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
  • F02B19/00—Engines characterised by precombustion chambers
  • F02B19/02—Engines characterised by precombustion chambers the chamber being periodically isolated from its cylinder
  • F02B19/04—Engines characterised by precombustion chambers the chamber being periodically isolated from its cylinder the isolation being effected by a protuberance on piston or cylinder head
• • 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
  • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
  • F02B25/02—Engines characterised by using fresh charge for scavenging cylinders using unidirectional scavenging
  • F02B25/04—Engines having ports both in cylinder head and in cylinder wall near bottom of piston stroke
• • 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
  • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
  • F02B25/20—Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18
  • F02B25/22—Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18 by forming air cushion between charge and combustion residues
• • 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

• the invention relates to an internal combustion engine of the reciprocating piston type for a motor vehicle, which holds in the cylinders, at each cycle, a mass of burnt gases from the preceding cycle to activate the combustion, and processes for supplying the engine with fuel. in such a way that combustion does not produce pollutants.
• the four-stroke engines of the spark ignition type or the diesel type of the prior art have the following drawbacks: Spark ignition engines fed with a homogeneous gas mixture have a poor efficiency because of the combustion mode of the mixture which feeds them. , this combustion being stoichiometric metric and triggered by an electric ignition.
• a spark initiates a flame front which passes through the combustible charge and propagates by thermal diffusion, the richness of the mixture being close to 1 (stoichiometric ratio) so that the temperature of the flame front is high and the propagation of the flame is fast enough, and to allow a three-way catalysis of the exhaust gas.
• the compression ratio should be less than 10 to prevent self-ignition of the compression mixture, commonly known as knock.
• the object of the present invention is to avoid these drawbacks of the prior art by virtue of the presence in the combustion chamber of a charge of retained flue gas, separated from a fresh charge of clean air or of carbureted air.
• an internal combustion engine comprising at least one cylinder provided with intake and exhaust ports, a piston displaceable in reciprocating movement in the cylinder, a combustion chamber communicating via an orifice with the cylinder, intake means in the cylinder of a fresh charge formed of a homogeneous mixture of air and gaseous fuel, and exhaust control means which hold in the combustion chamber and in the cylinder a certain amount of burnt gas, characterized in that the cylinder contains, at the beginning of the compression, a set of gases comprising a volume of burnt gases and a fresh charge volume which are separated from each other by an intermediate volume of a mixture of burnt gas and fresh charge and which are successively discharged into the combustion chamber, first the burnt gases, then the intermediate volume of mixing, then the fresh charge, in that the effective compression ratio is insufficient to cause at the end of compression a self-ignition in the fresh charge and is sufficient to cause ignition from a hot point in the intermediate volume of mixture of burnt gas and fresh charge which has been discharged into the combustion chamber, the engine
• the burnt gases discharged into the combustion chamber during the compression of the fresh feed which raise the temperature of the reaction zone and make it possible to initiate the combustion of the fresh feedstock in its border zone with the feedstocks. burned gas and then develop it at the rate of introduction of the fresh charge into the combustion chamber.
• This combustion which develops as the piston finishes compressing the fresh charge in the combustion chamber and remains confined to the combustion chamber, is gradual and silent.
• the richness of the fresh charge admitted into the cylinder is determined not to generate nitrogen oxides in the combustion chamber. It is therefore chosen at a low value, typically less than 0.6 in the case of gasoline, which guarantees a lack of production of nitrogen oxides.
• the intensity of combustion is higher in the engine according to the invention than in a flame front due to the fact that a fresh charge quantity which enters the reaction zone is violently mixed with a much larger amount of gas. hot to develop a very thick premix flame.
• the triggering of combustion in this environment favorable to chemical kinetics originates in a hot spot of the chamber that can result from spontaneous local self-ignition, electric spark or the injection of a liquid fuel mist into the recycled hot gases.
• the combustion chamber is a cavity arranged in the cylinder head of the engine and the piston comprises, at its end facing this cavity, a projection intended to penetrate into the engine. this cavity at the end of compression.
• the combustion chamber is a cavity formed in the end face of the piston and the cylinder head comprises, on its surface facing this cavity, a projection intended to penetrate into the cavity at the end. compression.
