WO2012152621A1 - Procédé et système pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz - Google Patents

Procédé et système pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz Download PDF

Info

Publication number
WO2012152621A1
WO2012152621A1 PCT/EP2012/058006 EP2012058006W WO2012152621A1 WO 2012152621 A1 WO2012152621 A1 WO 2012152621A1 EP 2012058006 W EP2012058006 W EP 2012058006W WO 2012152621 A1 WO2012152621 A1 WO 2012152621A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
spectrum
hydrogen
arc
measuring cell
Prior art date
Application number
PCT/EP2012/058006
Other languages
German (de)
English (en)
Inventor
Hans Bettermann
Peter Fischer
Arno Gödecke REICHELT
Björn Fischer
Original Assignee
Heinrich-Heine-Universität Düsseldorf
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 Heinrich-Heine-Universität Düsseldorf filed Critical Heinrich-Heine-Universität Düsseldorf
Publication of WO2012152621A1 publication Critical patent/WO2012152621A1/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
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/66—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence
    • G01N21/67—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence using electric arcs or discharges
    • 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
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/66—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence
    • G01N21/69—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence specially adapted for fluids, e.g. molten metal

Definitions

  • the invention relates to a method and an arrangement for detecting a first gas in a gas mixture comprising at least one further gas.
  • the present invention relates in particular to a method for detecting hydrogen in the presence of nitrogen, or a hydrogen detector, with which hydrogen is detectably detectable even in very low concentrations.
  • Fuel cells are currently the focus of global R & D activities, as they are compared to systems based on conventional energy sources based on efficiency and pollutant emission. In addition to the construction of stationary power plants, their greatest potential lies in automotive engineering.
  • PEM polymer electrolyte membrane
  • measurements of gases of low concentration with spectroscopic measuring methods or sensors are known.
  • a measuring device for use in the analysis of gas mixtures known.
  • This measuring device is based on a silent electrical discharge and enables the detection of gases, for example in a concentration range of 0.1-2%.
  • This sensor is particularly effective if the nitrogen concentration is kept low.
  • a disadvantage of such a sensor is therefore that measurements in air or in air-containing gas mixtures are not possible or only with limited sensitivity.
  • the detectable concentrations are not sufficient for a large number of especially safety-relevant applications.
  • a method and an arrangement for determining the purity and / or pressure of gases for electric lamps is also known.
  • This method is based on the influence of the gas pressure or impurities on the fluorescence spectrum of a gas discharge, in particular a glow discharge.
  • the detection is carried out in particular by means of the measured intensity of one or more suitable spectral lines, wherein the intensities in the relevant region or the intensity of at least one spectral line should be pressure-independent.
  • a spectral line of a gas can be selected, whose wavelength corresponds to a higher excitation energy, as the impurity.
  • a fluorescence sensor for monitoring gases is also known, which is based on a spark discharge.
  • the sensor serves to measure gaseous species as atmospheric pollutants, for example for fuel cells.
  • the fluorescence radiation is selective for individual molecules, such as for gaseous molecules, wherein the individual molecules are detected separately via individual detectors. The sensitivity is particularly high when interactions between the individual molecules are avoided. This method is quite complex and also partly difficult to control due to the operating conditions of a spark discharge and thus reproducible only in moderation.
  • An object of the present invention is therefore to provide a method and an arrangement for detecting a gas, in particular hydrogen, even in low concentrations safely and reproducibly. It is a particular object of the present invention to enable detection of a gas having a high selectivity with high sensitivity.
  • the present invention relates to a method for detecting a first gas in a gas mixture comprising at least one further gas, comprising the steps of: a) introducing the gas mixture into a measuring cell;
  • the further gas is selected such that its spectrum has a characteristic contour that changes depending on the presence and / or the concentration of the first gas; and f) evaluating the contour of the spectrum.
  • Detecting in the sense of the present invention here means in particular a qualitative detection as well as a quantitative detection of the respective gas.
  • the inventive method is based on the effect that the first gas to be detected in a spectroscopic investigation shows an interaction with a further, in particular molecular gas.
