DE102015217394A1 - Method for controlling a particle filter and motor vehicle - Google Patents

Abstract

Operating method (60) for a motor vehicle (10) with an engine (11), a supply air line (12), an exhaust line (13), a particle filter (22) arranged in the exhaust line (13), an injector (29, 68), adapted to introduce fuel (31) into a combustion chamber (34) of the engine (11) or into the exhaust line (13), a low-pressure exhaust gas recirculation train (19), which is formed exhaust gas (36) from the exhaust line (13) from a downstream of the particulate filter (22) arranged low pressure exhaust gas sampling point (24) to a in the Zuluftstrang (12) arranged low pressure Abgaseinleitstelle (25) to direct, and a high-pressure exhaust gas recirculation line (45) which is formed exhaust gas (36) from the exhaust line (13) from a high-pressure exhaust gas sampling point (46) arranged upstream of the particle filter (22) to a high-pressure exhaust gas inlet point (47) arranged in the supply air line (12), in which case the particle filter (22) is controlled in a particle film (66) by comparing at least one particulate filter actual value (A) with a particulate filter setpoint (B) a need for a measure is determined in a measure implementation (66) the measure is performed, wherein in the particulate filter test (63) an oxygen content in Exhaust gas (36) or a particulate filter temperature is considered, and wherein the measure comprises supplying to the engine (11) during a coasting operation of the motor vehicle (10) charge gas (35) having recirculated exhaust gas (37, 49).

Description

The present invention relates to an operating method for a motor vehicle and a motor vehicle for carrying out the operating method.

In the prior art, for example, from the DE 102013111110 A1 It is known that engines having exhaust gas recirculation systems can be configured to divert at least a portion of the exhaust gas from an engine exhaust passage to an engine intake passage. Exhaust gas recirculation (EGR) can reduce engine pumping work and NOx emissions. For example, exhaust gas recirculation at throttle working conditions causes the throttle to be opened to a greater extent for the same engine load. By reducing the throttling of the engine, pumping losses can be reduced, thereby improving fuel efficiency. Further, with exhaust gas recirculation, the combustion flame temperature can be reduced, which reduces an amount of NOx generated during combustion.

The DE 102011101079 A1 shows a method for the regeneration of NOx storage catalytic converters of diesel engines with low pressure EGR. In particular, the DE 102011101079 A1 on the regeneration of nitrogen oxide storage catalysts during special driving situations of the vehicle.

The DE 102008015600 A1 discloses a method for operating an internal combustion engine, in particular a diesel engine, wherein exhaust gas via a particulate filter, in particular a diesel particulate filter, passed into an exhaust system, branched off for a low pressure exhaust gas recirculation (low pressure EGR) downstream of the diesel particulate filter exhaust gas from the exhaust system and upstream of a compressor of an exhaust gas turbocharger Fresh air system is supplied via a low-pressure EGR valve, further for a high-pressure exhaust gas recirculation (high-pressure EGR) exhaust branched upstream of a turbine of the exhaust gas turbocharger from the exhaust system and is supplied downstream of the compressor of the fresh air system via a high-pressure EGR valve. During a regeneration of the particulate filter, the high-pressure EGR valve is completely closed and the low-pressure EGR valve is at least partially opened.

It is an object of the present invention to be able to influence parameters for at least one exhaust aftertreatment device more easily and thus to be able to better control the exhaust aftertreatment device.

This object is achieved with an operating method according to claim 1 and a motor vehicle according to claim 5. Advantageous developments of the invention are specified in the subclaims and described in the description.

In the operating method according to the invention for a motor vehicle with an engine, a Zuluftstrang, an exhaust line, disposed in the exhaust line particulate filter, an injector, which is designed to introduce fuel into a combustion chamber of the engine or in the exhaust line, a low-pressure exhaust gas recirculation train, which formed is to direct exhaust gas from the exhaust line from a arranged downstream of the particulate filter low-pressure exhaust sampling point to a disposed in the Zuluftstrang low-pressure Abgaseinleitstelle, and a high-pressure exhaust gas recirculation train, which is formed exhaust gas from the exhaust line from a high-pressure exhaust gas sampling point located upstream of the particulate filter To direct to a arranged in the Zuluftstrang high-pressure Abgaseinleitstelle, is used to control the particulate filter when in a particulate filter test by matching at least one particulate filter actual value with a particulate filter setpoint a need a measure is determined, carried out in a measure implementation of the measure, wherein in the particulate filter inspection, an oxygen content in the exhaust gas or a particulate filter temperature is considered and wherein the measure comprises supplying the engine during a coasting operation of the motor vehicle charge gas containing recirculated exhaust gas.

