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
  • F02D41/008—Controlling each cylinder individually
  • F02D41/0082—Controlling each cylinder individually per groups or banks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/42—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders
  • F02M26/43—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine
• • 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
  • F02D41/0002—Controlling intake air
  • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
• • 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
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/02—EGR systems specially adapted for supercharged engines
  • F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
  • F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/22—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
  • F02M26/23—Layout, e.g. schematics
  • F02M26/25—Layout, e.g. schematics with coolers having bypasses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/35—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P5/00—Advancing or retarding ignition; Control therefor
  • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
  • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
  • F02P5/15—Digital data processing
  • F02P5/1502—Digital data processing using one central computing unit
  • F02P5/1516—Digital data processing using one central computing unit with means relating to exhaust gas recirculation, e.g. turbo

Definitions

• the invention relates to combustion engines of motor vehicles with an exhaust gas recirculation system from at least one cylinder to the air intake of the cylinders.
• Such systems are well known under the acronym EGR corresponding to the Anglo-American Exhaust Gas Recirculation.
• EGR corresponding to the Anglo-American Exhaust Gas Recirculation.
• the exhaust gases reintroduced at the intake are typically loaded with hydrogen gas because of an operation in which the cylinder or cylinders whose exhaust gases are reintroduced operate with an air-fuel mixture of the type rich.
• Such engines are known as D-EGR for Dedicated Exhaust Gas Recirculation in English or a dedicated system for reintroduction or recirculation of exhaust gas in French.
• the D-EGR concept makes it possible to generate hydrogen-doped EGR gases by operating a cylinder in rich mode, advantageously a richness of the order of 1.5. This hydrogen makes it possible to improve the stability of the combustion and therefore the tolerance to the EGR.
• the D-EGR engine reduces pump-out losses at the engine intake for partial load points, and pushes the limit at which a knock for full load points occurs. It is advantageous to have a supercharging machine sufficiently powerful to restore the necessary air flow and thus maintain or even increase the performance of the engine.
• the object of the invention is to propose a strategy for eliminating such a condensation water appearing in the charge-air cooler.
• a motor vehicle combustion engine with exhaust gas reintroduction comprising a plurality of combustion cylinders, a fresh air intake member towards one or more cylinders and an exhaust gas return line from at least one combustion cylinder in the intake member, the exhaust gas reintroduction line being further configured to receive a charge air and the reintroduction line of exhaust gas comprising a charge air cooler, the engine, as it comprises a control module configured to selectively control a nominal operating mode and a modified operating mode of said at least one cylinder of which at least a part exhaust gas is reintroduced into the intake member which modified operating mode comprises an offset from the nominal mode of a moment of combustion of said at least one combustion cylinder, the offset of combustion time being such that it produces a heating of the exhaust gas of said at least one combustion cylinder which heating is sufficient to cause evaporation of condensate present in the cooler of charge air.
• the engine comprises a catalyst for producing hydrogen and the exhaust gas reintroduction line comprises two parallel branches, one of which passes through the hydrogen production catalyst and the other forms a bypass of the a hydrogen production catalyst, the exhaust gas re-introduction line being equipped with a controlled exhaust gas routing member which is configured to controllably drive the exhaust gases into the branch traversing the catalytic converter; production of hydrogen or in the derivation branch of the hydrogen production catalyst.
• the engine comprises an exhaust gas cooler and the exhaust gas reintroduction line comprises two parallel branches of which one passes through the exhaust gas cooler and the other forms a bypass of the exhaust gas cooler, the exhaust gas return line being provided with a controlled exhaust gas routing member is configured to controllably direct the exhaust gas into the branch passing through the exhaust gas cooler or into the bypass branch of the exhaust gas cooler.
• the engine comprises a control module of the exhaust gas routing member in the branch passing through the exhaust gas cooler or in the bypass branch of the exhaust gas cooler which modulus of control is configured to control the routing member such that the exhaust gas flows into the exhaust gas cooler in the nominal operating mode and the exhaust gas flows into the bypass branch of the exhaust cooler. exhaust gas in the modified operating mode.
• the derivation branch of the hydrogen production catalyst and the bypass branch of the exhaust gas cooler are the same branch.
• the engine comprises a module for identifying a state of presence of condensates in the charge air cooler and the control module is configured to control the modified operating mode in response to an identification by the module for identifying a state of presence of condensates in the charge air cooler.
• the module for identifying a state of presence of condensates in the charge air cooler comprises a condensate presence sensor.
• the motor is configured such that all of the exhaust gas from said at least one combustion cylinder is reintroduced into the intake member.
• the engine comprises a single combustion cylinder, all of the exhaust gas is reintroduced into the intake member.
• said at least one cylinder of which at least a portion of the exhaust gas is reintroduced into the intake member is a cylinder operating at greater than 1 richness so that it produces exhaust gas charged with hydrogen.
• the engine shown in the appended figure comprises a motor unit provided with four cylinders 11, 12, 13, 14.
