WO2012125148A1 - Système basé sur modèle et procédé pour réduire les dépôts de fluides des émissions de diesel - Google Patents

Système basé sur modèle et procédé pour réduire les dépôts de fluides des émissions de diesel Download PDF

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Publication number
WO2012125148A1
WO2012125148A1 PCT/US2011/028356 US2011028356W WO2012125148A1 WO 2012125148 A1 WO2012125148 A1 WO 2012125148A1 US 2011028356 W US2011028356 W US 2011028356W WO 2012125148 A1 WO2012125148 A1 WO 2012125148A1
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Prior art keywords
def
exhaust
given area
heat transfer
temperature
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PCT/US2011/028356
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English (en)
Inventor
Brad J. Adelman
Vadim Olegovich Strots
Shyam Santhanam
Edward M. Derybowski
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International Engine Intellectual Property Company, Llc
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Publication date
Application filed by International Engine Intellectual Property Company, Llc filed Critical International Engine Intellectual Property Company, Llc
Priority to EP11861284.5A priority Critical patent/EP2686528A4/fr
Priority to CN2011800692702A priority patent/CN103429860A/zh
Priority to US14/005,260 priority patent/US20140000247A1/en
Priority to PCT/US2011/028356 priority patent/WO2012125148A1/fr
Publication of WO2012125148A1 publication Critical patent/WO2012125148A1/fr

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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
    • 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
    • F01N9/00—Electrical control of exhaust gas treating apparatus
    • F01N9/005—Electrical control of exhaust gas treating apparatus using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
    • 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
    • F01N2610/14—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
    • F01N2900/0601—Parameters used for exhaust control or diagnosing being estimated
    • 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
    • F01N2900/08—Parameters used for exhaust control or diagnosing said parameters being related to the engine
    • 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
    • F01N2900/10—Parameters used for exhaust control or diagnosing said parameters being related to the vehicle or its components
    • 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
    • F01N2900/12—Parameters used for exhaust control or diagnosing said parameters being related to the vehicle exterior
    • 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
    • F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
    • F01N2900/1404—Exhaust gas temperature
    • 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
    • F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
    • F01N2900/1411—Exhaust gas flow rate, e.g. mass flow rate or volumetric flow rate
    • 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
    • F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
    • F01N2900/1631—Heat amount provided to 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
    • 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
    • F01N2900/1812—Flow rate
    • 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