The terms high pressure (HD) and low pressure (ND) are intended to serve only the assignment of the components according to the well-known nomenclature in exhaust gas recirculation systems and represent no restriction with respect to a pressure. The components designated as low pressure are associated with a system known as low pressure exhaust gas recirculation and the components designated as high pressure are associated with a system known as high pressure exhaust gas recirculation.

Advantageously, with the operating method according to the invention, it is possible to influence the operating conditions of the particulate filter and possibly further exhaust aftertreatment devices. The desired influence results either directly during the operating method or immediately after the motor vehicle has returned from the overrun operation in a driving operation.

With the operating method according to the invention, the particulate filter and optionally further exhaust aftertreatment devices are kept or brought into predefined parameters within which the exhaust aftertreatment devices function optimally and none Get damaged. In particular, it is prevented that in the particulate filter, an uncontrolled burning of the soot can occur. The particle filter is thus prevented from overheating.

By checking the oxygen content in the exhaust gas can be determined whether an uncontrolled Rußabbrand threatens. Exceeds the particulate filter actual value for the oxygen content of a particulate filter setpoint, for example, the exhaust gas composition can be changed by a fuel injection and the oxygen content can be reduced. It is also possible by means of the HP exhaust gas recirculation to influence so that the mass flow of the exhaust gas through the particulate filter, which is positioned downstream of the HD exhaust gas sampling point, is reduced. This at least partially prevents the oxygen-rich exhaust gas from reaching the particle filter.

By checking the particle filter temperature, it can be determined whether the particulate filter is in danger of overheating. Exceeds the particulate filter actual value for the temperature of a particulate filter setpoint, for example, by cooling the charge gas and / or the recirculated LP exhaust cooler gas can be passed to the particulate filter. In addition, it is possible to cool the hot soot in the particulate filter by means of introduced fuel until the end of the regeneration.

In an advantageous embodiment of the operating method according to the invention, the charge gas is at least partially formed from recirculated low-pressure exhaust gas and / or recirculated high-pressure exhaust gas. In particular, charge gas, which is formed entirely from recirculated exhaust gas, is supplied to the engine during the overrun operation.

This reduces the oxygen originating from the fresh air. An oversupply of oxygen molecules in the exhaust gas can be avoided.

In a further advantageous embodiment of the operating method according to the invention, fuel is introduced simultaneously into the engine or into the exhaust gas line as a measure.

With the introduction of the fuel during the measure, the exhaust gas composition is influenced. A richer off-gas containing unburned hydrocarbons may be generated. The fuel can be introduced in particular in a post-injection into the combustion chamber of the engine or in the exhaust line, in particular downstream of the HD exhaust gas sampling point.

In a further advantageous embodiment of the operating method according to the invention, the charge gas and / or the recirculated low-pressure exhaust gas are cooled. In particular, if the particulate filter actual value for the particulate filter temperature is greater than the particulate filter setpoint for the particulate filter temperature.

By cooling the charge gas and / or the recirculated LP exhaust gas, the temperature of the particulate filter can be kept below an upper threshold. The temperatures of the particulate filter and optionally further exhaust aftertreatment devices can thus be advantageously limited to the top.

The motor vehicle according to the invention is suitable for carrying out the operating method according to the invention. For this purpose, the motor vehicle according to the invention comprises an engine, a supply air line, an exhaust line, a particle filter arranged in the exhaust line, a low-pressure exhaust gas recirculation line which is configured, exhaust gas from the exhaust line from a low-pressure exhaust gas removal point arranged downstream of the particle filter to a low pressure arranged in the supply air line To direct exhaust starting point, and a high-pressure exhaust gas recirculation train, which is adapted to direct exhaust gas from the exhaust line from a high pressure exhaust gas sampling point located upstream of the particulate filter to a arranged in the Zuluftstrang high-pressure Abgaseinleitstelle. According to the invention, the motor vehicle comprises at least one valve assigned to the low-pressure exhaust gas recirculation train and a high-pressure valve associated with the high-pressure exhaust gas recirculation train, a particle filter value detection unit, a motor vehicle value detection unit and a control unit which is designed to detect a coasting operation of the motor vehicle and the valves during overrun operation in the overrun mode Way to provide that the engine charge gas having recirculated exhaust gas, can be supplied. The particulate filter may be an SDPF (SCR Diesel Particulate Filter), a CDPF (Catalysed DPF) or an ADPF (Additive DPF). SCR stands for Selective Catalytic Reduction.

This advantageously provides a motor vehicle with which it is possible to carry out both an LP exhaust gas recirculation and an HP exhaust gas recirculation during a coasting operation of the motor vehicle and thereby influence the operating parameters of the particulate filter and optionally further exhaust aftertreatment devices.

