Classifications

• • 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
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by 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
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
  • F01N13/0097—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series the purifying devices are arranged in a single housing
• • 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
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/011—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel
  • F01N13/017—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel the purifying devices are arranged in a single housing
• • 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
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
• • 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
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
  • F01N3/0233—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles periodically cleaning filter by blowing a gas through the filter in a direction opposite to exhaust flow, e.g. exposing filter to engine air intake
• • 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
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
  • F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
• • 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
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/037—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of inertial or centrifugal separators, e.g. of cyclone type, optionally combined or associated with agglomerators
• • 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
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
  • F02B37/02—Gas passages between engine outlet and pump drive, e.g. reservoirs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
  • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
  • F02D13/0276—Actuation of an additional valve for a special application, e.g. for decompression, exhaust gas recirculation or cylinder scavenging
• • 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
  • F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
  • F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus
• • 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
  • F02M26/22—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
  • F02M26/28—Layout, e.g. schematics with liquid-cooled heat exchangers
• • 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
  • 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
  • F01N2290/00—Movable parts or members in exhaust systems for other than for control purposes
  • F01N2290/02—Movable parts or members in exhaust systems for other than for control purposes with continuous rotary movement
• • 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

Definitions

• a reciprocating internal combustion engine and method for removing particulates from the flue gases for such an alternative engine are provided.
• the present invention relates to an internal reciprocating engine and a method for removing particles from the flue gases of such an internal combustion engine.
• Reciprocating internal combustion engines operating on two- or four-stroke cycles and fitted to motor vehicles are subject to frequent and rapid transient operating conditions, as well as severe limitations of pollutants released to the atmosphere.
• pollutants are mainly NOX nitrogen oxides, CO carbon monoxide, HC unburned hydrocarbons and particulates.
• Spark ignition engines are generally not associated with a turbocharger unit and they do not emit particles. On the other hand, they emit a lot of nitrogen oxide, carbon monoxide and unburned hydrocarbons which are most often eliminated in a three-way catalytic converter well adapted to stoichiometric mixture combustion. However, the efficiency of this type of engine is degraded by heat losses due to the high temperature of the operating cycle and the pumping work following the rolling of the intake flow. Diesel-type engines are increasingly associated with a turbocharger unit with a single turbocharger that is sufficient to produce an intake pressure of two to three absolute bars.
• the turbine of the turbocharger is generally variable geometry thus adapting to variations in speed and the variable back pressure of the exhaust line of the engine. Emissions of carbon monoxide and unburned hydrocarbons are low, but nevertheless require an oxidation catalyst in the exhaust line. In addition, nitrogen oxide emissions require recycling of cooled flue gases and particulate emissions are currently limited by the excess of air that generates nitrogen oxides.
• Diesel-type engines are likely to lose the qualities of efficiency and hardiness that make them prefer to the spark-ignition type engine, despite its higher cost.
• the after-treatment devices used to date are located downstream of the turbocharger unit turbines and these devices generate a back pressure that can reach 1 bar at full engine power. Under these conditions, the equalization of the turbine expansion ratio and the compressor compression ratio of the turbocharger unit assumes that the exhaust pressure is twice the engine intake pressure. A fortiori, a rate of expansion higher than a compression ratio leads to unacceptable pressure differences between intake and exhaust for very supercharged engines with a high rate of flue gas recirculation. In addition, the downstream temperature of the turbines is often insufficient to initiate catalysis of the treatment device.
• the upstream post-treatment turbines turbocompression group has already been tried by the manufacturers without success because the main difficulty is due to the volume of the device that dissipates the pressure pulsations of the gases needed to drive the turbocharger group at engine speeds below the engine speed (engine speed where the exhaust pressure crosses the intake pressure).
• French Patent Application No. 03 03 728 also known in the name of the Applicant, discloses an alternating motor with recirculation of burnt gases or the turbocompression is adapted for an engine speed below the minimum operating speed.
• One of the aims of the invention is to produce a high supercharging of the high rate of recirculation engines of the flue gases and low exhaust temperature by limiting the exhaust backpressure detrimental to the efficiency of this engine.
• Another object of the invention is to eliminate the pollutants generated by the cold cycles, essentially carbon monoxide, unburnt hydrocarbons and particles generated by the direct injection of a liquid fuel.
