EP2739843B1 - Device for dispensing a liquid additive into a fuel circulation circuit for an internal combustion engine, vehicle comprising such a device, and method for using said device - Google Patents

Description

The technical field of the present invention is that of internal combustion engines, especially motor vehicles, and more particularly devices for dispensing a liquid additive in the fuel circulation circuit of the internal combustion engine.

New engine technologies, such as common-rail diesel engines and ultra-high-pressure fuel injection engines, are very efficient but very sensitive to fuel quality.

Thus, it is advantageous to use a fuel containing additives which improve its quality, in particular additives for improving the distribution of fuel in the engine, additives for improving the performance of engine operation and additives for improving engine performance. the stability of the engine operation. These are, for example, detergent agents, lubricating additives or anticorrosive additives.

However, the quality of the available commercial fuels does not always make it possible to supply the engine with a fuel containing sufficient additives. In addition, fuels worldwide respond to more or less demanding standards and therefore have a variable quality. There is therefore interest for optimum operation of the engine to adjust the concentration of additive contained in the fuel.

In addition, to meet the new emission control standards for vehicles, including diesel, vehicles are gradually equipped with pollution control means of the particulate filter type. This is already the case in Europe since the advent of the Euro 5 standard. In most cases, a catalyst is used to help burn soot periodically and thus regenerate the particulate filter. The use of a particulate filter regeneration additive, vectorized by the fuel supplying the engine or Fuel Borne Catalyst (FBC), has been found to meet many criteria since it allows to regenerate the particulate filter more quickly and at a lower temperature than competing technology called Catalysed Soot Filter (CSF) or Catalytic Particulate Filter.

It is therefore advantageous to equip the vehicle with a device for introducing into the fuel an additive to aid the regeneration of the particulate filter and / or fuel additives improving the quality of the fuel and / or the operation of the engine and / or its durability.

It is known that there are systems for introducing such additives into the fuel, in particular catalytic additives FBC for assisting the regeneration of particulate filters. These systems generally rely on a large tank of 2 to 3 liters minimum volume containing the additive reserve and must be implanted in areas near the fuel tank.

The dosage of the additive is then generally performed using high precision metering pumps controlled using an additional electronic unit (or ECU). This metering device is finely managed to ensure an additive content in the fuel sufficient to allow good regeneration of the particulate filter, but not too excessive to prevent premature clogging of the particulate filter via the mineral residues of the particulate filter. regeneration of the particulate filter which remains collected within it.

Conventionally when the fuel level increases in the tank, following the addition of fuel, a calculator indicates to the pump the amount of additive to be injected into the tank so as to maintain a constant additive concentration in the fuel and this to any time.

These extremely precise dosing pumps, as well as the management of the ECU, significantly increase the cost of these additive dispensing devices.

In addition, the use of such an additive dispensing device involves slaving the dosing system of the additive and of verifying its operating state, which remains particularly intrusive in the management of the fault modes of the additive. vehicle.

In terms of maintenance, the filling of the tank is rather difficult especially because it is often done through a complex connectivity. In addition, depending on its location, accessibility to the reservoir can also be difficult.

• un réservoir contenant l'additif,
• une enceinte communiquant avec le circuit de circulation de carburant et à l'intérieur de laquelle est inséré le réservoir contenant l'additif, au moins une paroi mobile et étanche entre ladite enceinte et ledit réservoir assurant d'une part une séparation étanche et d'autre part maintenant une pression identique entre l'additif dans le réservoir et le carburant dans l'enceinte,
• des moyens d'injection de l'additif reliés au réservoir et au circuit de circulation de carburant et permettant de distribuer l'additif dans le circuit de circulation de carburant, lesdits moyens comprenant un canal de distribution reliant le réservoir et le circuit de circulation de carburant.

A device for dispensing a liquid additive in a fuel circulation circuit for an internal combustion engine of a vehicle has been protected by the applicant under the deposit number FR 11 00316 . This device comprises:

• a reservoir containing the additive,
• an enclosure communicating with the fuel circulation circuit and inside which is inserted the tank containing the additive, at least one movable and sealed wall between said enclosure and said tank providing on the one hand a tight separation and on the other hand, maintaining the same pressure between the additive in the tank and the fuel in the chamber,
• means for injecting the additive connected to the tank and the fuel circulation circuit and for distributing the additive in the fuel circulation circuit, said means comprising a distribution channel connecting the reservoir and the circulation circuit of the fuel fuel.

Similarly, the applicant has also protected the integration of a device for dispensing a liquid additive into a fuel tank under the deposit number FR 11 55310 .

Such devices are simple to implement and more economical than the high precision metering pumps commonly used.

However, such devices do not make it possible to adapt the supply of additive, especially to the running conditions of the vehicle.

One of the aims of the invention is to propose a dispensing device as described above making it possible to extend the autonomy of the additive reservoir by limiting the additive intake or even stopping it to avoid, under certain conditions, an excessive concentration of additive in the fuel.

One of the aims of the invention is also to optimize the concentration of additive in the fuel in order to find a compromise between the sufficient quantity needed and overconcentration that can reduce the autonomy of the additive reservoir and / or have repercussions. negative effects on other vehicle components, such as clogging of the particulate filter.

Similarly, the invention aims to optimize the injection of additive so that the injection takes place only when the vehicle needs, particularly depending on the driving conditions and / or the quality of the fuel.

For this purpose, the subject of the invention is a device according to claim 1.

• les moyens d'injection peuvent comprendre un moyen d'obturation du canal de distribution, le moyen d'obturation étant adapté pour obturer totalement ou partiellement le canal de distribution, le moyen d'obturation étant notamment de type clapet ou électrovanne ;
• le dispositif de distribution peut comprendre un capteur de température extérieure au véhicule, la température extérieure constituant un paramètre représentatif des conditions climatiques ;
• le dispositif de distribution peut comprendre un capteur détectant la mise sous-tension du véhicule et/ou d'un élément appartenant au circuit de circulation de carburant, notamment un filtre à carburant, la mise sous-tension constituant un paramètre représentatif de l'utilisation du véhicule ;
• le dispositif de distribution peut comprendre un capteur de bruit disposé de préférence à proximité du moteur, la détection d'un bruit par le capteur constituant un paramètre représentatif de l'utilisation du véhicule ;
• le dispositif de distribution peut comprendre un moyen de localisation de type GPS ou un capteur de mouvement, la détection d'un mouvement par le moyen de localisation ou le capteur de mouvement constituant un paramètre représentatif de l'utilisation du véhicule et/ou des conditions de roulage du véhicule ;
• la vitesse moyenne et/ou la vitesse instantanée du véhicule peut constituer un paramètre représentatif des conditions de roulage du véhicule ;
• la température des gaz d'échappement peut constituer un paramètre représentatif des conditions de roulage du véhicule ;
• l'évolution de la pression dans le circuit de circulation, notamment dans un circuit haute pression du véhicule composé d'une pompe haute pression et d'une rampe commune d'injection, peut constituer un paramètre représentatif des conditions de roulage du véhicule ;
• l'évolution du débit d'air alimentant la chambre de combustion du moteur peut constituer un paramètre représentatif des conditions de roulage du véhicule ;
• l'évolution du débit de carburant dans le circuit de circulation peut constituer un paramètre représentatif de l'évolution du débit d'additif ;
• l'évolution des émissions de NOx, de suies ou d'autres particules carbonées ou des rapports NOx/suies et/ou NOx/particules peut constituer des paramètres représentatifs des émissions polluantes issues de la combustion du carburant ;
• l'évolution de la qualité et/ou de la quantité d'huile permettant la lubrification du moteur peut constituer un paramètre représentatif de l'évolution de la qualité de la régénération du filtre à particules disposé dans la ligne d'échappement du moteur ;
• le dispositif de distribution peut comprendre un moyen de localisation de type GPS indiquant la zone géographique dans laquelle le véhicule se trouve, la localisation du véhicule fournie par le moyen constituant un paramètre représentatif de la qualité du carburant commercialisé dans la zone géographique ;
• des paramètres représentatifs de la combustion du carburant dans les cylindres du moteur peuvent constituer un paramètre représentatif de la qualité du carburant ;
• la consommation en carburant du moteur peut constituer un paramètre représentatif des conditions de roulage du véhicule ;
• l'additif peut être un additif de régénération de filtre à particules à base d'une terre rare et/ou d'un métal choisi dans les groupes IIA, IVA, VIIA, VIII, IB, IIB, IIIB et IVB de la classification périodique ;
• l'additif peut se présenter sous forme d'une dispersion colloïdale ;
• les particules de la dispersion colloïdale peuvent être à base de cérium et/ou de fer ;
• l'additif peut être une combinaison d'une dispersion colloïdale de particules qui comprend une phase organique et au moins un agent amphiphile et d'un détergent ;
• l'additif peut être un additif permettant l'amélioration de la distribution du carburant dans le moteur et/ou l'amélioration des performances du fonctionnement du moteur et/ou encore l'amélioration de la stabilité du fonctionnement du moteur ;
• l'additif peut être une combinaison d'un additif détergent et d'un additif de lubrification.

