FR2908472A1 - METHOD FOR SUPPLYING EXHAUST GAS TO AN ENGINE, EXHAUST ELEMENT, EXHAUST LINE AND VEHICLE COMPRISING MEANS FOR SUPPLYING SUCH AN EXHAUST GAS ENGINE - Google Patents

Abstract

The invention relates to a method for supplying gas to a heat engine (2) which a vehicle comprises and which is connected to an exhaust line (1) comprising at least one exhaust element (3) of which one depollution element (5, 5 '), characterized in that it consists in collecting at least a portion of the exhaust gases at and / or downstream of the depollution element (5, 5 ') and in that the engine (2) is supplied with these exhaust gases collected and cleaned up. This invention also relates to an exhaust element (3) comprising means (9) for supplying an engine (2) with exhaust gases defined by means (10) for collecting exhaust gases at a depollution element (5, 5 ') as well as by means (11) for conveying the gases collected to the engine (2) .The invention also relates to an exhaust line (1) and to a thermal engine vehicle (2) comprising means (9) for supplying the engine (2) with exhaust gases.

Description

The present invention relates to a method for supplying gas

  exhaust system of a heat engine that includes a vehicle.  This invention also relates to an exhaust element comprising means for supplying such an engine with exhaust gases, to an exhaust line and to a vehicle comprising such supply means.  This invention relates to the field of the automotive industry and, more particularly, that of equipment for ensuring the escape of gases from the combustion of a fuel within an internal combustion engine.  Such a heat engine requires, for its operation, a supply of fuel and oxidant, more particularly consisting of oxygen.  This oxygen usually comes from the ambient air which is introduced into the engine, especially after being mixed with the fuel.  A particular mode of operation consists, in fact, in compressing the air (diesel engine) or the air-fuel mixture (petrol engine) before it is introduced into the engine, which advantageously makes it possible to increase the power of the engine. this engine.  Such compression is usually provided by means of a turbocharger which comprises, on the one hand, a turbine driven in rotation by the exhaust gases leaving the engine and, on the other hand, a compressor driven by the turbine, and designed to suck either air at atmospheric pressure or an air-fuel mixture, and to compress it before its introduction into the engine.  In this connection, it should be noted that fuel combustion is optimal when oxygen and fuel are present in stoichiometric proportions.  This is not always the case and it is observed, usually (and, in particular for diesel engines), that the engine operates in excess of air, therefore in the presence of oxygen, which, by combustion of the fuel, produces exhaust gases heavily loaded with NOx nitrogen oxides.  These nitrogen oxides NOx are considered as pollutants that should be removed in order to release exhaust gases (without nitrogen oxides) into the atmosphere.  Such elimination is, in fact, provided by means of an exhaust element usually constituted by a catalytic converter that comprises the exhaust line of the vehicle.  In order to further improve a vehicle's pollution performance, one solution consists in immediately reducing the amount of nitrogen oxides produced by the combustion of the fuel within the engine.  This solution consists in ensuring an exhaust gas recirculation (EGR) which consists of collecting a part of the exhaust gases which are, in fact, depleted of oxygen and of redirecting this part of the exhaust gases into the collector. intake to dilute the air-fuel mixture which feeds the engine.  This advantageously makes it possible to reduce the quantity of oxygen available to ensure the combustion of the fuel and, consequently, to produce exhaust gas containing a reduced quantity of nitrogen oxides.  It will be observed that these exhaust gases are usually collected at the outlet of the engine and at an exhaust manifold to be reintroduced into this engine at an intake manifold.  Between these manifolds is interposed EGR valve designed to manage the flow of these recycled exhaust gas, more particularly to allow the passage of exhaust gas for certain engine speeds (especially the intermediate speeds) and cycles.  In fact, these recycled exhaust gases contain nitrogen oxides and soot (especially for a diesel engine) in the form of particles.  These particles are likely to foul the EGR valve or even to cause damage, usually having the consequence of blocking the EGR valve in the open position.  This has the effect of promoting the introduction of exhaust gases into the engine.  The combustion of the fuel then takes place in excess of recycled exhaust gas which leads to a bad combustion of this fuel due to lack of air.  This poor combustion has the effect of increasing the soot, carbon monoxide and hydrocarbons which can lead to degradations in the exhaust line, more particularly to a depollution element that includes the latter and which is, in particular, constituted by an oxidation pot.  Moreover, and in the event of detection of such a problem, in particular by a flowmeter, the means for managing the operation of the motor put it in degraded mode, which results in the transmission of a visual or audible signal to the engine. driver's attention and / or a drop in engine performance.  Another disadvantage is that at the outlet of the collector, the recycled exhaust gases are still particularly hot so that they subject said EGR valve to significant thermal stresses likely to cause damage to the valve.  It will also be observed that the introduction of a hot gas into an engine has the effect of lowering the power and the performance thereof.  In fact, this drop in power is all the more sensitive as the temperature of such a gas is high, which is all the more critical for recycled and hot exhaust gases.  In this connection, it will be observed that this disadvantage is already known in the context of the compression of the ambient air by a turbocharger which has the effect of increasing the temperature of this air.  In order to remedy this, it is known to complete the circuit with an intercooler.  Also and in the context of recirculation of exhaust gas, it would be appropriate to adapt such an intercooler to the temperature of these gases which is substantially higher than that of ambient air which is difficult to achieve, particularly expensive, bulky and energy consuming.  Another solution would be to develop an intercooler 35 specifically adapted to exhaust gas recirculation which, on the one hand, adds an element to the already congested engine compartment and, on the other hand, turns out to be still, difficult, expensive and energy consuming.  The present invention is intended to overcome the disadvantages of devices of the state of the art.  To this end, the invention relates to a method for supplying gas to a heat engine that includes a vehicle and which is connected to an exhaust line comprising at least one exhaust element including a depollution element, characterized by the fact that at least part of the exhaust gas is collected at the level (especially at the outlet) and / or downstream of the depollution element and in that the engine is supplied with these exhaust gases collected and cleaned up.  