FR2978203A1 - Burner for e.g. generating flame for heating exhaust fumes filtration element of diesel engine for car for urban transportation applications, has injecting unit independently injecting fuel and combustion agent into precombustion chamber - Google Patents

Abstract

The burner has a precombustion chamber (1) perpendicularly opened into a burner body (9), which is provided with a main injector (10) and a diffuser (11). An injecting unit comprising a pulse pump and a solenoid valve independently injects fuel i.e. diesel, and combustion agent into the precombustion chamber and the main injector against a flow direction of the exhaust fumes. A spark plug (3) is provided in the precombustion chamber for ignition of a mixture of the fuel and the combustion agent in the precombustion chamber. An independent claim is also included for an exhaust line of an internal combustion engine.

Description

BACKGROUND OF THE INVENTION The present invention relates generally to a burner intended to ensure the combustion of particulate filters of the internal combustion engine and the temperature rise of the systems in an exhaust line incorporating such a burner. the regeneration of particulate filters present in internal combustion engines, and more particularly diesel engines, characterized by a pre-chamber in bypass of the main flow of the exhaust gas associated with a main injection of the fuel air mixture in the flow against the current and at the mixing point between the main flow of the engine exhaust and the outlet of this prechamber. The objective is to obtain a good ignition and good combustion of the injected main air / fuel mixture while benefiting from the flame and the high temperature of the combustion gases generated by this prechamber and thus to ensure a good propagation of this flame in the flow of engine exhaust gas despite the variable oxygen content of the latter. Advantageously, the injection of this main air / fuel mixture will be made in the output stream of the combustion gases of this prechamber, with its jet directed in the opposite direction of the flow direction of the engine exhaust gases so as to benefit from a maximum dispersion and temperature effect.

This burner is arranged upstream of a particle filter type assembly with the objective of carrying the filter media integrated in said filter at a temperature sufficient to burn the solid particles, such as soot, retained on this filter, whenever necessary.

This same process can also be used to reach the operating temperature of the catalysts more quickly on motor engines, with the aim of obtaining optimum conversion efficiency.

In both cases the objective is to bring the particle filter or the catalyst to its operating temperature by means of this burner, which can be placed directly in the vicinity of the filter or the catalyst, for all the engine operating conditions, without being forced to wear a whole set at this temperature. This arrangement allows rapid warm-up for low fuel consumption.

PRIOR STATE OF THE ART The public authorities have introduced increasingly stringent standards to impose on car manufacturers the development of engines producing less and less polluting emissions. Manufacturers are therefore striving to develop heat engines, especially diesel engines and lean-burn engines, with as little as possible of unburned particles.

To this end, in addition to the development of new engines with ever lower fuel consumption, special efforts have been made to develop new exhaust systems designed to reduce emissions of unburned gaseous pollutants and solid particles.

For example, automobile manufacturers have developed catalytic converters, usually made of a stainless steel casing, a thermal insulator and a honeycomb support impregnated with precious metals, such as platinum (Pt). or rhodium (Rh). Such catalysts can reduce emissions of polycyclic hydrocarbons and carbon monoxide (CO), and this, in a proportion of the order of 90%.

However, they have no effect on solid particle emissions. Thus, such catalysts do not provide significant improvement in emissions of diesel engines producing many solid particles.

However, the change in engine combustion is no longer sufficient to meet the discharge guidelines. That is why the implementation of exhaust gas filtration methods and devices with regeneration of the filters by combustion is now unavoidable. Such a filtration makes it possible to reduce by more than 90% the total mass of particles emitted by diesel engines.

In known manner, the solid particles are generally trapped by a ceramic filtration cartridge, making up a particulate filter. To work well, a particulate filter requires regeneration to burn the carbon particles trapped in its filtering parts, mainly in the filter cartridge, intervening at regular intervals. The main difficulty concerns starting the combustion of these retained carbon particles, the temperature of the exhaust gas of these diesel engines being well below the temperature of 550 ° 1600 ° C required for this combustion to take place.