The dispensing device according to the invention may comprise one or more of the following characteristics:

• the injection means may comprise a closure means of the distribution channel, the closure means being adapted to completely or partially close the distribution channel, the closure means being in particular valve type or solenoid valve;
• the dispensing device may comprise a temperature sensor outside the vehicle, the outside temperature constituting a parameter representative of the climatic conditions;
• the dispensing device may comprise a sensor detecting the undervoltage of the vehicle and / or an element belonging to the fuel circulation circuit, in particular a fuel filter, the power-up constituting a parameter representative of the use of the vehicle ;
• the distribution device may comprise a noise sensor preferably disposed near the engine, the detection of a noise by the sensor constituting a parameter representative of the use of the vehicle;
• the dispensing device may comprise a GPS-type locating means or a motion sensor, the detection of a movement by the locating means or the motion sensor constituting a parameter representative of the use of the vehicle and / or the conditions driving the vehicle;
• the average speed and / or the instantaneous speed of the vehicle may constitute a parameter representative of the driving conditions of the vehicle;
• the temperature of the exhaust gas may be a representative parameter of the vehicle running conditions;
• the evolution of the pressure in the circulation circuit, in particular in a high-pressure circuit of the vehicle composed of a high-pressure pump and a common injection rail, may constitute a parameter representative of the running conditions of the vehicle;
• the evolution of the air flow supplying the combustion chamber of the engine may constitute a parameter representative of the running conditions of the vehicle;
• the evolution of the fuel flow in the circulation circuit may constitute a parameter representative of the evolution of the additive flow;
• the evolution of NOx, soot or other carbon particles emissions or NOx / soot and / or NOx / particulate ratios may be representative parameters of pollutant emissions from fuel combustion;
• the evolution of the quality and / or the quantity of oil allowing the lubrication of the engine can constitute a parameter representative of the evolution of the quality of the regeneration of the particulate filter disposed in the exhaust line of the engine;
• the distribution device may comprise a GPS-type location means indicating the geographical area in which the vehicle is located, the location of the vehicle provided by the means constituting a parameter representative of the quality of the fuel marketed in the geographical area;
• representative parameters of fuel combustion in the engine cylinders may be a representative parameter of fuel quality;
• the fuel consumption of the engine may be a representative parameter of the driving conditions of the vehicle;
• the additive may be a particulate filter regeneration additive based on a rare earth and / or a metal selected from Groups IIA, IVA, VIIA, VIII, IB, IIB, IIIB and IVB of the Periodic Table. ;
• the additive may be in the form of a colloidal dispersion;
• the particles of the colloidal dispersion may be based on cerium and / or iron;
• the additive may be a combination of a colloidal dispersion of particles which comprises an organic phase and at least one amphiphilic agent and a detergent;
• the additive may be an additive for improving the fuel distribution in the engine and / or improving the performance of the engine operation and / or improving the stability of the engine operation;
• the additive may be a combination of a detergent additive and a lubricating additive.

The invention applies in particular to combustion engines using gasoline or diesel fuel.

Similarly, the engines equipped with the device according to the invention can equip stationary installations, or so-called "off road" vehicles, such as construction machinery, or so-called "on road" vehicles, such as motor vehicles.

• un circuit de circulation de carburant pour un moteur à combustion interne du véhicule,
• un réservoir contenant un additif liquide,
• une enceinte communiquant avec le circuit de circulation de carburant et à l'intérieur de laquelle est inséré le réservoir contenant l'additif, au moins une paroi mobile et étanche entre ladite enceinte et ledit réservoir assurant d'une part une séparation étanche et d'autre part maintenant une pression identique entre l'additif dans le réservoir et le carburant dans l'enceinte,
• des moyens d'injection de l'additif reliés au réservoir et au circuit de circulation de carburant et permettant de distribuer l'additif dans le circuit de circulation de carburant, lesdits moyens comprenant un canal de distribution reliant le réservoir et le circuit de circulation de carburant,

caractérisé en ce que l'additif est injecté à l'aide d'un dispositif de distribution selon l'invention.The invention also relates to a motor vehicle comprising:

• a fuel circulation circuit for an internal combustion engine of the vehicle,
• a tank containing a liquid additive,
• an enclosure communicating with the fuel circulation circuit and inside which is inserted the tank containing the additive, at least one movable and sealed wall between said enclosure and said tank providing on the one hand a tight separation and on the other hand, maintaining the same pressure between the additive in the tank and the fuel in the chamber,
• means for injecting the additive connected to the tank and the fuel circulation circuit and for distributing the additive in the fuel circulation circuit, said means comprising a distribution channel connecting the reservoir and the circulation circuit of the fuel fuel,

characterized in that the additive is injected with the aid of a dispensing device according to the invention.

The invention also relates to a method of using a dispensing device according to the invention for which the additive distribution is stopped when the vehicle engine is not running or when the vehicle is stopped.

The invention also relates to a method of using a dispensing device according to the invention for which the additive distribution is activated when the sealing means is under electrical supply.

The invention also relates to a method of using a dispensing device according to the invention for which the additive distribution is activated when a pressure difference greater than 2 millibars between the dispensing orifice of the additive disposed at one end of the distribution channel, and the fuel inlet port disposed upstream in the circulation circuit is measured.

The invention also relates to a method of using a dispensing device according to the invention for which the additive distribution is activated when the temperature of the fuel flowing in the circulation circuit and / or the additive is greater than at a threshold value representative of a running engine, for example greater than 15 ° C.

The invention also relates to a method of using a dispensing device according to the invention for which the additive distribution is stopped when the external temperature and / or the temperature of the additive and / or the temperature of the fuel, in the fuel circulation circuit are lower than a minimum threshold temperature or greater than a maximum threshold temperature, said minimum and maximum threshold temperatures being defined for a given additive, the minimum threshold temperature possibly corresponding to a value for which the viscosity of the additive reaches a threshold value and the maximum threshold temperature may correspond to the vaporization value of the additive.

The invention also relates to a method of using a dispensing device according to the invention for which the injection is discontinuous and in that the frequency and / or the duration of opening of the sealing means depend on the information collected. by the control means, the additive distribution being carried out so as to keep a constant additive concentration in the fuel or to inject the additive into the fuel circulation circuit only when necessary.

According to a first embodiment, the frequency of distribution and / or the duration of additive distribution depends either on the time of use of the vehicle and / or on the number of kilometers traveled by the vehicle and / or on the consumption in vehicle fuel.

According to a second embodiment, the frequency and / or the duration of additive distribution depend on the temperature of the fuel and / or the additive, and / or the pressure between the dispensing orifice of the additive disposed at one end of the distribution channel, and the fuel inlet port disposed upstream in the circulation circuit.

The invention also relates to a method of using a dispensing device according to the invention for which the additive is injected at each addition of fuel in the fuel tank, the added amount of additive can be fixed or variable, the variable volume being determined according to the amount of fuel added.

The invention also relates to a method of using a dispensing device according to the invention for which the additive is injected when the analysis of the pollutant emissions resulting from the combustion of the fuel indicates that the gases and / or the particles emitted differ from the expected theoretical value.

The invention also relates to a method of using a dispensing device according to the invention for which the additive is injected before the regeneration of the particulate filter.

The invention also relates to a method of using a dispensing device according to the invention for which an additional amount of additive is injected before the regeneration of the particulate filter when the previous regeneration has not been of good quality.

• la figure 1 est une représentation schématique d'un dispositif de distribution d'un additif dans un circuit de circulation de carburant de moteur à combustion interne ;
• la figure 2 est une représentation schématique identique à celle de la figure 1, le dispositif de distribution d'additif étant disposé dans un réservoir de carburant ;
• la figure 3 est une vue en coupe illustrant un dispositif de distribution d'additif liquide ; et
• les figures 4 à 7 illustrent différentes stratégies d'ouverture/fermeture d'un moyen d'obturation contrôlant la distribution d'additif dans le circuit de circulation de carburant.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings in which:

• the figure 1 is a schematic representation of a device for dispensing an additive in an internal combustion engine fuel circulation circuit;
• the figure 2 is a schematic representation identical to that of the figure 1 the additive dispensing device being disposed in a fuel tank;
• the figure 3 is a sectional view illustrating a liquid additive dispensing device; and
• the Figures 4 to 7 illustrate different strategies for opening / closing a closure means controlling the distribution of additive in the fuel circulation circuit.

