Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/2066—Selective catalytic reduction [SCR]
  • F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/2066—Selective catalytic reduction [SCR]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
  • B01D35/02—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks
  • B01D35/027—Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks rigidly mounted in or on tanks or reservoirs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/008—Mounting or arrangement of exhaust sensors in or on exhaust apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
  • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
  • G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
  • G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
  • G01F23/242—Mounting arrangements for electrodes
• • 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
  • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/10—Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1406—Storage means for substances, e.g. tanks or reservoirs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
  • F01N2900/06—Parameters used for exhaust control or diagnosing
  • F01N2900/18—Parameters used for exhaust control or diagnosing said parameters being related to the system for adding a substance into the exhaust
  • F01N2900/1806—Properties of reducing agent or dosing system
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
  • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the invention relates to a method for determining the fill level in a tank in which (liquid) reducing agent, such as a urea water solution, is stored, in particular for a mobile application in the motor vehicle sector.
• (liquid) reducing agent such as a urea water solution
• exhaust gas purification devices in which a reducing agent for reducing certain exhaust gas components is supplied.
• a reducing agent for reducing certain exhaust gas components For example, nitrogen oxide compounds (NOx) in the exhaust gas can be removed particularly effectively if ammonia is supplied to the exhaust gas as a reducing agent.
• NOx nitrogen oxide compounds
• Typical reducing agents, such as ammonia are hazardous substances and therefore should not be stored directly in motor vehicles. Therefore, reducing agent is kept regularly as reducing agent precursor in a separate tank as additional fuel in the motor vehicle.
• a typical reducing agent precursor is, for example, urea. This is z. B. in the form of a 32.5-urea-water solution stored in the vehicle.
• Such a urea-water solution is available, for example, under the trade name "AdBIue.” Such a urea-water solution typically freezes at temperatures of -11 ° C. A device for conveying or metering liquid reducing agent is then Such low temperatures can occur in motor vehicles, in particular as a consequence of long downtimes.
• the invention relates to a method for operating a tank, which has a sensor with a first electrical contact and a second electrical contact. have contact, which comprises at least the following steps:
• step d) comparing the conductance determined in step c) with the guide values determined in steps al) to a.3) and determining whether liquid reducing agent, frozen reducing agent or air is present.
• the method according to the invention is also partially illustrated in connection with various embodiments of a tank for a reducing agent. Accordingly, this tank is particularly suitable for carrying out the method according to the invention and is therefore described in advance for the purpose of illustration.
• It has a tank wall and an at least partially bounded by the tank wall interior, wherein on the tank wall, a sensor having a first electrical contact and a second electrical contact is arranged, wherein the first electrical contact and the second electrical contact with the interior in electrically conductive Connection, the tank wall penetrate from the inner space to an outer side of the tank wall, and at a first distance of less than 5 cm [centimeters] are arranged to each other.
• the first electrical contact and the second electrical contact are preferably arranged at a first distance of less than 3 cm, more preferably even less than 2 cm. So that the first electrical contact and the second electrical contact penetrate the tank wall, it is essentially meant that the first electrical contact and the second electrical contact makes electrical connection from the interior of the tank to an outside of the tank.
• At least the first electrical contact and / or the second electrical contact may be formed by a metallic pot which is arranged in the tank.
• a metallic pot which is arranged in the tank.
• Such a pot can be, for example, a housing for a metering device, which serves to convey reducing agent out of the tank.
• At least the first electrical contact and / or the second electrical contact can also be formed by a withdrawal line, a return line, a withdrawal or a discharge for the metering device.
• An extraction line, a return line, a withdrawal and a discharge are different lines that connect the metering device for promoting reducing agent with the interior of the tank s.
• the first electrical contact it is necessary for the first electrical contact to be electrically insulated from the second electrical contact so that electrical properties of the reducing agent in the tank can be determined.
• the tank wall is preferably made of plastic.
• the electrical contacts which together form the sensor, are preferably cast in the tank wall.
• at least one sealing element may be cast into the tank wall, which seals the electrical contacts against the tank wall.
• the electrical contacts are preferably designed as metallic pins.
• these metallic pins may have a surface structure that favors the sealing of the tank wall to the metallic pins.
• a groove may also be formed in the metallic pins into which a sealing element, such as an O-ring seal, engages.
• the metallic pins may also have a recess through which improved sealing of the pins in the tank wall is achieved. It is also possible that the electrical contacts penetrate the tank wall individually. But it is also possible that the metallic pins are arranged in a common sealing element and this sealing element is inserted as a whole in the tank wall or penetrates the tank wall.