This process consists in that, before supplying the engine with the exhaust gases collected, cooling of these gases is ensured.  Another characteristic is that, before supplying the engine with the exhaust gases collected, these gases are removed from at least part of the particles they contain, in particular by ensuring their entrapment in a vehicle. particle trap.  In fact, it ensures the flow of gas towards the engine, as the case may be, by acting on a load valve that includes the exhaust line, especially downstream of a point of collection of these gases, and / or under the effect of a depression generated by a turbocharger connected to the collection point.  The invention also relates to an exhaust element for the exhaust line of the gases of a vehicle with a heat engine and comprising means for supplying an engine with exhaust gases, characterized in that the means for supply comprises, on the one hand, a means for collecting exhaust gases at an exhaust element constituted by a depollution element and, secondly, a means for conveying the collected gases to the engine .  One embodiment is that the means for collecting the gases is constituted by a tapping performed at the level of the exhaust element while the conveying means is constituted by a tube.  Another embodiment is that the depollution element takes the form of a housing having, at its outlet, a closure means of this housing constituting at least in part the means for collecting the gases.  In such a case, the closure means may comprise, on the one hand, a means for connecting it to a discharge tube of a part of the exhaust gas and, on the other hand, at least one means for its connection to at least one means for conveying the other part of these gases to the engine.  Yet another embodiment relates to a closure means comprising, on the one hand, a means for connecting it to a discharge tube of a part of the exhaust gas and, on the other hand, at least one opening constituting, at least in part, the means for collecting the other part of the gases.  In addition, the exhaust element has a hood, on the one hand, disposed over the opening or openings and on top of the closure means and, on the other hand, secured to the latter; hood constituting, at least in part, the means for collecting the other part of the gas intended to supply the engine.  In this embodiment, the exhaust element 25 has an envelope, disposed over a portion of the housing of the exhaust element, made integral therewith and delimiting, with this housing part, a duct constituting, at least in part, the means for conveying gases.  According to another embodiment, the exhaust element takes the form of a housing having, internally, two compartments separated by a partition and one of which receives means of depollution while the other constitutes, at least in part, the means for conveying the gases towards the engine.  Yet another embodiment consists in that the exhaust element has, internally, means of pollution control having, longitudinally, at least one channel constituting or receiving a means for conveying gases to the engine. .  Another feature of this exhaust element 5 is that it comprises means for cooling the exhaust gas collected and returned to the engine.  An additional feature is that this exhaust element has means for ridding the collected exhaust gases of at least a portion of the particles they contain.  Finally, the gas conveying means of this exhaust element is, at least in part, a tube whose shape and / or section are defined to adapt such a tube to the environment of the element. exhaust, more particularly to a cocoon defined at the motor vehicle and in which this exhaust element is positioned.  In addition, this invention relates to a gas exhaust line 20 for a heat engine vehicle and having at least one exhaust element as well as means for supplying the engine with exhaust gases, characterized in that the means on the one hand, a means for collecting exhaust gases at and / or downstream of an exhaust element constituted by a depollution element and, on the other hand, a way to route the collected gases to the engine.  A first embodiment is that this exhaust line has means for collecting gases at an exhaust element of the aforementioned type.  This exhaust line may, furthermore, comprise a means for collecting the gases constituted by a tapping performed downstream of the exhaust element while the conveying means are constituted by a tubular conduit or the like.  Finally, the invention relates to a heat engine vehicle, on the one hand, connected to a gas exhaust line having at least one exhaust element and, on the other hand, supplied with exhaust gas by supply means, characterized in that the motor supply means comprise, on the one hand, means for collecting exhaust gases at and / or downstream of an exhaust element constituted by by a depollution element and on the other hand, a means for conveying the collected gases to the engine.  A particular embodiment is that the means for conveying the collected gases is at least partly defined at an element of the environment of the exhaust line, in particular integrated in such an element.  In fact, said environment element is constituted by a protection element, by a covering element, by a vehicle structural element or the like.  The advantages of the present invention consist in that the engine is supplied with exhaust gases which have been previously cleaned by a depollution element, which makes it possible to prevent fouling of the supply means (by exhaust gases). ) of the engine and turbocharger and better fuel combustion which results in a decrease in the amount of particles emitted by the engine that was fed by these recycled exhaust.  Another advantage is that these exhaust gases are cooled before reaching the engine which allows not to penalize the performance of the engine.  The fact of ridding the exhaust gases of particles resulting from the degradation of the depollution element (in particular under the effect of the exhaust gases, their heat, shocks, for example thermal or physical or other) allows, Advantageously, to avoid degradation of the turbocharger or the engine and / or its supply members.  Other objects and advantages of the present invention will become apparent from the following description relating to embodiments which are given only as indicative and non-limiting examples.  The understanding of this description will be facilitated with reference to the appended drawings in which: FIG. 1 is a schematic view of a motor connected to an exhaust line and associated with means for its power supply; exhaust gas; FIG. 2 is a schematic and perspective view of an exhaust element comprising such supply means according to a first embodiment; FIG. 3 is a diagrammatic, partial and perspective view of an exhaust element comprising supply means according to a second embodiment; - Figure 4 is a schematic view in longitudinal section of an exhaust element having supply means according to a third embodiment; FIG. 5 is a schematic view in radial section of the exhaust element illustrated in FIG. 4; FIG. 6 is a schematic and perspective view of an exhaust element comprising supply means according to a fourth embodiment; FIG. 7 is a schematic view in longitudinal section of the exhaust element illustrated in FIG. 6; FIG. 8 is a schematic and perspective view of an exhaust element comprising supply means according to a fifth embodiment; FIG. 9 is a schematic view in longitudinal section of the exhaust element illustrated in FIG. 8; - Figure 10 is a schematic view of an exhaust line having supply means according to a sixth embodiment.  