• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a device (1) for the analysis of measurement gas and a method for their operation, in particular for the analysis of exhaust gas of an internal combustion engine which undergoes pressure and particle concentration changes, wherein for guiding the measurement gas at least one sample gas line (2) and for determining at least one Property of the measuring gas is provided at least one, connected to the sample gas line analysis unit (3). In this case, an expansion volume (4) in the form of a chamber-shaped extension of the sample gas line (2) is provided in the sample gas line (2) from which at least a portion of the sample gas of the at least one analysis unit (3) can be fed, wherein a pump (5) with the Expansion volume (4) is connected, by means of which in the expansion volume (4) an at least approximately constant pressure level is maintained and in the expansion volume (4) at least one pressure sensor (6) is provided which is connected to a control unit (7). This is to control the pump (5), in dependence of the pressure sensor (6) certain pressure levels, connected to the pump (5).
    公开号:AT518184A4
    申请号:T50029/2016
    申请日:2016-01-21
    公开日:2017-08-15
    发明作者:Dr Reingruber Herbert；Dr Bergmann Alexander
    申请人:Avl List Gmbh；
    IPC主号:
    专利说明:

    Sample gas removal device
    The present invention relates to a method and a device for analyzing measurement gas, in particular exhaust gas of an internal combustion engine, which is subject to pressure and particle concentration changes. In this case, at least one sample gas line is provided for guiding the sample gas, and at least one analysis unit connected to the sample gas line is provided for determining at least one property of the sample gas.
    Both for mobile applications and on test benches, or in workshops, evaluators, e.g. Particle measuring devices used by which e.g. the number, size, mass of particles in the exhaust gas of an internal combustion engine to be evaluated or analyzed. Such analyzes are required, for example, in the course of regular testing of internal combustion engines in use, for example in the context of the periodic inspection of motor vehicles. Of course, appropriate exhaust gas analyzes also take high priority in the development of internal combustion engines. Of course, such analyzes are also carried out in connection with chimneys, flues and various incinerators.
    The problem is that an analysis with highly dynamic changes in the exhaust gas or in the sample gas, that is, for example, with corresponding fluctuations in pressure and particle concentration, often not satisfactory. In this context, changes or fluctuations in periods of the order of magnitude of 0.1 to 1 seconds are usually referred to as highly dynamic. It should be noted that many of the analyzers used are very sensitive to pressure fluctuations on their input side, ie where sample gas is added for analysis. In the often used dilution stages, which dilute the exhaust gas taken before the actual analysis, fluctuations in the dilution rate and thus erroneous measurement results in the analysis of the sample gas occur as a result of the pressure fluctuations. Furthermore, in such particle measuring systems conventional diaphragms are to be used for pressure reduction, since the pressure level at the point at which the exhaust gas is removed, for example, at the exhaust of a motor vehicle, for the measuring or analysis equipment is often too high to meet the exact measurement requirements ,
    A corresponding structure is shown for example in EP 0 967 481 A2, wherein the exhaust gas to be analyzed is conveyed through an analyzer by means of a constantly running vacuum pump. In order to be able to ensure a constant pressure level for the analysis in the analyzer, a pressure regulator is provided in the line system, via which the exhaust gas is supplied to the analyzer, which performs the control by the supply of incorrect air. The disadvantage here, however, that changes in the particle concentration during a rapid change in pressure from the subsequent analysis system are detected only delayed or distorted. Another problem arises from the fact that when removing the sample gas, for example from an exhaust pipe of an internal combustion engine, usually at the discharge point high back pressures occur. However, as already mentioned, measuring and analyzing devices operate at a much lower pressure level. To reduce the pressure, as usual, appropriate panels are used. However, these lead to dynamic processes, such as pressure fluctuations, being distorted accordingly. In addition, the reduced blast pressure level is often still too high to ensure optimal functioning of the analyzers used.
    Object of the present invention is to allow the most representative possible removal of analysis gas.