  • the method according to the invention is based on the fact that the discharge spectrum or its contour, in particular of the further gas, can be influenced by the presence and / or concentration of another gas, ie in particular of the gas to be detected.
  • the additional gas can serve, in particular, as an indicator gas, by means of which, or by the evaluation of its spectrum, the presence and concentration of the gas to be detected can be detected.
  • the gas to be detected is passed together with the further gas into a measuring cell and the gas mixture is measured there.
  • an arc discharge takes place in the measuring cell, whereby an arc is generated.
  • the principle of an arc discharge has the particular advantage here that such a measuring method is radio-interference-proof, for example compared to a spark discharge, as a result of which no electromagnetic waves are generated outside the measuring cell.
  • the inventive method is particularly safe to carry out.
  • the arc discharge on the one hand offers the advantage of a higher light intensity and thus a higher sensitivity.
  • the arc excites the gas molecules in the measuring cell and thereby emits a defined radiation.
  • This radiation thus triggered by the arc and in particular emitted by the further gas is taken up in a further step and then optically filtered and / or spectrally decomposed in order to record a spectrum, in particular of the further gas.
  • the discharge in the form of the arc thus causes the gases to be analyzed to be partially ionized and, in addition, as a result of the electronic excitation of gas particles in the region of the arc, a light emission which can be absorbed. This light emission of the excited particles can then be used as specific detection for the respective gas types and concentration.
  • the further gas is selected such that its spectrum has a contour which changes as a function of the presence and / or the concentration of the first gas
  • a suitable evaluation of the spectrum or the contour of the spectrum of the further gas can be used Also quantitative detection of the gas to be detected take place. In this case, the gas to be detected is still detectable even if its own spectrum does not indicate or in an unsuitable manner a presence or a concentration.
  • the contour of the spectrum of the further gas has at least two spectral transitions, the relative strength of which depends on the presence and / or the concentration of the first gas. Consequently, in particular relative intensities of the discharge spectrum are changed or influenced by the interaction of the gas to be detected and the further gas.
  • the wavelengths of the corresponding spectral lines remain essentially unchanged. However, some spectral lines, in contrast to a pure, so uninfluenced spectrum, a significantly reduced intensity, while other spectral lines remain largely unaffected. This decrease in intensity occurring relative to further spectral lines is called quenching and offers particular advantages.
  • the presence of the gas to be measured can be selectively concluded.
  • the concentration of the gas to be detected can be determined very strongly by way of the extent of the intensity change or quenching.
  • the focus of an evaluation of the spectrum or the contour of the spectrum can be directed to defined wavelength ranges, which can make the detection according to the invention particularly accurate.
  • a gas which has molecular vibrations in order to achieve a quenching of a spectral line.
  • gases include, for example, carbon monoxide, carbon dioxide or methane.
  • the first gas is hydrogen and that the further gas is nitrogen.
  • a reliable and high-detection of the hydrogen as the gas to be detected is possible.
  • Hydrogen can be measured via the H a line up to a certain concentration, which can be particularly in the range of concentrations. This signal is essentially proportional to the partial pressure of the hydrogen over a large measuring range. Therefore, especially in the case of large water substance concentrations, the hydrogen can be measured directly in a nitrogen atmosphere. However, below a certain concentration limit of the hydrogen, which can be in the range of concentrations, a direct measurement of the hydrogen, for example through the H a - line, is only possible to a limited extent.
  • the influence of the hydrogen according to the invention on the contour of the discharge spectrum of the nitrogen now takes effect.
  • the presence of traces of hydrogen affects the signal intensities of the entire nitrogen spectrum.
  • the observed subband spectra of nitrogen are characteristically influenced.
  • the part spectrum C 3 n u -> B 3 ü g of the neutral N 2 is influenced differently than the part spectrum B 2 U + -> X 2 g + of the ionized nitrogen N 2 + .
  • nitrogen has the advantage that it has an overall spectrum, which is composed of several sub-spectra, whereby these sub-spectra behave differently, which allows a particularly advantageous measurement behavior.
  • the fact is used that molecular hydrogen is atomized in the electric arc to a certain extent, and in the visible spectral range the characteristic emission lines of these species are observed.
  • the molecular nitrogen is preferentially excited and emits a relatively intense spectrum compared to other gases with two band systems between 200nm and 290nm and between 290nm and 410nm in the ultraviolet spectral region.
