reformed gas varies greatly, a certain amount of C_ ⁇ 2 gas to fill evening one cell Even if sealed, infrared detectors are significantly affected by fluctuations in CO 2 concentration in the reformed gas.
  • Another approach to avoid the interference from co 2 is to use the bandpass filter with a narrow transmission band, such as the transmission of infrared radiation absorption band and O over burlap wavelength band of C_ ⁇ 2 does not permit .
  • the attenuation performance of a bandpass filter having such a narrow transmission band depends on the angle of incidence of infrared light on the filter.
  • the angle of incidence on the filter is defined as the angle formed by the incident ray with respect to the optical axis of the filter (ie, the normal to the filter).
  • the present inventor has found that the transmission band of the filter shifts to the shorter wavelength side as the incident angle of the infrared light incident on the filter increases. With such filters the shift of the transmission band of the occurs, since the infrared absorption bands that overlap the wavelength band of C_ ⁇ 2 enters the detector through the filter one still hampered that by the co 2 There is a risk.
  • an object of the present invention is to provide a C ⁇ sensor capable of measuring a trace amount of CO in a reformed gas of a fuel cell with high accuracy.
  • Another object of the present invention is not Rukoto affected high concentration of interfering gas in the reformed gas (C_ ⁇ 2), capable of infrared spectroscopy type CO sensor of detecting the CO concentration with high precision To provide services.
  • the c ⁇ sensor is:
  • a waveguide closed at both ends, having an inlet and an outlet for a test gas, and defining an infrared spectroscopy chamber having a reflective inner wall;
  • An infrared light source disposed at one end of the analysis chamber
  • An infrared detector located at the other end of the analysis chamber
  • a bandpass filter disposed between the light source and the detector adjacent to the detector;
  • Incident limiting means for limiting infrared rays having an incident angle larger than a predetermined angle from being incident on the band-pass filter.
  • the bandpass filter is designed to selectively transmit infrared light in a wavelength band that enters the carbon monoxide absorption band but does not overlap with the carbon dioxide absorption band.
  • bandpass fill evening one has a half width of the central wavelength of about 0.09 / zm to about 4.66 m, about 4.5 to 4.8 m, preferably has a narrow transmission band of 4.5 4 ⁇ 4. 78 / zm .
  • the bandpass filter has a narrow transmission band that does not allow transmission of infrared light in a wavelength band overlapping with the absorption band of carbon dioxide, the intensity of infrared light incident on the infrared detector is reduced by the intensity of the carbon dioxide in the test gas. The presence or absence of carbon Not affected. Therefore, even if the concentration of carbon dioxide, which is an interfering gas, is high in the test gas and the concentration of carbon dioxide fluctuates significantly, the infrared detector detects the change in the concentration of carbon monoxide in the test gas. Output signal that accurately reflects the However, as mentioned above, the narrow transmission band of a bandpass filter will shift to shorter wavelengths as the angle of incidence of infrared radiation increases. As a result, an undesired situation may occur in which infrared light in a wavelength band overlapping the absorption band of carbon dioxide passes through the filter and enters the detector.
  • the CO sensor is provided with the incident limiting means.
  • the incident limiting means includes an infrared ray having an incident angle larger than a predetermined angle among infrared rays emitted from the infrared light source and transmitted through the waveguide while being reflected by the reflective inner wall of the waveguide. Is restricted or restricted.
  • the narrow transmission band of the band-pass filter set so as not to allow the transmission of infrared light in the wavelength band that overlaps the absorption band of carbon dioxide is shifted to the shorter wavelength side.
  • the function of the band-pass filter is prevented, and the function of the band-pass filter to prevent infrared rays having a wavelength band overlapping with the carbon dioxide absorption band from being transmitted to the detector is effectively secured.
  • the incidence restricting means restricts the incidence of infrared rays having an incident angle of 30 ° or more, more preferably 25 ° or more.
  • the incidence limiting means comprises an antireflection layer coated on the inner surface of a section of the waveguide adjacent to the bandpass filter.
  • the entrance limiting means comprises a sleeve of a non-reflective material located between the waveguide and the bandpass filter.
  • an enlarged box having an antireflective inner surface is arranged between the waveguide and the bandpass filter, and this box constitutes the incident limiting means.