  • This disclosure relates to internal combustion engines, especially diesel engines like those used to propel large trucks, and in particular the disclosure relates to engine exhaust after-treatment that comprises injecting diesel emission fluid (DEF), such as a urea solution, into an engine exhaust system for promoting selective catalytic reduction (SCR) of certain constituents, NOx for example, in engine exhaust.
  • DEF diesel emission fluid
  • SCR selective catalytic reduction
  • An example of a diesel engine exhaust after-treatment system that uses selective catalytic reduction comprises an injector through which DEF is injected into the exhaust flow.
  • DEF is a solution that either comprises, or as it entrains with the exhaust flow is converted into, one or more constituents that promote catalytic action that treats certain exhaust constituents such as NOx.
  • DEF should completely vaporize and thoroughtly mix with the exhaust before the flow passes across catalytic surfaces.
  • the geometry of an exhaust after-treatment system and the spray pattern of a DEF injector may cause some of the injected DEF to wet interior surfaces of the exhaust system before it vaporizes. When the temperature of those surfaces is low enough, a potential exists for solute (urea for example) to come out of solution and form deposits on those surfaces. Accumulations of solid deposits may, over time, impair the effectiveness of the after-treatment system, such as by altering flow characteristics of the exhaust and/or the spray pattern of the injector, and/or they may damage exhaust and after-treatment system components. [0004] Removal of significant deposits typically requires disassembly of components because of lack of acceptable ways to satisfactorily remove them without such disassembly.
  • an injection of DEF may be temporarily delayed when a cold engine is first started, especially during cold ambient conditions. That delay however postpones the onset of SCR treatment of the exhaust.
  • the present disclosure provides a system and method for mitigating the potential for formation of DEF deposits in an engine exhaust system.
  • a general aspect of the disclosure relates to a control system, in a vehicle that is propelled by an internal combustion engine, for mitigating deposit of decomposition products of diesel emission fluid (DEF) on an interior of an exhaust system through which exhaust is flowing from the engine toward a catalyst that promotes chemical reaction between a constituent in the exhaust and a constituent that has become entrained in the exhaust as a consequence of injection of DEF from a DEF injector.
  • DEF diesel emission fluid
  • the system comprises a processor containing a model-based control algorithm for controlling an aspect of DEF injection by the DEF injector, the control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • the control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • the processor comprises an operating routine that:
  • Another general aspect of the disclosure relates to a method for mitigating deposit of decomposition products of diesel emission fluid (DEF) on an interior of an exhaust system through which exhaust is flowing from a motor vehicle internal combustion engine toward a catalyst which promotes chemical reaction between a constituent in the exhaust and a constituent that has become entrained in the exhaust as a consequence of injection of DEF into the exhaust system by a DEF injector.
  • DEF diesel emission fluid
  • the method comprises using a processor to control an aspect of injection of DEF by the DEF injector by repeatedly executing in the processor a model-based control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • Executing the model-based control algorithm comprises processing data relating to the exhaust and to atmospheric air that affect the convective and conductive heat transfers to calculate temperature (T i n wall ) of the given area of the interior surface, comparing the calculated temperature (T ; ⁇ wall ) of the given area of the interior surface and a temperature (T cr i t ) below which liquid DEF on the given area has potential to deposit solid material on the given area, and using the result of the comparison to control injection of DEF by the DEF injector.
  • Another general aspect of the disclosure relates to a control system, in a vehicle that is propelled by an internal combustion engine, for mitigating deposit of decomposition products of diesel emission fluid (DEF) on an interior of an exhaust system through which exhaust is flowing from the engine toward a catalyst that promotes chemical reaction between a constituent in the exhaust and a constituent that has become entrained in the exhaust as a consequence of injection of DEF from a DEF injector.
  • DEF diesel emission fluid
  • the system comprises a processor containing a model-based control algorithm for controlling an aspect of DEF injection by the DEF injector, the control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • the control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • the processor comprises an operating routine that: processes, according to the model, data relating to the exhaust and to atmospheric air that affect the convective and conductive heat transfers to calculate a desired flow rate for injection of DEF by the DEF injector; that selects, for the actual flow rate for DEF injected by the DEF injector, the lower of a flow rate based on a temperature of the given area of the interior surface below which liquid DEF on the given area has potential to deposit solid material on the given area and the desired flow rate calculated according to the model; and that uses the result of the selection to set the actual flow rate of injection of DEF by the DEF injector.
  • Another general aspect of the disclosure relates to a method for mitigating deposit of decomposition products of diesel emission fluid (DEF) on an interior of an exhaust system through which exhaust is flowing from a motor vehicle internal combustion engine toward a catalyst which promotes chemical reaction between a constituent in the exhaust and a constituent that has become entrained in the exhaust as a consequence of injection of DEF into the exhaust system by a DEF injector.
  • DEF diesel emission fluid
  • the method comprises using a processor to control an aspect of injection of DEF by the DEF injector by repeatedly executing in the processor a model-based control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • a model-based control algorithm comprising a model that models convective heat transfer from the exhaust to a given area of an interior surface of the exhaust system that is separated from an exterior surface in contact with atmospheric air by material of the exhaust system, conductive heat transfer from the given area to any liquid DEF on the given area, conductive heat transfer through the material of the exhaust system to the exterior surface, and convective heat transfer from the exterior surface to atmospheric air.
  • Executing the model-based control algorithm comprises: processing, according to the model, data relating to the exhaust and to atmospheric air that affect the convective and conductive heat transfers to calculate a desired flow rate for injection of DEF by the DEF injector; selecting, for the actual flow rate of DEF injected by the DEF injector, the lower of a flow rate based on a temperature of the given area of the interior surface below which liquid DEF on the given area has potential to deposit solid material on the given area and the desired flow rate calculated according to the model; and using the result of the selection to set the actual flow rate of injection of DEF by the DEF injector.
  • Figure 1 is a general schematic diagram of an engine and its exhaust system, including after-treatment.
  • Figure 2 is a more detailed schematic diagram of exhaust after- treatment useful in understanding the disclosed model-based system and method.
  • Figure 3 is a first embodiment of DEF injection control algorithm.
  • Figure 4 is a second embodiment of DEF injection control algorithm.
  • FIG 1 shows an example of a turbocharged diesel engine 10 having an intake system 12 through which charge air enters and an exhaust system 14 through which exhaust gas resulting from combustion exits, not all details of those two systems that are typically present being shown.
  • Engine 10 comprises a number of cylinders 16 forming combustion chambers into which fuel is injected by fuel injectors to combust with the charge air that has entered through intake system 12. Energy released by combustion powers the engine via pistons connected to a crankshaft.