To advantageously additionally allow introduction of fuel into a combustion chamber of the engine or in the exhaust line, the motor vehicle in particular has an injector which is designed for this purpose. The control unit is designed to actuate the injector.

In a further advantageous embodiment of the motor vehicle according to the invention, the motor vehicle has an exhaust gas cooler arranged in the LP exhaust gas recirculation line and an exhaust gas cooler bypass, which is designed to guide recirculated LP exhaust gas around the exhaust gas cooler.

With the exhaust gas cooler, it is possible to limit the temperature of the recirculated LP exhaust gas upward. With the cooling of the recirculated LP exhaust gas occurring upstream of a compressor disposed in the intake air line, the compressor is prevented from being damaged by excessively hot recirculated exhaust gas.

With the exhaust cooler bypass, it is possible to guide the recirculated LP exhaust gas around the exhaust gas cooler and to exclude the recirculated LP exhaust gas from the influence of the exhaust gas cooler if necessary.

If the particulate filter actual value for the particulate filter temperature is lower than the particulate filter setpoint, the mass flow of the recirculated exhaust gas or of the charge gas can also be conducted past the coolers.

In a further advantageous embodiment of the motor vehicle according to the invention, the motor vehicle has a charge air cooler arranged in the supply air line downstream of the LP exhaust inlet point and a charge air cooler bypass which is designed to direct charge gas around the charge air cooler.

With the intercooler, it is possible to limit the temperature of the charge gas upwards. With the charge air cooler bypass, it is possible to direct the charge gas around the intercooler and to exclude the charge gas from the influence of the intercooler.

With the motor vehicle according to the invention, it is possible to combine the LP exhaust gas recirculation and the HP exhaust gas recirculation with an injection of fuel and to influence the composition of the exhaust gas flow even during a coasting operation of the motor vehicle.

Embodiments and embodiments of the invention will be explained in more detail with reference to the drawings and the description below. They show schematically:

1 an inventive motor vehicle in a first exemplary embodiment;

2 the motor vehicle according to the invention in the exercise of an operating method according to the invention in a first exemplary embodiment;

3 the motor vehicle according to the invention in the exercise of the operating method according to the invention in a second exemplary embodiment;

4 the motor vehicle according to the invention in a second exemplary embodiment in the exercise of the operating method according to the invention in a third exemplary embodiment; and

5 the operating method according to the invention in a flow chart.

In the 1 to 4 is the motor vehicle according to the invention 10 illustrated in exemplary embodiments. The car 10 has an engine 11 which is an internal combustion engine. As is usual, the motor vehicle 10 with a Zuluftstrang 12 which is formed charge gas 35 to the engine 11 to direct, and an exhaust line 13 that is formed exhaust 36 from the engine 11 to guide away.

The motor vehicle shown 10 is designed to operate both a low-pressure (LP) exhaust gas recirculation and a high-pressure (HD) exhaust gas recirculation. For this purpose, the motor vehicle 10 an LP exhaust gas recirculation train 19 and an HP exhaust gas recirculation train 45 on.

The LP exhaust gas recirculation train 19 is with the exhaust system 13 at a LP exhaust sampling point 24 and with the supply air line 12 at a LP exhaust inlet point 25 coupled. With the LP exhaust gas recirculation train 19 An ND loop is formed by the ND exhaust port 24 in the exhaust system 13 via the LP exhaust gas recirculation train 19 to LP exhaust inlet point 25 in the supply air line 12 and about the engine 11 back to the LP exhaust port 24 leads. The LP exhaust gas recirculation train 19 is formed, according to the LP exhaust gas recirculation principle, at least part of the exhaust gas line 13 flowing exhaust gas 36 to the supply air line 12 to conduct. This part is here as recirculated LP exhaust 37 designated. The remaining part is here as discharged exhaust 38 declared.

The HD exhaust gas recirculation train 45 is with the exhaust system 13 at an HD exhaust sampling point 46 and with the supply air line 12 at an HD exhaust inlet point 47 coupled. With the HD exhaust gas recirculation train 45 an HD loop is formed within the ND loop. The HD loop leads from the HD exhaust port 46 in the exhaust system 13 via the HP exhaust gas recirculation train 45 to the HD exhaust inlet point 47 in the supply air line 12 and about the engine 11 back to the HD exhaust sampling point 46 , The HD exhaust gas recirculation train 19 is formed, according to the HD exhaust gas recirculation principle, at least part of the exhaust gas line 13 flowing exhaust gas 36 to the supply air line 12 to lead. This part is here as recirculated HD exhaust 49 designated.