The figure 1 schematically represents a fuel circulation circuit 2 for an internal combustion engine of a motor vehicle.

Conventionally, the fuel circulation circuit 2 is arranged between a fuel tank 4 and the high pressure rail 6 (also called "common rail") and ensures the flow of fuel between the tank and the high pressure rail, and possibly the return fuel to the tank 4.

The circulation circuit comprises a filter 8 for filtering the fuel and a high pressure pump 10. The high pressure pump 10 and the high pressure ramp 6 constitute the fuel injection system.

A first conduit 12, called "feed line", ensures the flow of fuel from the tank 4 to the high pressure ramp 6 and a second conduit 14, said "return line" ensures the flow of fuel from the injection system to the tank 4. The fuel is pumped into the tank 4, then filtered in the filter 8 and is sent under pressure, through the pump 10, in the high pressure rail 6 and a portion is directed to the injectors 16 of the engine and another part returned to the tank 4 by the return line 14. A portion of the fuel can also be sent from the high pressure pump 10 to the return line 14.

The fuel circulation circuit 2 also comprises a device 18 for dispensing a liquid additive according to the invention, whose operation will be described later. By way of illustration and not limitation, the device 18 for dispensing an additive has been shown on the feed line 12, but said device 18 for dispensing an additive may also be placed on the fuel return line 14.

Alternatively, as shown in FIG. figure 2 , the device 18 for dispensing an additive can also be placed in the fuel tank 4.

In this embodiment, the fuel circulation circuit 2 ensures the flow of fuel between the inside of the fuel tank 4 and the engine, and possibly the return of the fuel to the tank 4. Thus, the part of the circuit 2 of the fuel fuel circulation supporting the dispensing device 18 extends inside the fuel tank 4.

The figure 3 represents a sectional view of an exemplary embodiment of a dispensing device 18. In this embodiment, the device 18 for dispensing an additive comprises a head 20 and a replaceable cartridge 22 forming an additive enclosure 24 in which is disposed a reservoir 26 of liquid additive. The head 20 has a fuel inlet port 28, a fuel outlet port 30, a venturi 32 located between the fuel inlet and outlet ports 30, a conduit 34 providing a fuel passage between the fuel inlet port 28 and the additive enclosure 24 inside the replaceable cartridge 22 and an additive distribution channel 36 ensuring the passage of the liquid additive from the reservoir 26 to a diffusion orifice 38 additive in the venturi 32.

In this embodiment, the additive distribution channel 36 has a first portion 40 and a second portion 42 of reduced section. An actuator 44, consisting of a finger 46 and a coil 48, closes the passage between the portions 40 and 42 of the additive distribution channel.

In this embodiment, the reservoir 26 of additive is in the form of a flexible bag 50 constituting a movable and sealed wall between the fuel present in the additive enclosure 24 and the additive inside the tank 26.

• Le dispositif 18 de distribution d'un additif est connecté au circuit de circulation 2. Le carburant circule donc de manière continue entre les orifices 28 et 30 d'entrée et de sortie du carburant.

The operation of the invention is as follows:

• The device 18 for dispensing an additive is connected to the circulation circuit 2. The fuel therefore circulates continuously between the orifices 28 and 30 of entry and exit of the fuel.

The venturi 32, which is a known pressure difference generation means, generates a vacuum between the additive distribution port 38 and the fuel inlet port 28.

The additive enclosure 24, communicating via the conduit 34 with the fuel inlet port 28, is filled with fuel at the same pressure as the fuel flowing at the fuel inlet port 28, the flexible bag 50, constituting the movable and sealed wall of the additive reservoir maintains an identical pressure between the additive in the additive reservoir 26 and the fuel in the enclosure 24.

The pressure in the additive reservoir 26 is therefore greater than the pressure at the level of the additive diffusion orifice 38, which forces the additive to move from the reservoir 26 to the diffusion orifice 38. additive then to diffuse into the fuel flowing in the venturi 32 and therefore in the fuel circulation circuit.

The actuator 44 makes it possible to totally or partially prevent the flow of the additive.

In this embodiment, the actuator 44 illustrates an electromechanical means for total or partial closure of the additive distribution channel, but a valve or solenoid valve may, for example, also be used. In the following description these different means will be called shutter means.

In addition, pollution control means, such as a catalyzed particle filter or not, not shown, may be arranged in the exhaust line of the vehicle.

The catalyzed particle filters, referred to as CSF type, generally contain a catalyst that directly or indirectly aids the regeneration of the coated particle filter in the porosity of its filtering walls. These CSF-type particle filters may in particular contain precious metals such as platinum and / or palladium. However, under certain driving conditions, the regeneration of these CSF type particle filters can be improved using additive injected into the fuel.

Subsequently, the term "particle filter" will be used to evoke indifferently a non-catalyzed particulate filter or a catalyzed particulate filter.

The control of the closure means for controlling the flow rate of additive dispensed in the dispensing circuit goes from here to be described more particularly, the different control modes being grouped according to their goal to achieve.

The piloting is intended to inject the additive discontinuously and thus makes it possible to control the closing / opening frequency of the distribution channel 36 and / or the amplitude of the opening and / or closing times, and / or of modulating the degree of shutter in the case of partial sealing means.

First mode of steering

The objective of this first driving mode is to minimize the fluctuations in concentration of additive in the fuel, especially in the fuel tank 4.

Thus, this first control mode aims to detect the periods of stopping the vehicle and to interrupt the distribution of additive when such periods are detected.

This first control mode also makes it possible to interrupt the distribution of the additive in the circulation circuit during certain periods of the life of the vehicle in order to use the additive wisely and / or to avoid that the tank containing the additive does not empty too quickly.

Thus, in this first control mode, the interruption of the additive distribution can take place when the stopping of the engine of the vehicle is detected. This avoids an excess of additive in the fuel while the vehicle is parked and therefore does not consume the injected additive. Such a stop of the additive distribution makes it possible to increase the autonomy of the additive reservoir.

In addition, when the additive used is intended to aid the regeneration of a particulate filter disposed in the exhaust line of the vehicle, examples of additives will be given later, it is also advantageous to limit the concentration of additive in the fuel so as not to clog the particle filter channels too quickly by the mineral residues of the additive. In this case, the control of the additive distribution is aimed at ensuring that the concentration is between a minimum value, for which the regeneration of the particulate filter is facilitated, and a maximum value, beyond which the channels of the filter at particles get clogged quickly.

In order to implement this first control mode, the distribution device according to the invention may comprise means for analyzing at least one parameter representative of the use of the vehicle, such as means for detecting the operation of the engine. and / or to indicate whether the vehicle is moving.

In particular, these means can be adapted to detect the energization of the fuel filter and / or closure means of the distribution channel, and / or more generally the power of the vehicle.

These means may also include a temperature sensor adapted to detect the temperature of the additive and / or the fuel flowing in the fuel circulation circuit. Indeed, these temperatures are, when the engine is in operation, greater than a threshold value, for example greater than 15 ° C.

Likewise, these means may comprise pressure sensors for measuring the pressure at the orifice 38 for dispensing the additive and at the orifice 28 for the entry of fuel, a pressure difference between these two orifices greater than a threshold value, generally greater than 2 mbar, indicating the flow of fuel and thus the operation of the engine.

The figure 4 illustrates this mode of operation. The curve 52 of this figure represents an example of evolution as a function of time of the pressure difference between the orifices 38 and 28, the time being represented along the abscissa axis. Curve 54 represents the evolution as a function of time of the state of the closure means according to the pressure difference, the line portion disposed at the abscissa representing the closing state of the closure means, while that the line portion disposed at a distance from the abscissa represents the open state of the closure means. Curve 56 represents the triggering threshold, the shutter means being closed for a value of the pressure difference below this threshold and open for a value of the pressure difference greater than this threshold. Thus, as long as the pressure difference exceeds the triggering threshold, the sealing means remains open so as to allow the addition of additive, the addition of additive being stopped as soon as the pressure difference has a lower value. at the determined threshold value.

An identical curve can be obtained when the control is performed using a threshold temperature value triggering the opening / closing of the closure means.

Likewise, these means may comprise a GPS-type geolocation means or a motion sensor indicating the movement of the vehicle.

Similarly, these means may comprise a noise sensor disposed near the engine, the detection of noise by said sensor constituting a parameter representative of the use of the vehicle.

Preferably, in this first control mode, a closure means for completely closing the distribution channel is used, for example a thermoclapet, an "umbrella" valve, a non-return valve, a hydraulically or electromechanically operated valve or a solenoid valve.

Second driving mode

The objective of this second mode of control is to interrupt the distribution of additive when the conditions, in particular climatic conditions, are not favorable to the latter.