Many processes have been implemented to ensure the combustion of these particles associating the catalytic effects of additive, or the production of NO2 from the nitrogen oxides present in the exhaust gas, or even by the implementation of in place of a diesel injection device on an oxidation catalyst arranged upstream of the particulate filter.

However, the major difficulty in ensuring the operation of such particulate filters lies in the possibility or not to achieve the oxidation and combustion phases of the solid particles retained by the filter cartridge. Indeed, on an urban route, the exhaust gas hardly reach a temperature sufficient to ensure the regular and / or complete combustion of the solid particles and thus regenerate the filter significantly limiting its clogging. Even processes using post-injection devices no longer provide in these severe conditions a satisfactory service.

In addition, the known post-injection methods work satisfactorily only if a minimum exhaust gas temperature of about 300 ° C is reached for at least 5% of the operating time. Consequently, the devices and processes implementing the post-injection of diesel into the exhaust gas upstream of an oxidation catalyst become insufficient when the temperature is too low.

Another disadvantage of these systems is the spurious and polluting emissions of hydrocarbons generated during the injection phase, when the temperatures are too low, for example around 300 ° C.

To achieve the combustion of solid particles retained on the filter, the prior art also proposes to have a burner at the filter inlet and turn it on when the engine of the vehicle is stopped. However, this involves many disadvantages, among which one can cite the difficulty of controlling or even simply initiating combustion in the burner, the difficulty of thermally isolating the filter, the significant increase in the temperature of the burner during the combustion phase (beyond 1400 ° C) and the requirement of having a large filtration capacity to be able to provide a sufficiently long service, that is to say between two engine stops.

More recently burners have been proposed to completely overcome the operating conditions at low temperatures. However, none of them currently allows satisfactory operation for all operating conditions. In addition, these burners have some unacceptable defects, such as excessive size with often in this case an overconsumption of diesel fuel, the difficulty of operating satisfactorily when the engine is at full speed, the stability of the flame or a contribution in insufficient calories.

In addition, such burners have real difficulties to operate satisfactorily during normal operation of the engine, because of the difficulty of igniting the burner, the strong turbulence associated with pulsed regimes prevailing in the exhaust line and therefore in the burner rendering the combustion particularly unstable. Sophisticated and therefore expensive devices, presence of flame must be incorporated to avoid the parasitic hydrocarbon emissions that would follow in case of extinction of it.

The object of the present invention is to provide a method and a device for burning solid particles from the internal combustion of a heat engine solving the disadvantages of the devices of the prior art.

The object of the invention is to obtain the increase of the temperature necessary for the complete combustion of the solid particles or soot deposited on the filter cartridge, while reducing as much as possible the portion of the calories that will be absorbed upstream of the filter. particles by allowing a reduction in the volume of the materials used, such as the envelope and the volume of the catalyst.

Another object of the invention is to provide a method and a device for burning solid particles, avoiding any risk of accumulation of particles in the filter cartridge (clogging), and therefore any risk of inadvertent regeneration, whatever the engine operating conditions, in particular for urban transport applications. Furthermore, the invention may advantageously be associated with the known means already used alone or in combination with other devices to begin to oxidize the soot contained in the exhaust gas from the lowest temperatures (100 ° C) and ensure complete combustion, whatever the operating conditions. The use of an additive in the fuel, or the deposition of catalyst on the filter media can further reduce the heating duration and intensity, and thus further reduce overconsumption.

Another object of the invention is to provide a reduced-size burner which can be easily integrated on the particulate filter / exhaust line assembly of a motor vehicle to ensure the quantitative reduction or the elimination of the soot contained in the engine exhaust gases without additional emissions of unburnt.

Furthermore, the purpose of the invention is to achieve a quantitative reduction, or even elimination, of the particles contained in the exhaust gases of an internal combustion engine, without having to use a very specific oxidation catalyst, such as for post-injection, which allows the use of low precious metals concentration catalyst since only remains the oxidation function of hydrocarbons and residual carbon oxides to ensure.