• the subject of the invention is therefore an internal combustion internal combustion engine comprising, on the one hand, at least one cylinder provided with at least one intake valve and at least one exhaust valve through which a flow is evacuated.
• pulsed gas whose generating pressure is the pressure Pd prevailing in the cylinder at the opening of said at least one exhaust valve and, secondly, a turbocharging unit actuated by said burnt gas and said supply to less cylinder compressed air cooled, characterized in that at least a portion of the pulsed flow of burnt gas is discharged from said at least one cylinder by an exhaust pipe provided with an expansion nozzle opening tangentially to a peripheral wall of a bedroom revolution centrifugation and perpendicular to the axis of this chamber and in that the centrifugation chamber communicates with a turbocompressor group turbocharger supply duct by an annular radial diffuser coaxial with said chamber and having an inlet diameter D, the static pressure in the centrifuge chamber being maintained at a value Ps lower than the pressure Pd in order to accelerate
• the centrifugation chamber comprises an axial orifice of diameter d smaller than the inlet diameter D of the radial diffuser communicating with a recycle line for the flue gases and in that the volume of a space comprised between a dummy cylinder of diameter D and a coaxial cylinder of diameter d of lengths equal to the distance between the axial orifice and the inlet of the radial diffuser is preferably greater than two unit cubic capacities of the engine,
• the centrifugation chamber has a volume greater than at least three times the unit cubic capacity of the motor in order to stabilize the static pressure when the axial orifice is closed; the centrifugation chamber communicates via the axial orifice with a volume at less than three engine unit displacements to stabilize the static pressure,
• the centrifugation chamber communicates with the recycling duct via the axial orifice, the static pressure at said orifice being substantially equal to the intake pressure of the engine,
• the axial orifice supplies an annular radial diffuser having an inlet diameter, the static pressure at said axial orifice being lower than the intake pressure of the engine;
• said at least one nozzle opens into said centrifugation chamber at a substantially conical section extending between a zone of greater diameter of said chamber and said axial orifice of diameter d, the second exhaust valve is connected by a discharge duct to the recycling duct downstream from the corresponding axial orifice, the exhaust valve of the second duct opening after the exhaust valve of the first duct when the pressure in the corresponding cylinder has dropped sufficiently,
• the motor comprises between the annular radial diffuser of the supply duct of the turbocharger group turbines and said turbines, an axial flow particle filter, preferably a cylindrical filter associated with means for removing the particles deposited on the filter; with particles, the means for removing the particles comprise a collector applied to the inlet face of the particle filter and movable on this face to periodically sweep the entire surface of this face, said collector communicating with an area where the static pressure is less than the pressure downstream of the particulate filter to create a flow of countercurrent gas in the sector of this filter covered by the manifold,
• the collector communicates with the recycling duct to burn the particles extracted from said particulate filter in said at least cylinder,
• the collector communicates with an axial zone of the centrifugation chamber in the vicinity of the radial diffuser of the turbine supply duct, by a combustion zone of the particles situated in said chamber, and
• the particle filter has the shape of a cylinder of revolution whose two end faces are flat, said collector being rotated about the axis of this filter.
• the subject of the invention is also a method for removing particles from the flue gases of an internal combustion reciprocating engine as previously mentioned, characterized in that:
• the evacuated flue gases are passed through an axial flow particle filter, and each sector of the inlet face of the particulate filter is periodically brought into communication with an area where the static pressure is lower than the downstream pressure. of this particle filter to create a flow countercurrent gases in each sector of said particulate filter which carries particulates taken from said filter to an area where said particles are burned.
• the zone where the static pressure is lower than the pressure downstream of the particulate filter is formed by a flue gas recycling circuit provided with a valve for regulating the flow of recycled gas; particles removed being burned in said at least engine cylinder,
• the zone where the static pressure is lower than the pressure downstream of the particulate filter is formed by an axial zone of a centrifugation chamber;
• the axial zone communicates with the recycling circuit, the particles removed being burned in the at least one cylinder of the engine,
• the axial zone communicates with the turbocharging unit, the particles removed being burned in the centrifugation chamber.