The present invention relates to the field of the automotive industry and, more particularly, that of equipment for ensuring the escape of gases from the combustion of a fuel within an internal combustion engine which comprises a motor vehicle.  FIG. 1 illustrates such exhaust equipment, which is usually in the form of an exhaust line 1 connected to a heat engine 2 and constituted by a plurality of exhaust elements 3. .  In a manner known per se, the exhaust elements 3 that comprises such an exhaust line 1 are, at least in part, constituted by a manifold 4 connected to the engine 2 as well as by at least one depollution element 5, 5 .  In this respect, it will be observed that such a depollution element 5 may be of chemical and / or physical type.  Indeed, such a depollution element 5 can be of chemical type and be designed to remove, at least in part, pollutants by the chemical route.  In known manner, such a chemical-type depollution element 5 may then consist of a catalyst 6, in particular designed to remove at least a portion of the nitrogen oxides (NOx).  However, such a depollution element 5 may, again, be of a physical type and be designed to remove, at least in part, pollutants by the physical route.  In known manner, such a physical type of pollution control element 5 can then be constituted by a particulate filter 7 (FAP), designed to remove at least a portion of the particles contained in the exhaust gases, especially soot produced by the combustion of a diesel fuel.  Finally, such a depollution element 5 may consist of a combined physical and chemical system, especially a particulate filter catalyst (commonly called cata-FAP) or the like.  It will also be observed that such a depollution element 5 'may be constituted by an element 5' designed to ensure a pollution control of the noise pollution generated by the emission and the circulation of the exhaust gases in the exhaust line. 1.  Such a depollution element 5 'can then be constituted by a silencer or the like.  In fact, such an exhaust element 5 'of sound pollution is usually located at the level of the exhaust line 1, downstream of a chemical and chemical depollution element 2908472 10 and / or physical, this in the direction of exhaust gas flow in the exhaust line 1.  An additional feature is that an exhaust line 1 may, again, comprise an exhaust element 3 consisting of a turbocharger 8 interposed between the collector 4 and a depollution exhaust element 5, 5 '.  In known manner, such a turbocharger 8 comprises, on the one hand, a turbine implanted on the exhaust gas circuit from the engine 2 and driven in rotation by the flow of these gases and, on the other hand, a compressor driven by said turbine and designed to compress a gas, or even a mixture gas + fuel, before its introduction into the engine 2.  It will be observed that, in the context of a motor 2 operating on the principle of the recirculation of the exhaust gas (EGR principle) according to the invention, the compressor is, in fact, designed to compress such gases. exhaust, or a mixture of fuel + exhaust gas, this before its introduction into such an engine 2.  To do this, the vehicle equipped with such a motor 2 comprises, again, means 9 designed to ensure the supply of this engine 2 with at least part of the exhaust gas from the combustion of a fuel at within this engine 2.  According to the invention, such feed means 9 comprise, on the one hand, a means 10 for collecting exhaust gases at and / or downstream of an exhaust element 3 constituted by a depollution element 5, 5 ', this in the direction of the circulation of the exhaust gas within the exhaust line 1.  On the other hand, these feed means 9 comprise a means 11 designed to convey the exhaust gas collected to the engine 2, more particularly (and initially) to a turbocharger 8 designed to ensure the compression of these before introduction into this engine 2.  In this connection, it should be noted that the supply of this engine 2 with exhaust gases can, in fact, be provided by means of different systems which are now described in the following. description.  Thus and according to a first system according to the invention, it is, more particularly, the exhaust element 3 which comprises at least a portion of the means 9 for supplying the engine 2 with exhaust gases.  Such supply means 9 then comprise means 10 for collecting exhaust gases at an exhaust element 3 consisting of a depollution element 5, 5 '.  In fact and according to a preferred embodiment of the invention, this collection is preferably provided at the outlet of this exhaust element 3.  FIG. 2 shows a first embodiment of the invention in which the means 10 for collecting the gases is constituted by a stitching 12 made at the level of the exhaust element 3 while the conveying means 11 is, then, constituted by a tube 13 or the like.  It will be observed that this tube 13 has a shape and / or a section defined to adapt such a tube 13 to the environment of the exhaust element 3, more particularly to a cocoon defined at the level of the motor vehicle and in which this exhaust element 3 is positioned.  As regards the quilting 12, this can be constituted by a connection of a tube (in particular the end of the tube 13 constituting the conveying means 11) at the level of at least one opening in said element. 3, preferably in the vicinity of the outlet of this exhaust element 3, this in the direction of the flow of gas within the exhaust line 1.  It will be observed that this or these openings are preferably provided at the wall of a casing 14 containing depollution means 30 and constituting, at least in part, such an exhaust element 3.  In this connection, it should be observed that such an exhaust element 3 is, in the usual way, constituted, at least in part, by such a housing 14 which can then comprise means 15 designed to ensure the closure of this housing 14, this 5 at its output and in the direction of the flow of gas within the housing 14.  According to an additional feature of the invention, it is, more particularly, such a closure means 15 which can then constitute, at least in part, the means 10 for collecting the exhaust gases as visible in the embodiments. illustrated in Figures 3 to 5.  More precisely and as visible in these same figures, the closure means 15 may be designed to close a casing 14 which adopts, at least in part, the shape of a tube, in particular made by a known technique of roll-seaming, even by assembling two half-shells or other.  Also and according to an embodiment illustrated in FIG. 3, such a means 15 of closing comprises, on the one hand, a means 16 for its connection to a discharge tube 17 of a part of the exhaust gases towards the atmosphere (or even to a pollutant pollution abatement element 5 ') and, secondly, at least one means 18 for its connection to at least one conveying means 11 of the other part of these gases to the engine 2 .  