US20120042635A1 - Method for Operating a Reducing Agent Supply System - Google Patents

Method for Operating a Reducing Agent Supply System Download PDF

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Publication number
US20120042635A1
US20120042635A1 US13/258,027 US201013258027A US2012042635A1 US 20120042635 A1 US20120042635 A1 US 20120042635A1 US 201013258027 A US201013258027 A US 201013258027A US 2012042635 A1 US2012042635 A1 US 2012042635A1
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United States
Prior art keywords
reducing agent
stream
air stream
cleaning operation
pulses
Prior art date
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Abandoned
Application number
US13/258,027
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English (en)
Inventor
Michael Hochholzner
Horst Baier
Ralf Wandel
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Mercedes Benz Group AG
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Daimler AG
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Publication date
Application filed by Daimler AG filed Critical Daimler AG
Assigned to DAIMLER AG reassignment DAIMLER AG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BAIER, HORST, WANDEL, RALF, HOCHHOLZNER, MICHAEL
Publication of US20120042635A1 publication Critical patent/US20120042635A1/en
Abandoned legal-status Critical Current

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    • 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
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • 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
    • F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
    • F01N2550/05—Systems for adding substances into exhaust
    • 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
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • 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
    • F01N2610/08—Adding substances to exhaust gases with prior mixing of the substances with a gas, e.g. air
    • 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
    • F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
    • F01N2610/146—Control thereof, e.g. control of injectors or injection valves
    • 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
    • F01N2610/1493—Purging the reducing agent out of the conduits or nozzle
    • 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
    • F01N2900/1808—Pressure
    • 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
    • F01N2900/1824—Properties of the air to be mixed with added substances, e.g. air pressure or air temperature
    • 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
    • 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
    • Y02T10/40—Engine management systems