• FIG. 1 is a diagram of an example of an assembly for exhausting burnt gases and supplying oxidant to an internal combustion reciprocating engine according to the invention
• FIG. 2 is a diagrammatic view on a larger scale and in axial section of a centrifugation chamber of the pulsed flow of burnt gases emitted by the engine;
• FIG. 3 is a sectional view along the line 3-3 of FIG. 2
• FIG. 4 and 5 are diagrammatic views in axial section of two variants of the centrifugation chamber
• FIG. 6 and 7 are diagrammatic views respectively in axial section and along the line 7-7 of the centrifugation chamber associated with means for removing particles from the flue gas,
• - Figs. 8 to 9 are schematic views in axial section of two variants of the flue gas removal means
• - Figs. Figures 10 to 12 are diagrams of several examples of flue gas discharge and oxidizer feed systems of a four-cylinder reciprocating internal combustion engine.
• FIG. 1 schematically shows a motor 1 which comprises at least one cylinder 1a provided with at least one intake valve 2 and at least one exhaust valve 3.
• the cylinder 1a is provided with an intake valve
• the engine 1 is associated with a set of means which will be described later and which allows to deliver to this engine 1 a mixture of clean air and burnt gases whose pressure, temperature and the rate of recycled gas are adjustable at any time depending on the operating parameters of the moment.
• the intake valve 2 is connected to an intake manifold 4 and the exhaust valve 3 is connected to an exhaust duct 5 which opens into a centrifuge chamber designated by the general reference 10.
• This centrifuge chamber 10 transforms the pulsed flow of burnt gases emitted by the cylinder 1a of the engine 1 in two flows, respectively a flow designated by Qt and a flow designated by Qegr, at substantially constant pressures.
• the flow Qt is directed towards a turbocharger group generally designated by the reference 30.
• This turbocompression unit 30 relaxes the flow Qt to reject it to the atmosphere and takes the atmospheric air designated by Qair to feed the cylinder 1a of the motor 1 via a duct 6, a mixer 7 and the intake manifold 4.
• the turbocharger unit 30 is connected to the centrifugation chamber 10 via a duct 31.
• the fresh air flow Qair is advantageously compressed, in a conventional manner, in the turbocharger unit 30, for example a first time by a low pressure turbocharger, and is then cooled before being compressed a second time by a high-pressure turbocharger and cooled a second time.
• the Qt flow which represents 50 to 70% of the flue gas flow, equal to the fresh air flow Qair plus the burned fuel flow is successively relaxed in the high pressure turbine and the low pressure turbine before being released into the atmosphere.
• the flow Qt can feed the high-pressure turbine and the low-pressure turbine of the turbocharger unit 30 in parallel.
• the flow Qegr, at the outlet of the centrifugation chamber 10, is directed towards a recycling circuit which comprises a conduit 35.
• the recycling circuit Downstream of the assembly formed by the dispensing valve 36, the refrigerant 37 and the duct bypass 38, the recycling circuit comprises a flow control valve 39 Qegr connected to the mixer 7 by a conduit 40.
• the mixer 7 receives Qair flow and Qegr to supply the cylinder 1a of the engine 1 with a homogeneous combustion mixture.
• the flow Qegr which represents 30 to 50% of the flue gas stream is cooled under pressure and adjustably in the coolant 37, then intimately mixed with the flow of fresh air Qair in the mixer 7 to supply the intake manifold 4.
• the adjustment of the flow temperature Qegr can advantageously be carried out by short-circuiting by the distributor valve 36 all or part of the flow flowing in the coolant 37.
• the conduit 31 connecting the centrifugation chamber 10 to the turbocharger unit may be equipped with a post-processing system designated by the general reference 50 and will be described later.
• the limitation to about 1600 ° K of the maximum temperature of the operating cycle of the engine 1 causes a proportional limitation of the temperature at the end of expansion in the cylinder 1a, available for turbocharging.
• the power of the turbines of the turbocharger unit 30 is based on the total pressure of the flow Qt. It is therefore seen that it is advantageous to exploit optimally the generating pressure Pd available in the exhaust gases at the end of expansion in the cylinder 1a.
• the distribution and the circulation of the gas flows in the centrifugation chamber 10 are organized in an original way to optimize the use of this pressure in the context mentioned above. First of all, some physical bases of the operation of the reciprocating internal combustion engine are recalled.