Preferably, such a closure means 25 may be in the form of a cover 19 designed to close the housing 14 and at which 19 are defined, on the one hand (and in particular on the top of the cover 19) , said means 16 for connection to a discharge tube 17 and, on the other hand (and in particular at a bottom that this cover comprises 19), at least one lateral protrusion 20 comprising a means 18 for connection to the least one means of transportation 11.  It should be noted that such a closure means 15 in the form of a cover 19 can, according to a particular embodiment, be made by stamping and from at least one sheet metal plate.  Such an embodiment makes it possible to define, on the one hand, said connection means 16 to the discharge tube 17 at the top of the cover 19 and, on the other hand, the connection means or means 18 to a conveying means 11 (more particularly the lateral excrescence (s) 20) at the level of a bottom that this cover 19 comprises.  As mentioned above, such a closure means 15 may be designed so as to receive one or more exhaust gas conveying means 11 which can then preferably be implanted symmetrically with respect to a plane passing through an axis along which the exhaust element 3 extends.  In this regard, it will be observed that such a means 11 for conveying gases can then be in the form of a tube 21 whose shape and / or section (triangular, square, rectangular, trapezoidal, round, oval, polygonal or other) are defined to adapt such a tube 21 to the environment of the exhaust element 3, more particularly to a cocoon defined at the motor vehicle and in which said exhaust element, or the exhaust line 1, are positioned.  According to another characteristic, such a means 11 for conveying gases in the form of a tube 21 has a large exchange surface with the surrounding medium of the exhaust element 3 and the tube 21.  Such an embodiment advantageously allows an important heat exchange between the inside of this tube 21 and the external medium, in particular the ambient air, which advantageously allows the temperature of the exhaust gases to be reduced. to power the engine 2.  FIGS. 4 and 5 show another embodiment of a closure means 15 for a housing 14 which, again, can be produced by a traditional roll-set technique, or even by assembling two half -coquilles or other.  This closure means 15 comprises, on the one hand, a means 16 for connecting it to a tube 17 for evacuating part of the exhaust gas to the atmosphere (or even to a pollution pollution control element 5 ') and, on the other hand, at least an opening 22 constituting, at least in part, the means 10 for collecting the other part of the exhaust gas for supplying the engine 2.  In this connection, it should be noted that this closing means 15 may, again, be constituted by a cover 19 closing the housing 14.  Such a cover 19 may, advantageously, be of traditional design and, already, manufactured to close such a housing 14.  In fact and advantageously, this cover 19 would require only an arrangement consisting in making at least one opening 22 for the passage of the exhaust gas.  As can be seen in FIG. 4, this exhaust element 3 further comprises a hood 23, on the one hand, disposed over the opening or openings 22 and over the closure means 15 and, on the other hand, secured to it 15 (in particular in a sealed manner, for example by welding).  In fact, this cover 23 constitutes, at least in part, the means 10 for collecting the other part of the exhaust gas intended to supply the engine 2.  In such a case, said collection means 10 is then constituted by this hood 23 as well as by the opening or openings 22.  As can be seen in FIGS. 4 and 5, the exhaust element 3 further comprises an envelope 24 arranged (preferably longitudinally) over a portion of the casing 14 of the exhaust element 3.  In fact, the implantation of this envelope 24 is preferably provided so as to respect the environment of the exhaust element 3, in particular above, on the side and / or below this exhaust element 3 .  Such an envelope 24 is made integral with this housing portion 14 (sealingly, particularly by welding) and delimiting, with this housing portion 14, a conduit 25 constituting, at least in part, the means 11 for conveying the exhaust gas to the engine 2.  This envelope 24 may be extended by a tube or connected to such a tube constituting another part of this means 11 of routing.  According to another characteristic, the cover 23 and the casing 24 are interconnected, even (and preferably) defined at the same part as can be seen in FIG. 4, in particular made by stamping a sheet metal plate. .  Such a part 5 can be attached (and made integral, in particular by welding) over the housing 14 of the exhaust element 3 and constitute, so to speak, a double skin.  FIG. 5 shows that said envelope 24 extends over a substantial part of the casing 14 and has a large exchange surface 10 with the surrounding medium of the exhaust element 3.  Such an embodiment advantageously allows an important heat exchange between the interior of the duct 25 and the external medium, in particular the ambient air, which advantageously makes it possible to reduce the temperature of the exhaust gases intended for power the engine 2.  It will be observed that this duct 25 can, in addition, be thermally insulated from the internal volume of the exhaust element 3, in particular by the introduction of thermal insulation means inside this exhaust element. 3, more particularly at (or near) the wall portion 26 shared by the casing 14 of this exhaust element 3 with this duct 25, in particular between this wall portion 26 and the depollution means 30 received by internally, the housing 14.  FIGS. 6 and 7 show an embodiment of an exhaust element 3 adopting the shape of a housing 14 having, internally, two compartments 27, 28 which extend longitudinally in the direction of the flow of gases.  These compartments 27, 28 are preferably adjacent and can be separated by a partition 29 for separating the two compartments 27, 28 in a sealed manner.  One 27 of these compartments receives pollution control means 30 while the other 28 constitutes, at least in part, the means 11 for conveying the gases towards the engine 2.  Again, the compartment 28 constituting the means 11 for conveying the gases has a large exchange surface with the surrounding medium for a significant heat exchange between the interior of this compartment 28 and the external medium 5 which allows to reduce the temperature of the exhaust gases intended to supply the engine 2.  It will be observed that this compartment 28 may, in addition, be thermally insulated from the other compartment 27, in particular by the establishment of a thermal insulation means inside this other compartment 27, more particularly at the (or near) the partition 29 that share these two compartments 27, 28.  As can be seen in FIG. 7, the compartments 27, 28 open at the outlet 31 of the exhaust element 15 3.  Also and in such a case, the means 10 for collecting the exhaust gas is then constituted by the mouth 32 of the compartment 28 which defines, in part, the means 11 for conveying the gases to the engine 2.  It will be observed that this compartment 28 can be extended by a tube or connected to such a tube constituting another part of this means 11 of routing.  Another feature of this embodiment is that the exhaust element 3 is preferably made by assembling two half-shells, one of which defines a first portion of a depollution compartment 27 while the other defines a second portion of this compartment of pollution control 27 and at least a portion (or all) of the compartment 28 of the means 11 for conveying gas.  