  • the incidence limiting means comprises a light blocking member disposed between the light source and the bandpass filter, and the light blocking member is separated from the filter and the filter.
  • the filter has an opening aligned with the filter and an internal passage extending between the opening and the filter. The diameter of the opening and the distance between the opening and the filter are limited to infrared rays with an angle of incidence less than a predetermined angle. Are selected to be allowed to enter the filter.
  • the internal passage of the light-blocking member has a diameter larger than the diameter of the waveguide, and has an anti-reflective inner surface.
  • the internal passage of the light blocking member has an antireflective inner surface diverging toward the filter.
  • the CO sensor further comprises: a reference infrared detector disposed adjacent the infrared detector; a reference filter disposed between the light source and the reference detector adjacent the reference detector; A differential circuit that outputs an output signal proportional to the difference between the output of the detector and the output of the reference detector.
  • the reference filter is adapted to selectively transmit infrared radiation in a wavelength band that does not overlap with the absorption bands of carbon monoxide, carbon dioxide, and other interfering gases. According to this configuration, it is possible to compensate for a temporal decrease in output due to deterioration of the light source, a temporal decrease in the amount of reflected light due to contamination of the inner reflection surface of the waveguide, and a change in ambient temperature.
  • the first filter and the reference filter are respectively arranged on both sides of the axis of the waveguide, and the incidence limiting means is arranged coaxially with the waveguide adjacent to the filter and pointed toward the light source.
  • a conical light blocking member having a conical anti-reflective surface.
  • the CO sensor further includes means for pressurizing the test gas in the analysis chamber during measurement.
  • FIG. 1 is a schematic sectional view of a CO sensor according to a first embodiment of the present invention
  • FIG. 2 is a schematic enlarged sectional view of a part of the C ⁇ sensor shown in FIG. 1;
  • Graph 3 shows an infrared absorption scan Bae spectrum with CO and C 0 2;
  • Fig. 4 is an enlarged graph of a part of the absorption spectrum shown in Fig. 3;
  • Fig. 5 is a graph showing the shift of the transmission band of the bandpass filter
  • 6A and 6B are schematic cross-sectional views showing a variation of the incident limiting mechanism
  • FIG. 7 is a schematic sectional view of a C ⁇ sensor according to a second embodiment of the present invention.
  • Figure 8 is a block diagram of the detector output processing circuit
  • FIGS. 9A, 9B, 9C, 10A, 10B, and 10C are schematic cross-sectional views showing variations of various incident limiting mechanisms of the CO sensor shown in FIG. ;
  • FIG. 11 is a schematic sectional view of a CO sensor according to a third embodiment of the present invention.
  • FIG. 12 is a flowchart of a measurement sequence by the CO sensor shown in FIG.
  • a CO sensor 10 includes a waveguide 12 made of, for example, a metal tube. Both ends of the waveguide 12 are closed by end plates 14 and 16, and an infrared spectroscopic analysis chamber 18 is defined inside.
  • the waveguide 12 is provided with an inlet 20 and an outlet 22 for a test gas, and the test gas or its sample flowing out of the shift reaction section of the fuel reforming system of the fuel cell or the like is supplied to the infrared spectroscopy chamber 1. 8 is allowed to pass.
  • One end plate 14 is provided with an infrared light source 24, and an end plate 16 opposed thereto is provided with an infrared detector 26.
  • the inner wall of the waveguide 12 has a specular reflection surface 28 formed of, for example, gold, nickel, or aluminum plating, and the infrared light from the light source 24 is reflected by the inner wall of the waveguide 12 while the infrared light is reflected. It proceeds to detector 26.
  • an incandescent lamp having a tungsten filament can be suitably used.
  • a quantum-sensitive sensor such as a photoconductive sensor or a photovoltaic sensor, or a heat-sensitive sensor such as a thermopile, a bolometer, or a pyroelectric sensor can be used.
  • a thermopile thermopile
  • a bolometer bolometer
  • a pyroelectric sensor thermopile sensor
  • the band-pass filter 3 0 is entered in the absorption band of C_ ⁇ the absorption band of C_ ⁇ 2 have a narrow transmission band wavelength band that does not over one lap.
  • the bandpass filter 30 has a transmission band of 4.54 to 4.78 / im, a center wavelength of about 4.66 m and a half bandwidth of about 0.09 m.
