EP2956656B1 - Method for controlling a control valve for controlling the flow rate of a coolant for cooling the recirculated gases of an internal combustion engine - Google Patents

Description

TECHNICAL FIELD TO WHICH THE INVENTION REFERS

The present invention generally relates to the field of recirculation of burnt gases from the exhaust to the inlet of an internal combustion engine.

It relates more particularly to a control method of a control valve of a flow of coolant circulating in a cooling circuit of a recirculation line of an internal combustion engine.

• un échangeur thermique,
• deux conduits de circulation de liquide de refroidissement raccordés respectivement en entrée et en sortie dudit échangeur thermique, et
• une vanne de régulation d'un débit de liquide de refroidissement, qui est agencée sur l'un desdits conduits de circulation.

It also relates to a flue gas cooling circuit circulating in a recirculation line of an internal combustion engine comprising:

• a heat exchanger,
• two coolant circulation ducts connected respectively at the inlet and at the outlet of said heat exchanger, and
• a control valve for a coolant flow, which is arranged on one of said circulation ducts.

• un bloc-moteur qui définit intérieurement des cylindres,
• une ligne d'admission de gaz d'admission dans lesdits cylindres,
• une ligne d'échappement des gaz brûlés hors desdits cylindres,
• une ligne de recirculation des gaz brûlés, qui prend naissance dans ladite ligne d'échappement et qui débouche dans ladite ligne d'admission.

It further relates to an internal combustion engine comprising:

• an engine block that internally defines cylinders,
• an inlet gas intake line in said cylinders,
• an exhaust line of the burned gases out of said cylinders,
• a flue gas recirculation line, which originates in said exhaust line and which opens into said intake line.

BACKGROUND

Internal combustion engines of the aforementioned type use as an intake gas a mixture of fresh air and flue gas. These burnt gases are taken from the exhaust line directly downstream of the exhaust manifold of the internal combustion engine and are introduced into the fresh air intake line directly upstream of the engine air distributor. internal combustion. They are commonly referred to as recirculating gases or EGR gas (acronym for "Exaust Gas Recirculation").

These recirculating gases are charged with soot particles and hydrocarbon suspended when these gases are hot.

It is known to cool these recirculation gases by a cooling circuit before their introduction into the air intake line, so as to ensure the internal combustion engine better performance.

Such a cooling circuit then comprises a heat exchanger, said cooler EGR, which is crossed, on the one hand, by the recirculation gas, and, on the other hand, by a cooling liquid. The cooling circuit also comprises a bistable valve, located downstream of the EGR cooler, which is controlled in the open or closed position depending on the measured temperature of the recirculation gases.

The opening of the bistable valve generates a large and brutal cooling of the recirculation gases, in particular when the internal combustion engine has not yet reached its optimum operating temperature.

This sudden cooling of the recirculation gases exposes the EGR cooler to a large deposit of soot and hydrocarbon particles, which causes rapid fouling of this EGR cooler and reduces its performance.

The closure of the bistable valve also prevents any circulation of coolant in the EGR cooler, which can lead to a failure of cooling of the recirculation gases and a release into the atmosphere of a large amount of soot particles and dusts. 'hydrocarbon.

In addition, in this configuration, the coolant blocked in the EGR cooler may reach its boiling point and cause damage to the EGR cooler.

A similar method of controlling a control valve is known from DE102009028932 A1 .

OBJECT OF THE INVENTION

In order to overcome the aforementioned drawback of the state of the art, the present invention proposes a method for controlling the more reliable control valve.

1. a) acquérir la température dudit liquide de refroidissement,
2. b) déterminer, en fonction de la température acquise à l'étape a), une consigne de pilotage de ladite vanne de régulation dans une position stable choisie parmi au moins trois positions stables, et
3. c) piloter la vanne de régulation selon la consigne de pilotage déterminée à l'étape b).

More particularly, there is provided according to the invention a method for controlling a control valve for a flow rate of coolant circulating in a cooling circuit of a recirculation line of an internal combustion engine, which comprises steps of:

1. a) acquiring the temperature of said coolant,
2. b) determining, as a function of the temperature acquired in step a), a control setpoint for said control valve in a stable position chosen from at least three stable positions, and
3. c) control the control valve according to the control setpoint determined in step b).

