DE102017205860A1 - Method for operating a particle filter - Google Patents

Abstract

The invention relates to a method for operating a particle filter (4) of a vehicle, which is connected downstream of an internal combustion engine (2) of the vehicle, with which a fuel (10) is burnt to exhaust gas, whereby particles of the exhaust gas are filtered by the particle filter (4) wherein at least one property of the fuel (10) is dependent on a value of at least one parameter of the fuel (10), wherein a loading of the particulate filter (4) with particles as a function of a current value of the at least one parameter of a currently fueled fuel (10 ) is modeled.

Description

The present invention relates to a method of operating a particulate filter.

An exhaust system of a vehicle includes u. a. a particulate filter, with which it is possible to filter particles, for example, ashes, from exhaust gas of an internal combustion engine or of an internal combustion engine of the vehicle.

The publication DE 10 2011 108 908 A1 describes a method of predicting a peak temperature in a vehicle particulate filter.

A method for determining a soot particle filter efficiency of a soot particle filter is disclosed in the document DE 10 2011 122 165 A1 known.

In the publication DE 10 2012 222 104 A1 a method for operating an internal combustion engine in a motor vehicle is described.

The publication DE 10 2013 013 063 A1 describes a method for operating an automotive internal combustion engine with an exhaust particulate filter.

A method for the regeneration of an exhaust gas particulate filter in a vehicle is from the document DE 10 2015 102 753 A1 known.

Against this background, it was an object of the present invention to clean a particulate filter for an internal combustion engine.

This object is achieved by a method having the features of patent claim 1. Embodiments of the method are evident from the dependent claims and the description.

The inventive method is provided for operating a particulate filter of a vehicle, which is connected downstream of an internal combustion engine of the vehicle, with which a fuel is burned to exhaust gas. In this case, particles of the exhaust gas are filtered by the particulate filter, wherein at least one property of the fuel is dependent on a value of at least one parameter of the fuel. A loading of the particle filter with particles is modeled as a function of a current value and / or depending on this current value of the at least one parameter of a fuel currently being fueled.

In an embodiment, taking into account the at least one parameter of the currently fueled fuel, a soot model is provided, with which the loading of the particulate filter with particles of the exhaust gas due to combustion of this fuel is modeled.

By taking into account the at least one parameter, it is possible to determine the load of the particulate filter as accurately as possible and to adapt it to the present fuel or currently fueled. One type of regeneration of the particulate filter itself is not affected, only a frequency of regeneration is better controllable.

With the at least one parameter, a tendency of soot formation as a property of the currently fueled fuel is described.

Alternatively or additionally, in the method according to the invention with the at least one parameter, a boiling behavior is described as a property of the currently fueled fuel.

It is usually provided that the internal combustion engine is set for a defined type of fuel or is set ex works, for which the at least one parameter has a defined value. To operate the internal combustion engine, if possible, this defined type of fuel should also be used, whereby in addition to an optimal efficiency of the internal combustion engine, a minimal emission of particles and thus a low loading of the particle filter is achieved. If a currently fueled fuel is to be burned with the internal combustion engine, which differs from the defined fuel, it is possible to adapt the regeneration of the particulate filter to the currently fueled.

In this case, a difference between the current value of the at least one parameter of the currently fueled fuel and the defined value of the at least one parameter of the defined fuel is determined in design, wherein the loading of the particulate filter is determined taking into account this difference.

Furthermore, it is possible that the current value of the at least one parameter is determined at a start of the internal combustion engine.

Alternatively or additionally, for example, at the start of the internal combustion engine, a signal for a rotational speed of the internal combustion engine is evaluated, from which the current value of the at least one Parameters of the currently fueled fuel is determined.

It is also alternatively or additionally possible that an amount of fuel that is injected into the internal combustion engine, is determined, from which the current value of the at least one parameter of the currently fueled fuel is determined.

A poorly boiling currently fueled fuel is determined via an evaluation of the signal of the rotational speed at the start of the internal combustion engine. If a startup of the internal combustion engine is not as fast or in the same quality as actually expected, an injected amount of fuel is raised in a subsequent start of the internal combustion engine. This additional amount is an indication of the boiling behavior of the currently fueled fuel, which in turn correlates directly with the formation of soot. Therefore, by considering the necessary amount of fuel for startup, the modeling of the mass of soot that is burned is improved.