  • the inner wall 28 of the waveguide 12 has an infrared absorbing or anti-reflective coating 32 over a section of length Q adjacent to the bandpass filter-30. It is provided. Of the infrared light that exits the light source 24 and travels through the waveguide 12 while being reflected by the specular reflection surface 28, the infrared light incident on the antireflection coating 32 is absorbed by the antireflection coating 32 So it would never reach the bandpass filter 30.
  • Infrared rays whose angle with respect to the optical axis of the sensor 10 is smaller than ⁇ have the opportunity to reach the bandpass filter 130 without entering the anti-reflection coating 32, but infrared rays whose angle is greater than 0 must be reflected. Since it is incident on the section ⁇ of the protective coating 32, it will be prevented from reaching the bandpass filter 30. Therefore, the antireflection coating 32 constitutes an incident limiting means 34 for restricting infrared rays having an incident angle larger than the angle ⁇ from entering the bandpass filter 30.
  • the length ⁇ of the section of the antireflection coating 32 is set so that the angle 0 is 25 °.
  • the antireflection coating 32 can be formed by applying a suspension in which graphite or carbon powder is dispersed in a dispersion medium, drying and sintering.
  • the test gas or its sample When measuring the CO concentration, the test gas or its sample is caused to flow in the infrared spectroscopic analysis chamber 18 through the inlet 20 and the outlet 22 of the waveguide 12.
  • the infrared rays from the light source 24 travel toward the other end in the waveguide 12 while being reflected by the reflective inner wall 28 as shown by arrows in FIGS.
  • infrared rays inherent to molecules of various components of the test gas occur. Since the incident limiting means 34 is located in front of the bandpass filter 30, the incidence of infrared rays having an incident angle of 25 ° or more to the bandpass filter 30 is limited as described above.
  • the bandpass filter 130 selectively transmits infrared rays in the wavelength band of 4.54 to 4.78 m from the infrared rays incident thereon.
  • the infrared light transmitted through the bandpass filter 30 is detected by the infrared detector 26.
  • the output of the detector 26 changes according to the CO concentration of the test gas.
  • the output of the detector 26 is sent to a processing circuit (not shown), and the latter calculates the CO concentration based on the output of the detector 26.
  • the output of detector 26 is a function of the degree of infrared absorption by CO, the latter being a function of the CO concentration of the gas under test. Furthermore, in some circumstances, the output of the detector 2 6 can be affected interference gas C_ ⁇ 2.
  • C_ ⁇ and the relationship between the infrared absorption by the interference gas C_ ⁇ 2 and the output of the detector 2 6 will be described with reference to the graph of FIG. 3 and FIG. 4, the graph of FIG. 3 is a CO (concentration lOOOppm)
  • C Fig. 4 shows the infrared absorption spectrum at 2 (concentrations of 15 mol% and 25 mol%), and the graph in Fig. 4 is an enlargement of a part of the graph in Fig. 3.
  • infrared absorption by CO occurs in the wavelength band of about 4.45 to 4.80 m.
  • the interference gas infrared absorption by C_ ⁇ 2 is occurred at a wavelength band of about 4.54 / xm, is absorbed partially overlap C_ ⁇ As best seen from FIG. 4.
  • the output variation of the detector 2 6 by only the infrared absorption of CO is shown by a solid line hatching in the graph of FIG. 4 It will be proportional to the area of the absorbed region (however, only part of the infrared absorption region of CO is shown in the graph of Fig. 4).
  • the CO sensor of the present invention since the band-pass filter 3 0 (which has a transmission band limit corresponding to the upper limit 4 ⁇ 54 m of the absorption band of C_ ⁇ 2) is provided, Bandopasufu I Le evening one 3 Under the condition that 0 functions properly, the output fluctuation of the detector 26 due to the infrared absorption of CO is proportional to the area of the solid-line hatching region on the right side of the lower limit ⁇ of the transmission band in FIG. The output of 26 is the effect of infrared absorption by the interfering gas C ⁇ ⁇ 2 Will not receive.
  • the transmission band of the bandpass filter 30 depends on the incident angle of the light beam. This is illustrated by the graph of FIG. 5 (which shows the transmission band of the same bandpass filter for different incident angles). As can be seen from the graph of FIG. 5, the transmission band of the bandpass filter increases as the incident angle increases. Shifts to the shorter wavelength side according to.
  • the lower limit of the transmission band of the band-pass filter -30 is determined by the arrow as the incident angle increases! If shift to the short wavelength side to the output of the detector 2 6 will be inevitably affected by infrared absorption by interfering gases C_ ⁇ 2 (indicated by a broken line hearts quenching and cross hatching in FIG. 4) .