• the projection delimits with the orifice of the combustion chamber an annular conduit of reduced section in which the flow of gas pushed by the piston towards the combustion chamber is accelerated.
• the speed of the fresh charge in this duct is greater than the flame propagation velocity in this duct, which prevents a flame back in the cylinder.
• the small radial width of the annular duct can block the propagation of the flame by the phenomenon of jamming ("quenching").
• the engine also includes a spark plug, preferably of the spark type, which emerges in the combustion chamber.
• This spark plug can also be used to create the hot spot that triggers the ignition of the burnt gas mixture volume and fresh charge introduced into the combustion chamber, each cycle of operation of the engine.
• the hot spot can be created by self-ignition by compression in the intermediate volume of flue gases and fresh filler or by the direct injection of a liquid fuel mist into the flue gases.
• the invention also proposes a method of combustion of a homogeneous gaseous mixture in an engine comprising at least one cylinder provided with intake and exhaust ports, a piston displaceable in reciprocating motion in the cylinder, and a combustion chamber. communicating via an orifice with the cylinder, characterized in that it consists of:
• this method consists in controlling the auto-ignition in the combustion chamber via the effective compression ratio by adjusting the crankshaft angle where the valves close the cylinder.
• Self-ignition is also controllable by the mass of burnt gases that are retained in the cylinder, or by the richness of the fresh charge admitted into the cylinder.
• the ignition can also be triggered by an electric spark.
• the invention is particularly applicable to two-stroke cycle engines, in which the retention of a portion of the burned gases in the cylinder is done naturally.
• two-stroke cycle engines provide a low-compression, high-expansion asymmetric cycle by scanning the cylinders during the first portions of the compression strokes.
• intake valves When the engine is equipped with intake valves, one can also play on the opening and closing angles of these valves to control the auto-ignition in the combustion chambers.
• a combustion control method consists of regulating the section of the turbine in open loop according to the engine speed and adjusting the ignition angle by piloting. in a closed loop of the closing angle of the exhaust from the information given by an ignition detector.
• the fuel vapor carried by the fresh feedstock admitted into the cylinder is supplemented by a quantity of liquid fuel sprayed into the burned gas mass after this mass has been forced back into the combustion chamber and before it mixes with the fresh load.
• This direct injection controls the initiation of combustion.
• the engine then comprises a pressurized liquid fuel injector which opens directly into the combustion chamber.
• the liquid fuel injected directly into the combustion chamber may be slightly volatile like diesel fuel while the fuel introduced with the fresh charge must be volatile at the intake temperature.
• the invention is well suited to dual fuel engines that burn natural gas and diesel.
• the liquid fuel is injected into the area of the flue gas mass that is most difficult to reach by the fresh charge.
• the combustion chamber is preferably a cavity coaxial with the cylinder and is formed in the cylinder head, and the piston comprises, on its end opposite this cavity, a projection coaxial with the cylinder and intended to penetrate into the cavity. end of combustion.
• the exhaust port opens at the bottom of the combustion chamber and is closed by a valve coaxial with the cylinder.
• the fuel injector is arranged inside the stem of the exhaust valve and extends coaxially with the cylinder.
• it can be mounted in a bore of the cylinder head which is substantially perpendicular to the axis of the cylinder and which opens into the combustion chamber.
• each cylinder comprises intake ports consisting of a ring of lights located in the cylinder immediately above the piston at its bottom dead point, these lights being inclined relative to in the radial direction.
• This engine also comprises an external recirculation duct for injecting cooled flue gases into the fresh oxidizing charge introduced into the engine.
• This external recirculation duct is equipped with a controlled adjustment valve so that the external recycling mass rate decreases when the engine speed increases. In addition, the closing of the exhaust valve is delayed when the engine speed increases.
• the combustion method according to the invention which has been described above in the case of a homogeneous combustible gas mixture, can be controlled by a direct injection of liquid fuel sprayed into the combustion chamber.