• a plurality of such sensors may be provided, but it is preferred to provide only a single sensor on such a tank.
• Several such sensors may for example be provided in a tank in order to be able to reliably measure at least one of the sensors at low filling levels and / or an inclined position of the tank. At low levels, it may happen due to an inclined position of the tank, that no reducing agent is present at a sensor, although at a certain amount of reducing agent stored in the tank with horizontal alignment of the tank to the sensor would actually be present reducing agent. Consequently, the error rate of the level detection system can be reduced.
• aggregate state eg liquid or frozen
• the reserve level in the tank is preferably determined near the bottom of the tank because near the bottom both electrical contacts may be located at an equal height.
• an arrangement in the vicinity of the tank bottom allows a particularly advantageous determination of a residual volume.
• a residual volume regularly only represents a surface covering of the tank bottom.
• a sensor arranged in the tank bottom can also be arranged in the middle of the tank bottom. As a result, the sensor is less susceptible to sloshing in the tank and / or to a possible tilt of the tank, because sloshing and / or an inclined position (particularly pronounced) change the level just away from the center - at the edge near the side tank walls - cause.
• tanks in motor vehicles may be installed in such a way that access to the tank is only possible from below. Therefore, the sensor z. B. particularly well accessible for maintenance when it is located in the tank bottom.
• the senor can also be arranged on a tank wall.
• a plurality of sensors for example between two sensors and ten sensors, at a specific height over a circumference of the tank.
• monitoring of the tank can take place by means of this plurality of sensors, whereby at least one of the sensors is suitable for a representative measurement even in the case of inclined position and in the event of sloshing movements in the tank.
• the level signals determined by the individual sensors can be evaluated in a suitable controller in order to arrive at a corrected fill level signal. For example, an average value can be formed from the individual fill level signals in order to determine whether a reserve level to be monitored has been undershot or not. In a further embodiment variant, a distinction can also be made as to whether a reserve level has fallen below or not by comparing the number of sensors in which reducing agent is present with the number of all available sensors. If z. B. more than half of the sensors reports that the reserve level is below, the reserve height can be set as below.
• a statistical evaluation of the level signals of the plurality of sensors for example by means of a principal component analysis, is also possible.
• a shoulder with a reserve height is arranged in the region of the electrical contacts. This paragraph isolates the electrical contacts up to the reserve height. In this way, a reserve level amount is precisely defined when arranged in the tank bottom electrical contacts.
• the tank when the tank has a heater, and the heater is disposed at a distance of less than 50 cm [centimeter] to the sensor. Preferably, the second distance is less than 20 cm, and more preferably less than 10 cm.
• the heater is arranged for this purpose, in particular in the vicinity of the tank bottom.
• This heater is preferably a controllable, electrical heater (eg having at least one element from the group heating wire, heating foil, PTC element, cooling water heating).
• a heating coil is preferably passed through the tank through which the cooling water heated by the internal combustion engine flows and gives off heat energy to the reducing agent in the tank.
• the operation of a heater in the vicinity of the tank bottom forms a cavity in the frozen reducing agent (so-called "ice cave") in which (partially) liquid reducing agent is present
• the sensor can be used to determine the size of this ice cave, which can be determined by means of a conductivity measurement to determine whether liquid reducing agent or frozen reducing agent is present on the sensor
• the energy introduced into the tank by the heater can also be taken into account.
• a temperature sensor is mounted. Due to their own electrical conductivity, electrically conductive contacts also regularly have a good thermal conductivity.
• the tank wall preferably made of plastic, however, has a poor thermal conductivity.
• the electrical contacts This can be used to attach a temperature sensor on the outside of a tank wall and to determine with this temperature sensor via one of the two electrical contacts a temperature on the inside of the tank wall or in the interior of the tank. Such a sensor further improves the possibilities for determining a temperature distribution in the tank.
• the guide values of liquid reducing agent and frozen reducing agent are regularly so different that it can be concluded by determining the conductance whether liquid reducing agent or frozen reducing agent is present.
• Air is compared to reducing agent is a very good electrical insulator, so that air can be detected by a conductance determination between the two electrical contacts and air.
• the conductance of frozen reducing agent and the conductance of air are similar.
• the difference between the conductance of the frozen reductant and the conductance of air is significantly smaller than the differences between the conductance of air and the conductance of liquid reductant, and the conductance of frozen reductant and the conductance of liquid reductant.
• the method is particularly advantageous if a temperature sensor is provided on the tank and in step d) a temperature measured with this temperature sensor is taken into account.