Another object of the invention is to provide a solution for the quantitative reduction, or even elimination of soot contained in the exhaust gas of an internal combustion engine, which is relatively inexpensive, reliable and flexible, and which delays the clogging of the engine as much as possible. filter, or eliminating it, regardless of the engine load, without being affected by the possible presence of sulfur compounds, such as sulfur dioxide in the exhaust gas. The object of the invention thus makes it possible to use gas oils with a high sulfur content.

Finally, this reduced-size burner can also be advantageously used in combination with all the new catalytic processes used to meet the emissions imposed by the new standards, such as Euro 6.

SUMMARY OF THE INVENTION

The object of the invention therefore relates to a burner for heating at least one filter cartridge of the exhaust gas of an internal combustion engine at a temperature above the oxidation temperature and / or at the temperature of combustion of the solid particles trapped in said filter cartridge, or to temperature a catalytic system, that is to say a treatment member of said exhaust gas. This burner is fed with a mixture of fuel and oxidant, intended to generate a flame and corollary heat for heating said filter cartridge or said catalytic system. It comprises an antechamber disposed in branch of the exhaust line and opening perpendicular to the burner tube and preferably in a diffuser disposed in its central axis. The main air / fuel injector being disposed in the center of the same diffuser so as to preferentially inject this mixture in the opposite direction to the circulation of the engine exhaust gas and cause the venturi effect to generate a good homogenization of the fuel. together, exhaust gas, combustion gas from the antechamber with the main air / fuel mixture.

It further comprises: An electric ignition means disposed in the prechamber. A fuel metering pump associated with means for independently injecting air (oxidant) in a pulsating manner onto the ignition resistor disposed in the body of this prechamber. A complementary exhaust gas inlet in the body of this cylindrical prechamber opening tangentially preferably. This prechamber being directly connected to the body of the burner and to a diffuser disposed at its center and having the same axis as this burner, which it is arranged in the exhaust duct on the same axis. A main injector disposed in the center of the diffuser and oriented to inject against current, supplied with fuel by a suitable pump and air to have a flow rate sufficient to generate velocity and create a venturi effect and obtain a good combustion quality. . A calculator for controlling and controlling the process, from the "engine" data and the temperature of the exhaust gas measured at the inlet of the filter cartridge by a probe.

This calculator controls the injection rates into fuel (gas oil) and oxidant (air) as a function of the signals delivered by temperature sensors. This calculator also ensures the management of the resistance of the electrical ignition means, both during the preheating, and during the entire operating period, as well as the adjustment of the intensity of the electric current which supplies said resistance, so as to in spite of the flame, the temperature of the filaments which constitute it does not become excessive, at the risk of leading to its destruction.

In other words, the burner - object of the invention, comprises means for supplying it by a forced air flow (oxidant) on the prechamber part and continuously on the main injector at a rate sufficient to to have a sufficient ejection speed and to generate a venturi effect.

The thermal power generated in this prechambre may represent 10 to 30% of the total heating power provided. This proportion being a function of the geometry of the assembly and the operating conditions of the engine. However punctually during operation, when the computer controls the burner output temperature, the heating power provided by the prechamber can represent up to 100% of the power delivered for example for operating conditions at idle. The arrangement and the means used on the prechamber part will make it possible to obtain a flawless ignition because of its arrangement out of the flow allowing the generation of combustion gases at very high temperature (700 to 1500 ° C.) which will allow when they will be in contact in the diffuser with the air / fuel mixture introduced by the main injector to ignite first spontaneously but above all to ensure a very good quality of combustion even when the% of residual oxygen in the gas Exhaust will be reduced to around 10% as on most supercharged diesel engines operating at full load.

According to an advantageous characteristic of the invention, the main injector is placed in the center of the burner and injected into the diffuser, perpendicularly to the duct opening out of the micro-burner, and will inject the air / fuel mixture in the direction opposite to the direction of circulation of the gases. exhaust system so as to obtain a homogeneous mixture and whose characteristics, composition and temperatures will lead to a good quality of combustion. The other advantage provided by this provision is also to increase the duration of the combustion (residence time) and the temperature of the flame, the latter moving in the opposite direction to the flow direction of the exhaust gas and in the center from this flow, it will constantly exchange with the already heated gases circulating on its periphery.