• the engine is then characterized in that the richness of the fresh feed introduced into the cylinder can be modulated, in that the effective compression ratio in the cylinder is set at a value insufficient to cause self-ignition in the fresh feed and sufficient to cause self-ignition into the mass of retained flue gases, and that a liquid fuel is injected and sprayed into that mass of burnt gases retained after it has been forced back into the combustion chamber and before it mixes with the fresh charge, which is gradually pushed back into the mass of retained carbide gases.
• FIGS. 8 and 9 are partial schematic views in section and from below of a cylinder of a four-stroke engine according to the invention.
• FIG. 10 to 17 illustrate a variant of the invention where a fraction of the fuel is injected into the liquid phase in the combustion chamber.
• the engine a cylinder of which is schematically represented in axial section in FIGS. 1 to 7, is a two-cycle cycle engine which is powered by a homogeneous mixture of air and gasoline vapor via intake ports 10 formed in each cylinder 12 in the vicinity of the bottom dead center of the piston 14, these intake ports being connected to means 16 for supplying a homogeneous gas-air mixture.
• the lights 10 are inclined on the radius of the cylinder to impose on the mixture admitted into the cylinder a rotational movement about the axis of the cylinder, this rotational movement plating the mixture on the surface of the cylinder because of its density greater than that burnt gases.
• the upper part of the cylinder 12 is closed by a yoke 18 comprising a combustion chamber 20 which is formed by a cavity of the face of the cylinder head which is opposite the piston 14, this cavity being of revolution and centered on the axis of the piston and communicating with the cylinder through an orifice 21.
• An exhaust channel 22 is formed in the cylinder head and opens into the combustion chamber 20, for example in the axis of the piston 14 as shown in the drawings.
• An exhaust valve 24 controlled by means 26 in axial translation, makes it possible to open and close the outlet of the exhaust channel 22 in the combustion chamber 20.
• a spark plug 28 screwed into the cylinder head opens into the combustion chamber 20.
• a central projection 30 with a surface of revolution about the axis of the cylinder, whose meridian profile is intended to penetrate into the combustion chamber to define with the orifice 21 of this chamber an annular channel whose section is scalable up to at the top dead center of the piston, as shown in FIGS. 5 to 7, to compensate for the slowing down of the piston.
• the profile of this projection is determined so that the speed of the gases in this channel is greater than the flame propagation speed in the same channel or causes the "jamming" of the flame.
• FIG. 1 represents the end of a relaxation phase, in which the piston 14 is in the vicinity of its bottom dead center, in a position which corresponds to 150 ° of crankshaft after the top dead center of the piston, the exhaust 22 being open by the valve 24, the inlet ports 10 being closed by the piston 14 and the cylinder 12 being filled with flue gas.
• the piston 14 is in a position corresponding to a crankshaft angle of 210 ° after the top dead center and in which it closes again the intake ports 10, the exhaust channel 22 being always kept open by the exhaust valve 24. In this position, the scavenging of the gases burned by the fresh charge ends, the emptying of the burned gases continuing under the action of the upward movement of the piston.
• the exhaust valve 24 closes the exhaust channel 22 and retains a mass of burnt gas 34 in the combustion chamber.
• the fresh charge 36 occupies an annular space around the projection 30 of the piston 14 and is separated from the combustion chamber 20 by the mixing volume 38.
• the piston is in a compression position which corresponds to 330 ° crankshaft angle after the top dead center, in which the mixing volume 38 has begun to penetrate into the combustion chamber 20, the fresh load 36 always being outside this room.
• Compression of the mixing volume 38 in the combustion chamber 20 carries it to its self-ignition or spark ignition temperature, after which the fresh charge 36 begins to enter the combustion chamber 20 through the annular section conduit. formed between the projection 30 of the piston and the edge 21 of the orifice of the combustion chamber 20.
• the fresh charge which thus enters the combustion chamber 20 ignites by turbulent mixing with the hot gases present in this chamber. bedroom.
• the piston is in a position which corresponds to 345 ° of crankshaft angle after the top dead center, and the projection of the piston is partially introduced inside the combustion chamber 20, leaving a duct to remain. annular minimum dimension between this projection 30 and the edge 21 of the orifice of the combustion chamber 20.
• the speed of the fresh charge 36 in this annular duct is greater than the speed of propagation of the flame in the same place, this flame propagation velocity being generally less than 15 meters per second.