  • the filter cell is a than the amount of C_ ⁇ 2 in a test gas does not function effectively only if small enough to be ignored with respect to the amount of C_ ⁇ 2 enclosed in filter cell, the fuel cell If the C_ ⁇ 2 concentration of the test gas as reformed gas varies in the range of about 1 5 mole% to about 2 5 mole%, the filter cell is not valid.
  • the interfering gas is detected by the output of the detector 26 as easily understood from the comparison with the area of The impact on the industry will not be negligible.
  • FIGS. 6A and 6B show a variation of the incident limiting means that can be used as an alternative to the incident limiting means 34 shown in FIG.
  • the same components as those shown in FIG. 2 are denoted by the same reference numerals.
  • the entrance limiting means 34 is formed by a sleeve 36 of the same diameter, separate from the waveguide 12, formed of a non-reflective material.
  • sleep 36 has a non-reflective inner surface.
  • the incident limiting means 34 is composed of a box 38 that is larger in diameter than the waveguide 12, and the inner wall of the dark box 38 is covered with an anti-reflection coating 32. I have. Since the inner peripheral wall of the dark box 38 is enlarged in diameter, there is an increased likelihood that an infrared ray having an incident angle larger than 0 is repeatedly absorbed and attenuated as shown by the broken line.
  • FIG. 7 shows a CO sensor 40 according to a second embodiment of the present invention.
  • a reference bar is located next to the first infrared detector 26.
  • a reference infrared detector 44 with a low pass filter 42 is arranged.
  • the reference infrared detector 44 has the same characteristics as the first detector 26.
  • a thermopile with a built-in thermistor is used for the reference detector 44.
  • Reference band-pass filter 4 2 the absorption band and C_ ⁇ second absorption zone Contact and other interfering components of the CO (particularly, H 2 0 and CH 3 OH) IR absorption band overlaps Shinano have wavelength bands of It has a transmission band of about 3.85 to 4.55 im for selective transmission. Therefore, the output of the reference detector 44 is not affected by the CO concentration fluctuation.
  • the inner wall of the waveguide 12 has an anti-reflection coating 3 over a section of length Q adjacent to the bandpass filters 30 and 42. 2 is provided, and constitutes the above-described incidence limiting means 34.
  • the incident limiting means 34 functions in common for both the first bandpass filter 130 and the reference filter 42.
  • the CO sensor 40 further includes the processing circuit shown in FIG. 8, and the output of the infrared detector is processed by this processing circuit.
  • the processing circuit includes a differential circuit 46 and an adder 48, and the outputs of the first detector 26 and the reference detector 44 are supplied via amplifiers 50 and 52, respectively. Input to differential circuit 46.
  • the differential circuit 46 outputs an output signal proportional to the difference between the output of the detector 26 and the output of the reference detector 44, and the output of the differential circuit 46 is sent to the adder 48.
  • the output from the thermistor (not shown) built in the reference detector 44 is amplified by the amplifier 54 and input to the adder 48.
  • the adder 48 outputs an output signal proportional to the difference between the output of the differential circuit 46 and the output of the thermistor.
  • the output of the adder 48 is amplified by the amplifier 56 and then output from the sensor output terminal 58.
  • the time-dependent decrease in output due to the deterioration of the light source 24 and the time-dependent decrease in the amount of reflected light due to contamination of the inner reflection surface 28 of the waveguide 12 detect infrared absorption by CO. It equally affects both the output of detector 26 and the output of reference detector 44. Since the differential circuit 46 outputs an output signal proportional to the difference between the output of the detector 26 and the output of the reference detector 44, in this embodiment, the output decreases over time due to the deterioration of the light source 24, Compensates for the temporal deterioration of the amount of reflected light due to contamination of the inner reflecting surface 28 of the waveguide 12 be able to.
  • the ambient temperature is detected by the thermistor incorporated in the detector 26, and the adder 48 outputs an output signal proportional to the difference between the output of the differential circuit 46 and the output of the thermistor. Fluctuations in sensor output due to fluctuations in ambient temperature are also compensated.
  • FIGS. 9B and 9C show a variation of the incident limiting means 34 shown in FIG. 9A, in which two incident limiting means having the same structure as those shown in FIGS. 6A and 6B are used. Shown when applied to two juxtaposed filters 30 and 42.