  • the intensity of the first-mentioned transitions is thereby already selectively weakened (quenched) by the presence of small amounts of molecular hydrogen, while the influence on the transitions of the second group of bands is significantly less.
  • the relative intensity of the light emission of a transition from the band system between 200 and 290 nm and that of a transition from another band system of the nitrogen can be analyzed and the content of the be correlated to be examined gas mixture of elemental hydrogen.
  • the H a line normally used to detect hydrogen can also be present in the discharge spectrum in the presence of water in a gas mixture. Therefore, a H a - line does not necessarily indicate the presence of elemental hydrogen in any case. This uncertainty can be avoided according to the invention. Furthermore, it can be seen that it is possible according to the Invention to selectively detect hydrogen even in the presence of water or steam in the gas mixture, which for the measuring method according to the invention a particularly wide variety of applications while simplicity allows since no consideration for water vapor or water is.
  • the nitrogen, as well as generally the other gas may be added to the gas or the hydrogen to be detected, in order to generate the gas mixture.
  • the selection of the further gas is thus carried out by adding the additional gas or by measuring a gas atmosphere comprising the further gas.
  • the first gas in the gas mixture in a concentration of ⁇ 1%, in particular ⁇ lo, before.
  • the method according to the invention is particularly advantageous especially in such a concentration range of the gas to be measured or detected.
  • the arc is generated by the application of an AC voltage to electrodes.
  • the AC voltage at the electrodes must be sufficiently high and matched to the Elektrodenab stand to achieve the required current density.
  • the AC voltage is at a frequency between 20 kHz and 70 kHz. This makes it possible to also ionize molecules such as water, nitrogen or hydrogen and thus maintain the discharge.
  • the method according to the invention can therefore be used, for example, both in the atmosphere of a fuel cell and in air. By choosing the discharge conditions more precisely, optimal discharge characteristics can be achieved for the particular analytical task.
  • an AC voltage in said frequency range also offers further advantages: On the one hand, a one-sided electrode burn, which could occur in a DC arc and would lead to the geometric displacement of the focal length and thus the change in the optical properties of the system. On the other hand, the required voltage sources are commercially available and inexpensive. It is particularly advantageous here to use inverter circuits which are used, for example, for the operation of cold cathode fluorescent lamps (CCFL). In addition, the use of the aforementioned frequency range prevents interference with radio and mobile radio systems.
  • inverter circuits already ensure galvanic isolation, they also offer the advantage that it is possible to integrate the measuring cell described below without further isolation measures, for example, directly into a fuel cell stack or to operate in the range of potentially hydrogen-containing gas mixtures, the risk of unwanted sparkover and thus accidental ignition of the same can be avoided.
  • a voltage in a range between> 0.5 kV and ⁇ 5 kV is applied to the electrodes, so that current levels are set in a range between> 200 ⁇ to ⁇ 6 mA.
  • the emitted radiation is removed by a light guide.
  • a light guide it is possible, for example, mechanically integrate the arrangement for performing the method in a fuel cell stack or in a fuel cell stack or in the housing of the fuel cell stack, as well as in areas where to expect an increased risk of unwanted leakage of hydrogen whereas the other components of the analytics can be located outside the fuel cell or area.
  • a discharge may also be advantageous for a discharge to be carried out in at least two measuring cells, wherein the optical filtering of the emitted radiation and / or the spectral decomposition of the emitted radiation is carried out individually for each of the measuring cells or else in parallel.
  • the method is carried out following a process step g) determining that the first gas is not detectable by its spectrum.
  • the invention further relates to a method for monitoring a gas atmosphere, wherein the method for monitoring a gas atmosphere comprises a method according to the invention for detecting a first gas.
  • a method for monitoring a gas atmosphere comprises a method according to the invention for detecting a first gas.
  • Such a method may thus include, for example, a method of monitoring a fuel cell, such as the cathode compartment thereof. This makes an efficient and safe monitoring of one or more fuel cells possible.
  • monitoring of a hydrogen filling station or an atmosphere surrounding a hydrogen storage is included according to the invention. In principle, any atmosphere or any volume can be monitored in which gases, such as hydrogen can potentially occur and should be detected.
  • the present invention further relates to an arrangement for detecting a first gas in a gas mixture comprising at least one further gas