    This object is achieved in that an expansion volume in the form of a chamber-like widening of the sample gas line is provided in the sample gas line. From the expansion volume, the measurement gas can be fed to the at least one analysis unit. Furthermore, a pump is connected to the expansion volume, by means of which an at least approximately constant pressure level is maintained in the expansion volume. In the expansion volume, at least one pressure sensor is provided, which is connected to a control unit. To regulate the pump, depending on the pressure level determined by the pressure sensor, the control unit is connected to the pump. An expansion volume in the present disclosure is understood to mean an area with a cross-section or a cross-sectional area which is enlarged in relation to the sample gas line before or after the expansion volume, in particular upstream of the said area. In a variant of the invention, the cross-section or the cross-sectional area of the expansion volume is twice as large as the cross section of the sample gas line. With a high dynamics and small flow rates of the sample gas, a smaller cross-section of the expansion volume can also be favorable. The use of an expansion volume allows simultaneous mixing of the sample gas while reducing pressure, thereby reducing or avoiding inhomogeneities. When the sample gas to be analyzed is taken out of the expansion volume and supplied to the analysis unit, the sample gas supplied for analysis represents a sample representative of the exhaust gas of an internal combustion engine, for example, in terms of particle distribution. Since the pressure level is determined directly in the expansion volume and regulated as a function of that pump which is responsible for a constant pressure level, results in a compact control loop, by means of which it is possible to respond to dynamic pressure fluctuations in the best possible way. Particularly in the case of rapid and strong pressure fluctuations (from 2 bar / s) of the measuring gas or rapid and strong changes in the particle concentration in the measuring gas, this realization is advantageous. However, it is also an application with much smaller and less dynamic fluctuations in pressure possible, for example, in chimneys, boilers or heating plants.
    In order to prevent condensation, heating of the expansion volume can also be provided. Thus, condensation of the measurement gas can be prevented, which is e.g. can occur by cooling the sample gas during expansion into the expansion volume. The heating can take place in various ways, for example heating coils on the outside or inside of the expansion volume or arrangement of the expansion volume within a heated, closed area.
    It is advantageously provided that at least one further pressure sensor is provided for determining the pressure level at a removal point at which the measurement gas is supplied to the sample gas line, and that the further pressure sensor is connected to the control unit. The control unit thus two pressure values, those at the sampling point and that in the expansion volume from which the sample gas is fed to the analysis unit, provided. In this way it is possible to react even better to already mentioned pressure fluctuations. The maintenance of a constant pressure level in the expansion volume is thus further facilitated.
    It is advantageously provided that the sample gas line is flowed through by the measurement gas in a flow direction and the pump is arranged in the flow direction according to the expansion volume. Negative influences on the sample gas, which can result from the pump, are prevented in this way.
    Advantageously, it is provided that, viewed in the flow direction, an aperture for reducing the pressure is provided in the measuring gas line in front of the expansion volume. The diaphragm is understood essentially to be an arbitrarily designed cross-sectional constriction. Such a cross-sectional constriction can be both tapered and made jumpy.
    In this way, the pressure is "pre-reduced" even before the expansion volume. This makes it possible to dimension the expansion volume primarily to the extent that it comes to a homogeneous particle distribution as possible. The necessary pressure reduction, which is a further task of the expansion volume, can take place in coordination with the upstream diaphragm and thus has no predominant influence on the dimensioning of the expansion volume.
    The ratio between the inner diameter of the sample gas line and the smallest cross section of the diaphragm can be in the range of 1: 2 to 1: 100, depending on the desired dynamic range.
    Advantageously, it is provided that the pump is designed as a Venturi pump in combination with a control valve. In this way, the number of moving parts is reduced to a minimum. Possible impurities are less of a problem than, for example, pumps with rotating components. Also with regard to possible formation of condensate and associated potential damage, the Venturi pump is a much more robust device compared to conventional pump systems.
    As already mentioned, the invention also relates to a corresponding method for the analysis of measurement gas, in particular of exhaust gas of an internal combustion engine, wherein the measurement gas for determining at least one property is passed through a sample gas line to an associated analysis unit. It is provided that the sample gas is supplied to an expansion volume in the form of a chamber-like extension of the sample gas line, that the sample gas can be removed from the expansion volume and fed to the at least one analysis unit. In this case, an at least approximately constant pressure level is maintained in the expansion volume by means of a pump connected to the expansion volume, wherein the pressure level in the expansion volume is determined by means of at least one pressure sensor connected to a control unit, and the pump is controlled by the control unit as a function of the pressure sensor Pressure levels, is regulated.
