Hydrocarbon Retaining System Configuration for Combustion Engine

• US 20090120063A1
• Filed: 06/26/2008
• Published: 05/14/2009
• Est. Priority Date: 11/12/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Uhrich, Michael James, Lupescu, Jason Aaron, Kerns, James Michael, Elwart, Shane
• Granted Patent: US 8,112,985 B2
• Time in Patent Office: Days
• US Class Current: 60/278
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/2832 granular, e.g. pellets
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02B 23/104 the injector being placed on a side position of the cylinder
• CPC Class Codes: F02D 13/0207 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0219 by shifting the phase, i.e. the opening periods of the valves are constant
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system
• CPC Class Codes: F02M 25/0854 Details of the absorption canister
• CPC Class Codes: F02M 25/089 Layout of the fuel vapour installation
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

Systems, methods, and computer readable storage media are described in which exhaust gas is routed to a hydrocarbon retaining device during starting, and purged to the engine intake manifold. Various alternative approaches are described for controlling operation and diagnosing degradation. Further, various interrelated configurations are described.

Claims

1. A system for managing emissions of an engine of a vehicle, the system comprising:

a first exhaust passage including an emission control device, the first passage including a downstream section, the downstream section downstream of the emission control device and including a tailpipe of the vehicle;

a second exhaust passage coupled to the first exhaust passage downstream of the emission control device, the second exhaust passage including a hydrocarbon retaining system, the hydrocarbon retaining system including a vent passage, where at least a portion of the vent passage is positioned adjacent and thermally coupled to at least a portion of the downstream section of the first exhaust passage.

2. The system of claim 1 further comprising a purging passage coupled between an engine intake and the hydrocarbon retaining system.

3. The system of claim 2 further comprising a control system configured to route exhaust gases to the second exhaust passage during a first condition to stored exhaust hydrocarbon in the hydrocarbon retaining system, and during a second condition, purging the hydrocarbon retaining system to an engine intake.

4. The system of claim 3 wherein the control system, during purging, operates the hydrocarbon retaining system to draw fresh air into the vent passage to purge hydrocarbons from the hydrocarbon retaining system to the engine intake.

5. The system of claim 4, where the control system adjusts initiation of the purging responsive to exhaust temperature.

6. The system of claim 1 further comprising a plurality of valves to selectively route exhaust gas to the first and second passages.

7. The system of claim 1 further comprising a muffler in the first passage.

8. A method for operating an engine having a hydrocarbon retaining system coupled to an engine exhaust and an engine intake, the method comprising:

during an engine start, routing exhaust gas to the hydrocarbon retaining system and venting exhaust gases to ambient via a vent passage;

when temperature of a catalytic emission control device coupled in the exhaust reaches a threshold temperature, routing exhaust gases to atmosphere and bypassing the hydrocarbon retaining system;

purging the hydrocarbon retaining system with fresh air via the vent passage to the engine intake; and

transferring heat from exhaust downstream of the emission control device to fresh air in the vent passage, without mixing exhaust exiting the emission control device with fresh air in vent passage.

9. The method of claim 8 further comprising initiating the purging based on an alcohol composition of fuel combusted in the engine.

10. The method of claim 8 further comprising operating with spark timing at MBT timing during the engine start even when temperature of the catalytic emission control device is substantially below a light-off temperature.

11. The method of claim 8 further comprising adjusting the threshold responsive to an alcohol composition of fuel combusted in the engine.

12. The method of claim 8 further comprising determining degradation of the hydrocarbon retaining system responsive to air-fuel ratio in the exhaust during the purging.

13. The method of claim 8 further comprising routing fuel system vapors to the hydrocarbon retaining device.

15. The method of claim 13 wherein the hydrocarbon retaining system includes a plurality of hydrocarbon retaining devices with successively smaller pore sizes in the direction of exhaust gas flow during storing operation.

14. A method for operating an engine having a hydrocarbon retaining system coupled to an engine exhaust and an engine intake, the method comprising:

during an engine start, routing exhaust gas to the hydrocarbon retaining system and venting exhaust gases to ambient via a vent passage, and when temperature of a catalytic emission control device coupled in the exhaust reaches a threshold temperature, routing exhaust gases to atmosphere and bypassing the hydrocarbon retaining system;

during conditions other than the engine start, where the emission control device is above the light-off temperature, routing exhaust gas to the hydrocarbon retaining system when temperature of the hydrocarbon retaining system is below a threshold value, the routine continuing until the hydrocarbon retaining system reaches a threshold purging temperature, and then routine exhaust gases to atmosphere, bypassing the hydrocarbon retaining system, and purging the hydrocarbon retaining system with fresh air to the engine intake.