  • an electrode and a counter electrode which are arranged in the discharge chamber to a discharge path, wherein the electrodes are designed to form an arc
  • a means for removing the radiation emitted by the arc and emitted by the gas in the measuring cell a means for optically filtering the emitted radiation and / or means for spectrally dissecting the emitted radiation to produce a spectrum having a characteristic contour
  • an evaluation unit for evaluating the spectrum with respect to its contour, which is dependent on the presence and / or the concentration of the first gas.
  • the arrangement according to the invention is particularly suitable for carrying out the method according to the invention and therefore furthermore provides the advantages described with reference to the method according to the invention.
  • a measuring cell is in particular a device in which the gas mixture is excited, which leads to radiation emissions of the individual gases.
  • it has a discharge chamber in which an arc discharge and thus an arc is generated.
  • two electrodes are provided, which are arranged in the discharge chamber with a discharge path. They are also designed to form an arc, so have a shape, size and material properties, which is suitable for an arc discharge and are also advantageously connected to a voltage source or connectable.
  • a corresponding means for example a light guide, can also be provided, which can guide the radiation to an optical filter medium or a dispersion unit.
  • an evaluation unit which evaluates the contour of the spectrum, in particular of the spectrum of the further gas, the contour of which depends on the presence and / or concentration of the gas to be detected.
  • the evaluation unit may comprise, for example, a processor which can recognize, for example via suitable software, to what extent the contour of the spectrum of the further gas deviates from its normal state and based on the change, a quantitative and qualitative analysis of the to be detected Gases provides.
  • the electrode and the counter electrode may be formed, for example, pin-shaped.
  • an electrode is designed as a ring electrode.
  • the measuring cell has a housing, in which the discharge chamber is arranged, wherein the housing is formed thermostatable.
  • the housing is formed thermostatable.
  • the arrangement of the measuring cell within the fuel cell has the advantage that no additional thermostats to prevent the condensation of Water in the measuring cell is required.
  • the means for removing the emitted radiation is designed as a light guide.
  • the present invention further relates to the use of an arrangement according to the invention as a hydrogen sensor.
  • the arrangement according to the invention has advantages.
  • a detection of hydrogen is of importance, in all areas where this gas is handled, even in the lowest concentrations.
  • Hydrogen should be reliably detectable in addition to large nitrogen concentrations and / or different water vapor concentrations.
  • other fields of application include, but are not limited to, the area of hydrogen refueling stations, hydrogen storage facilities, hydrogen transport lines or reaction spaces in which a reaction with hydrogen is carried out.
  • FIG. 4 shows typical discharge spectra of a nitrogen / hydrogen mixture in a mixing ratio of 60:40 and 99: 1, FIG.
  • Fig. 5 is a diagram showing selected band intensities of nitrogen as a function of the hydrogen content.
  • FIG. 1 shows an embodiment of an arrangement 10 according to the invention for detecting a first gas in a gas mixture comprising at least one further gas.
  • the fiction, contemporary arrangement 10 includes a measuring cell 12.
  • the measuring cell 12 is formed as a discharge cell and arranged, for example, in an operation on a fuel cell at the end of the cathode gas channel thereof.
  • the measuring cell 12 can be looped directly into the cathode gas channel or connected via a bypass with this. But it is also possible to continuously suck gas from areas to be monitored and to guide through the described measuring cell 12. In this case, independent application areas of a fuel cell are possible.
  • a particularly preferred use of the inventive arrangement is a use as a hydrogen detector.
  • the measuring cell 12 comprises a gas-tight housing 14, the interior of which forms a discharge chamber 16.
  • the discharge chamber 16 is thus at least partially enclosed by the housing 14.
  • the housing 14 further includes a gas inlet 18 and a gas outlet 20, through which the gas mixture to be measured in the measuring cell 12 into or out of this can be derived.
  • a plug system is advantageous, it being possible to provide that it terminates gas-tight with respect to the environment. This guarantees a rapid replacement of the measuring cell 12 if necessary. This is particularly advantageous, since in the case of malfunctions, such as electrode burn-off or liquid water, rapid replacement can be ensured.
  • an electrode 22 and a counter electrode 24 with a discharge gap are arranged so that an arc discharge can take place between them.
  • the electrode 22 and the counter electrode 24 are thus formed to form an arc.
  • the electrode path ie the size of the distance between the electrodes 22, 24, can be variably adjustable in an advantageous embodiment of the measuring cell 12.