According to yet another advantageous characteristic of the invention, for the ignition of the flame of the antechamber, the ignition means will be placed in a cavity supplied directly by the pulsed air / fuel mixture so as to create a kind of torch which will maintain the flame of the antechamber permanently.

Advantageously, the means for injecting the fuel respectively consist of a micro-pump for feeding the prechamber and an injector fed with fuel under pressure or a variable-rate pump for the main injector part.

As regards the oxidant (air) it will be delivered directly from the engine-specific network when it exists as on the trucks, or from an additional compressor. In the latter case, advantageously the engine supercharging air can be used to supercharge the compressor so as to increase the flow rate when the engine is charging instead of sucking only the air at atmospheric pressure.

According to one embodiment of the invention, part of the mixture of fuel and oxidant emerges by means of a pipe in a pre-chamber, located in a bypass of the main pipe, the electric means for igniting said mixture being positioned directly in the antechamber.

In practice, the burner may further comprise a second electric ignition means, also positioned within the body of the prechamber, these electric ignition means being constituted by conventional heating plugs or automobile-type electric spark plugs. These candles represent an inexpensive and simple mounting means for lighting the mixture.

According to another advantageous embodiment of the invention, the additional exhaust gas opens into the body of the prechamber by at least one duct in a direction substantially tangential to said body of said prechamber, so as to print said mixture a swirling motion within it. In this case, the burner body is essentially cylindrical in shape.

In practice, the burner is preferably located upstream of the prechamber for a main injection against the current, the burner tube being concentric with respect to the pipe of the exhaust gas in which it is contained. Conveniently, the burner tube will be of sufficient length for the flame to be contained within it and can then flow concentrically in the direction of the exhaust gas stream. For a main injection in the same direction of flow. flow that the exhaust gas, the burner will be disposed downstream and must be of sufficient length so that the flame is mainly contained inside.

When the burner is for example installed on a vehicle exhaust line, it will advantageously be controlled by the same computer that manages the engine and all its environment.

In addition, the invention relates to an exhaust line of an internal combustion engine, comprising at least one inlet for gases from internal combustion, at least one filter cartridge for trapping the solid particles contained in the exhaust gases of said engine, and at least one exhaust port to the atmosphere of the gases, located downstream of the filter cartridge. According to the invention, this line comprises at least one burner as explained above.

It also relates to an exhaust line of an internal combustion engine, comprising at least one inlet for the gases resulting from the internal combustion, at least one nitrogen oxide reduction catalyst or an oxidation catalyst intended for reducing the pollutants NOx, HC, CO contained in said exhaust gas, and at least one exhaust port to the atmosphere of said gas located downstream of said catalyst. According to the invention, this line comprises at least one burner as explained above.