The car 10 is in particular designed in such a way that the entire mass flow of the exhaust gas 36 through the LP exhaust gas recirculation train 19 and / or at least partially by the HP exhaust gas recirculation train 45 to the supply air line 12 can be returned. The sum of the mass flows of recirculated high-pressure exhaust gas 49 and the recirculated LP exhaust 37 is equal to the mass flow of the exhaust gas 36 , The mass flow of the derived exhaust gas 38 here is zero. The exhaust 36 circulates through the loops. In this way, the motor vehicle 10 in the 2 to 4 shown.

The charge gas 35 is during normal operation with exhaust gas recirculation, shown in the 1 , basically from fresh air 30 and recirculated LP exhaust 37 and / or recirculated HD exhaust 49 can be produced in different proportions. In particular, the motor vehicle 10 formed in the way, the charge gas 35 to 100% from recirculated exhaust gases 37 . 49 to build. The mass flow of the charge gas 35 is equal to the sum of the mass flows of recirculated exhaust gases 37 . 49 , The mass flow of fresh air 30 is zero. In this way, the motor vehicle 10 in the 2 to 4 shown.

For adjusting the ratio of fresh air 30 and recirculated exhaust gases 37 . 49 in the charge gas 35 has the motor vehicle 10 at least one of the LP exhaust gas recirculation train 19 associated valve 26 . 32 . 33 and the HP exhaust gas recirculation train 45 assigned HD valve 48 on. In the in the 1 to 3 illustrated variant, the motor vehicle 10 a combination valve 26 in the supply air line 12 as the LP exhaust gas recirculation train 19 assigned valve on. In the 4 an alternative embodiment is shown in which the motor vehicle 10 an intake throttle 32 in the supply air line 12 and an exhaust throttle 33 in the exhaust system 13 as the LP exhaust gas recirculation train 19 having associated valves.

The combination valve 26 is in the supply air line 12 at the LP exhaust inlet point 25 arranged. The combination valve 26 is formed both the LP exhaust gas recirculation train 19 for a flow of recirculated LP exhaust gas 37 to release or lock in different degrees as well as the Zuluftstrang 12 for a flow of fresh air 30 to release or lock in different degrees. Depending on the position of the combination valve 26 are the mass flow rates of fresh air 30 and the recirculated LP exhaust 37 in the mass flow of the charge gas 35 variable.

The intake throttle 32 is in the supply air line 12 upstream of the LP exhaust inlet 25 arranged. The intake throttle 32 is formed, the Zuluftstrang 12 for a flow of fresh air 30 to release or lock in different degrees. Depending on the position of the intake throttle 32 is the mass flow of fresh air 30 variable.

The outlet throttle 33 is in the exhaust system 13 downstream of the LP exhaust sampling point 24 arranged. The outlet throttle 33 is formed, the exhaust system 13 for a discharge of discharged exhaust gas 38 to release or lock in different degrees. Depending on the position of the outlet throttle 33 is the mass flow of the exhaust gas emitted 38 variable.

The HD valve 48 is in the supply air line 12 at the HD-Abgaseinleitstelle 46 arranged. The HD valve 48 is formed the HP exhaust gas recirculation train 45 for a flow of recycled HD exhaust gas 49 to release or lock in different degrees. Depending on the position of the HP valve 48 is the mass flow rate of the back-fed HD exhaust 49 in the mass flow of the charge gas 35 variable.

The car 10 preferably has a plurality of exhaust aftertreatment devices. So includes the motor vehicle 10 at least one particle filter 22 , The particle filter 22 can be provided with an SCR coating or even an SCR catalyst. SCR stands, as it is known, for Selective Catalytic Reduction. The SCR catalyst may be known in the art as a passive system downstream of a NOx storage catalyst which under certain circumstances produces ammonia (NH3) or as an active system with a urea solution injector 69 be educated. The urea solution injector 69 may also be formed, instead of the urea solution from the exhaust 36 Ammonia is formed, also introduce another substance that provides a reducing agent in the SCR catalyst or this itself, in particular ammonia. In addition, the motor vehicle includes 10 in particular a second exhaust aftertreatment device 23 , The particle filter 22 and the second exhaust aftertreatment device 23 are in the exhaust system 13 upstream of the LP exhaust port 24 and downstream of the HD exhaust sampling point 46 arranged. The particle filter 22 and the second exhaust aftertreatment device 23 can also be accommodated in a common housing. In addition, the motor vehicle 10 have further exhaust aftertreatment devices. In the embodiment shown, the motor vehicle comprises 10 a third exhaust aftertreatment device 40 , Which here downstream of the LP exhaust sampling point 24 is arranged.