• Pd / Pc Vc / Vd x Td / Tc
• Pd, Vd, Td and Pc, Vc, Tc are respectively the pressure, the volume and the temperature of the gases at the end of expansion and at the beginning of compression.
• Pd / Vc can be set by playing Vc / Vd at constant inlet temperature. With fixed valve timing, Pd / Pc can be adjusted by adjusting the intake temperature. A fortiori, Pd / Pc can be adjusted by adjusting the two parameters to adjust another variable of the cycle, the compression temperature Pc which governs ignition, for example. For a given intake pressure, the pressure generating the flue gases can thus be adjusted by parameters internal to the engine (valve timing) or by external parameters (intake temperature).
• Half of the burnt gases present in the cylinder 1a can, in this embodiment, be expanded from a generating pressure greater than Pc, generating pressure whose mass average is 1, 5 Pc.
• one half of the hot gases is intended to be cooled and transferred into the intake manifold 4 where the pressure is close to Pc.
• the other half is intended to be expanded in turbines of the turbocharger unit to atmospheric pressure.
• the centrifuge chamber 10 is designed to direct the most energetic flue gases to the turbocharger turbines 30 and the least energy gases to the recycle conduit 35. In effect, the transfer of the recycled flow Qegr from the chamber centrifugation 10 to the intake manifold 4 can be carried out at a pressure close to Pc, if the recycling duct is sufficiently sized.
• the discharge work of the recycled gases of the cylinder 1a is developed by the piston of this cylinder in the case of an engine operating in a four-stroke cycle or by the fresh charge in the case of a motor operating in a two-cycle cycle. time.
• the centrifugation chamber 10 has a general shape of revolution of axis XX.
• the peripheral wall 11 of this chamber of revolution has the shape of a cylinder.
• the exhaust duct 5 placing the cylinder chamber 1a in communication with the centrifugal chamber 10 when opening the exhaust valve 3, is provided at its free end with a thrust nozzle 12 opening tangentially to the wall 11 of this centrifugation chamber 10 and perpendicular to the axis XX of said centrifuge chamber.
• a thrust nozzle 12 opening tangentially to the wall 11 of this centrifugation chamber 10 and perpendicular to the axis XX of said centrifuge chamber.
• this speed can approach the speed of sound and decreases to 0 when the pressures equalize.
• the axisymmetric field of the static pressures in the centrifugation chamber 10 is governed by the centrifugation effect which itself depends on the evolution of the tangential velocities along a radius of this chamber 10.
• the fastest burned gases are placed therefore naturally towards the periphery of the centrifuge chamber 10 while the slower burned gases are concentrated around the axis XX of this chamber 10.
• the static pressure and the total pressure decrease simultaneously between the periphery of the centrifuge chamber 10 and its axis XX where the static pressure can decrease significantly below the pressure at the beginning of compression Pc.
• the total pressure of the fast gases is equal to the static pressure increased by the dynamic pressure while the pressure at the outlet of the nozzle 12 is the static pressure minus the dynamic pressure.
• the centrifugation chamber 10 is dimensioned to limit the kinetic energy losses by friction of the gas ring against the walls of this chamber. The time of presence of the fast gases in the centrifuge chamber 10 must therefore be minimal. As shown in FIG. 2, to stabilize the static pressures in the centrifuge chamber 10, this centrifugation chamber 10 is sufficiently large or according to FIG. 5 communicates through at least one axial orifice 13 of diameter d less than the largest diameter of the centrifuge chamber 10 with a volume 14 communicating with the recycle conduit 35 and which has a large volume relative to the amplitude of the pulses. The orifice 13 sees the breathing of the chamber 10 when the ring C formed by the fast flue gas is inflated and depleted to the rhythms of the openings and closings of the exhaust valve 3.
• the fast gases Qt are collected in the toric zone of the centrifugation chamber 10 in the form of the ring C and in which the diameter of this chamber 10 is greater than the diameter d of the orifice 13.
• the volume of this zone toric must be greater than the amplitude of the high-volume pulsations Qt fast and this amplitude varies between one and two cubic units for a four-stroke engine and four-cylinder.
• the centrifugation chamber 10 communicates with the turbine feed duct 31 of the turbocharger unit 30 by an annular radial diffuser 15 coaxial with said chamber 10 and having a minimum inlet diameter D.
• the inlet diameter D of the radial diffuser 15 is equal to the largest diameter of the centrifuge chamber 10.