Advantageously, this burner can also be mounted on the machines to regenerate the filters used as an external cleaning means when the filter has operated for many hours or kilometers and a partial clogging is observed. The advantage of such a system being that it is completely integrable in the gas inlet pipe and that it can generate a considerable heating power without having to have behind this burner a large boiler which in addition incorporates a penalizing thermal inertia for the management of the exit temperatures.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will be better understood on reading the description which follows, made with reference to the drawings which show, in no way limiting, embodiments of the device associating a burner with a filtration system according to the invention and in which: FIG. 1 is a schematic representation for illustrating the geometry of the first embodiment of the entire system consisting of an air and diesel fuel supply of the burner prechamber to obtain the ignition of the mixture on a incandescent electrical resistance. This prechamber opening into a diffuser concentrically disposed in the burner tube and the exhaust duct, with in its center arranged the main injection system to be able to inject the air / fuel mixture against the current in the diffuser. FIG. 2 is a representation along the section A A 'of FIG. 1 illustrating the complementary feeding of the prechamber by tangential arrivals of the exhaust gases. FIG. 3 schematically illustrates, for a counter-current injection, the appearance of the flame front inside the burner with its diffuser associated with all the movements that the direction of circulation and the venturi effect generate between the gases of exhaust and flame, the assembly being represented by arrows differently oriented. FIG. 4 is a schematic representation of the second embodiment having the same prechamber but opening into a burner tube with its diffuser, situated downstream with respect to the direction of flow of the gases leading to the main injection in the same flow direction as the exhaust. This involves having a deflector at the outlet of this tube to homogenize the combustion. FIG. 5 is a schematic representation of a variant of the second embodiment differing from that illustrated in FIG. 4 by the different position of the incandescent ignition candle, which is disposed directly in the prechamber instead of being in an adjoining cavity. FIG. 6 is a diagrammatic representation of a variant of the second embodiment differing from that illustrated in FIG. 4 by a baffle at the output of geometry of larger size and substantially different from that illustrated in FIG. 4. EMBODIMENTS OF THE FIG. INVENTION According to a first embodiment of the invention, more particularly described in connection with FIGS. 1 and 2, the antechamber 1 equipped with a cavity 2 containing a spark plug 3 on which air is injected 4 and fuel at 5, supplemented by a tangential arrival at 6 directly on the body of this prechamber 1 by the tubes 7 dynamically extracting the exhaust gas from the main exhaust pipe $. A heating plug 3, preferably of the type with apparent turns, is supplied with electrical energy via the computer during a preheating period, to bring the incandescent filaments constituting it. This resistance is contained in the cavity 2, so as to force the air / diesel mixture arriving through the feed tubes 4 and 5, to bathe completely and ignite before being ejected to the body of the prechamber 1 .

The tangential arrival of the exhaust gases in this prechamber bringing the turbulence and the complementary oxygen so as to obtain at the outlet of the latter a true blowtorch effect.

The air flow, advantageously supplied with compressed air by a compressor, the turbocharger of the engine or the two associated, is admitted by a solenoid valve not shown also controlled by the computer in the form of a square wave signal, of the pulsed type, at a frequency can vary from 0.5 hertz to 10 hertz, to be introduced through the pipe 4.

Independently for supplying the cavity 2 containing the resistor, the diesel fuel is introduced from a metering micro-pump (electromagnetic pulse pump) not shown, for the supply through the tube 5 into a tee where it will mix with the air. This metering micro-pump is also controlled by the computer, it can be at the same frequency as the air solenoid valve or a different frequency Thus for start-up, the diesel injection rate of this prechamber can not represent that 5% of the nominal flow, or less, this start flow being implemented for about twenty seconds to bring the entire body of this antechamber temperature. The combustion of the mixture being accelerated by the turbulence provided by the tangential arrival of the exhaust gas in the body of the prechamber through the tubes 7 opening into 6 in this cylinder.

Then the flow is increased to the nominal flow rate, this feed rate of the prechamber will represent 10 to 80% of the total burner flow.

As shown, part of the prechamber 1 may be partially contained in the main exhaust duct 8 so as to also contain the complementary intake tubes 1 of the exhaust gases in the prechamber. In this main tube 8, the flow direction of the gases is shown schematically by arrows

This prechamber 1 opens perpendicular to the axis of the main tube 8 and in the cylindrical diffuser 11 contained in the body of the burner 9 it will preferably be located exactly in the center of the main tube 8 having exactly the same axis. The connection between the antechamber 1 and the diffuser 11 constituting a 90 ° elbow. At the axis of this bend, corresponding to the crossings of the axes of the diffuser and the prechamber, the main injector 10 will be arranged to inject against the current as represented by the arrow.

This main injector 10 will be implemented when the mode of combustion in the antechamber will be established, so as to inject some kind of new air / fuel flow directly into the flame exiting this prechamber. In fact it will be after a minimum of twenty seconds of operation that the main injection can begin.

This main injector 10 will be controlled by the engine computer and supplied with air and fuel (not shown) so as to achieve the set temperature objectives and not exceed them. A temperature sensor placed downstream of this assembly will control the temperature of the exhaust gas and give the information to the computer so that it constantly adjusts the fuel flow.