The second exhaust aftertreatment device 23 may be an oxidation catalyst or a nitrogen oxide adsorber, which may also be designed as an adsorber with conversion function. The second exhaust aftertreatment device 23 is here upstream of the particulate filter 22 arranged.

In the embodiment shown is the motor vehicle 10 further with a turbocharger 14 Mistake. This includes one in the supply air line 13 arranged compressor 15 in the familiar manner of one in the exhaust system 13 arranged exhaust gas turbine 16 is drivable. The exhaust gas turbine 16 is upstream of the LP exhaust sampling point 24 and upstream of the particulate filter 22 and the second exhaust aftertreatment device 23 arranged. The exhaust gas turbine 16 is also downstream of the HD exhaust sampling point 46 arranged.

The car 10 includes in particular a charge air cooler 18 for cooling the charge gas 35 , The intercooler 18 is in the supply air line 12 downstream of the compressor 15 and upstream of the HD exhaust entry point 47 arranged. Furthermore, the motor vehicle 10 a charge air cooler bypass 17 which is formed, the charge gas 35 on the intercooler 18 to pass by. The intercooler bypass 17 is parallel to the intercooler 18 arranged with a branch upstream of the intercooler 18 and a junction downstream of the intercooler 18 , For controlling the mass flow of the charge gas 35 through the intercooler bypass 17 is especially in the intercooler bypass 17 a charge air cooler bypass valve 27 intended. The intercooler bypass valve 27 is designed to charge the intercooler bypass 17 for a flow of charge gas 35 to release or lock in different degrees. The intercooler bypass valve 27 can also be designed as a switching valve and downstream or upstream of the intercooler 18 be arranged. In the 2 is a mass flow of the charge gas 35 through the intercooler bypass 17 shown.

The car 10 can also have an exhaust gas cooler 20 for cooling the exhaust gas 36 in particular for cooling the recirculated LP exhaust gas 37 , exhibit. The exhaust gas cooler 20 is especially in the LP exhaust gas recirculation train 19 arranged. Furthermore, the motor vehicle 10 an exhaust cooler bypass 21 formed, which is formed, the recirculated LP exhaust 37 on the exhaust gas cooler 20 to pass by. The exhaust cooler bypass 21 is parallel to the exhaust gas cooler 20 arranged with a branch upstream of the exhaust gas cooler 20 and a junction downstream of the exhaust gas cooler 20 , For controlling the mass flow of the recirculated LP exhaust gas 37 through the exhaust cooler bypass 21 is especially in the exhaust gas cooler bypass 21 an exhaust cooler bypass valve 28 intended. The exhaust cooler bypass valve 28 is formed, the exhaust gas cooler bypass 21 for a flow of recirculated LP exhaust gas 37 to release or lock in different degrees. The exhaust cooler bypass valve 28 can also be designed as a switching valve and downstream or upstream of the exhaust gas cooler 20 be arranged. In the 2 and 4 is a mass flow of recirculated LP exhaust gas 37 through the exhaust cooler bypass 21 shown.

The motor 11 of the motor vehicle 10 has in particular a direct injection. This can be done by the engine 11 a first injector 29 that is configured to fuel 31 in a combustion chamber 34 of the motor 11 to inject, and / or a second injector 68 that is designed to inject fuel into the exhaust line 13 contribute.

The car 10 includes a particulate filter value detection unit 41 , which is formed at least a current value of the particulate filter 22 capture. This particulate filter actual value A can be a value of the oxygen content in the exhaust gas 36 or the particle filter temperature. Thus, in particular an oxygen sensor or a lambda probe is part of the particle filter value detection unit 41 ,

In addition, the motor vehicle includes 10 a vehicle value detection unit 42 , which is formed at least a current value of the motor vehicle 10 capture. This motor vehicle actual value C can be a value of the variables motor vehicle speed or engine speed or motor vehicle load or fuel injection quantity or brake pedal position or accelerator pedal position.

The particulate filter value detection unit 41 and the vehicle value detection unit 42 can in other systems of the motor vehicle 10 be integrated and, for example, sensors in the engine 11 and / or in the exhaust system 13 include.

Furthermore, the motor vehicle includes 10 a control unit 39 , which is in particular an engine control unit. The control unit 39 is formed, the valves 26 . 27 . 28 . 32 . 33 . 48 to ask and the at least injector 29 . 68 to press. For this purpose, the motor vehicle has 10 via suitable actuators. Further, the control unit 39 trained, a pushing operation of the motor vehicle 10 to recognize. This is the control unit 39 in particular with the motor vehicle value acquisition unit 42 connected. The control unit 39 is formed, the gegenwertigen state of the motor vehicle 10 capture. The control unit 39 is also available with the particulate filter value acquisition unit 41 connected and formed, the gegenwertigen state of the particulate filter 22 capture.