• the centrifuge chamber 10 has a diameter D along its entire length.
• the radial diffuser 15 thus extends externally the fast-gas collecting zone Qt in the centrifugation chamber 10 to collect and slow down these fast gases.
• This diffuser 15 is advantageously formed by two parallel walls 16 and 17 extending perpendicularly to the axis XX of the centrifuge chamber 10 and delimiting therebetween a space 18 for the passage of fast gases Qt.
• the flow rate of these fast gases Qt which through the diffuser 15 is controlled by the turbines of the turbocharger group 30.
• the flow rate of the gas flow Qt is a function of the width of the space 18, that is to say the distance separating the walls 16 and 17 of the radial diffuser 15, and the turbine section of the turbocharger group 30.
• the static pressure in the centrifuge chamber 10 is maintained at a value Ps lower than the pressure Pd in order to accelerate a fraction of the flue gas supplying the ring of burnt gases.
• C in motion rapid rotation about the axis XX of the centrifuge chamber 10 and which escapes to the turbines of the turbocharger group 30 by compressing and slowing down in the radial diffuser 15.
• the centrifugation chamber 10 has a volume at least equal to three cubic units.
• the recycled Qegr gases can be recompressed in a radial diffuser 20, as will be described later.
• the centrifugation chamber 10 has a reduced volume to limit the wetted surface by the rapidly rotating gas ring and communicates through the orifice 13 with a volume 14 at least equal to three cubic units.
• the inlet of the radial diffuser 15 may have a diameter D less than the maximum diameter of the centrifugation chamber 10.
• the volume of a space between a dummy cylinder of diameter D and a cylinder Dummy coaxial of diameter d of lengths equal to the distance between the orifice 13 of diameter d and the diameter of inlet D of the radial diffuser 15 is preferably greater than two cubic units of the engine in order to maintain all the fast gases in the chamber 10 during the volume breaths of the rotating gas ring.
• the burnt gases still present in the cylinder 1a of the engine are discharged at low speed by the piston in the case of a motor operating in a four-stroke cycle or the fresh load in the case of an engine operating in a two-stroke cycle.
• These slow gases must reach the axial zone of the centrifugation chamber 10, mixing as little as possible with fast gases.
• the slow gases Qegr are partially mixed with the fast gases before being slowed down by an annular radial diffuser 20 which puts the centrifugation chamber 10 in communication with the recycling conduit 35.
• This radial diffuser 20 has a minimum diameter substantially equal to diameter d of the outlet orifice 13.
• the radial diffuser 20 is formed of two parallel walls, respectively 21 and 22, extending perpendicularly to the axis XX of the centrifuge chamber 10 and delimiting therebetween a gap 23 for passage of the slow gases Qegr.
• the total pressure at the inlet of this diffuser 20 is substantially at the intake pressure Qad of the engine 1 and the static pressure in said chamber 10 may be below this inlet pressure Pad.
• the radial diffuser 20 raises the pressure of the slow gas flow Qegr at the intake pressure in the manifold 4 of the engine 1.
• the radial diffuser 20 is optional in the case of a motor operating in a four-cycle cycle where the slow gas flow Qegr is pumped by the engine. On the other hand, it is necessary to create a slow gas flow Qegr in a motor operating in a two-cycle cycle.
• each of the diffusers 15 and 20 is smooth and the ratio of diameters D / d of these two diffusers sets the potential of the slow gas flow Qegr.
• the flow rate of Qegr gas to be recycled in the cylinder 1a is preferably and as shown in FIG. 2, idle by the radial diffuser 20 to supply either the exchanger 4 cooled by the hot cooling water of the engine 1 and which is optionally followed by a second exchanger cooled by a low temperature water circuit, not shown, or the bypass duct 38.
• the control valve 36 modulates the cooled fraction of the Qegr gas flow and the recycling valve 39 located upstream or downstream of the exchanger 37 to adjust the flow Qegr.
• the burnt gases thus cooled, the flue gases passing through the bypass duct 38 and the fresh air Qair are intimately mixed in the mixer 7 before entering the intake manifold 4 and the cylinder 1a through the intake valve 2 .