Advantageously, the injector may be of a type similar to that used on engines with indirect injection controlled by the computer in% opening, and powered by a conventional booster pump to provide a pressure of 2 to 8 bar, this pump being dimensioned according to the desired heating power level.

On this main injector 10 simultaneously with the fuel injection of air will also be injected, so as to obtain enough movement to propel the fuel air mixture over several tens of centimeters against the flow of the flow of exhaust gas. .

FIG. 3 illustrates, for a counter-current injection, the shape of the flame front inside the concentric tube of the burner associated with all the movements that the direction of circulation and the venturi effect generate between the exhaust gases. and the flame, the assembly being represented by differently oriented arrows.

As previously seen the main injection will start only when the regime of the combustion of the prechamber will be established, under these conditions, the main injector will inject directly into the flame and as it is an air and fuel mixture that is injected this flame will begin to be established directly at the outlet of the injector represented by the arrows 12 and will draw progressively as the residual oxygen of the exhaust gas circulating in the opposite direction This mixture being expelled with a certain energy and speed, the flame will establish on a length of 10 to 30 cm to turn as shown by the arrow 13 and flow peripherally in the tube of the burner 9, as shown by the arrows 14.

To avoid dynamic effects, it is also necessary to take into account the venturi effect generated by the speed of injection of the air / fuel mixture into the diffuser, which in the injected air / fuel flow causes a good portion of the very high combustion gases. hot from the prechamber, but also a portion of the combustion gases of the main flaminate which circulates against the periphery of the body of the burner 9 shown schematically by the arrows 14.

To summarize, the first factor conducive to the initialization of a flame of good quality is provided by the possibility of directly injecting the air / fuel mixture into a flame and a high temperature stream 800 at 1300 ° C, gas from from the antechamber and have an inflammation of spontaneous quality.

The second factor which makes it possible to obtain a complete combustion is of good quality is brought in the first embodiment by the main injection against the current of the air / fuel mixture in the exhaust gases. This arrangement also allows an exchange at the time of introduction to the outlet of the injector 10 with the high-temperature combustion gases favorable factor to achieve high combustion rates associated with high flame temperatures.

The third factor will be that thanks to this permanent exchange between the exhaust gases 13 and the flame the combustion will be done at a higher temperature, allowing to obtain an excellent combustion quality without being forced to inject with fuel all the same. air required for stoichiometric combustion. The flame finding the necessary oxygen in the residual oxygen of the exhaust gases at least 10% for supercharged diesel engines. The displacement against the current allowing the flame to draw as and when necessary oxygen in the residual oxygen of the exhaust gas.

FIG. 4 represents a second embodiment in which the main injection 10 of the air / diesel mixture 10 is always carried out in a diffuser tube 11 in direct relation with the antechamber 1, and contained in a burner tube 9 arranged in the center and in the exhaust gas supply axis but this injection is carried out in the same direction of circulation of the exhaust gas and no longer in opposition.

This arrangement can be used advantageously when a large source of compressed air is available, thus allowing practically through the injector 10 to inject an air / fuel mixture in stoichiometric proportions. However, to ensure a good quality of combustion and a uniform temperature at the outlet of the exhaust tube 8, a preferably cylindrical deflector 16 and made of refractory steel will be disposed at the outlet of the burner 9 to impose a change of direction as shown by the arrows 17 and a homogenization with the main flow of the exhaust gas to obtain a homogeneous temperature.

Figure 5 shows the second embodiment as Figure 4 but with a variation on the arrangement of the spark plug in the prechamber. This candle 3 instead of being disposed in a blind cavity 2 adjacent to this prechamber is in this variant disposed at the bottom of this prechamber 1. To ensure ignition in good condition the arrival of the air / fuel mixture is oriented from way to propel this flow directly on the turns of this candle worn red. This embodiment may be preferred whenever it is necessary to have a prechamber particularly compact and substantially integrated exhaust pipe.