For this purpose, a temperature sensor for taking the temperature of the additive and / or fuel in the fuel circulation circuit, disposed in particular near the dispensing device 18, may be used.

As soon as the temperature sensor detects a temperature lower than a minimum threshold temperature or a temperature higher than a maximum threshold temperature, the distribution device interrupts the distribution of additive in the circulation circuit.

Depending on the additive used, the minimum threshold temperature may correspond to a temperature for which the additive has a viscosity that is too high or for which the additive has reached its cloudy point or even becomes en masse; the maximum threshold temperature may correspond to the vaporization value of the additive, the minimum and maximum threshold temperatures being defined for a given additive.

Alternatively, an outdoor temperature sensor may be used. This variant is particularly advantageous when the dispensing device 18 is disposed in the fuel tank 4. Indeed, in this configuration the dispensing device 18 is more sensitive to changes in the outside temperature.

In this second control mode, it is intended to avoid any degradation of the distribution device and / or the circulation circuit created by the additive whose physical state has changed. Indeed, when for example the temperature is lower than the minimum threshold temperature, excessive viscosity of the additive may in particular block the channel 36 of additive distribution.

Third mode of steering

The objective of this third mode of control is also to minimize the fluctuations of concentration of additive in the fuel.

In this third control mode, the additive distribution is carried out in such a way as to minimize the fluctuations in the concentration of additive in the fuel following the fluctuations of parameters external to the device that can vary the concentration of additive.

In this third control mode, the frequency and / or the opening time of the shutter means are not dependent on the operation of the motor. Thus, even when the engine is running the additive distribution can be interrupted.

For a given additive and a given dispensing device, this third control mode aims at correcting the fluctuations due, in particular to the evolution of the amount of fuel in the fuel tank of the vehicle. This evolution can be linked on the one hand to the running conditions of the vehicle when the engine is running, and in particular to the fuel consumption, the latter being continuous but variable over time, and on the other hand to the addition of fuel in the tank by the user, causing a sharp increase in the amount of fuel in the tank.

As in the first control mode, the control can be done by controlling the opening / closing of the shutter means from either parameters managed autonomously by the device, or from external parameters provided for example by the electronic unit (ECU) of the vehicle, the control consisting in adapting the frequency and / or the duration of opening and / or the opening of the closure means to allow to adjust either the amount of additive introduced to each injection, ie the time interval between each injection, the quantity injected being then identical.

Different control variants can be envisaged in order to keep an average concentration of additive substantially constant in the tank fuel and / or to reduce the minimum and maximum fluctuations of this concentration.

A first variant consists in injecting the additive at regular intervals, the duration of distribution of the additive being constant at each distribution period.

The frequency and duration of distribution will be evaluated according to the vehicle manufacturer's average vehicle fuel consumption and / or fuel tank size, both of which are known during vehicle design.

According to this first variant, the frequency may be either temporal, for example by injecting all the hours of the additive into the circulation circuit, or depending on the number of kilometers traveled by the vehicle, for example by injecting every 100 km of the vehicle. 'additive. For this purpose, the distance traveled by the vehicle can be retrieved either locally by a GPS chip, or any other geolocation system installed at the level of the distribution device, either by retrieving the data from the ECU or GPS of the vehicle.

A second variant is to inject the variable frequency additive, the duration of distribution of the additive may also be variable from one distribution period to another.

The frequency and / or the duration of distribution are adjusted according to the average consumption of the vehicle. For this purpose, the average consumption of the vehicle can be obtained by recovering the data of the vehicle ECU.

Compared with the first variant, this second variant has the advantage of being more precise by adapting the amount of additive to be injected to the actual consumption of the vehicle.

A third variant is to inject the additive to each addition of fuel in the vehicle tank, the amount of additive dispensed being constant at each distribution period.

This additive addition can be made as soon as the opening of the fuel filler flap for filling the tank is detected or when a signal from the vehicle ECU indicates that the fuel volume in the tank has increased .

The amount of additive to be injected and therefore the injection time can then be calculated by considering a standard addition of fuel in the tank. It is considered that the user does not wait to completely empty the tank of his vehicle before filling it. Thus, for example for a tank with a total capacity of 60 liters, the quantity of additive injected will be evaluated so as to enrich 40 liters of fuel.

A fourth variant consists in injecting the additive with each addition of fuel in the tank of the vehicle, the quantity of additive dispensed being variable at each distribution period depending on the amount of fuel added.

This variant makes it possible to adjust the amount of additive to the amount of fuel actually introduced when adding fuel to the tank. This addition of additive can be achieved as soon as a signal from the vehicle ECU indicates that a certain amount of fuel has been added to the tank, the amount of additive and therefore the duration of distribution being adapted to the amount of fuel added.

The figure 5 illustrates this mode of operation. The curve 58 of this figure represents an example of evolution as a function of time of the volume of fuel in the tank 4, the time being represented along the abscissa axis. Each sudden increase referenced 60 corresponding to an addition of fuel in the tank. Curve 62 represents the evolution as a function of time of the state of the closure means according to the volume of fuel added, the line portion arranged at the abscissa representing the closing state of the closure means, while the line portion disposed at a distance from the abscissa represents the open state of the closure means.

Thus when the fuel level is stabilized in the tank, the amount of fuel added is calculated so as to know the amount of additive to be added, which allows to calculate the opening time of the sealing means to deliver a quantity of additive proportional to the amount of fuel added.

Here, the figure 5 illustrates three successive additions of fuel of variable volume, corresponding respectively to the first addition to a volume V, for the second addition to a third of this volume V and for the third addition to half of this volume V. As can be seen on the figure 5 each opening time of the closure means is then proportional to the added volume and corresponds respectively to a duration T, to a third of this duration T and to half this duration T.

Likewise, the fluctuations in the additive concentration in the fuel of the reservoir may be related to a variation of the additive flow rate as a result of a variation in the temperature prevailing at the level of the circulation circuit and / or a variation of the fuel flow rate in the fuel system. the circulation circuit.

Indeed, the temperature influences the viscosity of the additive and can therefore change the flow rate of the additive during its distribution. Thus, generally an increase in temperature reduces the viscosity and the density of the additive and causes an increase in the mass flow rate of additive. The origin of this fluctuation can be related in particular to the temperature of the air surrounding the distribution device, to the position of the dispensing device in the vehicle or to the temperature of the fuel, the temperature variations of the fuel circulation circuit. which can classically for a motor vehicle vary from ambient temperature, variable depending on the season, up to temperatures up to typically 120 ° C.

It is the same for the fuel whose density and viscosity are impacted by the evolution of the temperature at the level of the circulation circuit. These modifications can lead to a significant change in the concentration of additive in the fuel, the variations of the density and the viscosity of the fuel as a function of the temperature being well known.

Advantageously, a temperature sensor installed at the dispensing device makes it possible to know the temperature of the fuel circulating at the level of the device. Depending on the value of the temperature, the duration and / or the injection frequency and / or the opening amplitude of the closure means can be adapted.

The figure 6 illustrates this mode of operation. The curve 64 of this figure represents an example of evolution as a function of time of the temperature measured at the dispensing device, the time being represented along the abscissa axis. Curve 66 represents the evolution as a function of time of the state of the shutter means according to the measured temperature, the line portion arranged at the abscissa representing the closing state of the shutter means, while the line portion disposed at a distance from the abscissa represents the open state of the closure means. Curve 68 represents the tripping threshold, the shutter means being closed for a value of the temperature below this threshold and open for a value of the temperature above this threshold. Thus, adding additive is only allowed when the temperature has a value greater than the determined threshold value.

As shown, this control mode is adapted to take into account the evolution of the physicochemical characteristics of the fuel and the additive with the temperature. In this example, the additive used has a viscosity which increases when the temperature decreases. Thus, the opening of the sealing means is done regularly and each dose of injected additive is adapted to the measured temperature, the duration of the opening being all the longer as the temperature is low.

Similarly, the fuel flow in the circulation system can vary especially for vehicles equipped with low pressure fuel pump, whose flow is variable to save energy when the fuel consumption is lower. Variable flow pumps allow, for example, flow rates of 110 l / h +/- 50 l / h in the case of a particular vehicle engine (typically 2L displacement).

Fluctuations in fuel flow cause a fluctuation of the pressure difference between the additive delivery port 38 and the fuel inlet port 28, which influences the additive flow rate. Thus, an increase in the flow rate of the fuel causes an increase in the pressure difference between the orifice 38 for dispensing the additive and the orifice 28 for the entry of fuel, which causes an increase in the injection flow rate. additive.

Advantageously, pressure sensors installed at the orifices 28 and 38 can be used to control the fuel flow fluctuations and therefore to know the evolution of the additive flow rate in the distribution circuit. Depending on the values collected by the sensors, the duration and / or the injection frequency can be adapted.