• the Qegr Recycled Gas Flow Valve is very effective for transient engine operation to increase the amount of oxygen available for combustion of this engine. Indeed, it increases the Qt gas flow through the turbines turbocharger group 30 at the expense of recycled gas flow Qegr instantly replaced by fresh air. This maneuver, which moves the splitting points in the characteristic diagrams of the compressors, is done without waiting Turbocharger group turbocharging. In steady state, this method of increasing the pumping work done by the piston is used only for fine adjustments. Generally, it is preferred to adjust the flow of recycled Qegr gas by changing the valve timing or by operating the temperature control valve 36 of Qegr.
• the slow gases take the same exhaust duct 5 as the fast gases that open into the centrifuge chamber 10 via the expansion nozzle 12. separation of these two streams, ie the fast gas flow and the slow gas flow then takes place in this centrifuge chamber 10.
• the nozzle 12 opens, as shown in FIG. 4, in a conical zone of the centrifuge chamber 10 connecting a large diameter area to a small diameter area.
• the outer wall 11 of the centrifugation chamber 10 forms a cone along the entire length of this centrifugation chamber 10, the conicity of this wall being directed towards the outlet orifice 13. of diameter d.
• the gases from the expansion nozzle 12 are oriented alternatively to the smaller diameter zone or to the larger diameter zone depending on their ejection speed.
• the section of the nozzle 12 must be small enough to accelerate the fast gases and large enough not to brake the slow gases.
• the dimensioning of the exhaust duct 5 can be chosen according to the desired goals.
• the mass of gas immobilized in this duct 5 when the exhaust valve 3 is closed is propelled towards the centrifugation chamber 10 by the expansion of the gases of the next cycle which will lose momentum.
• the gaseous column thus accelerated in the conduit 5 entrains behind it by inertia a fraction of the low energy gases still present in the cylinder 1a. This double exchange of momentum degrades the energy differentiation between the Qt gas flow and the Qegr gas flow.
• the volume of the conduit 5 must be minimal.
• the volume of the duct 5 is preferably close to the engine capacity of the engine.
• valve 3a In the case of an AC motor provided with two exhaust valves 3a and 3b per cylinder 1a, a valve such as valve 3a, for example, is assigned to fast gases and a valve, such as valve 3b, is assigned to slow gases, as shown in FIG. 5.
• the fast gases take a duct 5a equipped with an expansion nozzle 12 and opening out at the periphery of the centrifugation chamber 10, like the exhaust duct 5 described above, whereas the slow gases take a second exhaust duct 5b. which emerges downstream of the outlet orifice 13.
• the internal volume of the centrifugation chamber 10 is separated into two volumes located on either side of the transverse partition 13a in which is formed the outlet port 13, a first volume in which are directed the fast gases from the exhaust valve 3a and a second volume in which are directed the slow gases from the exhaust valve 3b.
• the outlet orifice 13 then sees an alternating flow flow.
• the nozzle 12 fed exclusively by fast gases may have a smaller section than the previous embodiment.
• the valve 3a of the exhaust duct 5a opens first and when the pressure in the cylinder 1a has dropped sufficiently, the exhaust valve 3b of the duct 5b opens in turn to drain the cylinder 1a.
• the two valves 3a and 3b can close simultaneously at the end of the transfer, the separation of gases in two flows then taking place in the cylinder 1a of the engine.
• the quantity of burnt gases emitted by the engine is proportional to its operating regime.
• the flow of gas Qt is proportional to the section offered to the gases for venting to the atmosphere, in this case the section of an orifice equivalent to the turbines of the turbocharger unit 30 as well as the supply pressure of the turbocharger units. turbines, it itself depends on the efficiency of the radial diffuser 15.
• the minimum turbine section In order to guarantee the clearance of nitrogen oxide from the minimum operating speed of the engine, it is therefore necessary for the minimum turbine section to allow only about 60% of the flow of gas emitted by the engine to pass at its minimum speed. use.
• the ratio between the gas flow rate Qt and the gas flow rate Qegr can be adjusted by the engine valve timing, by the turbocharger group turbines section, by the recycling valve 39 or by the valve 36 which regulates the temperature of the flow Qegr, as mentioned in the patent application No. 03 03 728 also in the name of the Applicant.
• the ratio Qt / Qegr can also be adjusted by modifying the width of the space 18 formed between the walls 16 and 17 of the radial diffuser 15 or by the width of the space 23 formed between the walls 21 and 22 of the radial diffuser 20.