The car 10 is formed the operating method according to the invention 60 perform. In the 2 to 4 is shown as the motor vehicle 10 the operating procedure 60 exercises in different versions. In the 5 is the operating method according to the invention 60 in an exemplary implementation of a launch 61 to an end 67 shown in a flow chart.

With the operating method according to the invention 60 prevents being in the particle filter 22 An uncontrolled regeneration takes place, resulting in overheating of the particulate filter 22 can lead. During regeneration, soot accumulated in the particulate filter is burned off. This must be in the particle filter 22 a certain temperature prevail. If a sudden increase in the amount of oxygen during regeneration accelerates the burn-up of the soot and the regeneration proceeds uncontrollably. An increase in the oxygen content in the exhaust gas can occur, for example, when the motor vehicle 10 changes from a load operation to a coasting mode or an idle mode.

In the operating method according to the invention 60 a measure is executed. The measure includes that of the engine 11 during a pushing operation of the motor vehicle 10 gas charge 35 provided, the recirculated LP exhaust 37 and / or recycled HD exhaust 49 has, especially in high rates. This is unlike that in the 1 Normal operation shown the supply of fresh air 30 throttled, in particular to zero, and the LP exhaust gas recirculation train 19 and / or the HP exhaust gas recirculation train 45 be released. In particular, the engine 11 a charge gas is provided, which is formed exclusively from recirculated exhaust gas. In this way it is in the 2 to 4 shown.

In the 2 and 3 becomes the combination valve 26 posed in such a way that the mass flow of fresh air 30 is equal to zero. At the same time, the LP exhaust gas recirculation train 19 Approved. In addition, the HD valve 48 put in the way that even the HD exhaust gas recirculation train 45 is released.

In the 4 becomes the mass flow of fresh air 30 thereby zeroed out that the intake throttle 32 is closed. In order to bring about at the same time the LP exhaust gas recirculation, also the exhaust throttle 33 closed. Again, the HD valve 48 put in the way that even the HD exhaust gas recirculation train 45 is released.

During the operating procedure 60 In addition, the scope of the measure may include a predefined amount of fuel 31 into the combustion chamber 34 and / or in the exhaust system 13 be introduced. This can be done either by a single or multiple injections. In the 2 to 4 is an injection into the combustion chamber 34 shown. Instead of injection into the combustion chamber 34 or in addition to the injection into the combustion chamber 34 can also by means of a second injector 68 an injection of fuel 31 in the exhaust system 13 be made. By the injection of fuel 31 becomes a richer exhaust 36 produced, wherein the proportion of oxygen molecules in the exhaust gas is lowered. The enriched exhaust gas 36 becomes the flush of the particulate filter 22 used. Due to the HD exhaust gas recirculation, the mass flow of the exhaust gas 36 through the particle filter 22 decreases, resulting in an increase in the concentration of fuel downstream of the HD exhaust sampling point 46 into the remaining exhaust gas 36 is introduced, and causes a reduction in the concentration of oxygen.

In the in the 5 illustrated embodiment of the operating method 60 will after the start 62 a particle filter value detection 62 carried out. In this case, at least one particulate filter actual value A is detected. This particulate filter actual value A can in particular be a value for a particulate filter temperature or also for an oxygen content in the exhaust gas 36 be. The particulate filter actual value can be detected by measurement or model-based calculation.

Subsequently, the particulate filter actual value A is in a particle filter test 63 matched with a predetermined particulate filter setpoint B. If the particulate filter actual values A deviate from the particulate filter nominal values B, a need for the measure can be determined and implemented in a measure 66 at least one measure be taken for this purpose.

For example, by checking the particulate filter temperature, it can be determined if the particulate filter 22 Overheating threatens, which could occur, for example, if, during a regeneration phase, the proportion of oxygen in the exhaust gas 36 elevated. If, for example, the particulate filter actual value A for the particulate filter temperature lies above the particulate filter setpoint B for the particulate filter temperature, the particulate filter can 22 by using the intercooler 18 or the exhaust gas cooler 20 be cooled by passing through the particle filter 22 flowing exhaust gas 36 is cooled. By means of the intercooler 18 can the charge gas 35 be cooled during overrun, see 3 , through of the exhaust gas cooler 20 can the recirculated LP exhaust 37 be cooled during overrun, see 3 , Alternatively or additionally, by injecting fuel 31 into the combustion chamber 34 or in the exhaust system 13 the soot is cooled to extinguish the burning off of the soot.

