Hydrocarbon Retaining and Purging System for Flex-Fuel Combustion Engine

• US 20090120065A1
• 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 8,448,427 B2
• Time in Patent Office: Days
• US Class Current: 60/284
• 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 19/088 by estimation, i.e. without using direct measurements of a corresponding sensor
• 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 method of operating an engine having an intake, an exhaust, and a hydrocarbon-retaining system, the engine combusting fuel, the method comprising:

selectively routing exhaust gases of the engine to the hydrocarbon retaining system to store exhaust hydrocarbons;

selectively purging stored hydrocarbons from the hydrocarbon retaining system to the engine intake; and

varying an initiating of the selective purging of stored hydrocarbons responsive to a condition.

2. The method of claim 1, where the condition includes a fuel property.

3. The method of claim 2, where the fuel property includes an alcohol content of the fuel.

4. The method of claim 1, where the condition includes an amount of hydrocarbons stored in the hydrocarbon retaining system.

5. The method of claim 1, where the condition includes exhaust temperature.

6. The method of claim 1, where the selective routing is performed during an engine start.

7. The method of claim 6 further comprising communicating the hydrocarbon retaining system with a fuel tank to retain at least some fuel vapors from the tank in the hydrocarbon retaining system.

8. The method of claim 6 further comprising adjusting fuel injection to the engine based on the selective purging to learn an amount of hydrocarbons stored in the hydrocarbon-retaining system.

9. The method of claim 6 further comprising varying an ending of the routing to store exhaust hydrocarbons responsive to at least a fuel alcohol content.

10. The method of claim 9, where said varying includes ending routing at a higher temperature as the alcohol content is increased.

11. The method of claim 6 further comprising combusting a rich exhaust air-fuel ratio during at least a portion of the routing, even when temperature of emission control device is below a light-off temperature, and further operating with exhaust air-fuel ratio about stoichiometry after the ending.

12. The method of claim 6 further comprising transferring exhaust gas heat from the exhaust to the fresh air drawn in to purge the hydrocarbon retaining system.

13. The method of claim 1, where during the selective routing, exhaust gas first enters a first hydrocarbon retaining device, and then enters a second hydrocarbon retaining device, serially.

14. The method of claim 13, where during the selective purging, purge gases are routed in parallel to the first and second hydrocarbon retaining device.

15. The method of claim 1, where during selective routing, exhaust gases enter a hydrocarbon retaining device in a first direction, and during selective purging, purge gas exits with stored hydrocarbons from the hydrocarbon retaining device in a second direction opposite the first direction.

16. The method of claim 1 further comprising determining degradation of the hydrocarbon retaining system responsive to an exhaust air-fuel ratio sensor during the purging.

17. A system for a vehicle including an engine having an intake and an exhaust, the system comprising:

a fuel system of the vehicle;

a hydrocarbon retaining system selectively coupled to the engine intake, engine exhaust, and fuel system; and

a controller for selectively routing exhaust gases of the engine to the hydrocarbon retaining system to store exhaust hydrocarbons;

selectively routing fuel vapors from the fuel system to the hydrocarbon retaining system, selectively purging stored hydrocarbons from the hydrocarbon retaining system to the engine intake;

varying an initiating of the selective purging of stored hydrocarbons responsive to a condition, and varying an ending of the routing to store exhaust hydrocarbons responsive to at least an alcohol content of fuel combusted in the engine.

18. A system for a vehicle including an engine having an intake and an exhaust, the system comprising:

a fuel system of the vehicle;

a catalytic emission control device closely coupled in the exhaust;

a hydrocarbon retaining system selectively coupled to the engine intake, engine exhaust, and fuel system, the hydrocarbon retaining system having a vent positioned adjacent at least a portion of the exhaust of the engine; and

a controller for selectively routing exhaust gases of the engine to the hydrocarbon retaining system to store exhaust hydrocarbons;

selectively routing fuel vapors from the fuel system to the hydrocarbon retaining system, selectively purging stored hydrocarbons from the hydrocarbon retaining system to the engine intake by inducting fresh air into the vent;

varying an initiating of the selective purging of stored hydrocarbons responsive to a temperature of the emission control device; and

varying an ending of the routing to store exhaust hydrocarbons responsive to at least an alcohol content of fuel combusted in the engine.