• a temperature measured with this temperature sensor is taken into account.
• the conductance values of frozen reducing agent and of air do not differ so much from each other as the liquid reducing agent conductance. For this reason, it may be advantageous if, in order to distinguish whether air or frozen reducing agent is present, a measured temperature is taken into account in step d). If the temperature is above a threshold temperature, for example, more than -10 ° C or preferably more than -5 ° C and more preferably more than 0 ° C, no frozen reducing agent may be present, so that based on the conductance only between air and liquid Reducing agent must be distinguished.
• step d) it can be taken into account in step d) which values were measured in previous process iterations.
• step d) it can be taken into account whether and / or to what extent a heater was operated in a time interval before the procedure was carried out. If, for example, frozen reducing agent was detected in a preceding process iteration and, in addition, a heater was operated in step d) for thawing the reducing agent, it can be expected that liquid reducing agent will first be detected before air is detected. A conductance, which is normally characteristic of air, can thus be evaluated in step d) in such a way that frozen reducing agent is present if no liquid reducing agent could be detected in the meantime.
• the method according to the invention is furthermore particularly advantageous when the method steps a1) to a.3) are carried out in advance, the guide values of liquid reducing agent, frozen reducing agent and air are stored in a first store and then for step d) the guide values of liquid reducing agent, frozen reductant Onsffen and air are read out of this first memory.
• This first memory can be stored in a control unit such as the engine control of a motor vehicle.
• a control unit such as the engine control of a motor vehicle.
• a conductance measured at an earlier time point can be used. At this time, there should certainly have been liquid reductant in the tank. Whether this is the case can be determined with a temperature sensor.
• steps a) to a.3) can be carried out in advance in a test setup.
• These guide values can also be stored in a first memory, from which they are read out for the execution of step d) in later operation.
• the memory may in this case be a read-only memory which is not rewritable.
• reducing agent is regularly a 32.5 percent urea-water solution.
• the urea content may vary somewhat.
• impurities can also occur in the solution.
• the conductance values in particular the conductivities of liquid reducing agent and frozen reducing agent
• the method steps a1) to a.3) should at least be carried out if the properties of the reducing agent (detectable) could have changed. This is especially to be done after filling the tank with reducing agent, because the filled reducing agent may have different properties.
• an alternating voltage is applied in step b) to the first electrical contact and to the second electrical contact, which changes between a positive voltage value and a negative voltage value.
• the AC voltage is rectangular.
• the AC voltage is symmetrical. By this is meant that the negative voltage proportion and the positive voltage proportion correspond in form and amount. Thus it can be prevented that form deposits on one of the two contacts as a result of electrolysis.
• the method is advantageous if the tank has a heater and the method is extended by the following steps:
• step d) activating the heater if it has been determined in step d) that frozen reducing agent is present;
• step d) Disabling the heater if it has been determined in step d) that air is present.
• the invention finds application in a motor vehicle, comprising an internal combustion engine with an exhaust gas treatment device having a metering device for reducing agent, wherein the metering device has a tank described herein and a controller, and the controller is adapted to carry out the method according to the invention.
• a motor vehicle comprising an internal combustion engine with an exhaust gas treatment device having a metering device for reducing agent, wherein the metering device has a tank described herein and a controller, and the controller is adapted to carry out the method according to the invention.
• FIG. 9 shows a tank with a fifth embodiment for electrical contacts
• FIG. 10 shows a tank with a sixth embodiment for electrical contacts.
• a tank 1 is shown.
• This tank 1 has a tank wall 3 which limits an interior 4.
• frozen reducing agent 15 in which an ice cave 33 is formed.
• the ice cave 33 is partially filled with air 16 and partly with liquid reductant. onskar 14 (here in particular a urea-water solution) filled.
• the ice cave 33 is formed around a (electrically controllable, areal) heater 11.
• the heater 11 is arranged in the region of the tank bottom 10 on the tank wall 3.
• a sensor 5 In a second distance 12 to the heater 11 is a sensor 5.
• the sensor 5 is also there in the tank wall 3, namely the tank bottom 10, respectively.
• the sensor 5 has a first electrical contact 6 and a second electrical contact 7.
• the first electrical contact 6 and the second electrical contact 7 are arranged at a first distance 9 from each other and guided with a seal 20 through the tank wall 3 of the tank 1 therethrough.
• a temperature sensor 13 is attached, with which from an outside 8 of the tank 1, the temperature in the interior 4 of the tank 1 and the temperature of the reducing agent can be detected.