A frequency of the regeneration is performed in an embodiment depending on the current value of the at least one parameter of the fuel currently being fueled.

In this case, it is possible for the at least one parameter to describe an inclination of soot formation as a property of the fuel. It is possible to carry out the regeneration depending on the tendency of soot formation of the currently used fuel.

Alternatively or additionally, it is possible to carry out the regeneration depending on the boiling behavior of the currently used fuel.

Taking into account the at least one parameter of the fuel, a soot model is provided and / or determined with which a loading of the particulate filter with particles of the exhaust gas is modeled as a function before the current value of the at least one parameter of the fuel.

In an embodiment, the soot model depends on the value of the at least one parameter of the currently fueled fuel, for example, gasoline or diesel. The currently fueled, currently refueled fuel is a mixture of different hydrocarbon compounds, the quantitative mixing ratio of which results in the value of the at least one parameter. Thus, several types of soot models are possible depending on the fuel. In each embodiment, a type of regeneration to be carried out depends on the respective type of soot model and / or correlated therewith, one type of soot model in each case being assigned a type of regeneration.

Furthermore, each type of carbon black model describes at least one condition for carrying out the respective type of regeneration, wherein the type of regeneration is selected and carried out, the condition of which is given and / or fulfilled by the value or depending on the value of the at least one parameter.

In an embodiment, it is possible for each soot model to describe and / or control an intervention of the internal combustion engine to carry out the regeneration and / or a sequence of the regeneration.

In addition, the value of the at least one parameter describes a composition as a property of the fuel.

With the method it is u. a. it is possible to model an emission of soot as a particle of the fuel, in the form of soot emissions, with a soot model, taking into account a quality of the fuel used. Accordingly, the respective soot model and thus the type of regeneration also depends on the quality of the fuel as a possible parameter of the fuel. In the method, monitoring and control of the regeneration of the particulate filter in the vehicle are possible, whereby the soot load of the particulate filter is described and / or imaged via the soot model. Thus, for example, motor interventions and thus interventions of the internal combustion engine for the regeneration of the particle filter are controlled via the respective soot model. It is considered that the formation of soot and thus generally the formation of particles depends on various parameters of the operation of the internal combustion engine. This applies, for example, the temperature of the exhaust gas of the internal combustion engine and / or a combustion chamber of the internal combustion engine and a lambda value of the exhaust gas of the internal combustion engine. In the context of the method, it is taken into account that the composition of the fuel, on which the boiling behavior of the fuel used also depends, also influences an emission of particles and thus of soot, for example a raw emission of particles.

This takes into account that the composition of the fuel in the field is subject to significant fluctuations, which are taken into account when carrying out the method in a vote of the carbon black model.

Usually, it is provided in measures for regeneration, which are known from the prior art, an application or application of a soot model depending on a worst possible fuel, ie a fuel that causes a worst possible Siedeverlauf and thus the greatest possible emissions of soot, adjust. If, however, better boiling and thus better evaporating fuel should be used, there is a risk that due to one determined soot model in the regeneration too aggressive modeling is taken into account, so that regenerations are triggered too often and take too long. If regenerations are triggered too frequently, this can affect the vehicle's handling behavior. In addition, a consumption of fuel is increased.

The method is u. a. takes into account that poorly boiling fuel not only negatively affects the formation of soot but also other factors, for example a starting behavior of the internal combustion engine.

As part of the process, adaptations are used to detect low-boiling fuel to compensate for injection. Parameters of such adaptations are used in the soot model to account for a greater propensity for soot formation of the fuel and thus more accurately model a particulate filter load via the soot model and as a function of the current value of the at least one fueled parameter.

Consideration of the influence of the fuel on the boiling behavior and thus on soot emissions in one embodiment of the method optimizes the soot model, whereby the regeneration of the particulate filter can be improved.

Further advantages and embodiments will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

• 1 zeigt in schematischer Darstellung Komponenten eines Fahrzeugs bei der Durchführung einer Ausführungsform des erfindungsgemäßen Verfahrens.

The invention is illustrated schematically with reference to an embodiment in the drawing and will be described schematically and in detail with reference to the drawing.

• 1 shows a schematic representation of components of a vehicle in carrying out an embodiment of the method according to the invention.