    The subject invention will be explained in more detail below with reference to Figures 1 and 2, which show by way of example, schematically and not by way of limitation advantageous embodiments of the invention. It shows
    1 shows the device according to the invention for the analysis of sample gas,
    2 shows the device according to the invention in an advantageous embodiment.
    As already mentioned, investigations and analyzes of exhaust gases in various contexts play a major role. On the one hand, the emission of exhaust gases to the environment is subject to a wide variety of conditions, and on the other hand, the analysis of the emitted substances also allows conclusions to be drawn about previous combustion processes. For analysis, a part of the exhaust gas to be analyzed or analyzed is usually taken as an exhaust gas sample. This exhaust gas sample is referred to below as the measuring gas.
    Figure 1 shows a schematic representation of the device 1 according to the invention for the analysis of sample gas. The illustrated device 1 can of course be used in the analysis of various gases or exhaust gases used and are used, for example, in connection with chimneys and flues of different incinerators. In particular, the device 1 according to the invention for the analysis of measuring gas in connection with the analysis of exhaust gas of an internal combustion engine, which is subject to strong pressure and particle concentration changes, application.
    In this case, at least one sample gas line 2 is provided for guiding the sample gas and at least one analysis unit 3 connected to the sample gas line 2 is provided for determining at least one property of the sample gas. As can be seen from FIG. 1, an expansion volume 4 in the form of a chamber-shaped widening of the sample gas line 2 is provided in the sample gas line 2. As shown in FIG. 1 and subsequently also in FIG. 2 by an arrow, according to the invention at least part of the measurement gas is supplied to the at least one analysis unit 3 from this expansion volume 4. Furthermore, a pump 5 is connected to the expansion volume 4, by means of which in the expansion volume 4, an at least approximately constant pressure level is maintained. This is preferably a, with respect to the ambient pressure by a slight negative pressure, for example in the range of about -10 to -30 mbar. Of course, this pressure level is merely exemplary and may differ, depending on the field of application and the resulting requirements, from the value just given. According to the invention, at least one pressure sensor 6, which is connected to a control unit 7, is provided in the expansion volume 4. To control the aforementioned pump 5, in dependence on the pressure level determined by the pressure sensor 6, the control unit 7 is connected to the pump 5.
    In the course of the method for the analysis of measurement gas, in which the device 1 just described is used, the measurement gas for determining at least one property is guided through the sample gas line 2 to the analysis unit 3 connected thereto. In this case, the sample gas is the expansion volume 4, which is formed by a chamber-shaped extension of the sample gas line 2, respectively. The sample gas can then be removed from the expansion volume and fed to the at least one analysis unit 3. By means of the pump 5 connected to the expansion volume 4, an at least approximately constant pressure level is maintained in the expansion volume 4, the pressure level in the expansion volume 4 being determined by means of at least one pressure sensor 6 connected to a control unit 7. The pump 5 is controlled by means of this control unit 7, as a function of the pressure level determined by the pressure sensor 6.
    In an mentioned analysis unit 3, the measurement gas is examined, for example, for chemical composition, size of the particles contained, particle concentration, etc. However, this list is only to be regarded as an example since, depending on the field of application, the most varied measured variables or their measured values can be of interest. Of course, a plurality of analysis units 3 can also be provided for the determination of the respective measured variables or their measured values.
    In the previously mentioned removal of the sample gas, for example, from a schematically indicated exhaust pipes of an internal combustion engine, usually occur at the sampling point 10 high back pressures. Measuring or analysis devices, such as the aforementioned analysis unit 3, but work at a much lower pressure level. Usually, corresponding apertures are used to reduce the pressure. However, as already mentioned, their use leads to dynamic processes, such as pressure fluctuations, being correspondingly distorted. Furthermore, the pressure level reduced by diaphragms is often still too high to ensure optimal functioning of the analysis unit 3 used.