  • FIGS. 9B and 9C the same components as those shown in FIGS. 6A and 6B are denoted by the same reference numerals, and will not need to be described repeatedly.
  • FIGS. 10A, 10B and 10C also show an incident limiting means that can be used in the sensor of FIG. 7 instead of the incident limiting means 34 shown in FIG. 9A.
  • the incident limiting means 34 is a hollow light shielding member or box 60 placed between the waveguide 12 and the bandpass filters 30 and 42.
  • the light shielding member 60 has an inner cavity 62 having an inner diameter larger than the inner diameter of the waveguide 12, and the inner surface of the light shielding member 60 is covered with an antireflection coating 32.
  • an entrance opening 64 is provided on the front wall of the light shielding member 60, and an exit opening 66 is provided on the rear wall.
  • the diameter of the inlet opening 64 and the distance between it and the filters 30 and 42 are set so that only infrared rays having an incident angle of 0 or less are allowed to enter the filter.
  • the entrance restricting means 34 comprises an inlet opening 68 aligned with the filters 30 and 42, respectively, and a light blocking member 72 having an internal passage 70 formed therein.
  • Each internal passage 70 is divergently formed at an angle S toward the corresponding fill and is covered with an anti-reflection coating 32.
  • the end of the waveguide 12 is spaced from the filters 30 and 42, and the entrance limiting means 34 is a waveguide between the filters 30 and 42.
  • a conical light-shielding member 74 is disposed coaxially with the tube 12 and is pointed toward the waveguide 12. The surface of the light shielding member 74 is covered with an antireflection coating 76.
  • the conical light-shielding member 7 4 is used for the infrared light reflected by the reflective inner wall 28 of the waveguide 12. Of these, the infrared rays having an incident angle larger than 0 are prevented from entering the filters 30 and 42.
  • the gap between the end of the waveguide 12 and the filters 30 and 42 is surrounded by a hollow dark box 78, which also forms a part of the incident limiting means 34.
  • the dark box 78 has an inner cavity 80 having an inner diameter larger than the inner diameter of the waveguide 12, and the inner cavity 80 extends forward from an end of the waveguide 12.
  • the inner surface of the dark box 78 and the outer peripheral surface of the waveguide 12 of the dark box 78 are covered with an antireflection coating 32. Infrared rays having an incident angle larger than the angle S incident on the dark box 78 are attenuated by the anti-reflection coating 32 while repeatedly hitting the inner wall of the box 78, so that they reach the filters 30, 42. It is surely blocked.
  • FIG. 11 shows a CO sensor 90 according to a third embodiment of the present invention.
  • the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
  • an incident limiting mechanism similar to that described above is provided before the filter 30.
  • solenoid valves 94 and 96 controlled by a control circuit 92 are provided at the gas inlet 20 and the outlet 22 of the analysis chamber 18. Each of them is provided so that the test gas can be confined in the analysis room 18.
  • a gas pressurizing device 102 is arranged between the gas inlet 20 and the analysis chamber 18.
  • the pressurizing device 102 can be composed of, for example, a cylinder 98 and a piston 100, and the piston 100 is driven by a driving device such as a solenoid 104 controlled by a control circuit 92. can do.
  • the pressure of the gas pressurized by the pressurizing device 102 is detected by the pressure sensor 106.
  • the operation of the CO sensor 90 will be described with reference to the flowchart of FIG. 12 showing the measurement sequence.
  • the solenoid valves 94 and 96 are first turned on. Close and seal the analysis chamber 18 and cylinder 98.
  • the solenoid 104 is excited to operate the piston 100, and the compression of the test gas is started. Pressurization of the gas is performed while monitoring the gas pressure with the pressure sensor 106. When the gas pressure reaches the set pressure, the pressurization is stopped. In this state, the infrared light source 24 is turned on, and the infrared light that has passed through the filter 30 is detected by the detector 26.
  • the detector 26 Since the gas in the analysis chamber 18 is pressurized, the detector 26 outputs a voltage with a large fluctuation range even if the C ⁇ concentration in the test gas is extremely low, ie, less than 100 ppm. Therefore, the CO concentration can be measured with high accuracy.
  • the actual pressure in the analysis chamber 18 is detected by the pressure sensor 106, the concentration is corrected based on the detected pressure, and the CO concentration at the atmospheric pressure is calculated.
  • the detection and concentration calculations are repeated n times and the average is output.
  • the light source 24 is turned off, and the solenoid valves 94 and 96 are opened to evacuate and prepare for the next measurement.