According to the invention, in step b), the ambient temperature is measured, a target coolant temperature is deduced therefrom and the control setpoint is developed as a function of the temperature of the measured coolant and the target temperature. .

Thus, thanks to the invention, the control valve is controlled between a greater number of positions, which allows a better regulation of the flow of coolant and avoids any problem of boiling or sudden temperature change.

This better regulation also considerably reduces the fouling of the cooling circuit, especially when starting the engine or when the ambient temperature is low.

Finally, the control of the control valve as a function of the temperature of the coolant ensures a more precise regulation of the temperature of the recirculation gases.

• le circuit de refroidissement comportant un échangeur thermique positionné sur la ligne de recirculation, à l'étape a), on mesure la température du liquide de refroidissement dans ledit échangeur thermique ;
• le circuit de refroidissement comportant un échangeur thermique positionné sur la ligne de recirculation, à l'étape a), on mesure la température du liquide de refroidissement à distance dudit échangeur thermique ;
• à l'étape a), on mesure la température du liquide de refroidissement en aval dudit échangeur thermique ;
• à l'étape b), on estime une valeur de température du liquide de refroidissement en amont dudit échangeur thermique en fonction de la température mesurée de liquide de refroidissement, d'un débit de gaz brûlés dans ladite ligne de recirculation et d'une température de gaz brûlés dans ladite ligne de recirculation;
• la charge (C) instantanée du moteur à combustion interne (1) et/ou le régime (R) instantané du moteur à combustion interne (1), et/ou le débit de carburant injecté dans des cylindres (11) du moteur à combustion interne (1) sont utilisés pour calculer la température cible (Tc).

Other non-limiting and advantageous features of the control method according to the invention are the following:

• the cooling circuit comprising a heat exchanger positioned on the recirculation line, in step a), the temperature of the cooling liquid is measured in said heat exchanger;
• the cooling circuit comprising a heat exchanger positioned on the recirculation line, in step a), the temperature of the cooling liquid is measured at a distance from said heat exchanger;
• in step a), the temperature of the coolant is measured downstream of said heat exchanger;
• in step b), a coolant temperature value is estimated upstream of said heat exchanger as a function of the measured coolant temperature, a flue gas flow rate in said recirculation line and a temperature burnt gas in said recirculation line;
• the instantaneous load (C) of the internal combustion engine (1) and / or the instantaneous speed (R) of the internal combustion engine (1), and / or the flow rate of fuel injected into cylinders (11) of the combustion engine internal (1) are used to calculate the target temperature (Tc).

The invention also proposes a cooling circuit as defined in the introduction which comprises a control unit of said control valve, which is adapted to implement a control method as defined above.

The invention further provides an internal combustion engine as defined in the introduction which comprises a cooling circuit as defined above, the heat exchanger of which is positioned on said recirculation line.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

The following description with reference to the accompanying drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be achieved.

• la figure 1 est une vue schématique d'un moteur à combustion interne selon l'invention ;
• la figure 2 est une vue schématique d'une partie du circuit de refroidissement secondaire selon un premier mode de réalisation du moteur à combustion interne de la figure 1 ;
• la figure 3 est un chronogramme illustrant les étapes de mise en oeuvre du procédé de pilotage de la vanne de régulation du circuit de refroidissement secondaire de la figure 2.

In the accompanying drawings:

• the figure 1 is a schematic view of an internal combustion engine according to the invention;
• the figure 2 is a schematic view of a portion of the secondary cooling circuit according to a first embodiment of the internal combustion engine of the figure 1 ;
• the figure 3 is a timing diagram illustrating the steps of implementation of the control method of the control valve of the secondary cooling circuit of the figure 2 .

In the description, the terms "upstream" and "downstream" will be used in the direction of the flow of gases from the point of collection of fresh air into the atmosphere to the exit of the flue gases in the atmosphere. atmosphere.

On the figure 1 schematically shows an internal combustion engine 1 of a motor vehicle, which comprises a motor unit 10 provided with a crankshaft and four pistons (not shown) housed in four cylinders 11. This engine is here compression ignition ( Diesel). It could also be spark ignition (gasoline).

Upstream of the cylinders 11, the internal combustion engine 1 comprises an intake line 20 which takes fresh air into the atmosphere and which opens into an air distributor 25 arranged to distribute the air to each of the four cylinders 11 of the engine block 10. This intake line 20 comprises, in the direction of flow of fresh air, an air filter 21 which filters the fresh air taken from the atmosphere, a compressor 22 which compresses the air. fresh air filtered by the air filter 21, a main air cooler 23 which cools this compressed fresh air, and an inlet valve 24 which regulates the flow of fresh air into the air distributor 25 .