    The use of the expansion volume 4 allows a simultaneous mixing of the sample gas, while reducing pressure, whereby inhomogeneities are reduced or avoided. In this context, for example, a desired, as homogeneous as possible distribution of e.g. Soot particles mentioned in the sample gas. If the sample gas to be analyzed is taken from the expansion volume 4 and fed to the analysis unit 3, the sample gas supplied for analysis thus represents a sample, representative of the exhaust gas of an internal combustion engine, in terms of particle distribution. Since the pressure level is determined directly in the expansion volume 4 by means of the pressure sensor 6 is and depending on which pump 5 is controlled, which contributes to a constant pressure level care, resulting in a compact control loop by means of which can be responded to dynamic pressure fluctuations in the best possible way. As can be seen further in FIG. 1, that portion of the measurement gas which was not supplied to the analysis unit 3 can be released to the environment via a delivery point 20 of the pump 5, for example via a downstream filter system.
    FIG. 2 shows an advantageous embodiment of the device 1. It is provided that at least one further pressure sensor 9 is provided for determining the pressure level at the removal point 10 at which the measurement gas is supplied to the sample gas line 2 and that the further pressure sensor 9 is provided with the Control unit / is connected.
    Since the pressure level at the removal point 10, at which the measurement gas is supplied to the measurement gas line 2, is thus determined by means of the further pressure sensor 9, which is connected to the control unit 7, the control unit 7 is thus provided with two pressure values. Such, with respect to the pressure sensor 6 upstream, further pressure sensor 9 allows the control unit even better to respond to pressure fluctuations at the removal point 10. The maintenance of a constant pressure level in the expansion volume 4 is thus further facilitated.
    Both in Figure 1 and in Figure 2 is schematically seen that the sample gas line 2 is traversed by the sample gas in a flow direction 11 and the pump 5 is arranged in the flow direction 11 after the expansion volume 4. Depending on the type of pump 5 used, the measuring gas can be negatively influenced by the pump 5. Depending on the internal structure of the pump 5, particles can deposit at different locations and thus lead to segregation of the sample gas. In the opposite way, of course, there is also the possibility that, for example, previously deposited particles dissolve again and in this way falsify the measurement gas or its current composition accordingly. If the pump 5 is arranged correspondingly advantageously in the flow direction 11 after the expansion volume 4, such negative influences on the measurement gas are prevented.
    As can also be seen in FIG. 2, it may be advantageous for a diaphragm 12 to reduce pressure to be provided in the measuring gas line 2 in the flow direction 11 before the expansion volume 4. Although the use of apertures 12 for pressure reduction associated with the disadvantages mentioned above, but these disadvantages come depending on the difference in pressure levels more or less strong to wear. The diaphragm 12 used, which can of course also be formed by the juxtaposition of a plurality of diaphragms 12, serves primarily for a "pre-reduction" of the pressure level. By this is meant that the pressure which is present at the removal point 10 is not completely reduced by the diaphragm 12 to that pressure level which, as mentioned above, enables an optimal measurement or analysis in the analysis unit 3. The aforementioned possible distortions, for example of pressure fluctuations, can thus be reduced to a small extent, even though the diaphragm already reduces the pressure level that previously exists at the extraction point 10. This "pre-reduction" of the pressure level makes it possible to dimension the expansion volume primarily to the extent that it comes to a very homogeneous particle distribution. The necessary, further pressure reduction, which is another task of the expansion volume, can be done in coordination with the upstream diaphragm and thus has no primary influence on the dimensioning of the expansion volume.
    The pump 5 can advantageously be designed as a venturi pump in combination with a control valve 51. In this way, the number of moving parts is reduced to a minimum. Possible impurities, such as the aforementioned soot particulate build-up, present a lesser problem than with corresponding pump systems, for example, with rotating components. With regard to the possible formation of condensate Kon and possible damage, the Venturi pump represents a much more robust device compared to conventional pump systems. The mentioned control valve 51, which is only schematically indicated in Figure 2, may be formed for example by a needle valve, which, depending on the volume flow and other requirements, of course, other suitable valves can be used. It is also conceivable that the control valve 51 is integrated in the control unit 7.
    The described device 1 for the analysis of sample gas allows, in particular in the case of fast and strong or highly dynamic pressure fluctuations or changing particle concentrations, to permit the most representative possible removal of analysis gas. In this way, the reliability of measurement results, in particular in the analysis of exhaust gas of an internal combustion engine is significantly improved.