• FIG. 2 shows an example of how electrical contact can penetrate a tank wall 3.
• the tank wall 3 has an indentation 23 into which a threaded sleeve 34 is inserted.
• the first electrical contact 6 with a seal 20 is arranged in the threaded sleeve 34.
• the interior 4 of a tank, which is filled, for example, with frozen reducing agent 15, is sealed with the seal 20 against an outside 8.
• FIG. 3 shows a further example of how a first electrical contact 6 and a second electrical contact 7 can penetrate a tank wall 3.
• the tank wall 3 is penetrated here in the region of the tank bottom 10.
• the first electrical contact 6 and the second electrical contact 7 are embedded by means of seals 20 in the tank wall 3.
• the filled with reducing agent 15 interior 4 of a tank 1 is sealed against an outer side 8.
• a protective frame 28 is attached to the tank wall 3, through which the first electrical contact 6 and the second electrical Kon- 7 are protected.
• This protective frame 28 may be provided directly in the manufacture of the tank 1.
• the protective frame 28 may for example be injection-molded or cast on the tank 1.
• the protective frame 28 may also form a plug.
• a cable with a corresponding connector can then be connected directly to the first electrical contact 6 and to the second electrical contact 7.
• the protective frame 28 then gives mechanical stability to the connection between the tank 1 and the connector.
• a shoulder 21 is provided in each case in the region of the first electrical contact 6 and of the second electrical contact 7 on the tank wall 3 for the first electrical contact 6 and the second electrical contact 7.
• a reserve level 22 is defined in the tank (the reserve level represents the level in the tank, if only the reserve volume of liquid reducing agent is present).
• the first electrical contact 6 and the second electrical contact 7 each protrude out of the shoulders 21 for a first length 32.
• the first electrical contact 6 is designed here in the form of a rivet 25, wherein the rivet 25 braces a rubber sleeve 29 as a seal 20 with the tank wall 3.
• FIG. 5 shows a first electrical contact 6 inserted in a lateral region of a tank wall 3 (tank side wall).
• This first electrical contact 6 is also designed as a rivet 25, which is inserted by means of a seal 20 in a recess 23 of the tank wall 3.
• a reserve height 22 is defined here by the arrangement of the first electrical contact 6 in the tank wall 3 and not by the height of a shoulder 21. The further the first electrical contact 6 or the electrical contacts on the tank wall 3 are positioned away from the tank bottom, the larger the reserve height 22.
• FIGS. 4 and 5 particularly preferred forms of a first electrical contact 6 are shown in FIGS. 4 and 5. These shapes are chosen so that no deposits and / or accumulations of reducing agent and / or reducing agent residues may occur in the first electrical contact 6, or that such deposits and / or accumulations are avoided as far as possible. Such deposits may cause a short circuit between the first electrical contact 6 and the tank wall 3 and / or a short circuit between the first electrical contact 6 and the second electrical contact 7.
• the end of the first electrical contact 6 can be designed appropriately here.
• FIG. 4 shows, for example, a lens mold 37 for the end of the first electrical contact 6.
• Fig. 5 shows a first electrical contact 6, which has a preferably circumferential chamfer 38 at its end.
• the thickness 40 of the first electrical contact 6 can be suitably selected.
• the thickness 40 is at least 0.5 mm [millimeter], preferably at least 1 mm, and more preferably at least 2 mm.
• a width 40 is preferably meant a shortest path on the surface of the insulation from the tank wall 3 to the first electrical contact 6. The insulation is formed according to FIGS. 4 and 5 by the seal 20.
• the width 39 is at least 0.5 mm [millimeters] and more preferably at least 1 mm.
• FIG. 6 shows a further tank 1 with a sensor 5, which is designed with a first electrical contact 6 and a second electrical contact 7.
• the tank 1 has a metallic pot 27, in which a conveying unit 26 for transporting or for metering the reducing agent is arranged.
• the liquid reducing agent 14 can be removed via a removal 35 from the interior of the tank 1 out.
• Part of the conveyor unit 26 may, for. Example, a filter, a pump, a valve, transport lines, etc., which are integrated with in the metallic pot 27.
• the liquid reducing agent (possibly under elevated pressure) via a discharge line 36, for example, fed to an (not shown here) addition point or Zudosierstelle an exhaust system.
• FIG. 7 shows a motor vehicle 17 having an internal combustion engine 18 and an exhaust gas treatment device 19.
• a metering device 2 is provided, which has a tank 1.