At the outlet of the cylinders 11, the internal combustion engine 1 comprises an exhaust line 80 which extends from an exhaust manifold 81 in which the gases which have been previously burned into the cylinders 11 are discharged, to a silencer exhaust 87 to relax the burnt gases before they are discharged into the atmosphere. It also comprises, in the flow direction of the flue gas, a turbine 82, and a catalytic converter 83 for treating burnt gases.

The turbine 82 is rotated by the flow of burnt gas leaving the exhaust manifold 81, and it drives the compressor 22 into rotation, thanks to mechanical coupling means such as a simple transmission shaft.

The catalytic converter 83 is here a three-way catalyst which contains an oxidation catalyst 84, a particulate filter 85 and a nitrogen oxide trap 86.

Here, the internal combustion engine 1 also comprises a high-pressure flue gas recirculation line, from the exhaust line 80 to the intake line 20. This recirculation line is commonly called the EGR-HP line 40, in accordance with FIG. to the English acronym of "Exhaust Gas Recirculation - High Pressure". It originates in the exhaust line 80, between the exhaust manifold 81 and the turbine 82, and it opens into the intake line 20, between the inlet valve 24 and the air distributor 25.

This line EGR-HP 40 makes it possible to take a part of the flue gases circulating in the exhaust line 80, called recirculation gases or EGR gas, for reinjecting it into the cylinders 11 in order to reduce the polluting emissions of the engine, and in particular emissions of nitrogen oxides, soot and hydrocarbon particles.

This EGR-HP line 40 comprises an EGR-HP valve 41 for regulating the flow of EGR gas opening into the air distributor 25.

In addition or alternatively, this EGR-HP line could be supplemented or replaced by a low-pressure flue gas recirculation line, commonly known as EGR-LP line according to the English acronym of "Exhaust Gas Recirculation - Low Pressure" ". This line EGR-LP would then be born in the exhaust line, at the exit of the catalytic converter, and lead into the intake line, between the air filter and the compressor.

The internal combustion engine 1 also comprises a fuel injection line 60 in the cylinders 11. This injection line 60 comprises an injection pump 62 arranged to collect the fuel in a reservoir 61 to bring it under pressure in a distribution rail 63 which opens into the cylinders 11 via four injectors 64.

The internal combustion engine 1 further comprises a primary cooling circuit (not shown), which in particular passes through the engine block 10 and the main air cooler 23 and in which circulates a cooling liquid.

The internal combustion engine 1 also comprises a secondary cooling circuit 30, which could possibly be confused with the primary cooling circuit, and which comprises a heat exchanger 31 provided for cooling the EGR gases flowing in the line EGR-HP 40 (or alternatively, in line EGR-LP), so as to best reduce the temperature of the gases in the air distributor 25 to provide the internal combustion engine 1 better performance.

As shown by figure 2 , the heat exchanger 31, here called EGR cooler 31, is positioned on the line EGR-HP 40 to cool the EGR gas.

The EGR cooler 31 more specifically comprises a main pipe 31A through which the EGR gas flows, and a secondary pipe 31 B through which circulates a cooling liquid.

The main line 31A is connected, on one side, to the exhaust line 80 via an upstream line 42 of the EGR-HP line 40, and, on the other hand, to the EGR-HP valve 41 via a downstream duct. 43 of the line EGR-HP 40.

The secondary pipe 31 B is connected to the remainder of the secondary cooling circuit 30, on one side, by an upstream pipe 33, and on the other by a downstream pipe 34.

The secondary cooling circuit 30 further comprises a control valve 35 of the coolant flow.

This control valve 35 is here arranged on the upstream duct 33 of the secondary cooling circuit 30. In a variant, it could of course be arranged elsewhere, for example on the downstream duct.

• une position extrême de fermeture dans laquelle elle obture totalement le conduit amont 33, de sorte que le débit du liquide de refroidissement circulant dans le circuit de refroidissement secondaire 30 est nul,
• une position extrême d'ouverture dans laquelle elle libère totalement le conduit amont 33, de sorte que le débit du liquide de refroidissement circulant dans le circuit de refroidissement secondaire 30 est maximal, et
• au moins une position intermédiaire dans laquelle elle obture partiellement le conduit amont 33, de sorte que le débit du liquide de refroidissement circulant dans le circuit de refroidissement secondaire 30 est non nul et est strictement inférieur au débit maximal.