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Biochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Optical Measuring Cells (AREA)
  • Fuel Cell (AREA)

Abstract

Cette invention se rapporte à un capteur de CO utilisant la spectroscopie à infrarouge pour détecter la concentration de monoxyde de carbone dans un gaz reformé alimentant une pile à combustible (10). Ce capteur de CO (10) comprend un guide d'onde (12) contenant une entrée (20) et une sortie (22) pour le gaz à tester et définissant une chambre spectroscopique à infrarouge (18); une source d'infrarouge (24) placée à une extrémité de la chambre; un détecteur d'infrarouge (26) placé à l'autre extrémité de la chambre; un filtre à bande passante étroite (30) placé face au détecteur (26); et un moyen de limitation destiné à empêcher le filtre (30) de recevoir les rayons infrarouges à des angles d'incidence supérieurs à un angle prédéterminé. Dans un mode de réalisation, le moyen de limitation est constitué par un revêtement antiréflechissant (32) placé à l'intérieur de l'extrémité du guide d'onde. Une petite quantité de CO peut être détectée avec précision dans un gaz reformé qui contient une concentration élevée de gaz interférant (CO2).
PCT/JP2000/007055 1999-10-12 2000-10-11 Capteur de co WO2001027596A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU76837/00A AU7683700A (en) 1999-10-12 2000-10-11 Co sensor

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP11/290120 1999-10-12
JP29012099 1999-10-12
JP2000/18032 2000-01-25
JP2000018032A JP2004239611A (ja) 1999-10-12 2000-01-25 Ｃｏセンサ

Publications (1)

Publication Number Publication Date
WO2001027596A1 true WO2001027596A1 (fr) 2001-04-19

Family

ID=26557895

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2000/007055 WO2001027596A1 (fr) 1999-10-12 2000-10-11 Capteur de co

Country Status (3)

Country Link
JP (1) JP2004239611A (fr)
AU (1) AU7683700A (fr)
WO (1) WO2001027596A1 (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005078412A1 (fr) * 2004-02-07 2005-08-25 Rolls-Royce Plc Systeme de surveillance de la composition d'un gaz
JP2005281009A (ja) * 2004-03-26 2005-10-13 Aisin Seiki Co Ltd 改質装置
JP2006090775A (ja) * 2004-09-22 2006-04-06 Ushio Inc 吸光度測定ユニット
JP2007024545A (ja) * 2005-07-12 2007-02-01 Denso Corp 光検知式ガスセンサ装置
KR20150096622A (ko) * 2014-02-14 2015-08-25 한국전자통신연구원 가스 모니터링 장치 및 그를 포함하는 플라즈마 공정 설비
KR101760031B1 (ko) 2015-05-29 2017-07-21 (주) 휴마스 감도와 신뢰성 향상을 위한 광학적 가스 센서
US10153141B2 (en) 2014-02-14 2018-12-11 Electronics And Telecommunications Research Institute Apparatus for monitoring gas and plasma process equipment including the same
US10254222B2 (en) 2014-07-03 2019-04-09 Murata Manufacturing Co., Ltd. Gas concentration measurement device
CN109991186A (zh) * 2019-03-12 2019-07-09 湖北利安伟业消防工程有限公司 一种便携式智能可燃气体探测器
DE102010031919B4 (de) * 2010-07-22 2020-12-03 Schaeffler Technologies AG & Co. KG Messsonde für einen Sensor zur Analyse eines Mediums mittels Infrarotspektroskopie und Verfahren zur Herstellung der Messsonde
EP4242634A1 (fr) * 2022-03-10 2023-09-13 Christian Buck Dispositif et procédé de détermination spectroscopique des analytes à sensibilité dépendante de la pression variable

