METHOD FOR OPERATING A PARTICLE FILTER TAKING THE ASH QUANTITY INTO CONSIDERATION

Abstract

The invention relates to a method for operating a particulate filter (3) taking the ash loading into consideration, to an arrangement in this respect, to a control unit in this respect, and to a vehicle in this respect, wherein, during the operation of the internal combustion engine (1), fuel and/or lubricants are at least partially converted into ash by the internal combustion engine (1), wherein a first ash value is calculated on the basis of the fuel consumption and/or the lubricant consumption of the internal combustion engine (1), wherein, after regeneration of the particulate filter, the differential pressure across the particulate filter (3) is determined, wherein a second ash value is calculated on the basis of the determined differential pressure, wherein the ash quantity in the particulate filter (3) is determined from the first and the second ash value, and wherein, if the determined ash quantity exceeds a predefined value, a status device is activated.

Claims

1. Method for operating a particulate filter taking the ash quantity into consideration and/or for determining the ash quantity in a particulate filter of an exhaust gas aftertreatment system of an internal combustion engine, wherein, during the operation of the internal combustion engine, lubricants from the internal combustion engine and/or fuel are at least partially converted into ash, and wherein a first ash value is calculated on the basis of the fuel and/or lubricant consumption of the internal combustion engine-characterised in that after regeneration of the particulate filter, the differential pressure across the particulate filter is determined, a second ash value is calculated on the basis of the determined differential pressure, the ash quantity in the particulate filter is determined from the first and the second ash value, and, if the determined ash quantity exceeds a predefined value, a status device, in particular an engine malfunction indicator light, is activated.

2. Method according to claim 1, characterised in that the differential pressure across the particulate filter is determined if the soot loading in the particulate filter is substantially zero, and/or if the particulate filter is substantially free of soot.

3. Method according to claim 1, characterised in that the differential pressure across the particulate filter is determined if the exhaust mass flow is in the range of 100 kg/h up to and including 2000 kg/h, in particular in the range of 500 kg/h up to and including 1000 kg/h.

4. Method according to claim 1, characterised in that the exhaust gas aftertreatment system comprises several exhaust gas aftertreatment components, such as, in particular, a three-way catalytic converter, a diesel oxidation catalyst, the particulate filter an NOx storage catalyst, a catalyst for the selective reduction of nitrogen oxides and/or an ammonia slip catalyst, and/or the exhaust gas aftertreatment components, in particular the particulate filter, are at least partially flowed through by the exhaust gas and/or ash emitted by the internal combustion engine.

5. Method according to claim 1, characterised in that the first ash value is calculated according to the following rule:
A.sub.1=A.sub.m1?F.sub.1 where A.sub.1 is the first ash value, A.sub.m1 is the ash value calculated on the basis of the fuel and/or lubricant consumption and F.sub.1 states the percentage of the calculated ash value which remains in the particulate filter.

6. Method according to claim 1, characterised in that the exhaust gas temperature, in particular after leaving the internal combustion engine and/or on entering the particulate filter, is taken into consideration when calculating the first and/or second ash value and/or the temperature of the particulate filter is taken into consideration when calculating the first and/or second ash value.

7. Arrangement wherein the arrangement comprises an internal combustion engine and an exhaust gas aftertreatment system, wherein the exhaust gas aftertreatment system comprises at least one exhaust gas aftertreatment component, in particular a particulate filter and wherein fuel and/or lubricant are at least partially converted to ash during operation of the internal combustion engine, characterised in that the arrangement for carrying out the method is configured according to claim 1.

8. Arrangement according to claim 7, characterised in that the exhaust gas aftertreatment system includes a pressure measuring arrangement which is configured to measure the differential pressure of the particulate filter, in particular across the particulate filter.

9. Control unit for the exhaust gas aftertreatment system of an internal combustion engine, characterised in that the control unit is configured to carry out the method according to claim 1.

10. Vehicle, characterised in that the vehicle includes an arrangement according to claim 7.

Description

[0063] The invention will now be further explained with reference to exemplary, non-exclusive and/or non-limiting exemplary embodiments.

[0064] FIG. 1 shows a schematic graphic representation of a first embodiment of the method according to the invention,

[0065] FIG. 2 shows a schematic graphic representation of a first embodiment of the arrangement according to the invention, and

[0066] FIG. 3 shows a schematic graphic representation of a second embodiment of the arrangement according to the invention.

[0067] Unless otherwise indicated, the reference signs correspond to the following components: Internal combustion engine 1, exhaust gas aftertreatment system 2, particulate filter 3, first pressure measuring device 4, second pressure measuring device 5, first temperature measuring device 6, HC doser 7, second temperature measuring device 8, first NOx measuring device 9, third temperature measuring device 10, AdBlue doser 11, fourth temperature measuring device 12, second NOx measuring device 13, calculation of the first ash value 14, regeneration of the particulate filter 15, calculation of the second ash value 16, determination of the ash quantity in the particulate filter taking into consideration the first and second ash values 17, determined ash quantity is less than the predefined limit 18, determined ash quantity is greater than the predefined limit 19, status device not activated 20, status device activated 21, diesel oxidation catalyst 22, SCR catalyst 23 and ammonia slip catalyst 24.

[0068] FIG. 1 shows a schematic graphic representation of a first embodiment of the method according to the invention for the operation of a particulate filter 3 taking into consideration the ash quantity in a particulate filter 3 and/or for the determination of the ash quantity in a particulate filter 3 of an exhaust gas aftertreatment system 2 of an internal combustion engine 1.