FIGS. 8 and 9 illustrate another embodiment of an exhaust element 3 comprising, internally, depollution means 30 in the form of a depollution block.  This depollution block has at least one channel 33 extending longitudinally with respect to the exhaust element 3 and in accordance with the flow of the exhaust gases in this exhaust element 3.  Such a channel 33 completely crosses and through this block of pollution control and opens, just as the means of depollution 30, at the outlet 31 of the exhaust element 3.  It should be noted that such a channel 33 can be made, as the case may be, by machining the depollution block after the manufacture of the latter or else by extrusion during the manufacture of such a depollution block.  However, according to a preferred embodiment of the invention, the depollution means 30 consist of an assembly, juxtaposed, of a plurality of depollution modules adopting, in a manner known per se, the shape of bars of depollution whose assembly allows the realization of a bar filter.  In such a case, the channel 33 is, then, constituted by the absence of at least one such depollution module within such an assembly.  In this respect, it will be observed that the absence of such a module can be ensured by removing such a module after manufacturing the pollution control means 30, or even by assembling the modules by omitting at least one such module to define a module. such channel 33.  According to the invention, such a channel 33 may either constitute (at least in part) a means 11 for routing the gas to the engine 2, or receive such a means 11 for routing.  Thus, and according to a preferred embodiment illustrated in FIGS. 8 and 9, when this channel 33 constitutes, at least in part, a means 11 for routing the gases, the latter 33 opens, like the depollution means 30, at the of the outlet 31 of the exhaust element 3.  In such a case, the means 10 for collecting the gases is constituted by the mouth 32 of this channel 33 at the outlet 31 of this exhaust element 3.  It will be observed that this channel 33 is then connected (in a sealed manner), at its end opposite to that of the mouth, to a tube 34 (passing through the wall of the exhaust element 3). for conveying the gases to the engine 2 and constituting, at least in part, conveying means 11.  However, according to another embodiment not shown, this channel 33 receives a routing means 11 constituted by a tube or the like extending at least inside said channel 33.  Such a tube opens, just like the means of depollution 30, at the outlet 31 of the exhaust element 3.  In such a case, the means 10 for collecting the gases is constituted by the mouth of this tube at the outlet 31 of this exhaust element 3.  In this regard, it will be observed that this tube is secured, in a sealed manner, the depollution means 30, more particularly at this mouth.  This advantageously makes it possible to avoid any rise of the exhaust gases through the depollution means 30 and through the channel 33, this outside the tube.  As can be seen in FIGS. 8 and 9, the tube 34 (constituting the gas conveying means 11) passes through the wall of the exhaust element 3, at or near the end of the depollution means. opposite to that of their outlet outlet 31 exhaust element 3, and to join the engine 2.  In such a case, said tube 34 may have, apart from the exhaust element 3, a large exchange surface with the surrounding medium for a significant heat exchange between the inside of this tube 34 and the medium. outside which reduces the temperature of the exhaust gas for supplying the engine 2.  According to another characteristic of the exhaust element 3 according to the invention (and as described, in part, above), this exhaust element 3 comprises means 35 for cooling the exhaust gases. collected and returned to the engine 2.  As described above, such cooling means may be that the conveying means has a large heat exchange surface with the surrounding medium, especially with the atmospheric medium.  Another embodiment not shown may consist in that these cooling means 35 consist of a heat exchanger associated with the means 11 for routing the exhaust gases.  Such a heat exchanger may then be in the form of a conduit inside which circulates a heat-transfer fluid (in particular water) and which is associated with a radiator that the vehicle comprises.  According to another characteristic of the invention, these cooling means 35 may, furthermore, comprise means for thermally insulating the means 11 for conveying the gases and the depollution means 30 that the exhaust element 3 comprises.  Such embodiments have been described above and make it possible to substantially improve the cooling of these exhaust gases.  It should be noted that the exhaust gases from the engine 2 pass through at least one exhaust element 3 consisting of at least one depollution element 5, 5 '.  This depollution element 5, 5 'has, internally, depollution means 30 which, under the effect of the temperature of these gases, of shocks and / or aging, are capable of producing particles which can take the form of ceramic tips, fibers, pieces of cloth or other.  These particles constitute a danger for the compressor of the turbocharger 8 but also for the engine 2 and its environment to the extent that they are likely to cause them damage.  In order to remedy this drawback, the exhaust element 3 according to the invention may, again, comprise means 36 for ridding the exhaust gases collected of at least a portion of the particles they contain.  As can be seen in the figures of the appended drawings, such means 36 are preferably constituted by at least one particle trap defined, as the case may be, at the level of the means 10 for collecting these gases (FIGS. 4) or the means 11 for conveying gases (FIG. 7).  As evoked above and as visible in the appended figures, such a conveying means 11 may be constituted, at least in part, by a tube (13, 21, 34) whose shape and / or section (Triangular, square, rectangular, trapezoidal, round, oval, polygonal or other) are defined to adapt such a tube (13, 21, 34) to the environment of the exhaust element 3, more particularly to a cocoon defined at the level of the motor vehicle and in which said exhaust element, or even the exhaust line 1, are positioned.  Finally and as evoked above, the exhaust gas is collected at an exhaust element 3 consisting of a depollution element 5, 5 '.  Also and according to a preferred embodiment of the invention, the exhaust element 3 at which the collection of at least a portion of the exhaust gases is carried out is constituted by a chemical depollution element 5 and / or physical of the aforementioned type (for example a catalyst 6, a particulate filter 7, or even a combined catalyst 25 and particulate filter device).  However, according to one

  Another embodiment not shown, the exhaust element 3 at which the collection of at least a portion of the exhaust gas is carried out is constituted by a sound depollution element 5 'mentioned above (for example a quiet). Such a sound depollution element 5 'is usually located within the exhaust line 1 downstream of a chemical and / or physical depollution element 5 of the aforementioned type, in the direction of the flow of the gases. in the exhaust line 1.