The control valve 35 is adapted to be driven in one or the other of at least three stable positions, of which:

• an extreme closing position in which it completely closes the upstream duct 33, so that the flow rate of the cooling liquid circulating in the secondary cooling circuit 30 is zero,
• an extreme opening position in which it completely releases the upstream duct 33, so that the flow rate of the coolant circulating in the secondary cooling circuit 30 is maximum, and
• at least one intermediate position in which it partially closes the upstream duct 33, so that the flow rate of the cooling liquid flowing in the secondary cooling circuit 30 is non-zero and is strictly less than the maximum flow rate.

The control valve 35 is here a butterfly flap, but it could of course be otherwise.

Conventionally, the circulation of the coolant in this secondary cooling circuit 30 is provided by a pressurizing pump (not shown). The coolant used here is a mixture of water and glycol.

As shown in figure 1 to control the various members of the internal combustion engine 1, there is provided a computer 100 comprising a processor (CPU), a random access memory (RAM), a read-only memory (ROM), analog-digital converters (A / D) and input and output interfaces.

Thanks to its input interfaces, the computer 100 is adapted to receive different sensors input signals relating to engine operation and climatic conditions.

Among these sensors, a first temperature probe 101 is especially provided, which makes it possible to measure the instantaneous temperature T.sub.o of the coolant circulating in the secondary cooling circuit 30.

In the embodiment of the internal combustion engine 1 shown in FIG. figure 2 this first temperature probe 101 is located in the downstream duct 34. In this embodiment, a second temperature probe 102 is also provided for measuring the ambient temperature Ta, that is, the temperature outside the vehicle equipped with the internal combustion engine 1.

In this embodiment, the first temperature probe will therefore be positioned at a distance from the EGR cooler 31, preferably at 10 cm from the latter, so that the measurements are not disturbed by the EGR cooler 31.

According to a variant not shown, it could however be provided that the first temperature sensor is located inside the EGR cooler itself.

• la charge C instantanée du moteur à combustion interne 1,
• le régime R instantané du moteur à combustion interne 1,
• la température To du liquide de refroidissement,
• la température ambiante Ta (dans le premier mode de réalisation), et
• le débit de carburant injecté dans les cylindres 11.

Thanks to these temperature probes and to various other sensors, the computer 100 thus stores continuously in its random access memory:

• the instantaneous charge C of the internal combustion engine 1,
• the instantaneous R speed of the internal combustion engine 1,
• the temperature To of the coolant,
• the ambient temperature Ta (in the first embodiment), and
• the fuel flow injected into the cylinders 11.

The load C (also called "engine load") corresponds to the ratio of the work supplied by the engine to the maximum work that could develop this engine at a given speed. It is usually approximated using a variable called effective average pressure SME.

The R speed corresponds to the speed of rotation of the crankshaft, expressed in revolutions per minute.

Thanks to a predetermined mapping on test bench and stored in its read-only memory (ROM), the computer 100 is adapted to generate, for each operating condition of the engine, output signals.

Finally, thanks to its output interfaces, the computer 100 is adapted to transmit these output signals to the various components of the engine, in particular to the control valve 35.

Conventionally, when the driver of the motor vehicle puts the ignition, the computer 100 initializes and then controls the starter and the fuel injectors 64 for them to start the internal combustion engine 1.

When the engine is started, the fresh air taken from the atmosphere through the intake line 20 is filtered by the air filter 21, compressed by the compressor 22, cooled by the main air cooler 23, and then burned in the cylinders 11.

At their outlet from the cylinders 11, the burnt gases are expanded in the turbine 82, treated and filtered in the catalytic converter 83, then relaxed again in the exhaust silencer 84 before being released into the atmosphere.

Part of these flue gas is, however, taken by the line EGR-HP 40 to be reinjected into the inlet line 20. These EGR gases are then previously cooled in the EGR cooler 31.

The computer 100 for this purpose controls the control valve 35 of the coolant flow circulating in the secondary cooling circuit 30, so that these EGR gases are cooled to the desired temperature.

