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
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
  • F02D41/402—Multiple injections
  • F02D41/403—Multiple injections with pilot injections
• • 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
  • F02D41/0275—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 the exhaust gas treating apparatus being a NOx trap or adsorbent
• • 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
  • F02D41/0275—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 the exhaust gas treating apparatus being a NOx trap or adsorbent
  • F02D41/028—Desulfurisation of NOx traps or adsorbent
• • 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 present invention relates to a system for reducing polluting emissions linked to the operation of a diesel engine in a motor vehicle and relates more particularly to a system for assisting the regeneration of a Nox trap with storage / release, integrated in an exhaust line of such an engine.
• NOx trap composed for example of barium sulphate intended to absorb NOx during standard engine operation.
• this trap is saturated, it is proposed to trigger a transient destocking phase by momentarily switching the engine from this standard lean mixture operating mode to a rich mixture regeneration operating mode to produce reducers, such as for example HC and CO , which reduces the NOx which is then desorbed from the trap, as in a traditional catalyst.
• the subject of the invention is a system for assisting the regeneration of a NOx trap for storage / release, integrated in an exhaust line of a diesel engine of a motor vehicle, characterized in that it comprises means for admitting gas into the engine and means for injecting fuel into the cylinders thereof in the form of at least pilot and main injections and means for controlling these means of gas and / or fuel injection inlet to periodically switch the engine from a standard lean-mix operating mode, NOx storage in the trap, to a rich-mix regeneration operating mode, to at least two pilot injections and a main injection, destocking of NOx of the trap and regeneration of the latter.
• the control means are adapted to control the gas intake means in order to reduce the quantity of gas admitted into the engine when the latter is in its regeneration operating mode;
• control means are adapted to control the gas intake and / or fuel injection means according to these standard operating and regeneration modes for engine loads below a predetermined threshold value;
• the predetermined load threshold value is defined by an effective average pressure of approximately 3 bars;
• the engine being associated with means for recirculating the exhaust gases at the inlet thereof, the control means are adapted to regulate the operation of these recirculation means during operation of the rich mixture engine;
• the two pilot injections are triggered in a range between approximately 50 ° crankshaft and 5 ° crankshaft, before the top dead center of the cylinder concerned and the main injection is triggered in a sub-timed range up to approximately 35 ° crankshaft after top dead center;
• control means are adapted to control the gas intake and / or injection means in order to operate the engine in lean mixture for approximately 60 seconds and in rich mixture for approximately 2 seconds.
• - Figs.1 and 2 illustrate the phases of storage and release of NOx in a trap used in the constitution of a system according to the invention
• - Fig.3 illustrates the operation of fuel injection means implemented in an assistance system according to the invention
• - Fig.4 shows a block diagram illustrating the structure of a system according to the invention.
• the invention relates to a system for assisting the regeneration of a NOx trap for storage / retrieval integrated into an exhaust line of a diesel engine of a motor vehicle.
• the NOx trap absorbs NOx during standard operation of the lean mixture engine, while in a rich mixture regeneration operating mode, these NOx are destocked and treated by the production of reducers such as HC and CO, which reduces the NOx which is then desorbed from the trap as in a traditional catalyst.
• reducers such as HC and CO
• This operation is longer than the purge, which lasts only a few seconds, and is therefore even more difficult to manage.
• the present invention proposes to improve the characteristics of combustion in stability and in noise, at points with predetermined engine loads, by applying an injection strategy to two pilot injections and a main injection, as is illustrated in FIG. 3.
• the application of these two pilot injections makes it possible to delay the main injection, in order to meet the criteria for regenerating the NOx trap.
• the recirculation of the burnt gases can be regulated in order to meet the criteria for regenerating the NOx trap.
• the two-injection strategy pilots therefore makes it possible to meet the criteria for regenerating the NOx trap, because it makes it possible to significantly reduce on these points, the combustion instabilities thanks to the phasing of the two pilot injections, to reduce the noise also thanks to this phasing of the two injections pilots, delay the main injection and finally generate an engine map for the regeneration of the NOx trap based on a unique strategy.
• this strategy can be applied to points with predetermined engine operating loads, the EGR level then being regulated.
• This engine can also be associated with means for recirculating exhaust gas at the inlet thereof, designated by the general reference 9, associated with means for controlling the circulation of gases designated by the general reference 10.
• the adjustment means 8 and control means 10 can conventionally comprise controllable valves.
• the engine is also associated with means 11 for injecting fuel into the cylinders thereof, in the form of pilot and main injections, as has been indicated, having any suitable structure. .
• control means designated by the general reference 12 comprising any appropriate computer. , receiving for example as input, engine rotation speed and pressure information from the injection means, respectively from corresponding data acquisition means 13 and 14.
• the standard operating modes with lean mixture for storing NOx in the trap, and for operating with regeneration with rich mixture, destocking of NOx from the trap and therefore for regenerating the latter can be switched periodically, by the means control 12, the motor 4 operating for example in lean mixture for about 60 seconds, and in rich mixture for about 2 seconds.
• the control means 12 then act on the air intake means 7 in the engine 4 and the fuel injection means 11 in the cylinders thereof, for periodically switching the engine from the standard operating mode lean mix in the rich mix regeneration mode of operation.
• control means 12 can indeed be adapted to control the gas intake means in order to reduce the quantity of gas admitted into the engine when the latter is in its regeneration operating mode and for controlling the injection means in the manner indicated above.
• control means can also be adapted to regulate the operation of the exhaust gas recirculation means 9 during the operation of the rich mixture engine.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Exhaust Gas After Treatment (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32088219

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Family Cites Families (13)

• 2002
  • 2002-10-23 FR FR0213256A patent/FR2846372B1/fr not_active Expired - Fee Related
• 2003
  • 2003-10-14 JP JP2004546090A patent/JP2006504032A/ja active Pending
  • 2003-10-14 AU AU2003283510A patent/AU2003283510A1/en not_active Abandoned
  • 2003-10-14 WO PCT/FR2003/003025 patent/WO2004038205A1/fr active Application Filing
  • 2003-10-14 US US10/532,229 patent/US7500357B2/en not_active Expired - Fee Related
  • 2003-10-14 EP EP03775484A patent/EP1554481A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events