The present invention also relates to an exhaust line 1 which, according to a second system according to the invention, comprises means 9 for supplying the engine 2 with exhaust gases. According to the invention, these motor supply means 9 comprise, on the one hand, a means 10 for collecting exhaust gases at (and preferably at the outlet 31) and / or downstream of a an exhaust element 3 constituted by a depollution element 5, 5 'and, on the other hand, a means 11 for conveying the collected gases to the engine 2. In this connection, it should be noted that, according to a first 10 embodiment, the means 10 for collecting exhaust gases is defined at the level (in particular at the outlet 31) of an exhaust element 3 which has characteristics in accordance with the exhaust elements 3 which have been the subject of the above description (first system).

However, according to a second type of embodiment illustrated in FIG. 10, the means 10 for collecting the gases may consist of a tapping 37 made downstream of the exhaust element 3, this in the direction of the flow of gases in the exhaust line 1. Such a stitching 37 is, more particularly, made at an exhaust tube 38 extending from this exhaust element 3 and at the outlet of the latter 3, this for evacuate the exhaust gases to the atmosphere. In fact, such stitching 37 is provided through the connection, at at least one opening in the evacuation tube 38, of a tubular conduit 39 or the like constituting, at least in part, the means 11 An additional feature of the invention is that the conveying means 11 is at least partly as a tube (13, 21, 34) or as such a tubular duct 39 whose shape and / or section (triangular, square, rectangular, trapezoidal, round, oval, polygonal or other) are defined to be adapted to the environment of the exhaust line 1, more particularly at a defined cocoon 2908472 22 at the level of the motor vehicle and within which the exhaust line 1 is positioned. An additional feature of this exhaust line 1 is that it comprises, downstream of the exhaust element 3 (more particularly at the exhaust tube 17; 38 extending from this element 3 and outlet of the exhaust 3), a load valve 40 for regulating the flow and / or the pressure of the exhaust gas in the conveying means 11 thereof (FIG. 1) . In fact, such a load valve 40 is constituted by a counter-pressure valve, preferably of ball-type or the like. In this regard, it should be noted that this load valve 40 is designed to be driven by control means (not shown) that comprises the motor vehicle. In fact, such control is preferably ensured so that the exhaust gases are conveyed to the engine 2 when it is in low load or partial load 20 while, under full load of the engine 2, these gases are preferably discharged into the atmosphere. Yet another feature is that this exhaust line 1 comprises a turbocharger 8 having a turbine designed, on the one hand, to be driven by the exhaust gas leaving the engine 2 and, on the other hand, to The present invention relates, again, to a vehicle with a combustion engine 2, on the one hand, connected to an exhaust line 1 of the gases comprising at least one element 30 of the engine. exhaust 3 and, on the other hand, supplied with exhaust gas by supply means 9 according to a third system according to the invention. According to the invention, these means 9 for supplying the engine 2 comprise, again, on the one hand, means 10 for collecting exhaust gases at (and preferably at the outlet) and / or downstream an exhaust element 3 constituted by a pollution control element 5, 5 'and, on the other hand, a means 11 for conveying the collected gases to the engine 2. According to a first embodiment of this vehicle, the exhaust element 3 which this vehicle comprises is in accordance with the first system described above, more particularly with regard to the collecting means 10 and the conveying means 11. According to a second embodiment of this vehicle , the exhaust line 1 which this vehicle comprises is in accordance with the second system described above, more particularly as regards, again, the collecting means 10 and the conveying means 11. However and according to another type of embodiment, the means 11 for conveying the g The collected az is at least partly defined at an element of the environment of the exhaust line 1. A preferred embodiment of the invention is that such a conveyance means is embedded in such an environment element. In this regard, it will be observed that such an environment element 20 may then be constituted by a protection element (in particular against heat, for example a heat shield), by a covering element (in particular an element sill trim), by a structural member (including a rocker panel member, body member, frame member or the like) of the vehicle or the like. Such an embodiment advantageously makes it possible to integrate the gas routing function into an existing environment element, in particular by modifying it. In fact, such a modification may simply consist in producing a volume at such an element, especially by producing a double skin. The present invention also relates to a method for supplying gas to a heat engine 2 that a vehicle comprises and which is connected to an exhaust line 1 having at least one exhaust element 3, one of which depollution 5, 5 '.

This method is more particularly (but not exclusively) capable of being implemented by at least one of the three systems described above. In fact, this process consists in collecting at least a portion of the exhaust gases at the level (in particular at the outlet 31) and / or downstream of the depollution element 5, 5 'and in that that the engine 2 is fed with these exhaust gases collected and cleaned up. In this regard, it will be observed that these exhaust gases, 10 when they circulate in the supply means 9 of the engine 2 to supply the latter 2 with clean-up gases, circulate, in fact, in the direction opposite to that of the gases directly from the engine 2 and arriving in said depollution element 5, 5 '.

This method consists, again, in that before supplying the engine 2 with the exhaust gases collected, it ensures the cooling of these gases. In fact, the collected gases are cooled by circulating between the collection point (collection means 10) of these gases and the engine 2 in a duct (tube 13, 21, 34, duct 25, duct tubular 39) having a large heat exchange surface with the surrounding medium, including the atmospheric medium. Another embodiment consists in the cooling of the collected gases by ensuring their circulation, between the collection point (collection means 10) of these gases and the engine 2, in a conduit which comprises a heat exchanger. heat or associated with such a heat exchanger. According to an additional characteristic of this process, before supplying the engine 2 with the exhaust gases collected, these gases are freed of at least part of the particles they contain, in particular by ensuring their entrapment in In fact, such particles come, in particular, from the degradation of the exhaust element 3, in particular by the exhaust gases, and may consist of ceramic tips, fiber, tablecloth or other. Another characteristic consists in ensuring that the flow of gases towards the engine 2 is effected by acting on a load valve 40 that comprises the exhaust line 1, in particular downstream of a collection point (collecting means 10) of these gases. Another embodiment is to ensure such a flow of gas to the engine 2 under the effect of a depression generated by the turbocharger 8 connected to the collection point (collection means 10) of these gases. A particular embodiment is that the circulation of the exhaust gas to the engine 2 is ensured under the effect of such a depression generated by the turbocharger 8 as well as under the effect of an action exerted on said load valve 40. As mentioned above, the method consists in collecting exhaust gases at (especially, and preferably at the outlet) and / or downstream of an exhaust element 3 constituted by 20 by a depollution element 5, 5 '. In fact and according to a first embodiment, this depollution element 5 is of chemical and / or physical type, and may consist, in particular, of catalyst 6 and / or particulate filter 7 or the like.