1 shows a schematic representation of an internal combustion engine 2 , a particle filter 4 , a tank 6 as well as a control unit 8th , which are formed here as components of a vehicle. Here is the internal combustion engine 2 designed to drive the vehicle. This is fuel 10 who is currently in the tank 6 located to the internal combustion engine 2 promoted and burned by this. This produces exhaust gas, which is supplied to an exhaust system of the vehicle, wherein the particulate filter 4 is designed here as a component of the exhaust system of the vehicle. With the particle filter 4 become particles, usually soot, from the exhaust of the engine 2 filtered.

However, it is necessary to use the particulate filter 4 regularly cleaned by particles deposited therein, which is why this regeneration is performed. For this purpose, a temperature of the exhaust gas of the internal combustion engine is set to a value which is at least as great as a value for the temperature at which the particles in the particulate filter 4 to be burned.

In the embodiment of the method is provided, a value of at least one parameter of the currently fueled and combusted fuel 10 to take into account. The parameter usually relates to a boiling behavior of the fuel 10 and / or an inclination of the fuel 10 for the formation of particles and thus of soot, resulting in a soot model for that of the internal combustion engine 2 currently burnt fuel 10 in the particulate filter 4 is modeled. In addition, a load of the particulate filter 4 modeled with particles as a function of the value of the at least one parameter of the currently fueled fuel. The regeneration depends on the value of the at least one parameter of the fuel 10 carried out. In an embodiment, it is possible for a plurality of types of regeneration to be carried out, one type each being dependent on the value of the at least one parameter of the fuel 10 is selected.

In a further embodiment of the method, the at least one parameter of the fuel from a sensor 12 determined in the tank 6 is arranged. Based on the value of the at least one detected parameter of the fuel 10 is the regeneration and / or a type of regeneration of the controller 8th controlled. As an alternative or in addition, the value of the at least one parameter of the fuel currently to be combusted is determined via a sensor which has a behavior and / or an operating parameter of the internal combustion engine 2 when burning the fuel 10 includes. This concerns, for example, a speed or a resulting signal of the internal combustion engine 2 when it is started up at a start, and / or each injecting or injected amount of fuel 10 in a combustion chamber of the internal combustion engine 2 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011108908 A1 [0003]
• DE 102011122165 A1 [0004]
• DE 102012222104 A1 [0005]
• DE 102013013063 A1 [0006]
• DE 102015102753 A1 [0007]

Claims (10)

Method for operating a particle filter (4) of a vehicle, which is connected downstream of an internal combustion engine (2) of the vehicle, with which a fuel (10) is burnt to exhaust gas, wherein particles of the exhaust gas are filtered by the particle filter (4), wherein at least one Property of the fuel (10) is dependent on a value of at least one parameter of the fuel (10), wherein a loading of the particulate filter (4) is modeled with particles as a function of a current value of the at least one parameter of a currently fueled fuel (10). Method according to Claim 1 in which, taking into account the current value of the at least one parameter of the currently fueled fuel (10), a soot model is provided with which the loading of the particulate filter (4) with particles of the exhaust gas is modeled. Method according to Claim 1 or 2 in which the at least one parameter describes a tendency of soot formation as a property of the currently fueled fuel (10). Method according to one of the preceding claims, wherein with the at least one parameter a boiling behavior as a property of the currently fueled fuel (10) is described. Method according to one of the preceding claims, wherein it is provided that the internal combustion engine (2) is set for a defined type of fuel for which the at least one parameter has a defined value. Method according to Claim 5 in which a difference between the current value of the at least one parameter of the currently fueled fuel (10) and the defined value of the at least one parameter of the defined fuel is determined, wherein the load is determined taking into account this difference. Method according to one of the preceding claims, wherein the current value of the at least one parameter of the currently fueled fuel (10) at a start of the internal combustion engine (2) is determined. Method according to one of the preceding claims, wherein a signal for a rotational speed of the internal combustion engine (2) is evaluated, from which the current value of the at least one parameter of the currently fueled fuel (10) is determined. Method according to one of the preceding claims, in which an amount of fuel which is injected into the internal combustion engine (2) is determined, from which the current value of the at least one parameter of the currently fueled fuel (10) is determined. Method according to one of the preceding claims, in which a frequency of regeneration is carried out as a function of the current value of the at least one parameter of the currently fueled fuel (10).

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