METHOD FOR CONTROLLING A SYSTEM FOR THE TREATMENT OF EXHAUST GASES FROM AN INTERNAL COMBUSTION ENGINE

• US 20120227383A1
• Filed: 10/18/2010
• Published: 09/13/2012
• Est. Priority Date: 11/17/2009
• Status: Active Grant

• Current Assignee: Peugeot Citroen Automobiles SA (Stellantis NV)
• Original Assignee: Peugeot Citroen Automobiles SA (Stellantis NV)
• Inventors: Grise, Clement, Charial, Christope
• Granted Patent: US 9,051,865 B2
• Time in Patent Office: Days
• US Class Current: 60/274
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2900/0411 using a feed-forward control
• CPC Class Codes: F01N 2900/0412 using pre-calibrated maps, tables or charts
• CPC Class Codes: F01N 2900/1621 Catalyst conversion efficiency
• CPC Class Codes: F01N 3/0231 using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]
• CPC Class Codes: F01N 3/103 Oxidation catalysts for HC and CO only
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The invention relates to a method for controlling a system for the treatment of exhaust gases in an exhaust line of an internal combustion engine. The method comprises estimating the molar ratio of nitrogen dioxide to nitrogen monoxide at the inlet of an NOx selective reduction catalyst based on cartography that is dependent on the residence time of the exhaust gases in an oxidation catalyst disposed upstream of the gas treatment means leading to a reduction of nitrogen oxides.

Claims

1-7. -7. (canceled)

8. A method for controlling a system for the treatment of exhaust gas present in the exhaust line of an internal combustion engine, said method comprising:

mapping the sojourn time of exhaust gas in a DOC oxidation catalyst of the exhaust line installed upstream of a gas treatment means of the exhaust line, the gas treatment means operable to reduce nitrogen oxide in the exhaust line; and

estimating a molar ratio between nitrogen dioxide and nitrogen monoxide at an inlet of a selective reduction catalyst of the exhaust line utilizing the mapped sojourn time.

9. The method according to claim 8, wherein the gas treatment means comprises NOx reducing agent injector and the selective reduction catalyst located downstream the injector.

10. The method according to claim 9, further comprising:

calculating an aging state of the DOC oxidation catalyst; and

adjusting the estimated molar ratio based on the aging state of the DOC oxidation catalyst.

11. The method according to claim 10, wherein calculating the aging state of the DOC oxidation catalyst comprises:

calculating an accumulated time of exposure of the DOC oxidation catalyst above a first critical temperature that will cause degradation of the DOC oxidation catalyst; and

calculating a ratio between the accumulated time of exposure of the DOC oxidation catalyst above the first critical temperature that will cause degradation of the DOC oxidation catalyst and an exposure time to the first critical temperature for which the degradation of the DOC oxidation catalyst will be complete.

12. The method according to claim 11, wherein calculating the accumulated time of exposure of the DOC oxidation catalyst above a first critical temperature comprises multiplying the calculating the accumulated time of exposure of the DOC oxidation catalyst above a first critical temperature by a correction factor greater than 1 when the DOC oxidation catalyst is exposed to a second critical temperature that is higher than the first critical temperature.

14. The method according to claim 8, wherein the gas treatment means comprises a particle filter capable of operating in a continuous conversion mode.