• the wall 22 of the radial diffuser 2 may be displaceable by any appropriate type of means along the axis XX of the centrifugation chamber 10 to close the orifice 13.
• the movable wall 22 replaces the valve recycling 39.
• the work done by the turbocharger group turbines increases with the temperature and the total pressure of the gases that feed them.
• the adjustment of the power of the turbines is done essentially by adjusting the total pressure of the gas flow Qt using the actuators internal to the engine (valve timing and injection) and / or the external actuators (valve 39 and / or valve 36 of the Qegr gas flow circuit).
• the total pressure of the gas flow Qt is approximately the sum of the static pressure prevailing in the centrifuge chamber 10 and the dynamic pressure associated with the speed of rotation of the gases.
• the report between these two components can be chosen by adjusting the level of the static pressures in this centrifugation chamber 10.
• this adjustment can be done by throttling of the gas flow recycle line Qegr.
• the recycle valve 39 When the recycle valve 39 is closed, the dynamic pressure starts from a maximum value to cancel when the expansion ratio in the nozzle 12 is equal to unity.
• the annular radial diffuser 15 automatically adapts to intermediate aerodynamic speeds. Indeed, for a high dynamic pressure, the gas flow Qt penetrates tangentially into the annular space 18 to undergo diffusion. For a zero dynamic pressure, the gas flow Qt radially passes through the diffuser 15 without loss of load.
• the reciprocating internal combustion engine is equipped with after-treatment devices 50 of the gas flow Qt and which are situated between the annular radial diffuser 15 and the turbine inlet of the turbocharger unit 30.
• These post-treatment devices are formed by a catalytic particle filter 51 with axial flow and preferably cylindrical.
• the filter 51 is traversed by the flow of Qt gas at the outlet of the radial diffuser 15 whose temperature is always greater than 400 0 C, sufficient temperature for the catalytic oxidation of unburned hydrocarbons and carbon monoxide, but insufficient to burn the deposited particles which oxidize rapidly only above 600 ° C.
• a first method consists of allowing a certain weight of particles to accumulate at the inlet of the filter 51 and of burning these particles locally by periodically raising the temperature of the particles. gas passing through the particulate filter, for example by discharging into the atmosphere a portion of the air delivered by the high pressure compressor. The regeneration of the particulate filter 51 is all the more rapid as it is frequent.
• the heavy particles centrifuged in the radial diffuser 15 are concentrated on a cylindrical surface 52 arranged at the outlet of the radial diffuser 15 and upstream of the particle filter 51, with respect to the direction of flow of the gas flow Qt.
• the particulate filter 51 is associated with particle removal means which comprises a manifold 55 applied to the inlet surface 51a of the particulate filter 51.
• the manifold 55 is movable on this face to periodically scan the the entire surface of the face 51a of the particulate filter 51.
• the collector 55 communicates with an area where the static pressure is lower than the pressure downstream of the particulate filter 51 to create a countercurrent flow of gas in the sector of the filter 51 covered by the collector 55.
• the collector 55 is rotated by a suitable means 56, such as an electric motor 56 whose speed is adjusted to ensure a complete cleaning cycle of the particle filter 51, for example every second.
• the collector 55 is connected by a duct 57 located in the axis XX of the centrifugation chamber 10 and which opens out at the outlet orifice 13 where the static pressure is lower than the pressure downstream of the particle filter 51.
• a small fraction of the filtered flow returns the small sector of the particulate filter 51 covered by the collector 55, against the current to entrain the particles which have just deposited there towards the end of the conduit 57.
• the particles thus collected can to be reintroduced into the cylinder 1a with the recycled gases to be burned.
• the sweep flow thus formed then participates in the flow rate of the gas flow Qegr.
• a zone 60 of combustion of these particles can be created in an axial zone of the centrifugation chamber 10, as shown in FIG. 8.
• the particle-free gas stream is then vented to the turbocharger group turbines 30 through the particulate filter 51 and then participates in the flow rate of gas Qt.
• the flow of this flow of gas without particle can be regulated by a flame catch 61 formed for example by a cone in order to maintain an adequate richness in the combustion zone 60.
• an oxidation catalyst 62 separated from the particulate filter 51 may be disposed between the radial diffuser 15 and this particulate filter 51.