  • engine 10 When used in a motor vehicle, such as a truck, engine 10 is coupled through a drivetrain to driven wheels that propel the vehicle. Intake valves control the admission of charge air into cylinders 16, and exhaust valves control the outflow of exhaust through exhaust system 14 and ultimately to atmosphere. Before entering the atmosphere however, the exhaust is treated by one or more after-treatment devices in an after-treatment portion of exhaust system 14.
  • After-treatment portion of exhaust system 14 comprises a walled enclosure 18 circumscribing an exhaust flow path through which exhaust from cylinders 16 passes.
  • the interior of enclosure 18 contains a diesel particulate filter (DPF) 20 and a mixer 22 downstream of DPF 20.
  • DPF diesel particulate filter
  • a DEF injector 24 is mounted in a boss 26 on the wall of enclosure 18 for spraying DEF from a nozzle 28 into exhaust flowing along the exhaust flow path.
  • Flow that has passed through mixer 22 subsequently passes across catalytic surfaces of an SCR catalyst 30 that promotes treatment of an exhaust constituent by a chemical in the DEF and/or a decomposition product of a chemical in the DEF before the flow exits exhaust system 14 through a tailpipe.
  • a supply of DEF is stored in a tank 32.
  • An example of a DEF is an aqueous urea solution that has approximately a 32.5% concentration by weight and that can reduce NOx in exhaust.
  • FIG. 1 shows an example of an exhaust system design in which injector nozzle 28 lies substantially on an imaginary centerline aimed downstream of the exhaust flow, but at an acute angle to the prevailing axial direction of flow coming from DPF 20 to inject DEF as a spray 36 that contains droplets small enough to completely vaporize in exhaust that is sufficiently hot.
  • the reference numeral 36 depicts the spray pattern only generally and is not intended to imply that it will necessarily strike wall 18 or any other portions of the exhaust system.
  • Mixer 22 is intended to promote thorough mixing of the DEF with the exhaust flow during transit to SCR catalyst 30 which comprises catalytic surfaces for promoting the reaction of exhaust with product(s) in, and/or decomposition product(s) of product(s) in, vaporized DEF.
  • SCR catalyst 30 comprises catalytic surfaces for promoting the reaction of exhaust with product(s) in, and/or decomposition product(s) of product(s) in, vaporized DEF.
  • Mixer 22 can promote the vaporization of any DEF droplets that may strike it and decomposition of urea.
  • Figure 2 shows that the wall of enclosure 18 comprises an interior surface 40 and an exterior surface 42.
  • a sensor 44 senses temperature of exhaust that flows through enclosure 18 in the sense indicated by the arrow labeled "Exhaust".
  • An area of interior surface 40 lies within the pattern of spray 36. Limited vaporization of injected DEF occurs in the exhaust and consequently some droplets will impinge on internal exhaust system surfaces. If those surfaces are sufficiently hot, the impinging DEF will quickly evaporate. Sufficiently quick evaporation does not lead to surface wetting that can create deposits.
  • a parameter Q i n represents thermal energy (heat) input to the area of interior surface 40 in the path of spray 36. Assuming that the temperature of interior surface 40 is greater than that of exterior surface 42, a quantity of heat Q thru will be conducted through the wall of enclosure 18 to exterior surface 42. Assuming that the temperature of exterior surface 42 is greater than that of atmospheric air that is in contact with exterior surface 42, then a quantity of heat Q out will be transferred to the air.
  • 13 ⁇ 4 ⁇ is the convective heat transfer coefficient for heat transfer from the exhaust to interior surface 40 (based on sensor measurements, empirical data, and calculations),
  • Texh is temperature of the exhaust gas as measured by sensor 44.
  • T i n wa ii is the temperature of interior surface 40 and is described by the equation:
  • K 3 h DEFv a P /(h m + kext) [0044] and T am b is the temperature of atmospheric air (based on sensor measurements),
  • niDEF is the flow rate of DEF being injected by injector 24 (based on sensor measurements, empirical data, & calculations).
  • hoEFvap is the heat of vaporization (and decomposition, if any) of DEF
  • k wall is the thermal conductivity of the wall of enclosure 18.
  • h out is the convective heat transfer coefficient from exterior surface 42 to atmospheric air (based on sensor measurements, empirical data, & calculations).
  • h ou t is the convective heat transfer coefficient for heat transfer from exterior surface 42 to atmospheric air (based on sensor measurements, empirical data, and calculations), and T out wall is the temperature of exterior surface 42.
  • a parameter T cr i t represents a temperature below which the liquid phase of a particular DEF on a surface have the potential to form deposits on that surface.
  • the calculation of temperature T in wall utilizes the constants, h DEFvap and k wa ii and the variables h i n , h out , T amb , T ex h, and m D EF-
  • the parameter h i n is a variable because it is a function of the rate of exhaust flow through enclosure 18.
  • Parameter h out is a variable because it is a function of the rate of air flow along exterior surface 42.
  • Figure 1 shows various input data, represented generally by reference numeral 38, are processed by the DEF injection control algorithm in controller 34, a first embodiment 50A of which is shown in Figure 3.
  • DEF injection control algorithm 50A comprises certain processing steps, a first one of which (step 52) determines if a present value for DEF flow rate rri def needs to be updated. After that, a second step 54 is performed to calculate energy balance and a temperature ⁇ ; ⁇ wall of interior wall surface 40. After that, a third step 56 is performed to compare Ti n wall with a temperature T cr i t representing a temperature of the area of interior surface 40 in the path of spray 36 below which liquid DEF on the area have potential to deposit solid material on the area.
  • step 54 processes data 57 representing temperature and atmospheric pressure of ambient air, data 58 representing speed at which a vehicle that is being propelled by engine 10 is traveling (this affects air flow along exterior surface 42), data 60 representing temperature of engine exhaust at any suitable location in exhaust system 14, typically upstream of injector 24 but downstream of DPF 20, as provided by sensor 44, and data 62 representing flow rate of engine exhaust.
  • Data 57, 58, 60, and 62 are all variables.
  • Engine speed data 70 and engine fueling data 72 are used to calculate flow rate of engine exhaust.
  • Additional data 64, 66, 68 are also processed by step 54.
  • Data 64, 66, and 68 are typically non-variable for a given exhaust and after-treatment system and can therefore be embedded in controller 34.
  • Data 64 defines certain thermodynamic properties of atmospheric air.
  • Data 66 defines certain properties of walled enclosure 18 relevant to heat transfer through its wall between interior surface 40 across which exhaust flows and exterior surface 42 that is in contact with atmospheric air.
  • Data 68 defines certain thermodynamic properties of the particular DEF that is injected by injector 24.
  • the algorithm routine comprises:
  • FIG. 4 shows another DEF injection control algorithm 50B that comprises processing steps 90, 92, 94, and 98.
  • Each iteration of step 90 calculates a desired flow rate for injection of DEF by DEF injector 24 m DEF for securing optimum performance of SCR catalyst 30, by rearranging the above equation for T ; n wa ii to the equation:
  • m DEF (T m waii - Kl x T amb - K2 x T exh ) / K3
  • Step 94 calculates energy balance and a parameter m D EFcrit
  • m DEFcnt (T crit - Kl x T amb - K2 x T exh ) / K3 If the calculated value for HIDEF is not too high for the temperature T ; ⁇ wa ii, meaning that deposits will not form, then that calculated value is used instead of mDEFcrit to set the actual flow rate of DEF injected by DEF injector 24. On the other hand, if the calculated value for HIDEF is too high for the temperature T ; ⁇ wall , meaning that deposits can form, then m D EFcrit is used to set the actual flow rate of DEF injected by DEF injector 24. The selection of which is lower, m D EF or m D EFcrit, is made by step 98, and it is that selected value which is used as the actual flow rate of DEF injection.