Definitions

  • the invention relates to a method for operating a reducing agent supply system a reducing agent supply system for supplying an exhaust aftertreatment system of a motor vehicle with a reducing agent serving for emission control, in which an air stream and a reducing agent stream are supplied to a nozzle which opens into an exhaust line.
  • DE 10 2006 007 658 A1 discloses that, in addition to the air and to urea solution used, a third medium, preferably a solvent for urea, is used for flushing out deposits of urea.
  • a third medium preferably a solvent for urea
  • Exemplary embodiments of the present invention provide a method for operating a reducing agent supply system that permits simplified cleaning of the reducing agent supply system.
  • the method according to the invention is distinguished in that in normal metering operation of the reducing agent supply system, an at least approximately continuous air stream and a pulsed reducing agent stream are produced and released at least partially via the nozzle into the exhaust line, and in a cleaning operation for cleaning the reducing agent supply system, an air stream formed from a number of air stream pulses and a reducing agent stream formed from a number of reducing agent stream pulses are produced and are supplied to the nozzle.
  • An air stream pulse or reducing agent stream pulse in this case is to be understood to mean a sudden and considerable change in the air flow rate or in the reducing agent flow rate.
  • an air stream pulse or reducing agent stream pulse consists of briefly switching on an air stream or a reducing agent stream such that the air stream or the reducing agent stream suddenly changes from a switched-off state to a switched-on state and then back into the switched-off state.
  • the duration of a pulse lies preferably in the range from one to about twenty seconds.
  • pulses of HWL that are spaced apart from each other timewise are preferably supplied to the approximately continuous air stream such that an aerosol-like mixture of fine HWL liquid droplets and air is formed.
  • the HWL stream can be supplied to the air at the location of the nozzle, for example close to the exit opening.
  • part of the HWL stream can be returned from the nozzle back to a storage vessel for HWL, so that only part of the HWL stream is released into the exhaust.
  • a pulsed HWL stream is supplied into the at least approximately continuous air stream at a point remote from the nozzle, and the mixture is supplied via a mixture line to the nozzle which opens into the exhaust line, and is added to the exhaust stream.
  • the HWL pulses in this case are preferably calculated according to requirements such that overall a desired NOx conversion in an NOx reduction catalyst of the exhaust aftertreatment system is at least approximately achieved.
  • the production and admetering of the pulsed HWL stream preferably takes place by pulse width modulated operation of a metering valve.
  • the air stream is preferably delivered by a compressed air supply unit.
  • a cleaning operation is activated.
  • both air stream pulses and HWL stream pulses are produced and supplied to the nozzle.
  • the cleaning operation is activated as a preventive measure at pre-settable times, for example upon each second, each fifth, or generally each nth start-up of the reducing agent supply system.
  • a back pressure in a line of the reducing agent supply system for transporting the air stream to the nozzle is determined and the cleaning operation is activated upon exceeding a pre-settable, in particular first, upper pressure threshold value.
  • Reliable monitoring of the reducing agent supply system in particular with regard to deposits and other contaminants having the effect of constricting the cross-section in the line system, is made possible due to preferably continuous pressure monitoring. For example, deposits due to corrosion or alternatively urea deposits in the line system through which air flows of the reducing agent supply system result in an increased resistance to flow. In the case of an air stream of known or pre-settable size which is preferably used, this results in a measurable pressure increase.
  • a back pressure in a line of the reducing agent supply system for transporting the air stream to the nozzle is determined and an activated cleaning operation is deactivated if the pressure drops below a pre-settable lower pressure threshold value.
  • an activated cleaning operation is deactivated after exceeding a pre-settable total value of amount of reducing agent of the reducing agent stream formed from reducing agent stream pulses or after exceeding a pre-settable duration from the beginning of the cleaning operation.
  • a first operating mode is provided for the cleaning operation in which a sequence of reducing agent stream pulses and air stream pulses is produced such that a particular reducing agent stream pulse overlaps timewise with a particular air stream pulse.
  • an air stream pulse falls timewise completely in a reducing agent stream pulse.
  • the reducing agent stream preferably suddenly, is switched on, for example by opening a shutoff valve.
  • the air stream is switched on and thereafter switched off again while the reducing agent stream continues to exist.
  • the reducing agent stream is also switched off again. This produces short flushing phases with thorough flushing of the line system with liquid reducing agent, which phases precede and succeed a throughflow with reducing agent/air aerosol mixture. This has likewise proved very effective with regard to detachment of deposits.
  • a second operating mode is provided for the cleaning operation in which a number of successive reducing agent stream pulses is produced when the air stream is switched off and a number of successive air stream pulses is produced when the reducing agent stream is switched off.
  • a back pressure in a line of the reducing agent supply system for transporting the air stream to the nozzle is determined and the first operating mode of the cleaning operation is activated upon exceeding a pre-settable first upper pressure threshold value and the second operating mode of the cleaning operation is activated upon exceeding a pre-settable second upper pressure threshold value, the second upper pressure threshold value being higher than the first upper pressure threshold value.