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008082862A (ja) * 2006-09-27 2008-04-10 Neopt Kk ガス濃度測定装置及びガス濃度測定方法
JP5562539B2 (ja) * 2008-08-21 2014-07-30 矢崎総業株式会社 濃度測定装置
SE533411C2 (sv) * 2008-08-28 2010-09-21 Senseair Ab Ett för en spektralanalys av en komprimerad gas, såsom en gas vid små gaskoncentrationer vid atmosfärstryck, anpassat arrangemang
JP5399721B2 (ja) * 2009-01-14 2014-01-29 矢崎総業株式会社 ガス濃度検出装置
JP6202440B2 (ja) * 2014-01-20 2017-09-27 パナソニックＩｐマネジメント株式会社 赤外線式ガスセンサ
JP6206810B2 (ja) * 2014-01-20 2017-10-04 パナソニックＩｐマネジメント株式会社 赤外線式ガスセンサ
DE102016007825A1 (de) * 2016-06-25 2017-12-28 Hydac Electronic Gmbh Verfahren und Vorrichtung zur Überwachung der Qualität von gasförmigen Medien

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02116737A (ja) * 1988-10-26 1990-05-01 Horiba Ltd Ｃｏ分析計
JPH02236441A (ja) * 1988-11-04 1990-09-19 Instrumentarium Oy 複数のガスの同定装置および方法
JPH02118855U (fr) * 1989-03-13 1990-09-25
JPH0241563Y2 (fr) * 1984-07-07 1990-11-06
JPH04191654A (ja) * 1990-11-27 1992-07-09 Electric Power Dev Co Ltd ガス中の亜酸化窒素濃度の連続測定方法
JPH06148070A (ja) * 1992-11-05 1994-05-27 Japan Radio Co Ltd 同位体比分析方法および装置
JPH0662357U (ja) * 1993-02-08 1994-09-02 日新電機株式会社 ガス濃度計測装置
JPH0664142U (ja) * 1993-02-08 1994-09-09 日新電機株式会社 ガス濃度計測装置
JP3004459U (ja) * 1994-05-21 1994-11-15 株式会社堀場製作所 赤外線ガス分析計
JPH0798273A (ja) * 1993-09-29 1995-04-11 Furoo Syst:Kk ガス分析計
JPH09318534A (ja) * 1996-05-25 1997-12-12 Horiba Ltd ＨＣｌ計

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0241563Y2 (fr) * 1984-07-07 1990-11-06
JPH02116737A (ja) * 1988-10-26 1990-05-01 Horiba Ltd Ｃｏ分析計
JPH02236441A (ja) * 1988-11-04 1990-09-19 Instrumentarium Oy 複数のガスの同定装置および方法
JPH02118855U (fr) * 1989-03-13 1990-09-25
JPH04191654A (ja) * 1990-11-27 1992-07-09 Electric Power Dev Co Ltd ガス中の亜酸化窒素濃度の連続測定方法
JPH06148070A (ja) * 1992-11-05 1994-05-27 Japan Radio Co Ltd 同位体比分析方法および装置
JPH0662357U (ja) * 1993-02-08 1994-09-02 日新電機株式会社 ガス濃度計測装置
JPH0664142U (ja) * 1993-02-08 1994-09-09 日新電機株式会社 ガス濃度計測装置
JPH0798273A (ja) * 1993-09-29 1995-04-11 Furoo Syst:Kk ガス分析計
JP3004459U (ja) * 1994-05-21 1994-11-15 株式会社堀場製作所 赤外線ガス分析計
JPH09318534A (ja) * 1996-05-25 1997-12-12 Horiba Ltd ＨＣｌ計