FIG. 6 is a variant of FIG. 4 always with a main injection in the same direction of flow as the exhaust gases, with a burner disposed downstream from the prechamber, but having a particularity at the level of the deflector disposed in burner outlet. In this embodiment, the deflector 18 has a concentric shape to the burner so as to impose the combustion gas at the outlet of the burner 9 a substantially equal length of travel and especially allow a warming of its walls. Higher wall temperatures and longer flame travels being favorable for good combustion quality. According to the invention, it is intended to ensure proper operation and especially a correct start of the burner, whatever the operating conditions of the engine, including at full power, that is to say when prevailing in the burner conditions of extreme turbulence. For this, the principle consists in injecting into a pre-chamber in bypass of the exhaust pipe and containing a heating candle, a proportion representing 5 to 100% of the oxidant / fuel mixture and generating an energy flame in which the main injection is carried out. . This injection is preferably carried out against the current to improve combustion.

As stated in the prior art, this burner can be used in the same way as for the regeneration of particulate filters, whenever the pollutant emission requirements impose an optimum efficiency of the catalysts. used for the post-treatment of the exhaust gases from the start of the engines.

The very small size of this burner makes it possible to dispose it, for example directly in front of the catalyst, or even in the conduit for the arrival of the exhaust gases at the level of this catalyst, so that it becomes possible to heat this catalyst in an extremely short time, typically a few seconds, compared to a duration of several minutes in the absence of this artifice.

Claims (8)

REVENDICATIONS1. Burner fed with a mixture of fuel and oxidant, intended to generate a flame and, as a corollary, heat for heating at least one element for treating or filtering the exhaust gases of an internal combustion engine, said burner disposed in the exhaust gas duct comprises a burner body (9) with its main injector (10) and its diffuser (11) into which a prechamber (1) opens out perpendicularly, characterized in that it further comprises: electric ignition (3) of said mixture in the prechamber (2); means for injecting fuel and oxidant independently into the prechamber and the main injector. The injector being arranged to inject against the flow of the flow of exhaust gas, the burner (9) thus being mounted upstream of the injector (10). 2. Burner according to one of claims 1, characterized in that it comprises an additional arrival of the exhaust gas in the pre-chamber by pipes opening tangentially to the prechamber prechamber. 3. Burner according to one of claims 1 and 2, characterized in that the injection of air through the pipe (5) and fuel through the pipe (4) on the resistor (Electric ignition means (3 )), prechamber (2) is performed upstream thereof, air and fuel being introduced in a pulsed manner and at a specific frequency, the control frequency of said means being identical or different, and being between 0, 5 and 10 hertz. 4. Burner according to one of claims 1 to 3, characterized in that the means for injecting the fuel and the oxidant into the pre-chamber are respectively constituted by a pulse pump and a solenoid valve. 5. Burner according to one of claims 1 to 4, characterized in that the mixture of fuel and oxidant opens through the conduits (4 and 5) in a prechamber (1) located perpendicularly to the burner body (9), and in that the electric ignition means (3) of said mixture is positioned in the antechamber (1) or in a cavity (2) 6. Exhaust line of an internal combustion engine, comprising at least one inlet for the gases resulting from said internal combustion, at least one filter cartridge, intended to trap the solid particles contained in said exhaust gas of said engine. , and at least one exhaust port to the atmosphere of said gases located downstream of said filter cartridge, characterized in that it comprises at least one burner according to one of claims 1 to 5. 7. Internal combustion engine exhaust line, comprising at least one inlet for gases from said internal combustion, at least one nitrogen oxide reduction catalyst or an oxidation catalyst, intended to reduce pollutants NOx, HC, CO contained in said exhaust gas of said engine, and at least one exhaust port to the atmosphere of said gas located downstream of said catalyst, characterized in that it comprises at least one burner according to the one of claims 1 to 5. 8. Burner according to one of claims 1 to 5, incorporated directly into the heating line of a machine to regenerate independent of the engine to replace a boiler equipped with its burner and for regenerating filters clogged with incombustible ash .