    权利要求:
    Claims (9)
    [1]
    1. Device (1) for the analysis of measurement gas, in particular of exhaust gas of an internal combustion engine, which is subject to pressure and particle concentration changes, wherein at least one sample gas line (2) and for determining at least one property of the sample gas at least one, connected to the sample gas line for guiding the sample gas , Analysis unit (3) is provided, characterized in that in the sample gas line (2) an expansion volume (4) in the form of a chamber-shaped extension of the sample gas line (2) is provided, from which at least a portion of the sample gas of the at least one analysis unit (3) can be fed, that a pump (5) with the expansion volume (4) is connected, by means of which in the expansion volume (4) an at least approximately constant pressure level is maintained, that in the expansion volume (4) at least one pressure sensor (6) is provided, which with a control unit (7) is connected and that for controlling the pump (5), in dependence of the Dru cksensor (6) certain pressure levels, the control unit (7) with the pump (5) is connected.
    [2]
    2. Apparatus according to claim 1, characterized in that the expansion volume (4) is heated.
    [3]
    3. Apparatus according to claim 1 or 2, characterized in that for determining the pressure level at a removal point (10) to which the sample gas of the sample gas line (2) is supplied, at least one further pressure sensor (9) is provided, and that the further Pressure sensor (9) with the control unit (7) is connected.
    [4]
    4. Device according to one of claims 1 to 3, characterized in that the sample gas line (2) in a flow direction (11) flows through the sample gas and the pump (5) in the flow direction (11) seen after the expansion volume (4) is arranged ,
    [5]
    5. Device according to one of claims 1 to 4, characterized in that in the measuring gas line (2) in the flow direction (11) seen before the expansion volume (4) at least one aperture (12) is provided for reducing pressure.
    [6]
    6. Apparatus according to claim 5, characterized in that the ratio between the inner diameter of the sample gas line (2) and the smallest cross-section of the diaphragm (12) in the range of 1: 2 to 1: 100.
    [7]
    7. Device according to one of claims 1 to 6, characterized in that the pump (5) is designed as a Venturi pump in combination with a control valve (51).
    [8]
    8. A method for analyzing measurement gas, in particular exhaust gas of an internal combustion engine, wherein the measurement gas for determining at least one property by a sample gas line (2) to an associated analysis unit (3) is guided, characterized in that the sample gas an expansion volume (4) in the form of a chamber-like extension of the sample gas line (2), the sample gas can be taken from the expansion volume (4) and supplied to the at least one analysis unit (3) and by means of a pump (5) connected to the expansion volume (4) in the expansion volume (4) an at least approximately constant pressure level is maintained, the pressure level in the expansion volume (4) being determined by means of at least one pressure sensor (6) connected to a control unit (7) and the pump (5) by means of the control unit (7) , is regulated in dependence on the pressure level determined by the pressure sensor (6).
    [9]
    9. The method according to claim 8, characterized in that, by means of a further pressure sensor (9) which is connected to the control unit (7), the pressure level at a removal point (10), to which the measurement gas of the sample gas line (2) is supplied , is determined.
    类似技术:
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    同族专利:
    公开号 | 公开日
    AT518184B1|2017-08-15|
    WO2017125548A1|2017-07-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP0312458A2|1987-10-13|1989-04-19|L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude|Method for reducing pressure of highly compressed gases without generation of condensation droplets|
    WO1992008968A1|1990-11-13|1992-05-29|Rupprecht & Patashnick Company, Inc.|Diesel particulate monitor|
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    KR100551586B1|2003-05-06|2006-02-13|아주대학교산학협력단|A fast response sampling apparatus for obtaining sample gas|
    DE202012009711U1|2012-10-04|2012-11-15|Helmholtz-Zentrum Für Umweltforschung Gmbh - Ufz|Apparatus for the qualitative and quantitative analysis of the components of a gas|
    DE102013218930A1|2013-09-20|2015-04-16|Lubrisense Gmbh|Multiple oil emission meter for engines|AT522776A1|2019-11-29|2021-01-15|Avl List Gmbh|Method for testing the functionality of auxiliary units in an exhaust gas analysis system|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50029/2016A|AT518184B1|2016-01-21|2016-01-21|Sample gas removal device|ATA50029/2016A| AT518184B1|2016-01-21|2016-01-21|Sample gas removal device|
    PCT/EP2017/051186| WO2017125548A1|2016-01-21|2017-01-20|Measurement gas extraction device|
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