• the high rate of passage of the fresh charge in this annular conduit prevents the flame from propagating out of the combustion chamber 20 and generates a rotatable annular jet 40 of fresh charge which develops in the combustion chamber 20 along a hyperboloid of revolution centered on the axis of the piston, which has two contact surfaces with the surrounding hot gases, unlike a conventional flame front which has only one.
• the reactive zone of the jet 40 is thus maintained at a temperature sufficient to maintain the combustion.
• the piston 14 is in its top dead center position, where the chamber 20 is not completely closed by the upper face of the piston and where the fresh charge 36 has been completely admitted into the combustion chamber. In this chamber, the combustion becomes homogeneous under the effect of turbulence and the expansion of the gases can then begin.
• Optimum combustion conditions are achieved when compression self-ignition develops in the chamber 20 to the vicinity of the piston protrusion 30 which has already penetrated into the chamber. This requires that the burnt gases 34 occupy in the chamber a volume less than that of this chamber when the projection 30 of the piston reaches the entrance of the chamber. It is also necessary that the effective compression ratio is sufficient to self-ignite the entire fraction of the mixing zone 38 which is present in the chamber 20 just after ignition. Indeed, if the amount of burnt gas 34 is too large, self-ignition may occur early in the cylinder outside the chamber 20 and if this amount of burnt gas 34 is too low, a mass of Fresh charge can accumulate in the chamber 20 between the aforementioned annular conduit and the ignition zone and blow the flame.
• the invention therefore provides for simultaneously controlling the effective compression ratio and the volume of the flue gases 34 present in the combustion chamber.
• the effective compression ratio is controlled by the crankshaft angle controlling the closing of the exhaust channel 22 by the valve 24 and, for a given exhaust closure control angle, the volume of the zone containing the flue gases. depends on the volume of the fresh charge 36, which is itself a function of the rotational speed of the engine, the speed of the fresh charge in the intake ports during the scan and the crank angle corresponding to the scan.
• the volume of fresh charge admitted into the cylinder can be controlled in various ways, for example by the permeability of the intake ports 10 and the permeability of the exhaust ducts (for example by the flow section of a turbine of an associated turbocharger).
• a combustion control method consists of adjusting the turbine section according to the open-loop engine speed, and adjusting the ignition control angle by controlling the ignition angle. Closed loop exhaust closure control from information provided by an ignition detector. It is also possible, to improve the accuracy of the control of the ignition point, to produce a spark in the combustion chamber by means of a spark plug.
• the richness of the fresh charge of air and petrol vapor admitted into the cylinder 12 is limited to a value less than
• combustion chamber 20 is formed by an axial cavity of the upper surface of the piston 14, whereas the projection 30 which penetrates into this cavity at top dead center of the piston is formed on the surface of the cylinder head 18 which is opposite the piston.
• the cylinder head carries two exhaust ducts 22 and two intake ducts 42 opening on the annular face between the projection 30 and the cylinder 12. These ducts are advantageously staggered as shown in FIG. 9.
• the spark plug 28 is here in axial position in the projection 30.
• the filling mechanism consists in closing the exhaust valves 24 before the top dead center of the piston in order to retain the charge of the burned gases of the preceding cycle and to open the valves of inlet 44 after the top dead center of the piston when the cylinder pressure has fallen back to the inlet pressure of the fresh charge.
• this embodiment variant comprises the same means as those shown in Figures 1 to 7 and which have been described in the foregoing.
• the operation of this variant embodiment is substantially identical to that already described but reversed in the sense that the flue gases are under the fresh load, contrary to their arrangement in the engine described above.
• the invention provides, for the cold start of the engine, to feed stoichiometric mixture or rich, and trigger ignition by an electric spark.
• the invention also applies to the case where all the fuel is injected in the liquid phase according to the diesel cycle. This case will be described for a two-stroke engine corresponding to the engine of FIGS. 1 to 7.
• This engine M shown schematically in FIG. 10 is supplied with air by a two-stage turbocharger, comprising a high-pressure turbine T1 supplied with exhaust gas from an exhaust manifold 42 of the engine M, this turbine T1 driving in rotating the rotor of a high pressure compressor C1 whose output is connected, via a heat exchanger 44 for cooling the compressed air, to an intake manifold 46 of the motor M.