  • a cleaning operation of the first operating mode succeeds a cleaning operation of the second operating mode.
  • the first operating mode is activated immediately once the second operating mode has been deactivated.
  • FIG. 1 shows a diagrammatic representation of an advantageous embodiment of a reducing agent supply system
  • FIG. 2 shows a schematized time diagram for a pulse sequence of air stream pulses and reducing agent stream pulses in order to make clear an advantageous variant of the method according to the invention corresponding to a first cleaning operating mode
  • FIG. 3 shows a schematized time diagram for a pulse sequence of air stream pulses and reducing agent stream pulses in order to make clear an advantageous variant of the method according to the invention corresponding to a second cleaning operating mode.
  • a reducing agent supply system 1 comprises a liquid supply line 2 for a liquid that is to be metered.
  • a metering valve 4 which can be operated in timed manner, and an adjustable adjusting choke 5 , a first pressure sensor 6 are arranged in the liquid supply line 2 .
  • the liquid supply line 2 opens, as does an air supply line 3 for supplying compressed air, into a mixing region 11 of the reducing agent supply system 1 .
  • thorough mixing of supplied compressed air and liquid takes place such that an aerosol-like mixture with liquid droplets are produced that are as small as possible.
  • the mixing region 11 may be formed as a separate mixing chamber or as an integral component of the liquid supply line 2 or the air supply line 3 .
  • the liquid is an aqueous urea solution (HWL), which can be sprayed in the form of the aerosol-like mixture by means of a nozzle into an exhaust line of a motor vehicle upstream from what is called an SCR catalyst for removing nitrogen oxides, this not being shown in detail.
  • HWL aqueous urea solution
  • SCR catalyst for removing nitrogen oxides
  • HWL is fed into the liquid supply line 2 from a storage container preferably by means of a pump, this likewise not being shown in detail.
  • a preliminary pressure p HWL is produced and/or maintained in the liquid supply line 2 upstream from the metering valve 4 by means of the pump, which pressure is detected by the first pressure sensor 6 .
  • the metering valve 4 is preferably designed in the manner of a 2/2-way solenoid valve. Provision is made for the metering valve 4 to be able to be operated such that it is either opened or closed, for which purpose it is actuated accordingly.
  • the adjusting choke 5 serves for setting a beneficial operating point with regard to the liquid flow rate through the opened metering valve 4 under the prevailing pressure conditions.
  • the adjusting choke 5 is arranged in the liquid supply line 2 upstream from the metering valve 4 and downstream from the first pressure sensor 6 . It is likewise possible to arrange it at a different point of the liquid supply line 2 , in particular upstream from the mixing region 11 .
  • HWL flows through and mixes with the supplied compressed air in the mixing region 11 , or, as a result of the supplying of compressed air, is nebulized in the mixing region 11 .
  • a compressed-air reservoir not shown
  • a compressor can be employed for supplying compressed air.
  • a pre-set air pressure is set, for example, via a pressure reducer, likewise not shown.
  • the supply of air on the entry side of the air supply line 3 can be alternatively shut off or enabled by means of a preferably succeeding actuatable switching element 16 .
  • the mass flow of HWL through the opened metering valve 4 is mainly dependent on the differential pressure ⁇ p present above the metering valve 4 .
  • fluctuations in the differential pressure ⁇ p may result due to a fluctuating metering pressure p L , downstream from the metering valve 4 .
  • These are caused mainly by pressure conditions in the exhaust system that fluctuate dependent on engine operation, which conditions may affect the liquid supply line 2 back to the exit side of the metering valve 4 .
  • Arrangement of the second pressure sensor 7 at a different point downstream from the metering valve 4 is likewise possible.
  • a separating element 15 is arranged in the air supply line 3 on the entry side of the mixing region 11 .
  • the separating element 15 forms the end section of the air supply line 3 and opens out into the mixing region 11 .
  • the separating element 15 may for example also be designed in the manner of a non-return valve, it is preferred for the separating element 15 to be formed as a nozzle, in particular as what is called a supercritical nozzle, with which an air flow of supersonic speed can be achieved. In this manner, penetration of HWL into the air supply line 3 is largely avoided. Further, strong turbulence in the mixing region 11 is permitted.
  • the embodiment of the separating element 15 as a supercritical nozzle permits equalization of the air flow.
  • an air pressure on the entry side of the air supply line 3 or upstream from the separating element 15 is advantageous.
  • a third pressure sensor 14 is connected to the air supply line 3 upstream from the separating element 15 , so that the air pressure prevailing upstream from the separating element 15 can likewise be monitored.
  • the second pressure sensor 7 together with the first pressure sensor 6 allows a determination of the differential pressure ⁇ p present above the series connection of adjusting choke 5 and metering valve 4
  • the second pressure sensor 7 in conjunction with the third pressure sensor 14 allows for a determination of the differential pressure falling above the separating element 15 .
  • the latter may, however also be determined by taking into account a pre-set air pressure, thereby dispensing with the third pressure sensor 14 .
  • the mixture produced in the mixing region 11 is supplied to the nozzle or to the exhaust aftertreatment system via a mixture line 12 .