• Liquid reducing agent stored in the tank 1 can be added by means of a (preferably integrated in the tank) conveying unit of the exhaust gas treatment device 19 via an injector 30 with predetermined amounts.
• Fig. 8 shows a flow diagram of the method according to the invention. It can be seen the process steps al) to a.3), b), c) and d) and el) and e.2).
• the process takes the form of a fe iteratively (several times) can be carried out repeatedly, the method steps al) to a.3) need not be carried out at each iteration of the process with.
• a first memory 41 in which in the process steps al) to. a.3) certain conductivity values can be temporarily stored.
• the guide values stored in the first memory 41 can be taken into account in step d). This is indicated by corresponding signal arrows in FIG. 8.
• guide values can be taken into account that were measured in previous iterations of the method in step c) and stored in a second memory 42.
• the deposit of the guide values is indicated by a signal arrow from step c) to the second memory 42.
• step d) The consideration of the stored conductance in step d) is indicated by the signal arrow from the second memory 42 to the step d). Also, in step d) temperature signals 43 and information stored in the second memory 42 about the operation of a heater during a preceding time interval can be taken into account. This is also indicated in each case by corresponding signal arrows.
• the first memory and / or the second memory may be provided in a control unit of a motor vehicle.
• Information about the operation of a heater can for example be obtained from the process steps el) and e.2). On the basis of the switch-on or the switch-off of a heater can be detected when the heater was operated. The information about the operation of a heater can also be obtained from the control of the heater itself.
• FIG. 9 shows a fifth embodiment variant of a first electrical contact 6 and of a second electrical contact 7 for a tank 1 with a sensor 5.
• a metallic pot 27 is inserted in the tank 1.
• a conveyor unit 26 is arranged for the promotion of reducing agent.
• the metallic pot 27 forms a first electrical contact 6 of the sensor 5.
• a second ter electrical contact 7 is provided.
• the second electrical contact 7 penetrates in the embodiment of FIG. 9, the metallic pot 27, wherein it is sealed with a sealing element against the metallic pot 27.
• the sealing element is designed in the present case as a rubber sleeve 29. However, other embodiments of the sealing element are also conceivable.
• the second electrical contact 7, the tank wall 3 also separated from the metallic pot 27 penetrate.
• the second electrical contact 7 can be arranged next to the metallic pot 27 in the tank wall.
• the designed as a metallic pot 27 first electrical contact 6 and the second electrical contact 7 preferably have a first distance 9 of less than 5 cm [centimeters] to each other, as is in the sense of the tank 1.
• FIG. 10 shows a sixth embodiment variant for a first electrical contact 6 and a second electrical contact 7 for a tank 1 with a sensor 5.
• a metallic pot 27 with a delivery unit 26 is likewise inserted into the tank 1. Again, the metallic pot 27 forms the first electrical contact 6.
• a filter 44 is arranged.
• a removal 35 for reducing agent is arranged by which reducing agent is transported from the tank 1 to the conveyor unit 26.
• Reducing agent which passes from the tank 1 to the removal 35, is filtered by the filter 44.
• the second electrical contact 7 is arranged next to the metallic pot 27 with the filter 44. Between the first electrical contact 6 and the second electrical contact 7 there is also a distance of less than 5 cm [centimeters].
• the filter 44 is disposed between the first electrical contact 6 and the second electrical contact 7.
• this is not disadvantageous for the measurement of the electrical properties of the reducing agent between the first electrical contact 6 and the second electrical contact 7.
• a particularly advantageous method for operating ei ⁇ nes reducing agent tank has been specified with a level determination here.

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• Chemical & Material Sciences (AREA)
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• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
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• Exhaust Gas After Treatment (AREA)
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• 2010
  • 2010-03-11 DE DE102010011151A patent/DE102010011151A1/de not_active Withdrawn
• 2011
  • 2011-03-08 EP EP11706843A patent/EP2547988A1/de not_active Withdrawn
  • 2011-03-08 WO PCT/EP2011/053492 patent/WO2011110573A1/de active Application Filing
  • 2011-03-08 WO PCT/EP2011/053493 patent/WO2011110574A1/de active Application Filing
  • 2011-03-08 JP JP2012556497A patent/JP2013522584A/ja not_active Ceased
  • 2011-03-08 JP JP2012556498A patent/JP2013522515A/ja active Pending
  • 2011-03-08 EP EP11707662.0A patent/EP2547877B1/de active Active
• 2012
  • 2012-09-11 US US13/609,601 patent/US9074510B2/en active Active
  • 2012-09-11 US US13/609,607 patent/US8955308B2/en active Active

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