The figure 7 illustrates this mode of operation. The curve 70 of this figure represents an example of evolution as a function of time of the pressure difference between the orifices 38 and 28, the time being represented along the abscissa axis. Curve 72 represents the evolution as a function of time of the state of the closure means according to the pressure difference, the line portion arranged at the abscissa representing the closing state of the closure means, while that the line portion disposed at a distance from the abscissa represents the open state of the closure means.

In this example, the opening of the shutter means is regularly. The opening time of the shutter means is inversely proportional to the difference in measured pressure which makes it possible to compensate the impact of a variable flow of fuel circulation and thus ensure the absence of fluctuation of the flow of additive when the flow of fuel circulation is variable.

One of the advantages of this third control mode is to be able to dispense the additive with a higher flow rate over a shorter time, the additive distribution being blocked the rest of the time by closing the closure means. Thus, it is possible to use a dispensing device whose dimensions, especially at the level of the means for generating a pressure difference at the level of the additive distribution channel, such as the venturi, are larger. Similarly, the dimensions of the distribution channel 36 can be increased. This allows to control more precisely the amount of additive distributed in the circulation circuit.

Preferably, in this third control mode, a shutter means for completely closing the distribution channel will be used.

Advantageously, it is possible to couple the various embodiments examples described in the first, second and third control modes.

For example, it is possible to control the temperature prevailing at the level of the circulation circuit and the variation of the flow of fuel in the circulation circuit between the orifice 38 for dispensing the additive and the orifice 28 for fuel input. , so as to adapt the duration and / or the frequency of injection of additive.

Similarly, it is possible to have for the same vehicle means for detecting stops of the vehicle so as to interrupt the dispensing of additive when stopping the vehicle, means for identifying the amount of fuel in the tank so as to inject the additive into the circulation circuit following a fuel addition, means for monitoring the temperature evolution at the distribution device, and means for monitoring the evolution of the flow rate of fuel in the circulation circuit, so as to adapt the frequency and / or the duration of opening of the closure means so that the concentration of additive remains substantially constant in the fuel tank.

Fourth driving mode

The objective of this fourth control mode is to inject the additive into the circulation circuit only when it is necessary, this can notably be done in order to adjust the concentration of additive to the momentary needs of the vehicle. Thus, the injection of additive can take place at a regular interval, such as every minute, every hour or at each tank filling or for a determined rolling interval, for example every 100 kms.

Thus, only a dose of additive necessary for the proper functioning of the vehicle is distributed in the circulation circuit. In this control mode, the concentration of additive evolves voluntarily in time, the frequency and / or the duration of opening of the closure means being adapted according to the amount of additive to be injected.

Preferably, and as will be detailed later, the dose of additive delivered may be dependent on the conditions of travel and use of the vehicle, or the type of fuel used.

Preferably, the embodiments of the fourth control mode can be coupled with one or more examples of embodiments previously described and belonging to the first, second and third control modes.

Fuel quality

In the case where the additive used is intended to improve the properties of the fuel, in particular to stabilize the fuel used or to reduce the effects of its degradation on the engine or the fuel circulation circuit or to improve its combustion properties, examples of additives will be given later, an additional injection of additive can be performed when it is detected that the engine is fed by a fuel of poor quality or unsuitable quality. Thus, the amount of additive to be added will depend on the quality of the fuel used, a lower quality fuel generally requiring a larger amount of additive.

In fact, a fuel of poor quality leads to a fouling of the injectors and therefore deteriorates the quality of the fuel jet, which increases the time of realization of the air / fuel mixture and thus degrades the combustion. In particular, fuel consumption and pollutant emissions are increased. A fuel can also have a variable composition and intrinsic properties which will influence its combustion properties and thereby the engine performance and its polluting emissions.

A fuel may also have fractions that are unstable over time, such as certain fractions of biofuels, these unstable fractions being degraded for example by oxidation and may lead to fouling of the fuel circulation circuit.

A fuel may also have poor properties leading to premature degradation or aging of the equipment of the fuel circulation circuit, for example by lack of lubricating property.

The amount of additive used may depend on the geographical area in which the vehicle rolls, the fuel meeting different standards known for each geographical area of the world.

For this purpose, a GPS chip, or any other means of geolocation, installed at the level of the distribution device or the GPS of the vehicle makes it possible to locate the zone in which the vehicle is traveling and therefore the type of fuel sold in said zone. Depending on the geographical area identified, an additional quantity of additive may be distributed, the quantity injected may also depend on the geographical area.

Alternatively, a specific probe for analyzing the fuel used may be mounted at any point in the fuel circulation circuit and / or in the fuel tank.

This probe may for example comprise a sensor of the Near Infra Red (PIR) type which may for example measure the biodiesel content of fatty acid methyl ester (FAME) type of diesel fuel. Indeed, the higher this concentration, the more the fuel is prone to degrade over time, which may cause disruption of the engine operation and more it will be necessary to add the additive to stabilize it.

Other types of specific analyzes may of course be used, such as the content of alcoholic compound for example ethanol gasoline fuel, the fraction of alcoholic compound modifying the fuel combustion properties. Similarly, analyzes can provide access to fuel combustion properties, such as cetane number for diesel and octane number for gasolines. These analyzes can be managed by the vehicle ECU or directly by the distribution device.

Similarly, the quality of the fuel can be deduced from the parameters of the combustion carried out in the engine cylinders, such as rattling, the noise of combustion or the evolution of the pressure in the cylinders. This data can in particular be retrieved from the vehicle ECU. Indeed, certain characteristics of the fuel such as the cetane number modify the combustion parameters: the lower the cetane number, the more the combustion in the cylinders starts late generating a significant increase in pressure, which generates noise.

Thus, according to the results obtained, the amount of additive to be dispensed will be adapted.

Driving conditions

The concentration of additive may also be adapted according to the driving conditions of the vehicle, by rolling condition is meant the profile of urban, road, highway or mixed vehicle traffic.

These rolling conditions are particularly important when the additive used helps the regeneration of pollution control means disposed in the vehicle exhaust line, such as a particulate filter. Indeed, when the rolling profile is of urban type, the exhaust gas has a lower temperature compared to that encountered during a highway type taxiing profile, this situation is unfavorable to the regeneration of the particulate filter . In addition, the duration of urban journeys is generally shorter, which can prevent the total regeneration of the particulate filter.

On the other hand, when the driving profile is road or motorway type and the vehicle speed is high, the temperature of the exhaust gas is higher, which facilitates the regeneration of the particulate filter. Indeed, the temperature difference between the temperature of the exhaust gas and the temperature for the regeneration of the particulate filter is then lower.

In addition, for a highway-type taxiing profile, the quantity of nitrogen oxides NOx emitted is higher, which is also favorable for the regeneration of the particulate filter.

Thus, during the implementation of this example, the amount of additive used will be adapted to the running conditions of the vehicle. More particularly, a significant amount of additive, to increase the concentration of additive in the fuel, will be injected when it will be detected that the vehicle is driven in an urban environment for a specified period. Conversely, a reduced amount of additive will be injected when it will be detected that the vehicle is driving in a motorway for a specified period.

Similarly, in other cases and depending on the additive to be injected, it may be advantageous to increase the concentration of additive in the fuel, depending on whether it is desired that the vehicle has more power, this is particularly the case. when the driving profile is motorway type or in high load conditions such as in the mountains.

In order to appreciate the running conditions of the vehicle, a GPS chip, or any other means of geolocation, installed at the level of the distribution device or the GPS of the vehicle makes it possible to locate the geographical zone in which the vehicle is traveling and therefore to know the rolling profile of the vehicle. In addition, it is also possible to obtain from these equipment the average speed of the vehicle.

It should be noted that when the GPS, or any other means of geolocation, the vehicle is used, if necessary, the signal corresponding to the planned path can be recovered and the needs of additive can then be anticipated.

Similarly, the average speed of the vehicle can be recovered by the vehicle computer. Thus, in the case where the additive is adapted to the regeneration of the filter at particles, when an average speed of less than 50 km / h and more particularly less than 30 km / h is detected, the concentration of additive is increased.

It is also possible to use the instantaneous speed of the vehicle, the concentration of additive being increased when the instantaneous speed of the vehicle is, for example, less than 50 km / h over more than one hour.

Similarly, the temperature of the exhaust gas can be used, the latter being recovered from the ECU or directly by a dedicated sensor disposed in the exhaust line of the vehicle.

Thus, when the additive used is suitable for the regeneration of the particulate filter, an additional amount of additive can be dispensed when the temperature of the gases is low, especially when it is below 300 ° C., and especially below 250 ° C.