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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)
  • Analytical Chemistry (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

L'invention porte sur un système et un procédé pour atténuer le dépôt de produits de décomposition des fluides des émissions de diesel (DEF) sur les surfaces internes du système d'échappement d'un moteur à combustion interne (14). Un processeur inclus dans une unité de commande (34) contient un algorithme de commande basé sur modèle (50A ; 50B) pour commander l'injection de DEF par un injecteur de DEF (24) pour réduire la formation de dépôts.
PCT/US2011/028356 2011-03-14 2011-03-14 Système basé sur modèle et procédé pour réduire les dépôts de fluides des émissions de diesel WO2012125148A1 (fr)

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EP11861284.5A EP2686528A4 (fr) 2011-03-14 2011-03-14 Système basé sur modèle et procédé pour réduire les dépôts de fluides des émissions de diesel
CN2011800692702A CN103429860A (zh) 2011-03-14 2011-03-14 用于减少柴油排放液沉淀物的基于模型的系统与方法
US14/005,260 US20140000247A1 (en) 2011-03-14 2011-03-14 Model-based system and method for mitigating diesel emission fluid deposits
PCT/US2011/028356 WO2012125148A1 (fr) 2011-03-14 2011-03-14 Système basé sur modèle et procédé pour réduire les dépôts de fluides des émissions de diesel