  • the compressed air in this case serves as a transport medium.
  • a transport medium such as for example nitrogen or exhaust instead of the compressed air.
  • a metering control unit (not shown), to which the pressure sensors 6 , 7 , 14 and the metering valve 4 are connected via interfaces 8 , 9 , 10 , 13 .
  • the metering control unit is preferably embodied in the form of a microcomputer with input/output unit, CPU and memory unit, in order to be able to process the data and measured values obtained for controlling the reducing agent supply system 1 and to be able to determine and emit corresponding control signals.
  • the switching element 16 in the air supply line 3 can be actuated via a further interface 17 such that the air supply can be alternatively switched on and off.
  • clogging may occur in the line system or alternatively in the nozzle of the reducing agent supply system 1 , which clogging disrupts proper operation.
  • Deposits typically cause constriction of the cross section in an affected line, which becomes apparent due to an increased back pressure. This can be detected for example by evaluating one or more of the pressure values supplied by the pressure sensors 6 , 7 , 14 .
  • a disruption caused by clogging or deposition can, however, also be detected by monitoring the air and/or HWL flow rate, which in the event of breakdown typically drop below the values provided.
  • clogging is present in or downstream from the mixing region 11 , which is manifested by a pressure increase, detectable by the second pressure sensor 7 , upon conveying air through the air supply line 3 or the mixture line 12 . If in the case of the air flow rate provided an operating pressure which has risen to a first upper pressure threshold value is detected by the second pressure sensor 7 , the normal metering operation is interrupted and a cleaning operation is begun.
  • the cleaning operation involves producing an air stream formed by a number of air stream pulses and an HWL stream formed from a number of HWL stream pulses, and supplying them to the nozzle, which is explained in greater detail below with reference to FIG. 2 .
  • FIG. 2 shows a schematized time diagram for a pulse sequence of air stream pulses 20 and HWL stream pulses 21 corresponding to a first cleaning operating mode, which is preferably activated when an operating pressure that has risen to a first upper pressure threshold value of for example 2.5 bar is detected by the second pressure sensor 7 .
  • both the air stream and the HWL stream change periodically and at least approximately abruptly from an “off” state through an “on” state and back into the “off” state again, so that approximately square-wave pulses of pre-settable length or pre-settable period result. It is particularly preferred if the air stream pulses 20 and the HWL stream pulses 21 overlap timewise.
  • a rising edge 24 of an HWL stream pulse falls timewise in an active air stream pulse 20 and a falling edge 22 of an air stream pulse 20 falls in an active HWL stream pulse 21 .
  • a rising edge 23 of a particular air stream pulse 20 falls in an HWL stream pulse pause, and a falling edge 25 of an HWL stream pulse 21 in an air stream pulse pause.
  • the pulse/pause ratio of air stream pulses 20 and HWL stream pulses 21 is preferably set to approximately equal to one.
  • the air stream pulses 20 and HWL stream pulses 21 in this case have a duration of preferably 1 s to 10 s. Provision may be made to convey a pre-settable amount of HWL of for example 50 ml in a particular HWL stream pulse.
  • a duration of the cleaning operation in the manner outlined of approximately 0.5 min to approximately 10 min is sufficient for this.
  • Either the expiry of a pre-settable duration or the pressure dropping below a pre-settable lower pressure threshold value of for example about 1.9 bar, in the present case measured by means of the second pressure sensor 7 serves as end criterion for ending the cleaning operation. Thereafter, normal metering operation can be resumed.
  • FIG. 3 shows, in a representation analogous to FIG. 2 , a pulse sequence of air stream pulses 20 and HWL stream pulses 21 corresponding to the second cleaning operating mode.
  • a number of HWL stream pulses 21 are carried out one after the other alternating with a number of air stream pulses 20 that are carried out one after the other, such that in the case of pulses of one type the supply of the respective other medium remains switched off.
  • the starting point is the production of HWL stream pulses 21 . This permits softening of encrustations, which can be detached in improved manner by the air stream pulses 20 succeeding the sequence of HWL stream pulses 21 .
  • a particular set of pulses may consist of from one to about 10 pulses, the pulse/pause ratio and pulse duration preferably being set analogously to the first cleaning operating mode.
  • the cleaning operation is preferably maintained for a predetermined overall duration. However, provision may also be made to end the cleaning operation if the pressure drops below a pre-settable lower pressure threshold value, measured with active supply of air. Likewise, provision may be made to maintain the cleaning operation until a pre-settable amount of HWL has been conveyed in pulse form. This avoids an undesirably long cleaning operation.
  • a flushing phase may be provided in order to remove HWL residues from the line system, in which phase for a pre-settable amount of time merely an air stream is maintained. Provision may also be made generally to carry out only one cleaning operation exclusively corresponding to the first cleaning operating mode discussed above or the second cleaning operating mode.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
US13/258,027 2009-03-25 2010-02-19 Method for Operating a Reducing Agent Supply System Abandoned US20120042635A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102009014831A DE102009014831A1 (de) 2009-03-25 2009-03-25 Verfahren zum Betreiben eines Reduktionsmittelversorgungssystems
DE102009014831.0 2009-03-25
PCT/EP2010/001046 WO2010108575A1 (de) 2009-03-25 2010-02-19 Verfahren zum betreiben eines reduktionsmittelversorgungssystems