• the engine further comprises an intake manifold 20 opening into each of the cylinders 11, 12, 13 14 by a respective intake duct 21, 22, 23, 24.
• An exhaust manifold collects the exhaust gases emanating from each of the cylinders 11, 12 and 13.
• the cylinder 14 is associated with a circuit 40 for reintroduction of exhaust gas at the intake.
• the circuit 40 takes the exhaust gases from the cylinder 14 and directs them to the intake of the engine. More specifically, the exhaust gases of the cylinder 14 are conveyed here by the circuit 40 to the intake manifold 20.
• the cylinder 14 is here a cylinder type D-EGR.
• An engine control module controls an air and fuel supply of the cylinder 14 so that the cylinder 14 is the seat of a rich mixture combustion, that is to say in excess of fuel with respect to the fuel. air, here according to a wealth of about 1.5. Due to the richness of the air-fuel mixture, the cylinder 14 produces hydrogen gas H2. The H2 gas thus produced is found in the exhaust gases emitted by the cylinder 14 which are then, according to the principle of the D-EGR engine, reintroduced into the intake of at least one cylinder of the engine, here at the intake of the set of cylinders 11 to 14.
• the engine according to the present embodiment has only one cylinder producing hydrogen according to the D-EGR principle. In a variant, the motor may comprise several of them.
• the exhaust gas reintroduction circuit further comprises a catalyst for producing hydrogen 50 and an exhaust gas cooler 60.
• hydrogen 50 is here a WGS type catalyst for Water Gas Shift in English also called by gas reaction to water.
• the present engine further comprises a turbocharger 70 which is driven by the exhaust gases emanating from the cylinders 11, 12 and 13 and pressurizing a flow of fresh air which arrives at the intake of the engine once compressed .
• the turbocharger 70 provides fresh air under pressure to a mixer 80 disposed on the exhaust gas reintroduction circuit.
• the role of the mixer 80 is to mix the compressed air and the exhaust gases emitted by the dedicated cylinder 14.
• the exhaust gas reintroduction circuit 40 further comprises a charge air cooler 90 disposed downstream of the mixer 80 so that the mixture circulates in the charge air cooler 90 and opens once cooled in the intake manifold 20.
• the exhaust gas reintroduction circuit 40 also comprises a bypass branch 45, which extends in parallel with the hydrogen production catalyst 50 and the exhaust gas cooler 60. At the inlet of this branch bypass 45 is arranged a valve, not shown, which allows to direct the exhaust gas selectively to the catalyst 50 and the cooler 60 or in the bypass branch 45. This valve is controlled by a control module which will be more amply described below.
• an alert is sent towards the engine computer by a sensor or a processor implementing a prediction model based on a history of engine operation.
• the engine computer then adopts a combustion time modification strategy in the dedicated cylinder 14, here consisting of a sub-setting of the ignition advance in the dedicated cylinder 14.
• This change in the combustion time is chosen to cause an increase in the exhaust gas temperature of the dedicated cylinder 14, which in itself is easily implemented with the existing means.
• the increase in the exhaust gas temperature of the dedicated cylinder 14 causes an increase in the temperature of the gases reintroduced by the line 40 and in particular an increase in the temperature of the gases in the charge air cooler 90.
• the modification of the combustion instant is chosen sufficiently pronounced for the temperature of the gases in the cooler to Charge air 90 increases to be greater than the vaporization temperature of the condensation water.
• the vaporization temperature of the condensation water in the charge-air cooler is typically the ordinary temperature of 100 degrees Celsius.
• the condensation water present in the charge air cooler 90 is then vaporized and then discharged first into the intake manifold 20 and then into the combustion cylinders 11, 12, 13, 14.
• the inlet valve of the branch branch 45 is advantageously controlled, here by the engine computer, so that the catalyst 50 and the exhaust gas cooler 60 are not traversed by the exhaust gas.
• the temperature increase of the exhaust gas is thus preserved to reach the vaporization temperature of the condensates in the charge-cooler 90 and thus optimize the increase of the temperature of the reintroduced gases.
• the only time offset of the combustion makes it possible to increase the temperature of the exhaust gases sufficiently to such a vaporization.
• the strategy described here therefore allows alternatively to overcome a possible derivation of the exhaust gas cooler. It also makes it possible to avoid here a possible bypass of the charge air cooler 90 in a life situation where a large amount of condensate appears in it.
• the temperature of the walls of the charge air cooler 90 is advantageously controlled to prevent the presence of cold walls in this modified operation, for example by stopping or by reducing the cooling power supplied by the cooler 90.
• the condensation sensor detects the disappearance of the condensate and emits an indicator signal this arrival at the end of vaporization process.
• the engine computer on receipt of this signal, restores the conventional engine settings corresponding to the nominal operating mode of the cylinder 14.
• the thermal cylinder dedicated to 14 is used to vaporize the condensation water present in the charge air cooler 90 and reinject it to the intake. For this purpose, a stallation of the combustion is carried out making it possible to increase the temperature of the exhaust gases of the dedicated cylinder and evaporation of the condensation water accumulated in the charge air cooler.
• the described strategy does not result in significant overconsumption of fuel. In addition, such a strategy does not involve significant modifications of the engine architecture and therefore does not entail significant additional costs for its implementation.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Exhaust-Gas Circulating Devices (AREA)
• Exhaust Gas After Treatment (AREA)

Applications Claiming Priority (2)

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• 2013
  • 2013-08-27 FR FR1358213A patent/FR3010149B1/fr not_active Expired - Fee Related
• 2014
  • 2014-06-19 WO PCT/FR2014/051522 patent/WO2015028728A1/fr not_active Ceased
  • 2014-06-19 EP EP14738565.2A patent/EP3039271A1/de not_active Withdrawn

Non-Patent Citations (1)

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