Thus, for example, when the engine starts, when the ambient temperature Ta is low, this control valve 35 is controlled in extreme closed position (the time that the temperature of the EGR gas increases) before being gradually opened.

1. a) acquérir la température To du liquide de refroidissement,
2. b) déterminer, en fonction de la température To acquise à l'étape a), une consigne de pilotage C1 de la vanne de régulation 35 dans l'une de ses positions stables, et
3. c) piloter la vanne de régulation 35 selon cette consigne de pilotage C1.

According to a particularly advantageous characteristic of the invention, the computer 100 is adapted to implement a control method of the control valve 35 which comprises the following three steps:

1. a) acquiring the temperature To of the coolant,
2. b) determining, as a function of the temperature To, acquired in step a), a control setpoint C1 of the control valve 35 in one of its stable positions, and
3. c) control the control valve 35 according to this control setpoint C1.

Thanks to the invention, the coolant flow circulating in the secondary cooling circuit 30 is regulated as a function of the temperature T 0 of the coolant (and not as a function of the temperature of the EGR gases), which in particular avoids any risk of boiling or sudden change in coolant temperature, benefiting the longevity of the EGR cooler 31.

It will be noted here that the greater the number of stable positions (in which the regulation valve 35 can be controlled) will be greater, the more the regulation of the temperature of the EGR gases can be refined, which will consequently reduce the fouling of the EGR line. -HP 40, especially when the ambient temperature Ta is low.

Thus, if the minimum number of stable positions is three, it will preferably be provided that the control valve 35 may have at least five stable positions. It can of course be expected that it can have more than 10 stable positions.

In the example which will be explained in the rest of this discussion, the control valve 35 can take an infinity of stable positions.

When the internal combustion engine 1 is of the type shown on the figure 2 , the control method of the control valve 35 will be implemented as shown on the flowchart of the figure 3 .

More precisely, after the start of the internal combustion engine (operation 71), the initialization of the computer 100 and the beginning of the circulation of the coolant in the secondary cooling circuit 30 (operation 72), the computer 100 implements the following algorithm.

The computer 100 first checks whether a stopping of the internal combustion engine 1 is required (operation 73).

If a stop command of the internal combustion engine 1 is detected, the computer 100 controls the stopping of the coolant pressurizing pump (operation 74) and the stopping of the injection of fuel into the cylinders 11 (operation 75).

In the opposite case, the computer 100 acquires the temperature To of the coolant downstream of the cooler EGR 31 (operation 76) as well as the ambient temperature Ta (operation 77).

The calculator 100 then calculates a target temperature Tc of coolant as a function of at least ambient temperature Ta measured (operation 78). This target temperature Tc corresponds to the optimum temperature coolant, resulting in reduced fouling of the EGR-HP 40 line.

The calculation of this target temperature Tc is carried out using a mathematical formula or a map stored in the read-only memory (ROM) of the computer 100 (this map corresponding, at each ambient temperature Ta, a target temperature Tc ).

As a variant, it would be possible to use additional parameters for calculating this target temperature Tc, for example the instantaneous load C of the internal combustion engine 1 and / or the instantaneous R speed of the internal combustion engine 1, and / or the injected fuel flow rate. in the cylinders 11.

The computer 100 then compares the measured coolant temperature To with the calculated target temperature Tc (operation 79).

If the temperature To of the coolant is lower than the target temperature Tc, then the control valve 35 is controlled at the opening (operation 84), so as to increase the flow of coolant circulating in the EGR cooler 31.

dans laquelle :

• t est le temps,
• k est une constante prédéterminée enregistrée dans la mémoire morte (ROM) du calculateur 100,
• Δt est une différence de temps (en l'occurrence le pas de temps entre deux calculs successifs de la consigne de pilotage C1), et
• ΔC1 = C1 (t) - C1 (t - Δt).

The control set point C1 being here formed by the opening angle that the regulation valve 35 must take (C1 being equal to zero in the extreme closed position), this control setpoint C1 is calculated in the following manner (operation 83). ): $$\mathrm{VS}\mathrm{1}\left(\mathrm{t}+\mathrm{.delta.t}\right)=\mathrm{VS}\mathrm{1}\left(\mathrm{t}\right)+\mathrm{k}*\mathrm{.DELTA.C}\mathrm{1},$$

in which :

• t is the time,
• k is a predetermined constant stored in the read only memory (ROM) of the computer 100,
• Δt is a time difference (in this case the time step between two successive calculations of the control setpoint C1), and
• ΔC1 = C1 (t) - C1 (t - Δt).