Similarly, the fuel consumption of the engine, accessible either by a level sensor in the fuel tank or from the vehicle ECU, indicates for a given vehicle, the driving conditions of the vehicle, each vehicle having ranges of different consumption for urban / mixed / road use. For a given vehicle, high consumption is generally associated with urban use. These ranges are known during vehicle design and can be used to adjust the concentration of additive.

However, it is preferable to couple this data with other accessible data representative of the running conditions of the vehicle, such as the temperature of the exhaust gas. Indeed, a large consumption coupled with a low temperature of the exhaust gas, typically less than 300 ° C, is characteristic of urban use whereas a high consumption associated with a high temperature of the exhaust gas is characteristic of a road or motorway use requiring less additive for the regeneration of the particulate filter.

Likewise, the fluctuation of the pressure in the high-pressure system of the fuel circulation circuit, in particular in the high-pressure pump compressing the fuel or in the common injector feed-rail, can be used in order to know the driving conditions. of the vehicle.

Indeed, some vehicles have a pressure level in the high pressure part of the circulation circuit which varies. This is particularly the case for vehicles equipped with a device called "Stop and Start" or "Stop and Go" for stopping and restarting the engine automatically when it goes to neutral for example, or for hybrid-thermal vehicles. for which the engine does not operate continuously. So for these vehicles, the recorded pressure, provided for example by the vehicle ECU, in the high pressure part of the circulation circuit is reduced at each stop of the engine. Such operations are typically encountered during urban and / or short-term trips and can therefore be used to adjust the concentration of additive.

Similarly, the air flow to the combustion chamber of the engine, provided for example by the vehicle ECU, can be used to know the driving conditions of the vehicle.

Indeed, for example for diesel engines, a decrease in air flow indicates a slowdown of the engine and can therefore be associated with urban use. It may then be advantageous for vehicles equipped with particle filter type depollution means, when these conditions are detected, to increase the concentration of additive aiding the regeneration of the particulate filter.

Emissions of the engine

The concentration of additive can also be adapted according to the pollutant emissions of the engine, and more particularly according to the evolution of these pollutant emissions.

Thus, when an additive assisting the regeneration of pollution control means of the particulate filter type is used, it is particularly interesting to monitor the evolution of NOx emissions, soot or other carbonaceous particles or NOx / soot ratios. and / or NOx / particles, these various parameters being representative of the polluting emissions resulting from the combustion of the fuel.

For example, when the emissions of soot and other carbonaceous particles increase, and / or when the NOx emissions are reduced, and / or when the NOx / soot or NOx / particles ratio decreases, the concentration of additive aids in the regeneration of the Particle filter can be increased.

These different emissions can be evaluated directly by means of sensors arranged in the exhaust line.

The control of the injection of additive can then be achieved by comparing the recovered data and the expected theoretical values.

Thus, a concentration of NOx higher than the expected value is the sign of a degradation of the combustion, it may then be advantageous to increase the concentration of detergent type additive to improve the fuel combustion properties and / or allow better operation of the high pressure injectors.

It is also possible to recover from the vehicle ECU the combustion parameters of the engine, then to compare these values with the values theoretically expected in order to define the positioning of combustion in the engine mapping linking the rotational speed of the engine to its torque, each combustion point corresponding to typical emissions defining a mapping of polluting emissions.

Likewise, when the additive used aids in the regeneration of depollution means, such as a particulate filter, the evolution of the pressure drop during the soot loading of the particulate filter can be monitored in order to know the level. of emission in carbonaceous particles. Indeed, for a given particulate filter and for an architecture of the given exhaust line, an increase in the pressure drop corresponds to an increase in emissions of carbonaceous particles and can therefore trigger an additive distribution in order to increase the concentration of the latter in the fuel.

Quality of regeneration of the particulate filter

The concentration of additive may also be adapted according to the quality of the regeneration of pollution control means of the particulate filter type.

This example relates only to the additives used to help the regeneration of pollution control means disposed in the vehicle exhaust line, such as a particulate filter.

Thus, when the previous regeneration has not gone well, that is to say when the soot contained in the particulate filter have not completely burned, the concentration of additive in the fuel is increased to promote the next regeneration.

The quality of a regeneration can be evaluated in different ways.

The evolution of the pressure drop during the previous regeneration is a first indicator. Thus, when the pressure drop does not return to the expected baseline, or near this baseline, and there is for example at least 5 mbar deviation, and / or it returns slowly for example, in excess of 20 minutes, at the baseline, the concentration of additive can be increased.

Similarly, the evolution of the properties of the engine lubricating oil, called engine oil, can be observed.

The quality of the engine oil tends to deteriorate when the regeneration of the particulate filter is slower than usual. Indeed, slow regeneration requires late post-injections of fuel in the cylinders for a long time so as to maintain a high temperature in the particulate filter throughout the regeneration period. These post-injections or late injections with respect to Top Dead Center in the cylinder compression / decompression cycle result in a portion of the fuel in the engine oil, leading to the dilution of the engine oil. This dilution causes, on the one hand, an increase in the level of liquid in the engine oil circuit and, on the other hand, a deterioration in the properties of the engine oil, in particular a change in its viscosity, its lubricating properties and its acidity. . In addition, the oil can be contaminated with soot or carbonaceous particles.

Thus, when an increase in the oil level over time and / or a deterioration of the quality of the oil is detected, the concentration of additive can be increased so as to assist the next regeneration of the particulate filter.

The data can be retrieved from probes or sensors analyzing the engine oil, and sent directly to the control means controlling the injection means of the additive or the vehicle ECU in relation to said control means.

• d'un capteur détectant la variation de la constante diélectrique de l'huile, variation reliée à l'état de dégradation et de pollution par les matières charbonneuse comme les suies,
• d'un capteur détectant la variation de viscosité de l'huile moteur, et/ou
• d'un capteur détectant l'évolution de l'état d'oxydation et d'acidité de l'huile par un suivi de la corrosion d'un fil métallique au contact de l'huile.

The means of analysis of the engine oil used may consist of:

• a sensor detecting the variation of the dielectric constant of the oil, variation related to the state of degradation and pollution by carbonaceous materials such as soot,
• a sensor detecting the viscosity variation of the engine oil, and / or
• a sensor detecting the evolution of the oxidation state and acidity of the oil by monitoring the corrosion of a wire in contact with the oil.

Fifth driving mode

The objective of this fifth control mode is to recognize the nature and / or characteristics of the additive contained in the additive reservoir 26.

Thus, the additive distribution can be adapted to take into account either the identified additive or the precise value of certain physico-chemical characteristics of the batch of additive used.

This control mode thus makes it possible to change the nature and / or the characteristics of the additive used during the life of the vehicle, the latter being indeed able to be changed, for example to improve the performance of an aging engine, or more a modification of a fuel standard in a given geographical area, or when the vehicle changes its geographical location, or when modifications have been made to the vehicle, such as the addition of a particulate filter.

In addition, this control mode allows to adapt precisely to the additive used, the latter may have a viscosity, a density and / or a varying concentration from one batch to another.

In the latter case, the tank containing the additive, especially when it is in the form of a pocket, can be equipped with a barcode type information system for transmitting information and the dispensing device can be equipped with a means for reading the information.

Thus, according to the information collected by the dispensing device, the frequency and / or the duration of opening of the closure means allowing the distribution of the additive are recalculated in order to deliver the desired quantity of active elements in the fuel.

Obviously, the various piloting described above as examples are not limiting, other parameters for analyzing the use of the vehicle, and / or the vehicle running conditions, and / or the evolution the quantity of fuel contained in the fuel tank, and / or the quality of the fuel, and / or the polluting emissions resulting from the combustion of the fuel in the engine, and / or the quality of the regeneration of depollution means disposed in the exhaust line of the engine, and / or the type of additive used, and / or the evolution of the flow rate of additive dispensed into the fuel circulation circuit, which can be used.

In addition, as mentioned above, different driving examples can be combined with each other.

Similarly, several additives each stored in an independent reservoir can be distributed in the circulation circuit using the dispensing device according to the invention, each additive being injectable according to an embodiment previously described. The choice of additives is made by those skilled in the art taking into account, for example, the geographical area in which the vehicle is marketed, the quality of the fuel available in this geographical area, including the possible presence of biofuels in this area. or the weather conditions that we encounter there.

The choice of additives can also be made with regard to the regulation regulating the maximum pollutant emission levels in this same zone. In areas where the particulate filter is required to meet the emission standard for soot emissions, a suitable additive will be advantageously incorporated to help regenerate the particulate filter.

The choice of the composition of the additive can also be made according to the engine technology of the vehicle such as the nature and design of the high pressure fuel injectors, the type of fuel filter or the pressure available in the high pressure rail. supplying each of the injectors with pressurized fuel.

