Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/021—Introducing corrections for particular conditions exterior to the engine
  • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
  • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B3/00—Engines characterised by air compression and subsequent fuel addition
  • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/50—Input parameters for engine control said parameters being related to the vehicle or its components
  • F02D2200/501—Vehicle speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/70—Input parameters for engine control said parameters being related to the vehicle exterior
  • F02D2200/702—Road conditions

Definitions

• the present invention relates to a system for assisting in the regeneration of depollution means associated with means forming an oxidation catalyst implementing an OSC function constituting an oxygen reserve, integrated in an exhaust line of a diesel engine. of motor vehicle. More particularly, the invention relates to such a system in which the engine is associated with common rail means for supplying fuel to the cylinders thereof. To ensure the regeneration of depollution means such as a particle filter, the soot trapped in it is burned thanks to the thermal supplied by the engine and to the exotherm achieved by the conversion of HC on the catalyst forming means d oxidation placed upstream of the particulate filter.
• This combustion can be assisted by a catalyst element mixed with the soot, for example from an additive to aid regeneration, mixed with the fuel for supplying the engine or else by a catalyst deposited directly on the walls of the particle filter ( catalyzed particulate filter).
• a catalyst element mixed with the soot
• the thermal levels reached through the conventional regeneration aid strategies of the particulate filter may prove to be insufficient to ensure the correct regeneration of the filter, which can result in very long regenerations and therefore very fuel-consuming or even incomplete.
• the object of the invention is to propose such a strategy.
• the subject of the invention is a system for assisting in the regeneration of depollution means associated with means forming an oxidation catalyst implementing an OSC function, constituting a reserve of oxygen and integrated in a line d exhaust of a motor vehicle diesel engine in which the engine is associated with common rail means for supplying fuel to the cylinders thereof, characterized in that it comprises means for analyzing the running conditions of the vehicle and for comparing these with predetermined threshold values, for controlling the engine in a first lean-mix regeneration operating mode for driving conditions greater than the threshold values or in a second regeneration operating mode implementing alternating engine operating sequences rich mixture and lean mixture operating phases for conditions below the threshold values.
• the depollution means comprise a particle filter; - the particle filter is catalyzed; - the depollution means include a NOx trap; the fuel comprises an additive intended to be deposited with the particles with which it is mixed, on the depollution means to facilitate their regeneration; - the depollution means are impregnated with an SCR formulation, ensuring a CO / HC oxidation function; - the engine is associated with a turbocharger; - the driving conditions are determined from: - the engine load, - the engine speed, - the vehicle speed, and / or - the thermal level in the vehicle exhaust line.
• FIG. 1 has in fact illustrated a system for assisting the regeneration of depollution means designated by the general reference 1, associated with means forming an oxidation catalyst, implementing an OSC function. constituting an oxygen reserve, designated by the general reference 2, and placed in an exhaust line 3 of a motor vehicle engine.
• This engine is designated by the general reference 4 and can be associated for example with a turbocharger whose turbine portion 5 is associated with the exhaust line and whose compressor portion 6 is placed upstream of the engine.
• this system also includes means for analysis of the driving conditions of the vehicle and of the means of comparing these with predetermined threshold values to control the operation of the engine.
• the analysis means formed for example by the supervisor 8 are then connected to means for acquiring these driving conditions, designated by the general reference 9, delivering these to the supervisor 8, so as to allow the latter ci to compare them with threshold values as delivered by generation means 10 comprising all appropriate means for establishing these threshold values.
• These driving conditions can for example be determined from the engine load, the engine speed, the vehicle speed and / or the thermal level in the exhaust line of this vehicle.
• the supervisor and the common rail fuel supply means are adapted to control the engine in a first lean-mixture regeneration operating mode for driving conditions greater than the threshold values, or in a second regeneration operating mode implementing engine operating sequences alternating rich mixture and lean mixture operating phases, for conditions below the threshold values.
• These rich or lean mixture operating phases are established conventionally by modifying parameters for controlling the operation of the engine.
• These strategies are designated respectively by the general references 11 and 12 in this figure. This is illustrated in FIG. 2, in which we clearly see the exotherms linked to the transition to rich engine operating mode.
• the diesel engine In rich mode, the diesel engine emits a large amount of CO and unburnt hydrocarbons in the exhaust gases. Furthermore, the quantity of oxygen present in the gases is greatly reduced (less than 2-3% and sometimes less than 1%).
• the passage of these gases through the oxidation catalyst means allows the combustion of CO and HC by the oxygen present in the gases. In order to be able to convert a larger amount of CO and HC, it is desirable to provide a larger amount of oxygen.
• the presence of the OSC type component constituting an oxygen reserve (Oxygen Storage Capacity), such as for example cerium which stores the oxygen in the form of cerine - Ce0 2 - or a mixed oxide of cerium and zirconium in the means forming oxidation catalyst, makes it possible to release oxygen during the passages of the engine in rich mode.
• the combustion of CO and HC is an exothermic reaction and makes it possible to increase the thermal levels at the outlet of the means forming an oxidation catalyst, that is to say in fact at the inlet of the particulate filter.
• the depollution means can comprise a particle filter, catalyzed or not, a NOx trap, etc. These depollution means can also be impregnated with an SCR formulation ensuring a CO / oxidation function. HC in the classic way. Furthermore, the depollution means and the means forming an oxidation catalyst can be integrated into one and the same element, in particular on the same substrate.
• a particle filter integrating the oxidation function can be envisaged.
• a NOx trap incorporating such an oxidation function can also be envisaged, whether this is additive or not.
• This oxidation and / or NOx trap function can be fulfilled, for example, by an additive mixed with the fuel. It is therefore conceivable, as illustrated in FIG. 2, that the control of the engine makes it possible to increase the thermal levels compared to standard operation, in particular in critical driving conditions, which thus allows faster regeneration of the filter.

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 2003
  • 2003-11-25 FR FR0313828A patent/FR2862704B1/fr not_active Expired - Fee Related
• 2004
  • 2004-10-07 US US10/595,824 patent/US7946110B2/en not_active Expired - Fee Related
  • 2004-10-07 JP JP2006540501A patent/JP2007516379A/ja not_active Withdrawn
  • 2004-10-07 EP EP04791484A patent/EP1687519A1/de not_active Withdrawn
  • 2004-10-07 WO PCT/FR2004/002532 patent/WO2005064141A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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