  • this discharge gap is typically formed by a gap of several hundreds to several thousands of ⁇ between the electrode 22 and the counter electrode 24, which are suitable for maintaining an arc.
  • the electrodes 22, 24 should be formed from a suitable material. Suitable materials may include, for example, gold, platinum, or suitable nickel alloys, as well as other materials superficially coated with these metals, such as other metals. Furthermore, the electrodes 22, 24 according to FIG. 1 may be designed in the shape of a pencil and optionally with thickened ends.
  • the housing 14 is wholly or partly formed of metal. In particular, a thermostating of the housing 14 and the measuring cell 12, for example, to the temperature of a fuel cell, easily possible.
  • the AC voltage of the measuring cell 12 is preferably supplied through a coaxial line to shield an occurring stray electric field.
  • the housing 14 can be placed with respect to the supplied AC voltage to ground potential or the potential of the anode of the fuel cell or the stack to be measured. This prevents beyond that in the case of a leak in the fuel cell system escaping hydrogen can be ignited by flashovers between the measuring cell 12 and other electrically conductive parts.
  • heat-conducting diaphragms can be provided in the gas inlet 18 or the gas outlet 20 of the measuring cell 12, respectively, in order to reliably prevent ignition thereof outside the measuring cell 12 in the event of the occurrence of an oxyhydrogen gas mixture.
  • copper sieves or bronze sintered can be used as heat-conducting diaphragms.
  • the outer dimensions of the housing 14 are advantageously limited to a few centimeters.
  • the radius of the preferably cylindrical housing 14 can be between 1 cm and 1.5 cm and the length of the housing 14 may be in a range of 2 to 3 cm.
  • the measuring cell 12 is very compact and easily suitable for use, for example, in fuel cell systems or even in confined spatial conditions in other applications.
  • an alternating voltage can be supplied to the electrodes 22, 24.
  • the measuring cell 12 may preferably have at its electrode 22 a connection 26 which may be designed as a detachable electrical connection. This can be for example a commercially available BNC connection.
  • the electrode 22 is conductively connected to an inner contact spring 28.
  • the electrode 22 is preferably separated from the housing 14 by a gas-tight electrical insulator 30, wherein in an advantageous embodiment, an external contact 32 is in electrical connection with the housing 14.
  • the alternating voltage is preferably generated by an inverter circuit which converts a DC voltage into the required AC voltage.
  • inverter circuits are used for example for the operation of cold cathode fluorescent tubes (CCFL), as they are known, inter alia, for the backlight of TFT monitors.
  • CCFL cold cathode fluorescent tubes
  • an AC voltage in a range of 20 to 70 kHz is used depending on the circuit dimensioning.
  • the output voltage is preferably in the range of less than kV, in particular, the output voltage is between 0.5 and 5 kV, so that can be set during operation of the measuring cell 12 currents of 200 ⁇ to 6 mA.
  • a means can be provided laterally of the electrode path between the electrodes 22, 24 in order to remove the radiation emitted by the arc.
  • this means is a light guide 34, which may be provided with a standardized plug, which is also gas-tight against the environment.
  • the optical core 36 of the optical fiber 34 is made of glass fibers or optical fibers of organic polymers. The means or the light guide 34 serves to remove the emitted light of the gas mixture to be measured and forward it to a detection system, as will be explained later.
  • the advantage of using a light guide 34 is in particular that only the measuring cell 12 as such needs to be arranged within a fuel cell system or the stack or another, for example, spatially limited volume and a spatial separation between the optical detection system and the gas discharge cell or measuring cell 12 is possible ,
  • a plurality of means or light guides 34 emanating from different measuring cells 12 to only a single optical analysis unit, such as an optical dispersion and detection system, as will be explained later.
  • the signals of the individual measuring cells 12 can either be switched over optically or registered in parallel. If a voltage is applied to the electrodes 22, 24 as described above, an arc is generated between them, which excites the gases contained in the gas mixture to be examined to specific emissions. This will be explained in detail with reference to FIGS.
  • the emitted radiation is received and preferably forwarded to a means 40 for optically decomposing the emitted radiation.
  • This means 40 may in particular be an optical dispersion unit.
  • the emitted radiation is optically, ie spectrally decomposed.
  • the spectral decomposition can be over Transmission or reflection grating, optical film grids, prisms or prism combinations made of polymer materials or different types of glass done.
  • a means 42 for optically filtering the emitted radiation for example in front of or behind the dispersion unit, ie to optically filter the emitted radiation.
  • color filters, edge filters, interference filters, bandpass filters or combinations of these can be used.