The choice of the additive (s) can also be done according to the mapping of the polluting emissions of the engine.

additives

The different additives that can be used by the dispensing device according to the invention are from this point more particularly described, these additives being known and widely used in the automotive industry.

As indicated above when describing the various control modes, certain additives are more particularly concerned by the examples described above.

These additives, which will now be described, can be classified into two categories: on the one hand, those which have a catalytic function of assisting the regeneration of particulate filters and, on the other hand, those which have a function other than catalytic function.

The additives used are generally in liquid form and can consist of a liquid or a mixture of liquids, a colloidal suspension in a liquid base, or in the form of a gel whose viscosity allows the flow of the additive.

Regeneration aid additives

These additives are ideally liquid in the operating temperature range, generally between 20 and 45 ° C but they can also be in another physical form such as a gel.

These additives may contain any type of catalyst effective to catalyze the combustion of soot including platinum, strontium, sodium, manganese, cerium, iron and / or their combination.

The amount of additive required in the fuel is generally at least about 1 ppm and at most about 100 ppm, this amount being expressed as a mass of metal additive element relative to the fuel mass.

These additives may be in the form of an organometallic salt or a mixture of organometallic salts which are soluble or dispersible in the fuel. These salts are characterized in that they comprise at least one metal part and a complexing organic part generally of acid origin, all suspended in a solvent.

The BCF additives may also be in the form of an organometallic complex or a mixture of organometallic complexes soluble or dispersible in the fuel. These complexes are characterized in that they comprise at least one metal part and at least two organic complexing parts. Such a product is for example described in GB 2,254,610 .

Also, the BCF additives may also be in the form of a colloidal suspension or dispersion of nanoparticles, for example amorphous or crystalline metal oxide or oxyhydroxide.

The term "colloidal dispersion" designates in the present description any system consisting of fine solid particles of colloidal dimensions based on the additive, in suspension in a liquid phase, said particles possibly also possibly containing residual amounts of bound or adsorbed ions such as, for example, nitrates, acetates, citrates, ammoniums or chlorides. By colloidal dimensions is meant dimensions of between about 1 nm and about 500 nm. These particles may more particularly have an average size of at most 100 nm and even more particularly of at most 20 nm.

In the case of BCF additives in the form of a colloidal dispersion, the particles may be based on a rare earth and / or a metal selected from groups IIA, IVA, VIIA, VIII, IB, IIB, IIIB and IVB of the periodic table.

Rare earth means the elements of the group constituted by yttrium and the elements of the periodic classification of atomic number inclusive between 57 and 71.

The periodic table of elements to which reference is made is that published in the Supplement to the Bulletin of the Chemical Society of France No. 1 (January 1966).

For these additives that may be used in the form of a colloidal dispersion, the rare earth may be chosen more particularly from cerium, lanthanum, yttrium, neodymium, gadolinium and praseodymium. Cerium can be chosen especially. The metal may be selected from zirconium, iron, copper, gallium, palladium and manganese. Iron can be chosen especially. The iron may be in the form of an amorphous or crystalline compound.

Colloidal dispersions based on a combination of cerium and iron may also be mentioned more particularly.

• une phase organique,
• des particules de l'additif, du type décrit ci-dessus (notamment terre rare et/ou d'un métal choisi dans les groupes IIA, IVA, VIIA, VIII, IB, IIB, IIIB et IVB), en suspension dans la phase organique ;
• au moins un agent amphiphile.

The colloidal dispersions may more particularly comprise:

• an organic phase,
• particles of the additive, of the type described above (in particular rare earth and / or a metal chosen from groups IIA, IVA, VIIA, VIII, IB, IIB, IIIB and IVB), suspended in the phase organic ;
• at least one amphiphilic agent.

These colloidal dispersions may especially contain an additive based on iron or an iron compound.

The colloidal dispersions can be presented according to various embodiments described in particular the following patent applications: EP 671,205 , WO 97/19022 , WO 01/10545 , WO 03/053560 , WO 2008/116550 .

Other additives

Other types of known additives, different from BCFs and having a function other than a catalytic function, can also be injected into the circulation circuit. These additives allow the improvement of the fuel distribution in the engine and / or the improvement of the performance of the engine operation and / or the improvement of the stability of the operation of the engine.

Among the additives for improving the fuel distribution in the engine are, for example, anti-foam additives, such as organosilicones, de-icing additives, such as low molecular weight alcohols or glycols.

Other additives are those improving the operation of the cold engine. These include polymeric additives that reduce the temperature at which fuel is cloudy or freeze, flow-promoting additives, such as high molecular weight polymers that reduce turbulence in fluids, and can increase throughput by 20 to 40 percent. .

Corrosion inhibiting additives may also be used.

Engine performance improvement additives may also be used, such as procetane additives, prooctane additives, smoke inhibiting additives, friction loss reducing additives called FM additives for "Friction Modifier" or "additive" additives. 'extreme pressure' ..

Detergent additives intended to limit any deposit at the injectors can also be used. The fuel can form deposits in the fuel system, especially at the high-pressure fuel injectors and especially at the holes of the injectors. The extent of deposition formation varies with the design of the engine, including the characteristics of the injectors, the fuel composition and the composition of the oil used to lubricate the engine. In addition, these detergents are also effective in reducing the negative impact of the presence of metal compounds in the fuel such as Zn or Cu that may arise from a contamination for example of the fuel distribution system or be traces of compounds from the process of synthesis of fatty acid esters.

Excessive deposits can alter the aerodynamics of, for example, the jet of fuel from the injector, which in turn can impede the air-fuel mixture. In some cases this results in overconsumption of fuel, loss of engine power and increased pollutant emissions.

Detergent additives have the particularity of dissolving already formed deposits and reducing the formation of deposit precursors, in order to avoid the formation of new deposits. An example of a detergent additive is, for example, described in WO 2010/150040 .

Additives for improving the lubricating power can also be used to avoid wear or seizure of the high-pressure pumps and injectors, the lubricating power of the fuels being poor. They contain a polar group that is attracted to the metal surfaces to form a protective film on the surface.

Additives for improving the operating stability of the engines can be envisaged. Indeed, the instability of fuels causes the formation of gums that participate in the fouling of the injectors, the clogging of the fuel filter and fouling of the pumps and the injection system.

• des additifs de type antioxydants ;
• des additifs stabilisateurs ;
• des additifs désactivateurs de métaux visant à neutraliser les effets catalytiques de certains métaux ;
• des additifs dispersants visant à disperser les particules formées et prévenir l'agglomération de particules assez grosses.

The following additives can also be used:

• antioxidant type additives;
• stabilizing additives;
• metal deactivator additives to neutralize the catalytic effects of certain metals;
• dispersant additives to disperse the formed particles and prevent agglomeration of rather large particles.

According to a particular embodiment, the additive is a combination of a detergent additive and a lubricating additive, and possibly a corrosion inhibiting additive.

In the case of a vehicle equipped with a particulate filter, it will be advantageous to associate with an additive type FBC at least one detergent-type fuel performance additive as described in the patent application. WO 2010/150040 .

In the case of a vehicle equipped with a particulate filter, it will also be advantageous to associate with an additive type FBC several fuel performance additives, especially when the vehicle is marketed in a geographical area where the fuel is of variable quality. and / or mediocre.

In the case of a vehicle not equipped with a particulate filter, different types of additive combinations can be envisaged such as that combining one or more detergents with a lubricating additive and a corrosion inhibitor.