A second embodiment consists in that this depollution element 5 'is of sound type consisting, in particular, of a silencer or the like. In fact, such a sound depollution element 5 'can be located downstream of a chemical and / or physical depollution element, in the direction of the flow of gases in the exhaust line 1.

Claims (45)

  A method for supplying gas to a heat engine (2) which comprises a vehicle and which is connected to an exhaust line (1) having at least one exhaust element (3) including a depollution element (5, 5 '), characterized in that at least part of the exhaust gas is collected at and / or downstream of the depollution element (5, 5') and in that the engine (2) is fed with these exhaust gases collected and cleaned up.   2. Method for supplying a gas engine (2) according to claim 1, characterized in that before supplying the engine (2) with the exhaust gas collected, it is ensured that the cooling of these gases.   3. Method for supplying a gas engine (2) according to claim 2, characterized in that it ensures the cooling of the collected gases by ensuring their circulation, between the collection point (10) of these gas and the motor (2), in a conduit (13, 21, 25, 34, 39) having a large heat exchange surface with the surrounding medium, including the atmospheric medium.   4. A method for feeding a gas engine (2) according to claim 2, characterized in that it ensures the cooling of the collected gas by ensuring their circulation, between the collection point (10) of these gas and the engine (2), in a conduit that includes a heat exchanger or associated with such a heat exchanger.   5. Method for supplying a gas engine (2) according to any one of the preceding claims, characterized in that before supplying the engine (2) with the exhaust gas collected, it removes these gases from at least a portion of the particles they contain, including by ensuring their entrapment in a particle trap (36).   6. Process for supplying a gas engine (2) according to any one of the preceding claims, characterized in that the flow of gases towards the engine (2) is ensured, as the case may be. , by acting on a load valve (40) that includes the exhaust line (1), in particular downstream of a collection point (10) of these gases, and / or under the effect of a depression generated by a turbocharger (8) which comprises the exhaust line (1) and which is connected to the collection point (10).   7. Process for supplying a gas engine (2) according to any one of the preceding claims, characterized in that exhaust gases are collected at the level and / or downstream of the engine. a chemical and / or physical depollution element (5), in particular consisting of a catalyst (6) and / or a particulate filter (7) or the like.   8. Process for supplying a gas engine (2) according to any one of Claims 1 to 6, characterized in that exhaust gases are collected at the level and / or downstream. a sound depollution element (5 '), in particular constituted by a silencer or the like.   9. Exhaust element (3) for the exhaust line (1) of the gases of a heat engine vehicle (2) and comprising means (9) for supplying an engine (2) with exhaust gases. , characterized in that the supply means (9) comprise, on the one hand, means (10) for collecting exhaust gases at an exhaust element (3) consisting of an element of depollution (5, 5 ') and, on the other hand, means (11) for conveying the collected gases to the engine (2).   10. Exhaust element (3) according to claim 9, characterized in that the means (10) for collecting the gases is constituted by a stitching (12) formed at the exhaust element (3) while that the conveying means (11) is constituted by a tube (13). 2908472 28   11. Exhaust element (3) according to claim 9, characterized in that the depollution element (5) takes the form of a housing (14) having, at its outlet (31), a means (15) closing this housing (14) at least partially constituting the means (10) for collecting the gases.   12. Exhaust element (3) according to claim 11, characterized in that the closure means (15) comprises, on the one hand, a means (16) for its connection to a discharge tube (17). a part of the exhaust gas and, on the other hand, at least one means (18) for its connection to at least one conveying means (11) of the other part of these gases to the engine ( 2).   13. Exhaust element (3) according to claim 12, characterized in that the means (15) for closure is in the form of a cover (19) designed to close the housing (14) and at the which are defined, on the one hand, the connecting means (16) to a discharge tube (17) and, on the other hand, at least one lateral projection (20) comprising means (18) for connection to the least one conveying means (11).   14. Exhaust element (3) according to claim 11, characterized in that the means (15) for closing comprises, on the one hand, means (16) for its connection to a discharge tube (17). a part of the exhaust gas and, on the other hand, at least one opening (22) constituting, at least in part, the means of collection (10) of the other part of the gases.   15. Exhaust element (3) according to claim 14, characterized in that the exhaust element (3) comprises a cover (23), on the one hand, disposed over the opening or openings ( 22) and over the closure means (15) and, secondly, secured to it (15), this cover (23) constituting, at least in part, the means (10) for collecting the other part of the gases intended to supply the engine (2).   16. Exhaust element (3) according to any one of claims 14 or 15, characterized in that the exhaust element (3) comprises an envelope (24) arranged by a part of the casing (14) of the exhaust element (3), secured thereto and delimiting, with this housing portion (14), a duct (25) constituting, at least in part, the means (11) ) gas routing. 5   17. Exhaust element (3) according to claims 15 and 16, characterized in that the cover (23) and the casing (24) are connected or defined at one and the same part, in particular in stamped sheet metal. .   18. Exhaust element (3) according to claim 9, characterized in that the exhaust element (3) takes the form of a housing (14) having, internally, two compartments (27, 28). separated by a partition (29) and one of which (27) receives means (30) of pollution control while the other (28) constitutes, at least in part, the means (11) for routing 15 direction of the engine (2).   19. Exhaust element (3) according to claim 18, characterized in that the means (10) for collecting the gases is constituted by the mouth (32) of the compartment (28) which defines the means (11) of the delivery of gases and which, like the compartment (27) for receiving the means (30) for pollution control, opens at the outlet (31) of the exhaust element (3).   