  • the emitted radiation can preferably be converted into an electrical signal in order to evaluate it. This happens, for example, in a detector 44.
  • a detector 44 which carries out the conversion into an electrical signal, photocells, photomultipliers, photodiodes, CMOS or CCD detectors can serve here, for example.
  • an evaluation unit 46 can be provided, for example as part of the detector 44 or connected thereto, which in particular evaluates the contour of the generated spectrum in an automated manner.
  • a measuring cell 12 is provided for each fuel cell. Accordingly, in the case of more extensive installations in which gas mixtures containing elementary hydrogen or elementary hydrogen are used, it should be ensured for reasons of safety that coverage should be as comprehensive as possible, whereby a plurality of measuring cells 12 can likewise be provided.
  • a plurality of measuring cells 12 can likewise be provided.
  • the optical fibers 34 are brought together before the means 40 or the detector 44.
  • FIG. 2 shows a further embodiment of an arrangement 10 according to the invention.
  • the measuring cell 48 is shown and other parts omitted. It is understood by those skilled in the art that the components further shown in Figure 1 can also cooperate with the measuring cell 48.
  • the construction according to FIG. 2 is similar to that of FIG. 1.
  • the measuring cell 48 has a gas inlet 52 and a gas outlet 50. By means of this, the gas or gas mixture to be measured can be introduced or diverted into the measuring cell 48.
  • the measuring cell 48 has an electrode 54, which may be designed like the electrode 22 in FIG. 1, whereas it is provided that the counter electrode 56 is designed as a ring electrode. As such, it may be formed as a part of the housing 58.
  • the embodiment of the measuring cell 48 according to the invention according to FIG. 2 again has a connection 60, in particular a plug connection, such as a BNC connection, which is described in detail in FIG.
  • a voltage as explained with reference to FIG. 1 may be applied to the electrodes 54, 56 so as to effect an arc discharge.
  • a means for receiving the emitted radiation such as a light guide 62, may again be provided.
  • this can be arranged in the geometric axis of the ring electrode 56 according to Figure 2, as well as the electrode 54.
  • Impurities can be formed, for example, by sputtered material of the electrodes 54, 56.
  • the gas inlet 52 can also be arranged in such a way to the light guide 62 that the impurities are kept away from the light guide 62 by the direction of flow of the gas. The same applies to alternative means for decreasing the emitted radiation.
  • the process according to the invention is described in a non-restrictive manner for a gas mixture of hydrogen as gas to be detected and nitrogen as further gas.
  • the method according to the invention can also be carried out for other gas mixtures as long as the presence of the gas to be detected influences the contour of the spectrum of the further gas selectively and in a defined manner.
  • FIG. 3 shows a typical discharge spectrum of pure hydrogen (H 2 dry).
  • H a line is visible, which lies at 656.28 nm, the intensity being specified in au (arbitrary units), that is to say not being conclusively defined.
  • the hydrogen is usually well detectable in high concentrations. If, however, the concentration of hydrogen is too low, for example at concentrations in a range of less than 1%, in particular less than 1% c, or if water vapor is present in the gas mixture, suitable hydrogen detection via the H a line is less Circumstances are no longer suitably possible. In this case, a detection can take place via the evaluation of the spectrum or the contour of the spectrum of the further gas, that is to say in particular of the nitrogen. The contour should mean here in particular the position and above all the intensity or strength of individual bands.
  • the spectral emission of molecular nitrogen shows a characteristic band pattern in the near ultraviolet range which clearly differs from the continuous emission of molecular hydrogen (FIG. 3) which is weak in this spectral range.
  • FOG. 3 continuous emission of molecular hydrogen
  • the band intensities of nitrogen as a function of the hydrogen concentration are also shown in FIG. 5 by way of example by the amount of the respective background signal corrected intensities of the spectral bands at 235.5nm and 296, 5nm.
  • the respective background signals were approximated with the aid of the intensity minimum located behind the respective spectral band, ie the measured values at 240.0 nm and 304.5 nm. There is a clear difference in the relative change in the intensity of each band as a function of the concentration of water in the substance.
  • the assembly 10 can be connected directly to an alarm. In this way, for example, when a critical hydrogen content is reached, a warning signal is issued, fuel cell processes can be stopped if necessary, or the hazardous area can be separated if necessary.
  • the method according to the invention can be carried out, for example, following a method step in which it is determined that the electrical signal has no signal line of the first gas.
  • a direct measurement can be carried out at high concentrations of the first gas, whereas at low concentrations an indirect measurement according to the invention can take place.