• a two-stage turbocharger comprising a high-pressure turbine T1 supplied with exhaust gas from an exhaust manifold 42 of the engine M, this turbine T1 driving in rotating the rotor of a high pressure compressor C1 whose output is connected, via a heat exchanger 44 for cooling the compressed air, to an intake manifold 46 of the motor M.
• the output of the high pressure turbine T1 feeds a low pressure turbine T2 whose output is connected in a conventional manner to an exhaust duct.
• the low-pressure turbine T2 drives the rotor of a low-pressure compressor C2 which is supplied with fresh external air mixed, if necessary, with cooled recycled flue gases and which supplies the high-pressure compressor C1 with compressed gas via a cooling exchanger 50.
• Recycled flue gases externally are taken and cooled downstream of the turbine T2 by means of a controlled adjustable valve 48 and mixed in a chamber 52 with fresh air outside to supply the low pressure compressor C2.
• the externally uncooled recycled gases are taken upstream of the turbine T2 and reinjected downstream of the compressor C2 and upstream of the refrigerant 50 where they are cooled before feeding the high pressure compressor C1.
• each cylinder of the engine M is equipped with an injector 54 for liquid fuel which can be mounted in a bore of the cylinder head 18 opening into the combustion chamber 20 or which can, in a variant, be housed at the inside of the stem of the exhaust valve 24 to extend coaxially with the cylinder, this injector then opening into the combustion chamber 20 through an orifice of the head of the exhaust valve 24.
• injector 54 for liquid fuel can be mounted in a bore of the cylinder head 18 opening into the combustion chamber 20 or which can, in a variant, be housed at the inside of the stem of the exhaust valve 24 to extend coaxially with the cylinder, this injector then opening into the combustion chamber 20 through an orifice of the head of the exhaust valve 24.
• each cylinder retaining a mass of flue gases which remain separated from the fresh feed introduced into the cylinder, as previously described.
• the bottom of the combustion chamber 20 is filled with retained flue gases that have not been mixed with the fresh batch. These gases have a low mass concentration of oxygen whereas the fresh charge has a high mass concentration of oxygen, modulated by the supply of externally recycled burned gases.
• the axisymmetric architecture of the gas working chamber with its axial exhaust orifice has the advantage of discharging to the turbine T1 the hot gases which are located in the axial zone of the cylinder and of retaining the peripheral burned gases cooled by the wall of the cylinder 12 and the combustion chamber 20.
• the cooling of the burnt gases recycled during expansion and compression is less detrimental to the efficiency of the cycle than an external cooling of the type of that achieved in four-stroke engines which in addition to the aforementioned heat losses to the walls.
• the combustion process comprises three successive phases:
• the entire liquid fuel is sprayed as homogeneously as possible into the mass of burnt gases retained after it has been forced back into the combustion chamber and before it is mixed with the fresh charge discharged by the piston 14.
• the fuel injected vaporizes immediately in the turbulent flue gases which have been recompressed and partially cooled by the walls, and consumes all of the residual oxygen to bring this mixture to a temperature below 1600 0 K, temperature below which no particles or oxides of nitrogen are created. In this first rich phase, the local temperature increase is limited by the low mass concentration of residual oxygen.
• the fuel is preferably injected into the zone which is the most difficult to reach by the charge. fresh. Under these conditions, the fresh feedstock must first mix with the non-carburized flue gases before reaching the carburized zone.
• the piston 14 delivers a first portion of the fresh charge in the form of a turbulent jet to the heart of the mass of hot gases which still contains about three quarters of the fuel injected in the form of steam mixed with a mass of burned gas without oxygen.
• the fresh charge jet mixes with the non-carburized flue gases to bring all the residual burnt gases into the reactive zone.
• the turbulent mixing of the fresh charge stream, non-carburized flue gas and hot carbide gases triggers a turbulent diffusion flame.
• the local temperature of the gases being mixed is maximum in the stoichiometric reaction zones where the proportion of fresh air just burns all the fuel vapor carried by the residual flue gases.