• the sticky soluble particles are burned in the oxidation catalyst 62 before entering the the particulate filter 51 which stops only the dry particles readily entrained by the recirculated gas stream from the manifold 55.
• the aforementioned particle removal methods can be used separately or in combination.
• Figs. 10 to 12 there are shown several examples of configuration of the flue gas discharge circuit and the combustion circuit of a four-cylinder reciprocating internal combustion engine. Other configurations can of course be considered.
• the engine 1 comprises four cylinders 1a each provided with an intake valve 2 and an exhaust valve 3.
• the exhaust valve 3 of each cylinder 1a is connected to an exhaust pipe 5 which opens in the centrifugation chamber 10 identically to the previous embodiments, that is to say via an expansion nozzle.
• the engine 1 has four cylinders 1a each provided with an intake valve 2 and an exhaust valve 3.
• the exhaust valves 3 of two cylinders 1a contiguous are arranged side by side and are each connected by a connecting duct 5a to the exhaust duct 5 which opens into the centrifugation chamber 10.
• Each exhaust duct 5 is equipped with a nozzle arranged in the centrifugation chamber 10 in a manner identical to the previous modes of centrifugation. production.
• the engine 1 comprises four cylinders 1a each equipped with two intake valves, respectively 2a and 2b, and two exhaust valves respectively 3a and 3b.
• the exhaust valves 3a and 3b of two cylinders 1a contiguous are arranged side by side.
• the exhaust valve 3a of each cylinder 1a is assigned to fast gases and the valve 3b is assigned to the slow gases.
• the exhaust valve 3a of a cylinder 1a is connected by a connecting pipe 5a to the exhaust valve 3a of the adjoining cylinder 1a and this exhaust valve 3a is connected to the exhaust pipe 5 provided with a nozzle of small section which opens into the centrifuge chamber 10 in the same manner as the previous embodiments.
• the exhaust valves 3b are connected to each other by a recycling duct 35, which is largely dimensioned to an assembly designated by A which groups together the elements of the Qegr gas recycling circuit as well as the mixer 7.
• the flow rate of gas recovered by the manifold 55 is directly channeled through the conduit 51 to the assembly A to be sucked by the engine 1.
• the valves 3a open first to reduce the pressure in the cylinders. Valves 3b then open for the discharge of slow gases.
• the invention is particularly advantageous for a thermodynamic cycle with a high rate of recycling of flue gas (30 to 50% of the oxidizing mass) which at no time has the favorable conditions for the formation of thermal nitrogen oxides.
• This constraint boils down to never exceed a local temperature of 1900 0 K approximately.
• the maximum temperature of the cycle at each point of the combustion chamber is the sum of the local temperature at the start of combustion Tcomb (compression temperature) and the temperature rise due to combustion (Tcomb). This maximum local temperature depends primarily on internal engine parameters such as the compression ratio that governs Tcomb, the local fuel concentrations and the ignition advance that govern Tcomb.
• This temperature also depends on the admission conditions such as the chemical composition of the oxidizing mixture that governs the oxygen concentration, the Tad admission temperature that governs Tcomb and the intake pressure Pad that governs the mass of oxidizing gas to be heated. .
• the specificity of these cycles is a high inlet pressure to introduce into the cylinder burnt gases that add to the fresh air required by the combustion and a low exhaust temperature resulting from the reduction of the combustion temperature.
• the turbocharging system must therefore provide more work with less energy.
• the reciprocating internal combustion engine according to the invention avoids these disadvantages.
• the reciprocating engine according to the invention has the advantage of collecting in a single pressurized module the operations of turbocompression, refrigeration, the physical and chemical post-treatment of the gases emitted into the atmosphere, thereby reducing its cost.
• the reciprocating engine according to the invention also makes it possible to neutralize exhaust noise at the source in order to simplify or even eliminate the silencer downstream of the turbocharger group turbines.

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• 2005
  • 2005-02-04 FR FR0501156A patent/FR2881793B1/fr not_active Expired - Fee Related
• 2006
  • 2006-01-30 EP EP06709199A patent/EP1844218A1/de not_active Withdrawn
  • 2006-01-30 WO PCT/FR2006/000203 patent/WO2006082302A1/fr active Application Filing
• 2007
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