Method and internal combustion engine arrangement for regenerating an exhaust after-treatment device

Patent metadata

Field	Value
Publication number	US-9850795-B2
Application number	US-201314779019-A
Country	US
Kind code	B2
Filing date	Apr 3, 2013
Priority date	Apr 3, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A process is provided for regenerating an exhaust gas after-treatment device in an exhaust line of an internal combustion engine arrangement, the exhaust line including a particle filter. The process includes identifying when soot loading of the particle filter exceeds a predetermined level. After that, temperature of exhaust gases at the particle filter is maintained within a first temperature range until at least one of a predetermined period of time has lapsed or a determination is made that soot loading of the particle filter is below the predetermined level. After that, the temperature of the exhaust gases at the particle filter is increased to within a second temperature range above the first temperature range. An internal combustion engine arrangement is also disclosed.

First claim

The invention claimed is:

1. A process for regenerating an exhaust gas after-treatment device adapted to be fitted in an exhaust line of an internal combustion engine arrangement, wherein the exhaust gas after-treatment device comprises a particle filter and the process oxidizes soot particulates trapped in the particle filter, the process comprising:
determining an initial soot loading in the particle filter,
performing a particle filter regeneration when the initial soot loading is above a predetermined level, wherein the particle filter regeneration comprises:

when the initial soot loading is above the predetermined level and further above a safe high temperature regeneration level,
a) setting a temperature of exhaust gases at the particle filter within a first temperature range comprised between 420 and 550 degrees Celsius,
b) maintaining the temperature of the exhaust gases at the particle filter at the first temperature range during a first period of time that is at least one of a predetermined period of time and a time sufficient to reduce soot loading to below the safe high temperature regeneration level, and
c) after the first period of time, further increasing the temperature at the particle filter to a second temperature range which is over 550 degrees Celsius, and
when the initial soot loading is above the predetermined level but below the safe high temperature regeneration level, increasing the temperature at the particle filter to the second temperature range without first setting the temperature of exhaust gases within the first temperature range and without maintaining the temperature of the exhaust gases at the first temperature range for the first period of time.

2. A process according to claim 1 , wherein, during step c), the temperature at the particle filter is increased at a controlled rate of temperature increase over time.

3. A process according to claim 1 , wherein, during step c), the temperature at the particle filter is increased at a controlled rate of temperature increase over time which is controlled as a function of a soot loading determination of the particulate filter.

4. A process according to claim 1 , wherein the temperature at the particle filter is increased at a rate of temperature increase over time which decreases over time.

5. A process according to claim 1 , wherein, during step c), the temperature at the particle filter is increased at a variable rate of temperature increase over time, a variation of which is controlled as a function of a first period soot loading determination of the particle filter at an end of the first period of time.

6. A process according to claim 1 , wherein, during step c), the temperature at the particle filter is increased in at least two sub-steps:
in a first sub-step c1) at a first rate of temperature increase over time;
a second sub-step c2) at a second rate of temperature increase over time,

where the second rate is lower than the first rate.

7. A process according to claim 6 , wherein the second rate of temperature increase over time during the second sub-step c2) is adjusted at a higher value when soot loading of the particle filter is estimated at a lower value.

8. A process according to claim 6 , wherein the first rate of temperature increase over time during the first sub-step c1) is fixed.

9. A process according to claim 1 , wherein the soot loading of the particle filter is an estimated soot loading.

10. A process according to claim 9 , wherein the soot loading is estimated depending on a duration of the first period of time of step b).

11. A process according to claim 9 , wherein the soot loading is estimated depending on a duration of the first period of time of step b) and depending on an estimated soot loading at step a).

12. A process according to claim 9 , wherein the soot loading is estimated depending on a pressure difference through the particle filter.

13. A process according to claim 9 , wherein the soot loading is estimated using an engine out soot emission model that estimates the soot emitted by engine as a function of engine operating parameters and using a soot regeneration model that estimates soot oxidation in the particle filter based on operating conditions at the particle filter.

14. A process according to claim 9 , wherein the soot loading is estimated taking into account a rate and/or efficiency at which NO is converted into NO2 in a catalyst upstream of the particle filter.

15. A process according to claim 1 , wherein the exhaust after treatment device further comprises a NOx reducing device, and wherein the process is further used to de-poison the NOx reducing device.

16. A process according to claim 15 , wherein the step of detecting a regeneration trigger further comprises estimating that the NOx reducing device is poisoned.

17. A process according to claim 1 , wherein the process comprises, prior to the step a), a step of detecting a regeneration trigger further comprises estimating that an accumulated engine operating parameter since a previous regeneration has exceeded a threshold.

18. A process according to claim 1 , wherein the first temperature range is between 450 and 510 degrees Celsius.

19. A process according to claim 1 , wherein the step of increasing the temperature at the particle filter to a second temperature range comprises increasing the temperature at the particulate filter up to over 600° C.

20. A process according to claim 1 , wherein the temperature at the particle filter is maintained within the second temperature range during a second period of time.

21. An internal combustion engine arrangement, comprising:
an internal combustion engine,
an exhaust line for collecting the exhaust gas from the engine and conducting the exhaust gas towards the atmosphere;
an exhaust after-treatment system in the exhaust line, the exhaust after-treatment system comprising at least a particle filter,
heating means arranged to increase a temperature at the particle filter; and
a controller for controlling the heating means
wherein the controller is arranged to perform a process according to claim 1 .

22. The internal combustion engine arrangement according to claim 21 , comprising means for providing a triggering signal to the controller to begin raising the temperature at the particle filter to be within the first temperature range in response to a triggering event indicative of a need for regeneration of an exhaust gas after-treatment device in the exhaust after-treatment system.

23. The internal combustion engine arrangement according to claim 22 , wherein the exhaust gas after-treatment device is at least one of a particle filter, a diesel oxidation catalyst, and a NOx reducing catalyst.

24. The internal combustion engine arrangement according to claim 21 , wherein the controller is arranged to control the heating means to control a rate of increase of the temperature at the particle filter from the first temperature range to the second temperature range.

25. The internal combustion engine arrangement according to claim 21 , comprising means for estimating soot loading of the particle filter.

26. The internal combustion engine according to claim 21 , wherein the controller is arranged to control a heater so that soot on the particle filter is oxidized by passive NO2 regeneration until soot loading of the particle filter is at a second predetermined level and

Assignees

• Renault Trucks
• Volvo Truck Corp

Inventors

• Iojoiu Eduard Emil
• Pourret Raphaël
• Petersson Martin
• Häggendal Björn
• Dahl Johan

Classifications

• F01N3/2006 Primary

  Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating (by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235) · CPC title

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• F01N3/0231

  using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT] · CPC title

• F01N2900/08

  said parameters being related to the engine · CPC title

• F01N2900/1602

  Temperature of exhaust gas apparatus · CPC title