It can also be determined whether a reduction in the regeneration capacity of the particulate filter 22 threatening. If the particulate filter actual value A for the particulate filter temperature is below the particulate filter setpoint B for the particulate filter temperature, the mass flows at the charge air cooler can 18 and / or the exhaust gas cooler 20 be led past. The recirculated LP exhaust 37 can through the exhaust cooler bypass 21 on the exhaust gas cooler 20 be passed by the exhaust gas cooler bypass valve 28 is opened. The charge gas 35 can through the intercooler bypass 17 on the intercooler 18 be passed by the intercooler bypass valve 27 is opened.

By checking the oxygen content of the particulate filter 22 flowing exhaust gas 36 can be determined whether an uncontrolled regeneration threatens. If, for example, the particulate filter actual value A for the oxygen fraction is above the particulate filter setpoint B for the oxygen fraction, the oxygen fraction can be determined by targeted introduction of fuel 31 be lowered. Additionally or alternatively, the mass flow of the recirculated high-pressure exhaust gas 49 by placing the HP valve 48 be increased, reducing the mass flow through the particle filter 22 flowing lean exhaust gas 36 is reduced.

It is also possible to scale the measures required by the particulate filter test 63 to investigate. By checking the particulate filter temperature and / or the oxygen content in the exhaust gas 36 In particular, a period of time can be determined for how long the measure is to be carried out for a successful execution.

There are various combinations of exhaust gas recirculation, fuel injection and cooling conceivable, which can be performed depending on the particulate filter actual value A.

In the in the 5 shown embodiment is also in a motor vehicle value detection 64 at least one motor vehicle actual value C detected. This motor vehicle actual value C may in particular be a value for a vehicle speed, an engine speed, an automobile load, a fuel injection quantity, a brake pedal position, an accelerator pedal position, navigation information, traffic information or cruise control information.

Subsequently to the vehicle value registration 64 can the actual vehicle value C in a motor vehicle inspection 65 be matched with a predetermined motor vehicle setpoint D. By the motor vehicle inspection 65 For example, it is determined whether the motor vehicle 10 in overrun mode.

In addition, the motor vehicle inspection 65 include an increase probability test, which relates to the onset of an increase in oxygen content. The increase probability can in particular be made from a comparison with a driving profile acquired over a certain period of time or also from navigation data. The driving profile can be generated from collected motor vehicle actual values C. If the increase probability exceeds a critical value, the measures can be carried out as a precautionary measure.

The vehicle value acquisition 64 and the vehicle inspection 65 can also be timed before the particle filter value acquisition 62 and the particle filter test 63 respectively. In the case of the operating method according to the invention, the setpoint values B, D can of course also be value ranges. The actual values A, C can be measured or calculated.

LIST OF REFERENCE NUMBERS

10

 motor vehicle

11

 engine

12

 Zuluftstrang

13

 exhaust gas line

14

 turbocharger

15

 compressor

16

 exhaust turbine

17

 Charge air cooler bypass

18

 Intercooler

19

 Low-pressure exhaust gas recirculation strand

20

 exhaust gas cooler

21

 EGR cooler bypass

22

 particulate Filter

23

 Second exhaust aftertreatment device

24

 Low pressure exhaust gas extraction point

25

 Low pressure Abgaseinleitstelle

26

 combination valve

27

 Intercooler bypass valve

28

 EGR cooler bypass valve

29

 First injector

30

 fresh air

31

 fuel

32

 intake throttle

33

 Auslassdrosselklappe

34

 combustion chamber

35

 gas charge

36

 exhaust

37

 Recycled low-pressure exhaust gas

38

 Derived exhaust

39

 control unit

40

 Third exhaust aftertreatment device

41

 Particulate acquisition unit

42

 Automobile acquisition unit

45

 High-pressure exhaust gas recirculation strand

46

 High pressure exhaust extraction point

47

 High pressure Abgaseinleitstelle

48

 High-pressure valve

49

 Recirculated high pressure exhaust gas

60

 operating procedures

61

 begin

62

 Particulate acquisition

63

 particulate filter test

64

 Automobile acquisition

65

 Motor vehicle testing

66

 Implementing measures

67

 The End

68

 Second injector

69

 Harnstofflösungsinjektor

A

 Particulate actual value

B

 Particulate setpoint

C

 Automotive value

D

 Automotive setpoint

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 102013111110 A1 [0002]
• DE 102011101079 A1 [0003, 0003]
• DE 102008015600 A1 [0004]

Claims (8)