On the other hand, if the temperature To of the coolant is greater than or equal to the target temperature Tc, then the regulation valve 35 is controlled at closing (operation 82), so as to reduce the flow rate of coolant circulating in the EGR cooler 31.

The control setpoint C1 is then calculated in the following manner (operation 81): $$\mathrm{VS}\mathrm{1}\left(\mathrm{t}+\mathrm{.delta.t}\right)=\mathrm{VS}\mathrm{1}\left(\mathrm{t}\right)+\mathrm{k}*\mathrm{.DELTA.C}\mathrm{1.}$$

This control setpoint C1 is then transmitted to the control valve 35, which opens or closes accordingly (operations 82 or 84).

Then, the computer 100 returns to the beginning of the loop (operation 73).

The present invention is not limited to the embodiment described and shown, but the art can apply any variant within his mind.

For example, it will be possible to control the valve for regulating the coolant flow otherwise, especially when the temperature probe is located in the EGR cooler or downstream of the EGR cooler.

In this variant, it will be possible to evaluate, as a function of the measured temperature and possibly other parameters (for example the flow rate and the temperature of the EGR gases), an estimated temperature of the coolant upstream of the EGR cooler.

In this variant, the flow rate and the temperature of the EGR gases can be measured or calculated as a function of engine speed and torque.

Claims (8)

1. Method for controlling a regulating valve (35) that regulates a flowrate of liquid coolant circulating in a cooling circuit (30) of a recirculation line (20) of an internal combustion engine (1), characterized in that it comprises steps consisting in:

   a) acquiring the temperature (To) of the said liquid coolant,

   b) determining, as a function of the temperature (To) acquired at step a), a control point (C1) for the said regulating valve (35) in a stable position chosen from at least three stable positions, and

   c) controlling the regulating valve (35) according to the control point (C1) determined in step b),

   characterized in that, in step b), the said control point (C1) is determined as a function of the acquired temperature (To) of the liquid coolant and of a liquid coolant target temperature (Tc) which is deduced from the ambient temperature (Ta) measured beforehand.
2. Control method according to Claim 1, in which, with the cooling circuit comprising a heat exchanger positioned on the recirculation line, in step a) the temperature of the liquid coolant is measured inside the said heat exchanger.
3. Control method according to Claim 1, in which, with the cooling circuit (30) comprising a heat exchanger (31) positioned on the recirculation line (20), in step a) the temperature (To) of the liquid coolant is measured some distance away from the said heat exchanger (31).
4. Control method according to Claim 3, in which in step a) the temperature (To) of the liquid coolant is measured downstream of the said heat exchanger (31).
5. Control method according to one of Claims 2 and 4, in which, in step b) a value for the temperature of the liquid coolant upstream of the said heat exchanger is estimated as a function of the measured liquid coolant temperature, of a flowrate of burnt gases in the said recirculation line, and of a temperature of burnt gases in the said recirculation line.
6. Control method according to any one of Claims 1 to 5, in which the instantaneous load (C) on the internal combustion engine (1) and/or the instantaneous speed (R) of the internal combustion engine (1), and/or the flowrate of fuel injected into the cylinders (11) of the internal combustion engine (1) are used to calculate the target temperature (Tc).
7. Cooling circuit (30) for cooling the burnt gases circulating in a recirculation line (20) of an internal combustion engine (1), comprising:

   - a heat exchanger (31) positioned on the said recirculation line (20),

   - two liquid-coolant circulation pipes (33, 34) connected respectively at the inlet and outlet of the said heat exchanger (31), and

   - a regulating valve (35) for regulating a flowrate of liquid coolant, which valve is arranged on one of the said circulation pipes (33, 34), characterized in that it comprises a control unit (40) for controlling the said regulating valve (35), which is able to implement a control method according to one of Claims 1 to 6.
8. Internal combustion engine (1) comprising:

   - an engine block which internally defines cylinders,

   - an intake line admitting intake gas into the said cylinders,

   - an exhaust line exhausting burnt gases from the said cylinders,

   - an exhaust gas recirculation line (20) which starts in the said exhaust line and which opens into the said intake line, characterized in that it comprises a cooling circuit (30) according to Claim 7.

Images