[0069] According to the first embodiment, during the operation of the internal combustion engine 1 fuel and/or lubricant is at least partially converted to ash. This ash then flows at least partially through the exhaust gas aftertreatment system 2 of the internal combustion engine 1, which includes a particulate filter 3.

[0070] A first ash value 14 is calculated on the basis of the fuel and/or lubricant consumption of the internal combustion engine 1.

[0071] According to this embodiment, the first ash value is calculated according to the following rule:

A.sub.1=A.sub.m1?F.sub.1

where A.sub.1 is the first ash value, A.sub.m1 is the ash value calculated on the basis of the fuel and/or lubricant consumption and F.sub.1 states what percentage of the calculated ash value remains in the particulate filter.

[0072] During the course of the method, the particulate filter is regenerated 15. The regeneration of the particulate filter 3 is carried out with oxygen at a particulate filter temperature greater than 480? C., in particular greater than 580? C. However, regeneration is not essential.

[0073] After regeneration, in particular immediately after regeneration, the differential pressure across the particulate filter 3 is determined and the second ash value is calculated on the basis of the differential pressure 16.

[0074] The differential pressure across the particulate filter 3 is determined according to this embodiment if the soot loading in the particulate filter 3 is substantially zero and/or if the particulate filter 3 is substantially free of soot. This allows the determined differential pressure to be used to infer the ash quantity, which is present in the particulate filter 3.

[0075] According to this embodiment, the second ash value is calculated according to the following rule:

A.sub.2=A.sub.m2?F.sub.2

where A.sub.2 is the second ash value, A.sub.m2 is the ash value calculated on the basis of the pressure loss across the particulate filter and F.sub.2 states the percentage of the calculated ash value which remains in the particulate filter 3.

[0076] Furthermore, according to this embodiment the differential pressure across the particulate filter 3 is determined if the exhaust gas mass flow is above 100 kg/h.

[0077] When calculating the first and second ash values, the exhaust gas temperature and/or the temperature of the particulate filter 3 are taken into consideration.

[0078] The ash quantity in the particulate filter is then determined from the first and second ash value 17.

[0079] If the determined ash quantity in the particulate filter is greater than a predefined value 19, a status device, in particular an engine malfunction indicator light, is activated 21, as a result of which the driver is informed of the condition of the exhaust gas aftertreatment system 2.

[0080] If the determined ash quantity in the particulate filter is less than the predefined value or corresponds to the predefined value 18, the status device, in particular the engine malfunction indicator light, is not activated 20.

[0081] FIG. 2 shows a schematic graphic representation of a first embodiment of the arrangement according to the invention.

[0082] According to this embodiment, the arrangement includes an internal combustion engine 1 and an exhaust gas aftertreatment system 2. The exhaust gas aftertreatment system 2 includes a particulate filter 3.

[0083] During operation of the internal combustion engine 1, fuel and/or lubricant are at least partially converted to ash. This ash then flows through the exhaust gas aftertreatment system 2 and thus also through the particulate filter 3.

[0084] The arrangement according to the first embodiment is configured to carry out the method according to the invention. In particular, the method according to the invention is regulated and/or controlled by a control unit, not shown.

[0085] Furthermore, the arrangement includes a pressure measuring arrangement which is configured to measure the differential pressure across the particulate filter 3. The pressure measuring arrangement comprises two pressure measuring devices, wherein the first pressure measuring device 4 is arranged before the particulate filter 3 and the second pressure measuring device 5 is arranged after the particulate filter 3.

[0086] Optionally, the status information regarding the function of the exhaust gas aftertreatment system 2 may be output by means of a status device, in particular a MIL malfunction indicator lightof a vehicle, a display and/or an acoustic message, as a result of which the driver is informed about the condition of the functionality of the exhaust gas aftertreatment system 2, in particular the functionality of the particulate filter 3.

[0087] FIG. 3 shows a schematic graphic representation of a second embodiment of the arrangement according to the invention. The features of the second embodiment according to FIG. 3 may preferably correspond to the features of the first embodiment according to FIG. 2.

[0088] The arrangement according to the second embodiment is configured to carry out the method according to the invention. In particular, the method according to the invention is regulated and/or controlled by a control unit, not shown.

[0089] According to this embodiment, the arrangement includes an internal combustion engine 1 and an exhaust gas aftertreatment system 2.

[0090] According to this embodiment, the exhaust gas aftertreatment system 2 comprises a diesel oxidation catalyst 22, a so-called DOC, a diesel particulate filter, a so-called DPF, a catalytic converter which is configured for the selective reduction of nitrogen oxides, a so-called SCR catalyst 23 and an ammonia slip catalyst 24, a so-called ASC.

[0091] A first temperature measuring device 6 and a so-called HC doser 7 are arranged between the internal combustion engine 1 and the diesel oxidation catalyst 22.

[0092] A second temperature device 8 and a first pressure measuring device 4 are arranged between the diesel oxidation catalyst 22 and the diesel particulate filter.

[0093] A second pressure measuring device 5, a first NOx measuring device 9, a third temperature measuring device 10 and a so-called AdBlue doser 11 are arranged between the diesel particulate filter and the SCR catalyst 23.

[0094] The ammonia slip catalyst 24 is arranged after the SCR catalyst 23. A fourth temperature measuring device 12 and a second NOx measuring device 13 are arranged after the ammonia slip catalyst 24.

[0095] According to this embodiment, the pressure measuring arrangement comprises the first and the second pressure measuring device 4, 5, which is configured to measure the differential pressure across the particulate filter 3.

[0096] The effects according to the invention can be achieved through this exemplary configuration.

[0097] The invention is not limited to the embodiments described, but includes any method, arrangement, control unit and vehicle according to the following claims.