• the local mass concentration of oxygen must be limited so that the temperature does not substantially exceed 2 000 0 K. the local temperature remains well below the onset of nitrogen oxides threshold.
• the desired oxygen concentration is obtained by a complementary supply of externally recycled cooled flue gases.
• a third step the rest of the fresh charge which contains the excess combustion air is introduced into the combustion chamber to oxygenate the charge and complete the oxidation of any residual rich areas.
• the temperature of the reaction zone thus increases to 1600 0 K during the first phase and reaches 2000 0 K during the second oxidation phase, then down again to 1800 0 K during the final oxygenation phase.
• FIG. 11 represents the end of an expansion phase, in which the piston 14 is in the vicinity of its bottom dead center, in a position which corresponds to 150 ° of crankshaft after the top dead center of the piston, the exhaust 22 being open by the valve 24, the inlet ports 10 being closed by the piston 14 and the cylinder 12 being filled with flue gas.
• the oxidant mixture 36 'admitted by the lumens 10 pushes the burnt gases 34 towards the exhaust channel 22 and is centrifuged on the inner wall of the cylinder 12 under the effect of the directing the lumens 10, forming an annular bag filled with a fresh charge 36 'and separated from the flue gases 34 by a mixing volume 38 located at the interface between the flue gases 34 and the fresh charge 36' and wherein the flue gases and the fresh charge are mixed.
• the piston 14 is in a position corresponding to a crankshaft angle of 210 ° after the top dead center and in which it again closes the intake ports 10, the exhaust channel 22 being always kept open by the exhaust valve 24. In this position, the flue gas is flushed with the fresh charge, the flue gas is discharged. continuing under the action of the upward movement of the piston.
• the exhaust valve 24 closes the exhaust channel 22 and retains a mass of flue gas 34 in the combustion chamber.
• the fresh charge 36 'occupies an annular space around the projection 30 of the piston 14 and is separated from the combustion chamber 20 by the mixing volume 38.
• the piston is in a compression position which corresponds to 330 ° crankshaft angle after the top dead center, in which the mixing volume 38 has begun to enter the combustion chamber 20, the fresh load 36 'being always outside this chamber and the liquid fuel is sprayed into the flue gases 34.
• the compression of the recycled volume 34 in the combustion chamber 20 carries it to the instantaneous self-ignition temperature of the fuel mist rapidly delivered by the injector 54 into the recycled feed 34 before it mixes with the fresh feed 36 .
• the pulverized fuel ignites instantly to exhaust the residual oxygen of the charge 34 and is a mixture of fuel vapor and oxygen-free flue gases, after which the fresh charge 36 'begins to enter the combustion chamber 20 through the annular conduit of reduced section which is formed between the projection 30 of the piston and the edge 21 of the orifice of the combustion chamber 20.
• the fresh charge which thus enters the combustion chamber 20 by driving the mixing zone 38 continues oxidation of the fuel vapor mixed with the recycled hot gases present in the latter.
• the piston is in a position which corresponds to 345 ° crank angle after the top dead center and the projection 30 of the piston is partially introduced into the combustion chamber 20, leaving an annular duct of minimum size between this projection 30 and the edge 21 of the orifice of the combustion chamber 20.
• the speed of the fresh charge 36 'in this annular duct is sufficient to generate a rotatable annular jet 40 of fresh charge which develops in the combustion chamber 20 along a hyperboloid of revolution centered on the axis of the piston, which has two surfaces of contact with the hot gases surrounding carbides to generate two turbulent diffusion flames that oxidize almost all of the fuel.
• the reactive zone of the jet 40 is thus maintained at a temperature sufficient to maintain the combustion.
• the piston 14 is in its top dead center position, where the chamber 20 is not completely closed off by the upper face of the piston and where the excess air has been completely admitted into the combustion chamber.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combustion Methods Of Internal-Combustion Engines (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

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• 2007
  • 2007-02-12 FR FR0700989A patent/FR2912465B1/fr not_active Expired - Fee Related
• 2008
  • 2008-02-07 EP EP08761850A patent/EP2118464A2/de not_active Withdrawn
  • 2008-02-07 WO PCT/FR2008/000147 patent/WO2008113909A2/fr active Application Filing

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