Operating procedure ( 60 ) for a motor vehicle ( 10 ) with a motor ( 11 ), a Zuluftstrang ( 12 ), an exhaust gas line ( 13 ), one in the exhaust line ( 13 ) arranged particulate filter ( 22 ), an injector ( 29 . 68 ), which is designed to fuel ( 31 ) in a combustion chamber ( 34 ) of the motor ( 11 ) or in the exhaust line ( 13 ), a low pressure exhaust gas recirculation train ( 19 ), which is designed to exhaust ( 36 ) from the exhaust gas line ( 13 ) from a downstream of the particulate filter ( 22 ) arranged low-pressure exhaust gas sampling point ( 24 ) to one in the Zuluftstrang ( 12 ) arranged low-pressure Abgaseinleitstelle ( 25 ), and a high-pressure exhaust gas recirculation train ( 45 ), which is designed to exhaust ( 36 ) from the exhaust gas line ( 13 ) from an upstream of the particulate filter ( 22 ) arranged high-pressure exhaust sampling point ( 46 ) to one in the Zuluftstrang ( 12 ) arranged high-pressure Abgaseinleitstelle ( 47 ), characterized in that for controlling the particulate filter ( 22 ) when in a particulate filter test ( 63 ) by matching at least one particulate filter actual value (A) with a particulate filter setpoint (B) a need for a measure is determined in a course of action ( 66 ) the measure is carried out, whereby in the particulate filter test ( 63 ) an oxygen content in the exhaust gas ( 36 ) or a particulate filter temperature and where the measure comprises, the engine ( 11 ) during a coasting operation of the motor vehicle ( 10 ) Charge gas ( 35 ), the recirculated exhaust gas ( 37 . 49 ), supply. Operating procedure ( 60 ) according to claim 1, wherein the charge gas ( 35 ) at least partially or completely from recirculated low-pressure exhaust gas ( 37 ) and / or recirculated high-pressure exhaust gas ( 49 ) is formed. Operating procedure ( 60 ) according to claim 1 or 2, wherein as a measure at the same time fuel ( 31 ) in the engine ( 11 ) or in the exhaust line ( 13 ) is introduced. Operating procedure ( 60 ) according to any one of claims 1 to 3, wherein the charge gas ( 35 ) and / or the recirculated low-pressure exhaust gas ( 37 ) are cooled. Motor vehicle ( 10 ) with a motor ( 11 ), a Zuluftstrang ( 12 ), an exhaust gas line ( 13 ), one in the exhaust line ( 13 ) arranged particulate filter ( 22 ), a low pressure exhaust gas recirculation train ( 19 ), which is designed to exhaust ( 36 ) from the exhaust gas line ( 13 ) from a downstream of the particulate filter ( 22 ) arranged low-pressure exhaust gas sampling point ( 24 ) to one in the Zuluftstrang ( 12 ) arranged low-pressure Abgaseinleitstelle ( 25 ), and a high-pressure exhaust gas recirculation train ( 45 ), which is designed to exhaust ( 36 ) from the exhaust gas line ( 13 ) from an upstream of the particulate filter ( 22 ) arranged high-pressure exhaust sampling point ( 46 ) to one in the Zuluftstrang ( 12 ) arranged high-pressure Abgaseinleitstelle ( 47 ), characterized in that the motor vehicle ( 10 ) at least one of the low pressure exhaust gas recirculation train ( 19 ) associated valve ( 26 . 32 ) and a high-pressure exhaust gas recirculation train ( 45 ) associated high-pressure valve ( 48 ), a particulate filter value detection unit ( 41 ), a motor vehicle value acquisition unit ( 42 ) and a control unit ( 39 ), which is adapted to a pushing operation of the motor vehicle ( 10 ) and the valves ( 26 . 32 . 48 ) during overrun operation in such a way that the engine ( 11 ) Charge gas ( 35 ), the recirculated exhaust gas ( 37 . 49 ), can be supplied, is designed, an operating method ( 60 ) according to one of the preceding claims. Motor vehicle ( 10 ) according to claim 5, wherein the motor vehicle ( 10 ) an injector ( 29 . 68 ), which is formed, fuel ( 31 ) in a combustion chamber ( 34 ) of the engine or in the exhaust line ( 13 ), and the control unit ( 39 ) is formed, the injector ( 29 . 68 ). Motor vehicle ( 10 ) according to claim 5 or 6, wherein the motor vehicle ( 10 ) in the low-pressure exhaust gas recirculation train ( 19 ) arranged exhaust gas cooler ( 20 ) and an exhaust gas cooler bypass ( 21 ), which is formed, recirculated low-pressure exhaust gas ( 37 ) around the exhaust gas cooler ( 20 ) around. Motor vehicle ( 10 ) according to one of claims 5 to 7, wherein the motor vehicle ( 10 ) one in the supply air line ( 12 ) downstream of the exhaust inlet point ( 25 ) arranged intercooler ( 18 ) and a charge air cooler bypass ( 17 ), which is designed to charge gas ( 35 ) around the intercooler ( 18 ) around.

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