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US20120042635A1 true US20120042635A1 (en) 2012-02-23

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US13/258,027 Abandoned US20120042635A1 (en) 2009-03-25 2010-02-19 Method for Operating a Reducing Agent Supply System

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US (1) US20120042635A1 (de)
EP (1) EP2411635B1 (de)
JP (1) JP5552529B2 (de)
CN (1) CN102362052A (de)
DE (1) DE102009014831A1 (de)
RU (1) RU2489579C2 (de)
WO (1) WO2010108575A1 (de)

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US20220042432A1 (en) * 2018-12-14 2022-02-10 Cummins Filtration Ip, Inc. Diesel fuel dosing module for regeneration of diesel particualte filters with continuous purging

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DE102011075482A1 (de) * 2011-05-09 2012-11-15 Robert Bosch Gmbh Dosiervorrichtung zur Einbringung eines Reduktionsmittels in einen Abgaskanal einer Brennkraftmaschine
WO2013028714A1 (en) 2011-08-22 2013-02-28 Cummins Emission Solutions Inc. Urea injection systems wash cycles
JP5906637B2 (ja) * 2011-09-28 2016-04-20 いすゞ自動車株式会社 異物除去方法及び選択還元触媒システム
KR101842296B1 (ko) * 2013-04-24 2018-03-26 현대중공업 주식회사 환원제공급관 세정장치를 구비한 scr 장치
JP5991285B2 (ja) * 2013-08-26 2016-09-14 トヨタ自動車株式会社 内燃機関の排気浄化装置
JP5835293B2 (ja) * 2013-09-12 2015-12-24 トヨタ自動車株式会社 内燃機関
US9284872B2 (en) * 2013-09-17 2016-03-15 Cummins Emission Solutions Inc. System, methods, and apparatus for low temperature dosing in diesel exhaust systems
CN105626215A (zh) * 2014-10-27 2016-06-01 金有纯 调控进入排气系统的尿素实际供给量的装置及调控方法
US9845717B2 (en) * 2014-10-28 2017-12-19 Ford Global Technologies, Llc Systems and methods for managing diesel exhaust fluid stratification
DE102019216392A1 (de) * 2019-10-24 2021-04-29 Robert Bosch Gmbh Verfahren zum Spülen eines Fördermoduls eines SCR-Dosiersystems

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WO2010108575A1 (de) 2010-09-30
EP2411635A1 (de) 2012-02-01
RU2489579C2 (ru) 2013-08-10
CN102362052A (zh) 2012-02-22
DE102009014831A1 (de) 2010-09-30
JP2012521509A (ja) 2012-09-13
RU2011142812A (ru) 2013-05-20
EP2411635B1 (de) 2015-01-07
JP5552529B2 (ja) 2014-07-16

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