Claims (35)

1. A device for dispensing a liquid additive in a fuel circulation circuit (2) for an internal combustion engine, in particular for an engine equipping a vehicle, said device comprising:

   - a tank (26) containing the additive,

   - an enclosure (24) communicating with the fuel circulation circuit (2) and inside which the tank (26) containing the additive is inserted, at least one movable sealing wall (50) between said enclosure (24) and said tank (26) providing a sealing separation on the one hand and maintaining an identical pressure between the additive in the tank (26) and the fuel in the enclosure (24) on the other hand,

   - means for injecting the additive connected to the tank (26) and the fuel circulation circuit (2) and making it possible to dispense the additive in the fuel circulation circuit (2), said means including a dispensing channel (36) connecting the tank (26) and the fuel circulation circuit (2), and

   - means for controlling the injection means, characterized in that it further includes:

   - a temperature sensor intended to indicate the temperature of the fuel in the fuel circulation circuit (2), in particular near the dispensing channel (36), and/or of the additive, the temperature of the additive and/or the fuel constituting a parameter representative of the evolution of the additive flow rate and/or the use of the vehicle and/or climate conditions; and

   - pressure sensors measuring the pressure at an additive dispensing orifice (38) positioned at one end of the dispensing channel (36) situated at the fuel circulation circuit (2), and at an inlet orifice (28) for the fuel positioned upstream from the dispensing orifice in the circulation circuit (2), a pressure difference between the orifices constituting a parameter representative of the use of the vehicle and/or the evolution of the additive flow rate and/or the travel conditions;

   the control means being associated with:

   - means for analyzing at least one parameter representative of the use of the vehicle; and/or

   - means for analyzing the travel conditions of vehicle, and/or

   - means for analyzing the evolution of the quantity of fuel contained in a fuel tank (4), said tank being accessible to a user so as to add fuel, and/or

   - means for analyzing the quality of the fuel, and/or

   - means for analyzing the polluting emissions resulting from the combustion of the fuel in the engine and/or

   - means for analyzing the quality of the regeneration of a particle filter positioned in the exhaust line of the engine, and/or

   - means for analyzing the type of additive used, and/or

   - means for analyzing the evolution of the additive flow rate dispensed in the fuel circulation circuit (2), and/or

   - means for analyzing climate conditions,

   to monitor the operation of the injection means.
2. The dispensing device according to claim 1, characterized in that the injection means include means for closing off the dispensing channel (36), the closing off means being suitable for completely or partially closing off the dispensing channel (36), the closing off means in particular being of the valve or solenoid valve type.
3. The dispensing device according to claim 1 or 2, characterized in that it includes a temperature sensor outside the vehicle, the outside temperature constituting a parameter representative the climate conditions.
4. The dispensing device according to any one of claims 1 to 3, characterized in that it includes a sensor detecting the turning on of the vehicle and/or an element belonging to the fuel circulation circuit (2), in particular a fuel filter, the turning on constituting a parameter representative of the use of the vehicle.
5. The dispensing device according to any one of claims 1 to 4, characterized in that it includes a noise sensor positioned preferably near the engine, the detection of noise by the sensor constituting a parameter representative of the use of the vehicle.
6. The dispensing device according to any one of claims 1 to 5, characterized in that it includes location means of the GPS type or a movement sensor, the detection of movement by the location means or the movement sensor constituting a parameter representative of the use of the vehicle and/or the travel conditions of the vehicle.
7. The dispensing device according to any one of claims 1 to 6, characterized in that the average speed and/or instantaneous speed of the vehicle constitutes a parameter representative of the travel conditions of the vehicle.
8. The dispensing device according to any one of claims 1 to 7, characterized in that the temperature of the exhaust gases constitutes a parameter representative of the travel conditions of the vehicle.
9. The dispensing device according to any one of claims 1 to 8, characterized in that the evolution of the pressure in the circulation circuit (2), in particular in a high-pressure circuit of the vehicle made up of a high-pressure pump and a shared injection ramp, constitutes a parameter representative of the travel conditions of the vehicle.
10. The dispensing device according to any one of claims 1 to 9, characterized in that the evolution of the air flow rate supplying the combustion chamber of the engine constitutes a parameter representative of the travel conditions of the vehicle.
11. The dispensing device according to any one of claims 1 to 10, characterized in that the evolution of the fuel flow rate in the circulation circuit (2) constitutes a parameter representative of the evolution of the additive flow rate.
12. The dispensing device according to any one of claims 1 to 11, characterized in that the evolution of the emissions of NOx, soot or other carbon particles or the NOx/soot and/or NOx/particle ratios constitute parameters representative of the polluting emissions resulting from the combustion of the fuel.
13. The dispensing device according to any one of claims 1 to 12, characterized in that the evolution of the quality and/or quantity of oil allowing lubrication of the engine constitutes a parameter representative of the evolution of the quality of the regeneration of the particle filter positioned in the exhaust line of the engine.
14. The dispensing device according to any one of claims 1 to 13, characterized in that it includes a location means of the GPS type indicating the geographical area in which the vehicle is located, the location of the vehicle provided by the means constituting a parameter representative of the quality of the fuel marketed in the geographical area.
15. The dispensing device according to any one of claims 1 to 14, characterized in that parameters representative of the combustion of the fuel in the cylinders of the engine constitute a parameter representative of the quality of the fuel.
16. The dispensing device according to any one of claims 1 to 15, characterized in that the fuel consumption of the engine constitutes a parameter representative of the travel conditions of the vehicle.
17. The dispensing device according to any one of claims 1 to 16, characterized in that the additive may be a particle filter regenerating additive with a base of a rare earth and/or a metal chosen from groups IIA, IVA, VIIA, VIII, IB, IIB, IIIB and IVB of the periodic table.
18. The dispensing device according to claim 17, characterized in that the additive assumes the form of a colloidal dispersion.
19. The dispensing device according to claim 18, characterized in that the particles of the colloidal dispersion have a base of cerium and/or iron.
20. The dispensing device according to any one of claims 17 to 19, characterized in that the additive is a combination of a colloidal particle dispersion that includes an organic phase and at least one amphiphilic agent and a detergent.
21. The dispensing device according to any one of claims 1 to 16, characterized in that the additive is an additive allowing the improvement of the dispensing of fuel in the engine and/or the improvement of the running performance of the engine and/or the improvement of the running stability of the engine.
22. The dispensing device according to claim 21, characterized in that the additive is a combination of a detergent additive and a lubrication additive.
23. A motor vehicle comprising:

    - a fuel circulation circuit (2) for an internal combustion engine of the vehicle,

    - a tank (26) containing a liquid additive,

    - an enclosure (24) communicating with the fuel circulation circuit (2) and inside which the tank (26) containing the additive is inserted, at least one moving sealing wall (50) between said enclosure (24) and said tank (26) ensuring sealed separation on the one hand and maintaining an identical pressure between the additive in the tank (26) and fuel in the enclosure (24) on the other hand,

    - means for injecting the additive that are connected to the tank (26) and the fuel circulation circuit (2) and that make it possible to dispense the additive in the fuel circulation circuit (2), said means comprising a dispensing channel (36) connecting the tank (26) and the fuel circulation circuit (2),

    characterized in that the additive is injected using a dispensing device according to any one of claims 1 to 22.
24. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that dispensing of the additive is stopped when the engine of the vehicle is no longer running or when the vehicle is stopped.
25. A method for using a dispensing device according to any one of claims 1 to 22 combined with claim 2, characterized in that the additive dispensing is activated when the closing off means is powered on.
26. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that the dispensing of additive is activated when a pressure difference greater than 2 mbar is measured between the additive dispensing orifice (38) positioned at one end of the dispensing channel (36) and the fuel inlet orifice (28) positioned upstream in the circulation circuit (2) on the other hand.
27. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that the additive dispensing is activated when the temperature of the fuel circulating in the circulation circuit (2) and/or of the additive is above a threshold value representative of a running engine, for example greater than 15°C.
28. A method for using a dispensing device according to any one of claims 1 to 22 combined with claim 4, characterized in that the additive dispensing is stopped when the outside temperature and/or the temperature of the additive and/or the temperature of the fuel in the fuel circulation circuit (2) are below a minimum threshold temperature or above a maximum threshold temperature, said minimum and maximum threshold temperatures being defined for a given additive, the minimum threshold temperature being able to correspond to a value for which the viscosity of the additive reaches a threshold value and the maximum threshold temperature being able to correspond to the vaporization value of the additive.
29. A method for using a dispensing device according to any one of claims 1 to 22 combined with claim 2, characterized in that the injection is discontinuous and in that the frequency and/or opening time of the closing off means depend on information collected by the control means, the dispensing of additive being done so as to preserve a constant additive concentration in the fuel or to inject the additive in the fuel circulation circuit (2) only when necessary.
30. The method according to claim 29, characterized in that the dispensing frequency and/or the dispensing duration of the additives depend either on the usage time of the vehicle and/or on the number of kilometers traveled by the vehicle and/or the fuel consumption of the vehicle.
31. The method according to claim 29, characterized in that the frequency and/or duration of additive dispensing depend on the temperature of the fuel and/or the additive, and/or on the pressure between the additive dispensing orifice (38) positioned at one end of the dispensing channel (36) and the fuel inlet orifice (28) positioned upstream in the circulation circuit (2).
32. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that the additive is injected each time fuel is added in the fuel tank (4), the volume of said additive being able to be fixed or variable, the variable volume being determined based on the quantity of fuel added.
33. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that the additive is injected when the analysis of the polluting emissions resulting from the combustion of the fuel indicates that the gases and/or particles emitted diverge from the theoretical expected value.
34. A method for using a dispensing device according to any one of claims 1 to 22, for which the additive is injected before regenerating the particle filter.
35. A method for using a dispensing device according to any one of claims 1 to 22, characterized in that an additional quantity of additive is injected before the regeneration of the particle filter when the previous regeneration was not of good quality.

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