Abstract

L'invention concerne un procédé pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz. Le procédé selon la présente invention permet une détection hautement sélective et sensible d'un gaz dans un autre gaz, en particulier d'hydrogène dans une atmosphère contenant de l'azote. Le procédé selon la présente invention comprend les étapes suivantes : a) introduction du mélange gazeux dans une cellule de mesure (12) ; b) production d'un arc électrique dans la cellule de mesure (12) au moyen d'une décharge en arc ; c) réception du rayonnement déclenché au moyen de l'arc électrique et émis par le mélange gazeux ; d) filtrage optique du rayonnement émis et/ou décomposition spectrale du rayonnement émis pour la production d'un spectre, e) l'autre gaz étant choisi de telle sorte que son spectre possède un profil caractéristique qui se modifie en fonction de la présence et/ou de la concentration du premier gaz ; et f) exploitation du profil du spectre.
PCT/EP2012/058006 2011-05-06 2012-05-02 Procédé et système pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz WO2012152621A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102011050171.1 2011-05-06
DE102011050171A DE102011050171A1 (de) 2011-05-06 2011-05-06 Verfahren und Anordnung zum Detektieren eines ersten Gases in einem wenigstens ein weiteres Gas umfassenden Gasgemisch

Publications (1)

Publication Number Publication Date
WO2012152621A1 true WO2012152621A1 (fr) 2012-11-15

Family

ID=46025711

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2012/058006 WO2012152621A1 (fr) 2011-05-06 2012-05-02 Procédé et système pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz

Country Status (2)

Country Link
DE (1) DE102011050171A1 (fr)
WO (1) WO2012152621A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114424039A (zh) * 2019-09-20 2022-04-29 英福康有限公司 确定压力的方法和压力传感器

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0192919A1 (fr) * 1985-02-25 1986-09-03 AVL Gesellschaft für Verbrennungskraftmaschinen und Messtechnik mbH.Prof.Dr.Dr.h.c. Hans List Méthode et dispositif de détermination quantitative des constituants de gaz d'échappement combustibles
US5168323A (en) * 1988-03-31 1992-12-01 Sulzer Brothers Limited Device and method for determining impurities in a gas
WO1993010438A1 (fr) 1991-11-15 1993-05-27 Hughes Aircraft Company Detecteur a fluorescence excite par etincelle
DE19505104A1 (de) 1995-02-15 1996-08-22 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Verfahren und Anordnung zur Bestimmung der Reinheit und/oder des Drucks von Gasen für elektrische Lampen
DE69424382T2 (de) 1993-12-16 2001-02-08 Instrumentarium Oy Helsinki Messfühler und -einrichtung zur Verwendung in der Analysierung von Gasmischungen
WO2011069948A1 (fr) * 2009-12-08 2011-06-16 Heinrich Heine Universität Düsseldorf Procédé de contrôle et/ou de régulation de piles à combustible

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1232558B (de) * 1961-03-06 1967-01-19 Siemens Ag Verfahren zum Herstellen von kristallinem, insbesondere einkristallinem Bor
US3600122A (en) * 1966-03-11 1971-08-17 Surface Aviat Corp Method of grafting ethylenically unsaturated monomer to a polymeric substrate
CA1225441A (fr) * 1984-01-23 1987-08-11 Edward S. Fox Incineration des dechets par pyrolyse avec apport de plasma
US5110565A (en) * 1988-02-05 1992-05-05 The Dow Chemical Company Apparatus for producing uniform, fine ceramic powder
US5782952A (en) * 1996-08-30 1998-07-21 Massachusetts Institute Of Technology Method for production of magnesium
DE19813582A1 (de) * 1998-03-27 1999-09-30 Abb Research Ltd Verfahren zur Entsorgung eines in einem Behälter eingeschlossenen, fluorierten Gases und Vorrichtung zur Durchführung dieses Verfahrens
DE19903533A1 (de) * 1999-01-29 2000-08-10 Degussa Verfahren zur selektiven katalytischen Reduktion von Stickoxiden in sauerstoffhaltigen Abgasen
DE10162245A1 (de) * 2001-12-18 2003-07-10 Siemens Ag Verfahren zur selektiven Erzeugung reaktiver Teilchen
US20040245993A1 (en) * 2002-09-27 2004-12-09 Ulrich Bonne Gas ionization sensor
US7701578B1 (en) * 2003-09-12 2010-04-20 Herring Cyrus M Planar micro-discharge gas detector
DE102010033787B4 (de) * 2010-08-09 2012-04-19 PLASUS Ingenieurbüro Dr. Thomas Schütte Verfahren zum Bestimmen einer Sauerstoffkonzentration in einer Atmosphärendruck-Plasmakammer während eines Plasmaprozesses