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005078412A1 (fr) * 2004-02-07 2005-08-25 Rolls-Royce Plc Systeme de surveillance de la composition d'un gaz
JP2005281009A (ja) * 2004-03-26 2005-10-13 Aisin Seiki Co Ltd 改質装置
JP4490717B2 (ja) * 2004-03-26 2010-06-30 アイシン精機株式会社 改質装置
JP2006090775A (ja) * 2004-09-22 2006-04-06 Ushio Inc 吸光度測定ユニット
JP4506375B2 (ja) * 2004-09-22 2010-07-21 ウシオ電機株式会社 吸光度測定ユニット
JP2007024545A (ja) * 2005-07-12 2007-02-01 Denso Corp 光検知式ガスセンサ装置
DE102010031919B4 (de) * 2010-07-22 2020-12-03 Schaeffler Technologies AG & Co. KG Messsonde für einen Sensor zur Analyse eines Mediums mittels Infrarotspektroskopie und Verfahren zur Herstellung der Messsonde
KR20150096622A (ko) * 2014-02-14 2015-08-25 한국전자통신연구원 가스 모니터링 장치 및 그를 포함하는 플라즈마 공정 설비
KR101871809B1 (ko) * 2014-02-14 2018-08-03 한국전자통신연구원 가스 모니터링 장치 및 그를 포함하는 플라즈마 공정 설비
US10153141B2 (en) 2014-02-14 2018-12-11 Electronics And Telecommunications Research Institute Apparatus for monitoring gas and plasma process equipment including the same
US10254222B2 (en) 2014-07-03 2019-04-09 Murata Manufacturing Co., Ltd. Gas concentration measurement device
KR101760031B1 (ko) 2015-05-29 2017-07-21 (주) 휴마스 감도와 신뢰성 향상을 위한 광학적 가스 센서
CN109991186A (zh) * 2019-03-12 2019-07-09 湖北利安伟业消防工程有限公司 一种便携式智能可燃气体探测器
EP4242634A1 (fr) * 2022-03-10 2023-09-13 Christian Buck Dispositif et procédé de détermination spectroscopique des analytes à sensibilité dépendante de la pression variable

Also Published As

Publication number Publication date
AU7683700A (en) 2001-04-23
JP2004239611A (ja) 2004-08-26

Similar Documents

Publication Publication Date Title
WO2001027596A1 (fr) Capteur de co
US6843102B1 (en) Gas sensor arrangement
JPS5836057Y2 (ja) 螢光反応測定装置
JPH08114501A (ja) ガス用赤外線分光センサ
CN105992942B (zh) 气体检测器
JPS60228940A (ja) 軽減されたガスを検出する方法および装置
EP0619879A1 (fr) Chambre d'echantillons gazeux a plusieurs voies
EP0904529A1 (fr) Dispositif pour spectroscopie d'absorption non dispersive dans l'infrarouge et procede de mesure de rapports isotopiques dans des echantillons gazeux
US7132657B2 (en) Infrared gas detector
KR20110043549A (ko) 스펙트럼 분석용 장치
CN106170689B (zh) 气体探测器堵塞探测
US20070044540A1 (en) Radiation source for gas sensor
US6512230B1 (en) Method and an arrangement for initiating radiation absorption measurements of gaseous media
JPH06508443A (ja) 光度計
JP2016176778A (ja) 光学式水素ガス検知装置及び方法
US6121617A (en) Infrared gas analyzer
US9030665B2 (en) Method for monitoring and/or regulating fuel cells
KR20210127719A (ko) 분자 종의 광학 감지를 위한 분광 장치, 시스템, 및 방법
JP2019522195A (ja) 気相媒質の品質を監視するための方法及び装置
US11280726B2 (en) Assembly and method for measuring a substance concentration in a gaseous medium by means of absorption spectroscopy
KR20050106116A (ko) 촉매적 변형에 의한 분석 민감도 증진법
US5818598A (en) Nondispersive optical monitor for nitrogen-oxygen compounds
US6661011B2 (en) Multi-component gas analyzer having cassette-type light path system
JP5422493B2 (ja) ガス発熱量計測装置及びガス発熱量計測方法
JPH05196569A (ja) 水素センサ

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP