WO2012007200A1 - Dispositif de détermination d'une propriété d'un gaz dans une chambre de gaz de mesure - Google Patents

Dispositif de détermination d'une propriété d'un gaz dans une chambre de gaz de mesure Download PDF

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Publication number
WO2012007200A1
WO2012007200A1 PCT/EP2011/057750 EP2011057750W WO2012007200A1 WO 2012007200 A1 WO2012007200 A1 WO 2012007200A1 EP 2011057750 W EP2011057750 W EP 2011057750W WO 2012007200 A1 WO2012007200 A1 WO 2012007200A1
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WIPO (PCT)
Prior art keywords
electrode
gas
potential
pumping
sensor element
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
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PCT/EP2011/057750
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German (de)
English (en)
Inventor
Lothar Diehl
Helge Schichlein
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Robert Bosch GmbH
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Robert Bosch GmbH
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Filing date
Publication date
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Priority to JP2013518996A priority Critical patent/JP5642275B2/ja
Publication of WO2012007200A1 publication Critical patent/WO2012007200A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/416—Systems
    • G01N27/417—Systems using cells, i.e. more than one cell and probes with solid electrolytes
    • G01N27/419—Measuring voltages or currents with a combination of oxygen pumping cells and oxygen concentration cells
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/4065—Circuit arrangements specially adapted therefor

Definitions

  • the invention is based on known sensor elements which are based on ion-conducting properties of certain solids, ie on the use of so-called
  • Solid electrolytes based. Such solid electrolytes can be designed in particular as ceramic solid electrolytes. Examples of such solid electrolytes which
  • ionic species are oxygen ion-conducting solid electrolytes, in particular based on zirconium dioxide.
  • solid-electrolyte such as yttrium-stabilized
  • sensor elements are basically usable.
  • broadband lambda probes which operate according to the limiting current principle and can be constructed as a single cell or multiple cell.
  • a pumping current is detected as a function of a pumping voltage on at least one pumping cell and closed from the pumping current to an oxygen content in the gas.
  • unicellular broadband lambda probes are known from the prior art in which one electrode can be acted upon by exhaust gas by means of a diffusion barrier, whereas the other electrode of a pump cell comprising the electrodes is arranged in a reference channel.
  • Newer sensor types have only a reference channel with a small limiting current, which is also referred to as exhaust duct (ALK).
  • ALK exhaust duct
  • such sensor elements can usually only be used in the lean exhaust gas, as in the rich exhaust gas the limiting current of the exhaust air duct is exceeded and the exhausted exhaust duct delivers too small a signal.
  • this sensor can basically be operated in that the reference channel is inflated to be operated in this way, for example, for 30 s, in a rich gas range. For many operating modes, this is sufficient to measure short fat phases, such as an NSC regeneration (NSC: NOx storage catalyst, Nöx storage catalyst).
  • NSC NSC regeneration
  • a similar measuring principle is described for example in DE 10 2006 011 480 AI.
  • a gas sensor is shown, in particular a lambda probe, in which, in addition to a pumping cell, an outer electrode exposed to the exhaust gas and acted upon by a negative current is provided.
  • Electrode cavity in which one of the electrodes of the pumping cell is arranged, additionally filled with oxygen to provide an offset in the characteristic of the sensor element.
  • a first electrode facing the exhaust gas also referred to as internal pumping electrode or IPE
  • IPE internal pumping electrode
  • the second electrode is arranged in the exhaust air duct and is also referred to as exhaust air electrode (ALE).
  • ALE exhaust air electrode
  • It is typically electronically controlled to a pumping voltage of 200 mV to 900 mV to equally allow pumping in both directions with lean or rich exhaust gas.
  • the measurement of the pumping current is usually carried out at the second electrode, ie at the exhaust air electrode.
  • Known sensor elements can usually only temporarily, i. typically for periods of less than 30 s, measuring gasses.
  • a further disadvantage of known sensor elements is that unicellular organisms with a large air reference channel are unfavorable in terms of their mechanical structure due to the large cross section of the reference channel and nevertheless have a static fatigue measurement capability limited by the limiting current. Furthermore, there is a disadvantage that at an extreme pressure in the exhaust duct, despite a throttle, the sensor element can be blown, since usually the porous filling of the exhaust duct strongly attenuates the flow and only allows a diffusion outlet. This can happen
  • the gas may in particular be an exhaust gas, for example an internal combustion engine.
  • the sample gas space may be, for example, an exhaust tract. At least one
  • Property of the gas in the sample gas space can basically be any physical and / or chemical property. However, it is particularly preferred if this at least one property is a fraction of a gas component in the gas, for example a proportion which can be quantified by means of a partial pressure, a percentage or another variable.
  • the gas component may be oxygen.
  • other types of gas components are detectable.
  • the property can be detected qualitatively or quantitatively.
  • the property may be an oxygen content, for example an oxygen partial pressure and / or an air number, of which below, without limitation, other possible
  • the device can thus in particular comprise at least one lambda probe.
  • the device comprises at least one sensor element and at least one
  • the sensor element can be designed, for example, as a ceramic sensor element and can be accommodated, for example, in a housing.
  • the sensor element may comprise at least one lambda probe or be designed as a lambda probe.
  • the at least one drive can be completely or partially integrated into the sensor element, but can also be designed, preferably completely or partially, separately from the at least one sensor element.
  • the control may, for example, comprise one or more electronic components to control the functions described below
  • control can be at least one
  • Pump voltage source for acting on the below-described pump cell with a pumping voltage
  • at least one current measuring device for Measuring a pumping current through the pumping cell
  • the at least one virtual mass in the form of, for example, an adjustable voltage source, and optionally
  • control for example, one or more
  • Data processing devices include to perform a method according to the following description.
  • the control can be configured as a central control, which is connected to the at least one sensor element, for example via at least one interface, for example at least one plug.
  • the control can also be configured wholly or partly as a decentralized control.
  • the control can for example also be part of an engine control of a motor vehicle.
  • Various embodiments are possible in principle.
  • the sensor element comprises at least one pump cell with at least one first electrode and at least one second electrode and at least one solid electrolyte connecting the first electrode and the second electrode.
  • the first electrode and / or the second electrode can be configured, for example, as metal-ceramic electrodes. In particular, these may be platinum cermet electrodes. However, other embodiments are possible in principle.
  • Sample gas space acted upon This can be done in different ways.
  • the first electrode may be exposed directly to the gas from the measurement gas space, for example by the first electrode being arranged on a surface of a layer structure of the sensor element and / or being separated from the measurement gas space by only one or more gas-permeable protective layers.
  • the first electrode which may also be designed in several parts, may also be arranged in the interior of a layer structure of the sensor element,
  • the electrode cavity can be connected, for example via at least one gas inlet hole with the sample gas space. It is particularly preferred if the connection between the measuring gas space and the first electrode or the optional electrode cavity, in which the first electrode can be arranged, via at least one diffusion barrier, ie an element which at least largely prevents gas from flowing through and only one Diffusion transport allowed. With respect to possible embodiments of such diffusion barriers, reference may be made to the above-described prior art.
  • the second electrode is arranged in at least one reference gas space, ie a space which is separated from the measurement gas space such that different gas mixtures form in the reference gas space and in the measurement gas space between which an adjustment takes place at least on a time scale which is long in comparison to conventional measuring processes.
  • the reference gas space is completely separated from the sample gas space.
  • the reference gas space may be a reference gas channel.
  • this reference gas channel can be designed as an air reference channel, which connects the second electrode, for example, to an environment of an engine compartment, which is formed separately from the measurement gas space, for example an exhaust gas tract of an internal combustion engine, in particular in a motor vehicle. Accordingly, the
  • Reference gas channel for example, as an air reference, as a reference air duct or as
  • Out exhaust duct be configured, analogous to the above-described sensor elements according to the prior art.
  • the sensor element furthermore has at least one third electrode.
  • the third electrode forms an auxiliary pumping cell with the second electrode. This can be done, for example, by the fact that the above-described solid electrolyte also connects the third electrode and the second electrode to one another. Alternatively or additionally, however, it is also possible to provide at least one further solid electrolyte which produces the named compound.
  • the drive is set up such that the second electrode is connected to a virtual ground.
  • a virtual ground is to be understood as meaning a voltage source, preferably a constant-voltage source, which defines a potential of the second electrode, for example to a specific value relative to a ground.
  • the virtual ground may be arranged to set the second electrode to an electrode potential between 0 and ⁇ 3 V, in particular to a
  • Electrode potential of 0.2 to 2.5 V 0.2 to 2.5 V.
  • other configurations are possible. Examples are explained in more detail below.
  • the drive is further configured to apply a pump voltage to the pump cell and to detect a pump current at the first electrode.
  • a detection of a pumping current at the first electrode is to be understood as meaning a direct or indirect measurement of the pumping current in a supply line to the first electrode.
  • the third electrode can in principle, for example, also with gas from the
  • Measuring gas chamber be acted upon.
  • the third electrode can be acted upon by gas from the measuring gas space, for example via a diffusion barrier.
  • the third electrode can be arranged on a surface of a layer structure of the sensor element and optionally covered with one or more gas-permeable protective layers. Alternatively or additionally, however, the third electrode can also be acted upon by gas from a further reference gas space, for example.
  • the virtual mass is designed as an adjustable virtual mass.
  • This can be done, for example, by the activation comprising an adjustable voltage source.
  • This adjustable voltage source may, for example, be connected directly or indirectly to a ground at one pole, and at another pole directly or indirectly to the second electrode.
  • the adjustability may include, for example, electronic adjustability.
  • the value occupied by the virtual ground, in particular an electrode potential with which the second electrode is acted upon can be externally adjustable, for example via at least one data processing device and / or via at least one interface within and / or outside the drive.
  • the drive can in particular be designed such that a voltage between the third electrode and the second electrode can be applied. By this voltage, an auxiliary pumping current can be forced through the auxiliary pumping cell, which can be designed adjustable.
  • the control can in particular such
  • the third electrode with an electrode potential, in particular a constant electrode potential, is applied.
  • This electrode potential can also be zero.
  • the third electrode may be closer as below is executed, preferably be placed on a ground potential. The voltage at the auxiliary pumping cell can then result, in particular, as the potential difference between the electrode potential and a potential of the virtual ground, with which the second electrode is acted upon.
  • the property to be determined which is to be determined by means of the device (wherein several properties may also be determinable), may in particular, as stated above, be an oxygen content in the gas, in particular an exhaust gas.
  • the voltage can then be selected in particular such that an amount of
  • Oxygen is pumped through the auxiliary pumping cell to the second electrode such that oxygen is present at the second electrode within a given range of air ratios at each air ratio when measured statically.
  • the air range may in particular also include a rich gas range.
  • Reference gas channel compensated.
  • Hilfspumpzelle be chosen such that it always forms or is at least the difference between the required oxygen flow to the second electrode and the limiting current of the reference gas channel. This can be realized, for example, as explained in more detail below, by adapting the potential of the virtual mass applied to the second electrode to the air ratio. This can be done, for example, that a last measured, known
  • Air value is used and, for example by a
  • a suitable virtual ground is selected so that the condition described above is met.
  • the control can in particular for acting on the pump cell with the
  • Pump voltage comprise at least one pump voltage source.
  • Pump voltage source can be configured in particular by means of the present invention as a unipolar pump voltage source, ie as a pump voltage source, which is not umpolbar. Such pump voltage sources are technically particularly easy to implement. A potential of virtual mass, with which the second
  • Electrode is applied, in particular within the specified
  • Air number range can then be selected such that the potential of the first electrode within the predetermined air ratio range undergoes no sign change. This means that the potential difference between the first electrode and the second Electrode within the predetermined air range always has the same sign. This can be done, for example, as described above and as explained in more detail below, by a corresponding tracking of the virtual mass and / or by a change in the virtual mass as a function of the air ratio.
  • Control can basically be done with a current equal or changing sign.
  • the sensor element can furthermore have at least one heating element with at least two heater contacts.
  • this heating element reference may be made to the prior art.
  • Heating element may in particular be designed as a resistive heating element, with at least one heating resistor, which is acted upon by two heating contacts (H + and H) with a heating current.
  • the third electrode may in particular be electrically connected to at least one, preferably exactly one, of the heater contacts. This connection can preferably take place within the sensor element, so that the heater contact and the third electrode are electrically contactable via a common supply line and / or via a common electrode contact.
  • the third electrode can in principle also completely or partially with the
  • the heater contact which is combined with the third electrode, may be the negative heater contact (H).
  • the control can in particular be designed such that this common heater contact and the third electrode are connected to an electrical ground.
  • the third electrode and the heater contact can be acted upon in particular with a constant potential, in particular a ground potential.
  • the sensor element has four connection contacts. For example, a first connection contact for the first electrode, a second connection contact for the second electrode, a third connection contact for the negative heater contact (H) and the third electrode and a fourth contact for the positive heater contact may be provided. In this way, despite increased functionality, connection contacts and / or cables to the control unit and / or pins on the control unit can be saved.
  • the first electrode may be arranged on a surface of a layer structure facing the measurement gas space, and the second electrode in particular in the interior of a layer structure.
  • the first electrode and the second electrode both in the interior of the layer structure of Sensor element are arranged.
  • the first electrode may, for example, as stated above, through at least one gas inlet hole with gas from the
  • Measuring gas can be acted upon spatial.
  • the at least one optional diffusion barrier can be arranged.
  • the third electrode is preferably arranged on a rear side of the layer structure facing away from the gas inlet hole.
  • the gas inlet hole and the third electrode are arranged on the same side of the layer structure. In this case can
  • the pasture H - Connection be contacted by the sensor element.
  • the first electrode and the third electrode are arranged on the same side of the layer structure are also possible.
  • the virtual ground may be configured as an adjustable virtual ground.
  • the virtual mass can be designed controllable and / or controllable.
  • the virtual ground can be used to apply an electrode potential to the second electrode.
  • the drive can be set up to detect the electrode potential as a function of the detected voltage
  • Measuring period Other settings are possible.
  • a setting by a device other than a data processing device is possible, for example, an automatic adjustment via a control.
  • a setting over, for example, an electronic table (lookup table) is possible.
  • the adjustment can be continuous, discontinuous or else stepwise.
  • the adjustability can take place in particular over a predetermined measuring range of the property of the gas, for example a predetermined air-fuel ratio range, which in particular can also include a rich-gas range.
  • the sensed property of the gas may be an air ratio or at least an air ratio.
  • this local minimum may be above 0.1 V, in particular at least 0.2 V and particularly preferably 0.25 V or more.
  • Various other embodiments are possible.
  • this change should in particular be made on a time scale which deviates from the time scale of the actual measurement by means of the device.
  • the change can take place with a time constant of at least 1 s, preferably with a time constant of 1 s to 10 s and particularly preferably with a time constant of 5 s.
  • the time constant can be chosen small enough, so that, for example, a storage time of 30 s, which at usual
  • the reference gas space can in particular, as stated above, as open
  • this may be an open air reference channel.
  • the reference gas channel is wholly or partially configured with a gas-permeable porous medium.
  • a method for determining at least one of them is also provided Property of a gas proposed in a sample gas space.
  • the method can be carried out using a device according to one or more of the embodiments described above, so that reference can be made to the above description of the device with regard to possible embodiments of the method.
  • the method uses a sensor element having a pump cell with at least one first electrode, at least one second electrode and at least one solid electrolyte connecting the first electrode and the second electrode.
  • the first electrode can be acted upon with gas from the sample gas space.
  • the second electrode is arranged in at least one reference gas space.
  • the sensor element furthermore has at least one third electrode, wherein the third electrode forms an auxiliary pumping cell with the second electrode.
  • the second electrode is connected to a virtual ground.
  • the pumping cell is supplied with a pumping voltage, and a pumping current at the first electrode is detected. Further, as stated above, a voltage may be applied between the third electrode and the second electrode such that an auxiliary pumping current flows through the auxiliary pumping cell, for example, for one or more of the purposes described above.
  • Oxygen can be transported to the second electrode by means of the auxiliary pumping cell and the reference gas space can be pumped up to such an extent that a permanent, static grease measurement is possible without the usual restrictions of the reference gas space, for example the exhaust air duct.
  • the third electrode may be completely or partially combined with the heating element and / or a heater contact, wherein, for example, the heating element itself may be part of the auxiliary pumping cell. A restriction of a fat gas measurement to usual short storage times of, for example, 30 s is thus eliminated, and the device can also be operated in the fat gas range at least in a certain, preferably fully static.
  • the virtual ground allows the second electrode to be set to a predetermined electrode potential, for example an electrode potential of +2.5 V.
  • the pump current of the pump cell can be measured at the first electrode, for example an inner pumping electrode.
  • the reference gas space for example the exhaust air duct, can preferably be provided with an open throttle, that is to say as an open throttle
  • An open reference gas channel acts as a true diffusion barrier that allows gas to flow through the reference gas channel but limits diffusion. In this way you can prevent yourself from getting in Overpressure builds up in the area of the second electrode. The flow can be
  • the third electrode which, for example, as an outermost electrode
  • Pump electrode may be configured, is preferably in the sample gas space
  • an exhaust space so for example in the exhaust gas, but may also be arranged in the reference gas space of the sensor element and / or in another reference gas space.
  • the proposed device has, as stated above, a static
  • Fat measurement capability and is therefore also suitable for gasoline engine applications, for example.
  • the current measurement is carried out only on the inner pumping electrode, that is to say on the first electrode, which contains information about the oxygen partial pressure in the exhaust gas.
  • a heater input is therefore no longer effective on the actual measurement signal.
  • the additional current that flows through the auxiliary pump cell and, for example, fills the reference gas space, also does not appear in the measurement signal, but is effective as a replenishment for the extended static fatigue capability.
  • the described device can be manufactured technically easily.
  • existing designs for example unicellular limit current sensors from Robert Bosch GmbH, can be easily expanded by a third electrode in the form of, for example, an external electrode.
  • a third electrode in the form of, for example, an external electrode.
  • the existing modular small sensor elements can be extended without the need for five wires or even another measuring principle would have to be used. This remains except for the additional track and the possibly changed control, which, for example, a modified ASIC
  • FIG. 2B shows an equivalent circuit diagram of the device according to FIG. 2A.
  • FIGS. 3A to 3D different electrode potential profiles in one embodiment
  • inventive method in particular using a device according to FIG 2A.
  • FIG. 1 shows a device 110 for determining at least one property of a gas in a measuring gas space 112, as corresponds to the prior art.
  • the sample gas space 112 may be, for example, an exhaust gas tract of an internal combustion engine.
  • the device 110 comprises in the illustrated embodiment a
  • the Sensor element 114 as well as a drive 118 connected to the sensor element 114 via an interface 116.
  • the drive 118 may comprise one or more electronic components and may also be configured in whole or in part as an application-specific integrated circuit (ASIC).
  • ASIC application-specific integrated circuit
  • the sensor element 114 may be configured, for example, as a lambda probe and comprises in the illustrated
  • a first electrode 120 which is also referred to as retepumpelektrode (IPE), a second electrode 122, which is also referred to as exhaust air electrode (ALE), and a the electrodes 120, 122 connecting solid electrolyte 124, For example, yttrium-stabilized zirconia.
  • the electrodes 120, 122 are arranged in the illustrated embodiment inside a layer structure.
  • the first electrode 120 is arranged in an electrode cavity 126, which can be acted upon by gas from the measuring gas space via a gas inlet hole 128.
  • a diffusion barrier 130 is arranged, ie a porous element which at least largely prevents a backflow of gas from the sample gas space 112 into the electrode cavity 116 or in the opposite direction and only allows diffusion transport.
  • the second electrode 122 is in a reference gas space 132 in the form of a
  • Reference gas duct 134 or exhaust ducts arranged. This is filled in the illustrated embodiment with a porous, gas-permeable medium.
  • the electrodes 120, 122 and the solid electrolyte 124 connecting these electrodes together form a pumping cell 136.
  • the electrodes 120, 122 can be electrically contacted by connecting contacts 138, which in FIG. 1A are labeled ALE (exhaust air electrode) or IPE (inner pumping electrode).
  • the sensor element 114 in the illustrated embodiment comprises a heating element 140 with a heater insulation 142, which surrounds a heating resistor 144 with two heater contacts H + and H " .
  • the sensor element 114 shown in FIG. 1A is designed as a single cell.
  • the control 118 is usually chosen such that the heater contacts H + and H " are acted upon by a heater control 146, which is usually a regulated
  • Heater control performs, for example, to a constant internal resistance of the pump cell 136.
  • the inner pumping electrode or first electrode 120 which is located in the exhaust gas is connected to a virtual mass 148 of the driver 118.
  • This virtual ground 148 applies the first electrode 120 to a constant electrode potential relative to an electrical ground 150.
  • the second electrode 122 or exhaust air electrode is at a variable potential.
  • About one in Figure 1A merely indicated
  • Pumping voltage source 152 is measured by means of a current measuring device 154, for example by means of a measuring resistor 156, a pumping current I p through the pumping cell 136. In conventional circuits, this is done in such a way that, for example, via a feed to a non-inverting input of an operational amplifier, the pumping voltage U p of the pumping voltage source 152 is controlled to set a higher pumping voltage of 900 mV in a measurement in air, in contrast, a smaller pumping voltage with grease gas U p of 200 mV.
  • FIG. 1B shows an equivalent circuit diagram of the device 110 according to FIG. 1A.
  • V M denotes the potential or voltage of the virtual ground 148, U N a Nernst voltage (in this case between the electrodes 120, 122), R H the resistance of the heating resistor 144, P H a
  • Heater power which in this case is a function of an internal resistance R, the pump cell 136, and U Ba t is a battery voltage of a heater control, which in this embodiment has been set to 12 V by way of example.
  • the heater circuit lower partial image
  • the pumping cell 136 are formed virtually completely separated both on the side of the sensor element 114 and on the side of the control 118.
  • the heating element 140 is driven clocked to control the internal resistance R ,.
  • the heater contact H " can be switched, for example, with a low-side FET, whereas the heater contact H +, for example, on the
  • Battery voltage U Ba t can lie.
  • electrode potentials of the first electrode (curve 158) or of the second electrode (curve 160) as a function of the air ratio ⁇ are plotted for the known measuring method according to FIGS. 1A and 1B.
  • the electrode potential 158 of the first electrode remains constant at the potential V M of the virtual ground 148.
  • the electrode potential 160 of the second electrode 122 goes from the rich air frequency range ⁇ ⁇ 1) to the lean air frequency range ⁇ > 1 ), for example, from 200 mV in the rich gas to 900 mV in air.
  • FIGS. 2A and 2B show a device 110 according to the invention. This in turn comprises at least one sensor element 114 and at least one drive 118.
  • the sensor element 114 is shown in the drawing
  • Embodiment example configured analogous to the sensor element 114 according to Figure 1A, so that for the description of this sensor element 114 can be largely referenced to the above description of Figure 1A.
  • a third electrode 162 is additionally provided in FIG. 2A. This is configured as an additional pumping electrode (hence also referred to as "2nd PE" in FIG.
  • the third electrode 162 can be acted upon with gas from the measurement gas space 112 and separated from the measurement gas space, for example by a porous protective layer 164.
  • This porous protective layer 164 can also be used as a Act diffusion barrier and limit gas access by diffusion access.
  • the third electrode 162 is arranged in the hot region of the exhaust gas, but in principle may also be arranged in a reference gas space,
  • auxiliary pumping cell 166 In a reference space of a probe housing of the sensor element 114, which is not shown in Figure 2A.
  • the third electrode 162 together with the second electrode 122, forms a pumping cell, which in the context of the present invention is referred to as auxiliary pumping cell 166 without restriction of possible functionalities.
  • the function of this auxiliary pump cell 166 is to compensate for an oxygen deficiency in the region of the second electrode 122, which may be due to the limited reference gas channel 134, in particular in the rich exhaust gas.
  • the contact of the second electrode 122 denoted ALE is connected to a virtual mass 148.
  • the first electrode 120 is connected to a pump voltage source 152, and the pumping current I p is detected at the first electrode 120. This is evident from that shown in FIG. 2B
  • a connection contact 138 of the third electrode 162 may be combined with a connection contact of the heating element 140, preferably with the connection contact H " .
  • the connection contact H + is shown only symbolically in FIG 2A, behind the connection contact H " , so that, for example, leads for H + and H " can be arranged side by side on the underside of the sensor element 114.
  • these can be printed connection contacts and / or plated-through holes
  • the third electrode 162 is easily connectable to a via for the negative terminal H " by a printing technique.
  • the heater contact H + can be switched, for example, with a high-side FET. Since the first electrode 122 by means of the virtual mass 148 to a predetermined
  • Electrode potential is set and since preferably the third electrode 162 is connected via the heater contact H " to an electrical ground 150, formed between the second electrode 122 and the third electrode 162, ie at the auxiliary pumping cell 166, a effective pumping voltage, which results from a superposition of the voltage V M and a Nernst voltage U N in the auxiliary pumping cell 166.
  • Electrode 162 and / or the porosity and / or the thickness of the protective layer 164 can be selected so that even in the rich gas at the applied pumping voltage,
  • the diffusion current can be calculated according to the thickness, porosity and area.
  • the additional pumping current through the auxiliary pumping cell 166 does not or only slightly contributes to the measuring signal in the current measuring device 154. This can be explained with reference to the equivalent circuit in FIG. 2B.
  • the pumping current I p is detected as a function of ⁇ at the first electrode 120. Also for the first electrode 120, oxygen ions can be transported from the third electrode 162.
  • the oxygen ions at the first electrode 120 are formed in the expansion first four free electrodes which initially reduce the measuring current l p to ⁇ ⁇ .
  • the measuring current I p is again increased by ⁇ ⁇ .
  • FIGS. 3A to 3D show, in an illustration analogous to FIG. 1C, various embodiments of an embodiment of the electrode potentials.
  • the reference numeral 158 again denotes the course of the electrode potential of the first electrode 120, whereas the reference numeral 160 denotes the course of the
  • Electrode potentials of the second electrode 122 each as a function of the air ratio ⁇ .
  • FIG. 3A shows a profile in which the potential 160 of the second electrode 122 is kept constant.
  • the potential difference across the pumping cell 136 which acts as a measuring cell, is unchanged from the prior art.
  • Only the potentials of the electrodes 120, 122 are due to the fact that the virtual mass 148 is now is applied to the second electrode 122 (ALE), changed.
  • the potential of the second electrode 122 may be held firmly at 2.5V.
  • the potential 158 of the first electrode 120 may vary between 2.3 V in the rich gas range and 1.6 V in air.
  • the virtual mass 148 may also be configured as an adjustable, variable or even controllable virtual mass. This is illustrated by way of example in FIGS. 3B to 3D.
  • the virtual mass 148 or the potential with which the virtual ground 148 is applied to the second electrode 122 is adapted to the exhaust gas composition determined from the measurement current I p .
  • the reference gas channel 134 for example the exhaust air duct (ALK)
  • the storage effect of typical reference gas channels 134 can buffer the oxygen demand for about 30 seconds of fat measurement.
  • the potential 160 of the second electrode 122 can be varied continuously from 2.5 V in the rich gas range to 1.1 V in the lean range, or also batchwise or, for example, stepwise.
  • the potential of the first electrode 120 may vary, for example, between 2.3 V in the rich gas range to 0.2 V in air.
  • the potential difference across the pumping cell 136 functioning as a measuring cell is at least substantially unchanged from the prior art and unaffected by the auxiliary pumping current through the pumping cell 166.
  • the reference gas channel 134 can be made relatively small. This increases the stability of the sensor element 114 and reduces the mechanical impairment of the sensor element 114 by the reference gas channel 134. Namely, by using the virtual mass 148, which can be configured as a controlled virtual mass, the storage effect of the reference gas channel 134 can only be claimed to a minor extent be that this can be equipped with a very small volume and thus no mechanical impairment of the sensor element 114 represents more.
  • the reference gas channel 134 may even be executed closed, with an optimized control. This is illustrated in FIG. 3C by a profile of the electrode potentials 158, 160. While that
  • Potential of the ALE 122 (curve 160) is at a constant value, for example 2.5 V, the potential of the IPE 120 (curve 158) decreases continuously with increasing air ratio, for example from 2.3 V to 1.6 V.
  • the potential curves illustrated in FIGS. 3A to 3C are particularly suitable for a high-impedance design of the auxiliary pumping cell 166.
  • the auxiliary pumping cell 166 requires a larger pumping voltage due to the voltage drop across the electrolyte resistance. If the resistance of the auxiliary pumping cell 166 is made extremely large, for example, by selecting small electrodes (for example, 500 ohms), then the cases shown in FIGS. 3A to 3C provide a linear one
  • V M is chosen to be very large at the end of the rich gas region, for example 2.5 V for 2 mA auxiliary pumping current.
  • a fivefold larger pumping current of the pumping cell 136 is possible in comparison to the auxiliary pumping cell 166, because the current through the auxiliary pumping cell 166 in the lean air-fuel ratio range is unnecessary.
  • the pump voltage is not selected larger than the sum of the decomposition voltage of the Zr0 2 and the internal resistance multiplied by the limiting current of the protective layer of the third electrode 162 in the high-voltage design on the side facing the rich Beeriere Symposium, otherwise a Zr0 2 decomposition can occur.
  • the pump voltage U p should not exceed the course of the pump voltages U p of conventional devices according to the prior art, so that no additional measuring current due to a
  • the potential 160 of the virtual mass V M should not exceed a value of approximately R * 1 p + 1.1 V, so that it is not destroyed by ZrGy decomposition
  • FIG. 3D shows a particularly preferred profile of the electrode potentials 158, 160 and of an electrode potential 168 of the third electrode 162.
  • This exemplary embodiment and similar exemplary embodiments with a non-linear profile of the electrode potentials 158, 160 is particularly advantageous in the case of auxiliary pumping cells 166 having a comparatively small internal resistance, for example internal resistances of 150 ohms or less, for example 80 ohms.
  • This refinement has the advantage that a unipolar pump voltage source can be used as the pump voltage source 152, since polarity reversal is not required.
  • the electrode potential 158 of the first electrode 120 is obtained by subtracting the pumping voltage U p of
  • the local minimum in the range around ⁇ -1 causes in this region, which is particularly critical with respect to the characteristic curves, no decomposition of non-oxygen components in the exhaust gas to take place, for example no water decomposition, or Such decomposition is at least largely reduced.
  • the potential difference U p is tracked in the embodiment according to FIG 3D with ⁇ .
  • the potential difference V M of the virtual mass 148 is also tracked with ⁇ .
  • a high V M is chosen, resulting in a sufficient additive pump flow. As stated above, this means that even with a small
  • Reference gas channel 134 can be worked because by the auxiliary pumping cell 166th
  • Oxygen is replenished at the second electrode 122.
  • the low V M causes little or no water decomposition in this region.
  • the electrode potential 160 of the second electrode 122 rises again to a high V M so that no negative potential occurs at the first electrode 120, which prevents a reversal of the polarity of the pump voltage source 152.
  • the third electrode 162 is always at the constant electrode potential 0, since it is connected to the electrical ground 150 via the heater contact H.
  • other configurations are possible in principle.

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)

Abstract

L'invention concerne un dispositif (110) pour la détermination d'au moins une propriété d'un gaz dans une chambre de gaz de mesure (112), notamment pour la détection d'une quantité d'au moins un composant gazeux. Le dispositif (110) comporte au moins un élément de détection (114) et au moins une commande (118). L'élément de détection comporte au moins une cellule de pompe (136) pourvue d'au moins une première électrode (120), d'au moins une deuxième électrode (122), et d'au moins un électrolyte solide (124) reliant la première électrode (120) et la deuxième électrode (122). La première électrode (120) peut être exposée à un gaz issu de la chambre de gaz de mesure (112). La deuxième électrode (122) est disposée dans au moins un espace de gaz de référence (132), notamment un canal de gaz de référence (134). L'élément de détection (114) comporte par ailleurs au moins une troisième électrode (162) formant avec la deuxième électrode (122) une cellule de pompe auxiliaire (166). La commande (118) est conçue de telle manière que la deuxième électrode (122) est reliée à une masse virtuelle (148). La commande (118) est par ailleurs conçue pour appliquer une tension de pompe à la cellule de pompe (136) et pour détecter un courant de pompe sur la première électrode (120).
PCT/EP2011/057750 2010-07-13 2011-05-13 Dispositif de détermination d'une propriété d'un gaz dans une chambre de gaz de mesure Ceased WO2012007200A1 (fr)

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DE201010031299 DE102010031299A1 (de) 2010-07-13 2010-07-13 Vorrichtung zur Bestimmung einer Eigenschaft eines Gases in einem Messgasraum
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210270768A1 (en) * 2020-03-02 2021-09-02 Ngk Insulators, Ltd. Gas sensor

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014203063A1 (de) 2014-02-20 2015-08-20 Robert Bosch Gmbh Vorrichtung zur Erfassung mindestens einer Eigenschaft eines Gases
DE102014224009A1 (de) 2014-11-25 2016-05-25 Robert Bosch Gmbh Vorrichtung und Verfahren zur Bestimmung einer Eigenschaft eines Gases in einem Messgasraum
DE102015226017A1 (de) * 2015-12-18 2017-06-22 Robert Bosch Gmbh Sensorelement zur Erfassung mindestens einer Eigenschaft eines Messgases in einem Messgasraum
DE102016220649A1 (de) * 2016-10-20 2018-04-26 Robert Bosch Gmbh Steuereinheit zum Betrieb einer Lambdasonde

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4487680A (en) * 1983-04-18 1984-12-11 Ford Motor Company Planar ZrO2 oxygen pumping sensor
DE4447033A1 (de) * 1994-12-28 1996-07-11 Bosch Gmbh Robert Meßfühler zur Bestimmung des Sauerstoffgehaltes in Gasgemischen
DE10115872A1 (de) * 2001-03-30 2002-10-17 Bosch Gmbh Robert Gassensor
DE102006011480A1 (de) 2006-03-13 2007-09-20 Robert Bosch Gmbh Gassensor
DE102006014681A1 (de) * 2006-03-28 2007-10-04 Robert Bosch Gmbh Gassensor

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10147390A1 (de) * 2001-09-26 2003-04-30 Bosch Gmbh Robert Breitband-Lambda-Sonde mit verbessertem Startverhalten
DE102006062056A1 (de) * 2006-12-29 2008-07-03 Robert Bosch Gmbh Sensorelement mit unterdrückter Fettgasreaktion
DE102006062060A1 (de) * 2006-12-29 2008-07-03 Robert Bosch Gmbh Sensorelement mit innen liegender Anode

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4487680A (en) * 1983-04-18 1984-12-11 Ford Motor Company Planar ZrO2 oxygen pumping sensor
DE4447033A1 (de) * 1994-12-28 1996-07-11 Bosch Gmbh Robert Meßfühler zur Bestimmung des Sauerstoffgehaltes in Gasgemischen
DE10115872A1 (de) * 2001-03-30 2002-10-17 Bosch Gmbh Robert Gassensor
DE102006011480A1 (de) 2006-03-13 2007-09-20 Robert Bosch Gmbh Gassensor
DE102006014681A1 (de) * 2006-03-28 2007-10-04 Robert Bosch Gmbh Gassensor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Sensoren im Kraftfahrzeug", 2007, ROBERT BOSCH GMBH, pages: 154 - 159

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210270768A1 (en) * 2020-03-02 2021-09-02 Ngk Insulators, Ltd. Gas sensor
US11680926B2 (en) * 2020-03-02 2023-06-20 Ngk Insulators, Ltd. Gas sensor

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