20. Exhaust element (3) according to any one of claims 18 or 19, characterized in that the exhaust element (3) is made by assembling two half-shells one of which defines a first part of a compartment (27) depollution while the other defines a second portion of the compartment (27) of pollution and at least a portion of the compartment (38) of the means (11) for routing the gas.   21. Exhaust element (3) according to claim 9, characterized in that the exhaust element (3) has, internally, means (30) of depollution having, longitudinally, at least one channel ( 33) constituting or receiving a means (11) for conveying gases to the engine (2). 2908472 30   22. Exhaust element (3) according to claim 21, characterized in that the means (11) for conveying gas is constituted by a tube extending inside a channel (33). 5   23. Exhaust element (3) according to any one of claims 21 or 22, characterized in that the means (10) for collecting the gases is constituted by the mouth (32) of the channel (33) or the tube which constitutes the means (11) for routing the gas and which, like the means (30) for decontamination, opens at the outlet (31) of the exhaust element (3).   24. Exhaust element (3) according to any one of claims 21 to 23, characterized in that the means (30) of depollution are in the form of a depollution block provided with a channel ( 33) produced by machining or extrusion.   25. Exhaust element (3) according to any one of claims 21 to 23, characterized in that the means (30) depollution are constituted by an assembly, juxtaposed manner, of a plurality of modules of depollution while the channel (33) is constituted by the absence of at least one such module within such an assembly.   26. Exhaust element (3) according to any one of claims 9 to 25, characterized in that it comprises means (35) for cooling the exhaust gas collected and returned to the engine ( 2).   27. Exhaust element (3) according to claim 26, characterized in that the means (35) for cooling comprise means for thermally isolating the means (11) for routing the gases and means (30) for depollution that comprises the exhaust element (3).   28. Exhaust element (3) according to any one of claims 26 or 27, characterized in that the means (35) for cooling consist in that the conveyor means (11) has a large surface area. thermal exchange with the surrounding environment, especially the atmospheric environment. 2908472 31   29. Exhaust element (3) according to any one of claims 26 or 27, characterized in that the means (35) for cooling are constituted by a heat exchanger associated with the means (11) for conveying the gases . 5   30. Exhaust element (3) according to any one of claims 9 to 29, characterized in that the means (11) for conveying gases is at least partly like a tube (13, 21 , 34) whose shape and / or section are defined to fit such a tube (13, 21, 34) to the environment of the exhaust element (3), more particularly to a cocoon defined at the level of the motor vehicle and in which this exhaust element (3) is positioned.   31. Exhaust element (3) according to any one of claims 9 to 30, characterized in that it comprises means (36) for ridding the exhaust gases collected of at least a portion of the particles they contain.   32. Exhaust element (3) according to claim 31, characterized in that the means (36) for ridding the particles are constituted by at least one particle trap 20 defined, as the case may be, at the level of the means (10). ) for collecting these gases or the means (11) for conveying gases.   33. Exhaust element (3) according to any one of claims 9 to 32, characterized in that the depollution element is constituted by a chemical and / or physical depollution element (5), such as a catalyst (6), a particulate filter (7), or even a combined catalyst and particulate filter device.   34. Exhaust element (3) according to any one of claims 9 to 32, characterized in that the depollution element is constituted by a sound pollution control element (5 '), such as a silencer.   35. Exhaust line (1) of the gases for a motor vehicle (2) and comprising at least one exhaust element (3) as well as means (9) for supplying the engine (2) with gases of exhaust system, characterized in that the supply means (9) of the engine (2) comprise, on the one hand, means (10) for collecting exhaust gases at and / or downstream from the engine. an exhaust element (3) consisting of a depollution element (5, 5 ') and, on the other hand, means (11) for conveying the collected gases to the engine (2). 5   36. Exhaust line (1) according to claim 35, characterized in that it comprises means (10) for collecting gases at an exhaust element (3) according to any one of the claims 9 to 34.   37. Exhaust line (1) according to claim 35, characterized in that the means (10) for collecting the gases is constituted by a stitching (37) made downstream of the exhaust element (3). while the means (11) for conveying are constituted by a tubular conduit (39) or the like. 15   38. Exhaust line (1) according to any one of claims 35 to 37, characterized in that the means (11) for routing is at least partly as a tube (13, 21, 34 ) or a duct (39) whose shape and / or section are defined to be adapted to the environment of the exhaust line (1), more particularly to a cocoon defined at the level of the motor vehicle and in which the exhaust line (1) is positioned.   39. Exhaust line (1) according to any one of claims 35 to 38, characterized in that it comprises, downstream of the exhaust element (3), a load valve (40) for regulating the flow and / or the pressure of the exhaust gases in the means (11) for conveying them.   40. Exhaust line (1) according to any one of claims 35 to 39, characterized in that it comprises a turbocharger (8) having a turbine designed, on the one hand, to be driven by the gases exhaust outlet of the engine (2) and, secondly, to suck the exhaust gas collected and to route to the engine (2).   41. A vehicle with a combustion engine (2), on the one hand, connected to an exhaust line (1) of gases having at least one exhaust element (3) and, on the other hand, supplied with gas 2908472 33 exhaust system by means of supply (9), characterized in that the supply means (9) of the engine (2) comprise, on the one hand, means (10) for collecting exhaust gases. at and / or downstream of an exhaust element 5 (3) constituted by a depollution element (5, 5 ') and, on the other hand, a means (11) for conveying the collected gases to the engine (2).   42. A motor vehicle (2) according to claim 41, characterized in that the exhaust element (3) is according to any one of claims 9 to 34.   43. A motor vehicle (2) according to claim 41, characterized in that the exhaust line (1) is in accordance with any one of claims 35 to 40.   44. A heat engine vehicle (2) according to claim 41 for conveying vehicles at an exhaust (1),   45. Vehicle claim 44, environmentcharacterized in that the means (11) gas collected is at least partly defined element of the environment of the line including integrated in such an element. with a heat engine (2) according to the characterized in that the element constituted by a protective element, by is a covering element, a structural element of the vehicle 25 or the like.