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0192919A1 (fr) * 1985-02-25 1986-09-03 AVL Gesellschaft für Verbrennungskraftmaschinen und Messtechnik mbH.Prof.Dr.Dr.h.c. Hans List Méthode et dispositif de détermination quantitative des constituants de gaz d'échappement combustibles
US5168323A (en) * 1988-03-31 1992-12-01 Sulzer Brothers Limited Device and method for determining impurities in a gas
WO1993010438A1 (fr) 1991-11-15 1993-05-27 Hughes Aircraft Company Detecteur a fluorescence excite par etincelle
DE69424382T2 (de) 1993-12-16 2001-02-08 Instrumentarium Oy Helsinki Messfühler und -einrichtung zur Verwendung in der Analysierung von Gasmischungen
DE19505104A1 (de) 1995-02-15 1996-08-22 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Verfahren und Anordnung zur Bestimmung der Reinheit und/oder des Drucks von Gasen für elektrische Lampen
WO2011069948A1 (fr) * 2009-12-08 2011-06-16 Heinrich Heine Universität Düsseldorf Procédé de contrôle et/ou de régulation de piles à combustible

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114424039A (zh) * 2019-09-20 2022-04-29 英福康有限公司 确定压力的方法和压力传感器

Also Published As

Publication number Publication date
DE102011050171A1 (de) 2012-11-08

Similar Documents

Publication Publication Date Title
EP2510572B1 (fr) Procédé de contrôle et/ou de régulation de piles à combustible
EP2252883B1 (fr) Procédé de détection et d'identification de gaz dans les espaces intérieurs d'aéronef
DE112011103405B4 (de) Funkenemissions-Teilchendetektor
DE69926845T2 (de) Verfahren zum überwachen von gas(en) in einer dielektrischen flüssigkeit
EP3788346B1 (fr) Spectromètre d'émission d'étincelles à chambre à étincelles séparable
DE2717436A1 (de) Verfahren und vorrichtung zur bestimmung des partialdruckes eines gases zur vakuummessung, leckanzeige, messung der niederschlagsrate o.dgl.
DE60223961T2 (de) Verfahren und Vorrichtung zur Messung von Stickstoff in einem Gas
DE112014001431T5 (de) Verfahren und Vorrichtung zum Steuern eines Plasmas für eine Spektrometrie
EP2382460B1 (fr) Procédé et dispositif de détection de gaz ionisables
DE102009052957A1 (de) Gassensor mit Prüfgasgenerator
EP3553499B1 (fr) Analyseur de gaz et procédé de mesure des oxydes d'azote dans un gaz d'échappement
DE2806208B2 (de) Verfahren und Vorrichtung zum Nachweis von Schwefeldioxyd in einer Gasprobe
DE69530189T2 (de) Verbessertes gepulstes Entladungssystem
Niemelä et al. Comparison of microwave-assisted digestion methods and selection of internal standards for the determination of Rh, Pd and Pt in dust samples by ICP-MS
DE19505104A1 (de) Verfahren und Anordnung zur Bestimmung der Reinheit und/oder des Drucks von Gasen für elektrische Lampen
EP0965035B1 (fr) Dispositif pour analyser des echantillons gazeux
DE1163053B (de) Gasanalytischer Ionisationsdetektor
DE2322293A1 (de) Vorrichtung und verfahren zur analyse von organischem kohlenstoff in waessrigen systemen
WO2012152621A1 (fr) Procédé et système pour la détection d'un premier gaz dans un mélange gazeux comprenant au moins un autre gaz
DE60036801T2 (de) Vorrichtung zur kontinuierlichen überwachung von emissionen verschiedener metalle in rauhen umgebungen
DE3840106C2 (de) Meßfühler für ein tragbares Analysegerät zur Analyse der optischen Emission eines durch elektrische Entladung an einer festen leitfähigen Probe erzeugten Plasmas
DE3921895C2 (de) Aerosol-Elektrometer und Aerosol-Sensoreinrichtung
DE10306900B4 (de) Spektrometer mit Laseranordnung zur Gasanalyse
DE2546565B2 (de) Verfahren und vorrichtung zur bestimmung der konzentration von schwefeldioxid
WO2021052599A1 (fr) Dispositif pour déterminer une pression et capteur de pression

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12718209

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12718209

Country of ref document: EP

Kind code of ref document: A1