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014137280A1 (fr) * 2013-03-07 2014-09-12 Scania Cv Ab Dispositif et procédé de sélection d'un dosage maximal d'un agent réducteur d'un système de réduction catalytique sélective - scr - pour l'épuration des gaz d'échappement
WO2019209162A1 (fr) * 2018-04-24 2019-10-31 Scania Cv Ab Procédé et système de détermination et de réduction d'un risque de formation de dépôts solides

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2599822B (en) 2016-12-07 2022-08-17 Cummins Emission Solutions Inc Real-time control of reductant droplet spray momentum and in-exhaust spray distribution
JP2018119471A (ja) * 2017-01-25 2018-08-02 いすゞ自動車株式会社 排ガス浄化装置及びその制御方法
SE540842C2 (en) * 2017-03-31 2018-11-27 Scania Cv Ab Method and system for control of at least one of a dosage device and an engine
SE544027C2 (en) * 2020-03-06 2021-11-09 Scania Cv Ab A method and a control arrangement for a process of selective catalytic reduction after-treatment of an exhaust gas

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6063350A (en) * 1997-04-02 2000-05-16 Clean Diesel Technologies, Inc. Reducing nox emissions from an engine by temperature-controlled urea injection for selective catalytic reduction
US20090056315A1 (en) * 2007-08-30 2009-03-05 Gm Global Technology Operations, Inc. Method for reducing nh3 release from scr catalysts during thermal transients
US20100122525A1 (en) * 2008-11-18 2010-05-20 Denso Corporation Exhaust purification control device and exhaust purification system of internal combustion engine
US20100281855A1 (en) * 2009-05-06 2010-11-11 Min Sun Model based method for selective catalyst reducer urea dosing strategy
US20110036078A1 (en) * 2009-08-14 2011-02-17 International Engine Intellectual Property Company , Llc Method for urea injection control
US20110041477A1 (en) * 2009-08-20 2011-02-24 Gm Global Technology Operations, Inc. System and method for controlling reducing agent injection in a selective catalytic reduction system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003120279A (ja) * 2001-10-05 2003-04-23 Toyota Motor Corp 内燃機関の排気浄化装置
JP4091013B2 (ja) * 2004-03-25 2008-05-28 日産ディーゼル工業株式会社 エンジンの排気浄化装置
JP4438729B2 (ja) * 2005-09-28 2010-03-24 三菱自動車工業株式会社 排気浄化装置
US8171724B2 (en) * 2007-05-02 2012-05-08 Ford Global Technologies, Llc Vehicle-based strategy for removing urea deposits from an SCR catalyst
US8061123B2 (en) * 2007-10-30 2011-11-22 Caterpillar Inc. Method and system of thermal management in an exhaust system
US8205606B2 (en) * 2008-07-03 2012-06-26 International Engine Intellectual Property Company, Llc Model for inferring temperature of exhaust gas at an exhaust manifold using temperature measured at entrance of a diesel oxidation catalyst

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6063350A (en) * 1997-04-02 2000-05-16 Clean Diesel Technologies, Inc. Reducing nox emissions from an engine by temperature-controlled urea injection for selective catalytic reduction
US20090056315A1 (en) * 2007-08-30 2009-03-05 Gm Global Technology Operations, Inc. Method for reducing nh3 release from scr catalysts during thermal transients
US20100122525A1 (en) * 2008-11-18 2010-05-20 Denso Corporation Exhaust purification control device and exhaust purification system of internal combustion engine
US20100281855A1 (en) * 2009-05-06 2010-11-11 Min Sun Model based method for selective catalyst reducer urea dosing strategy
US20110036078A1 (en) * 2009-08-14 2011-02-17 International Engine Intellectual Property Company , Llc Method for urea injection control
US20110041477A1 (en) * 2009-08-20 2011-02-24 Gm Global Technology Operations, Inc. System and method for controlling reducing agent injection in a selective catalytic reduction system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2686528A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014137280A1 (fr) * 2013-03-07 2014-09-12 Scania Cv Ab Dispositif et procédé de sélection d'un dosage maximal d'un agent réducteur d'un système de réduction catalytique sélective - scr - pour l'épuration des gaz d'échappement
WO2019209162A1 (fr) * 2018-04-24 2019-10-31 Scania Cv Ab Procédé et système de détermination et de réduction d'un risque de formation de dépôts solides

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EP2686528A4 (fr) 2015-04-08
US20140000247A1 (en) 2014-01-02
CN103429860A (zh) 2013-12-04
EP2686528A1 (fr) 2014-01-22

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