Engine Starting Control for Engine with Hydrocarbon Retaining System

• US 20090120064A1
• 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 8,448,422 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 3/2846 specially adapted for granular supports, 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 19/087 with determination of densities, viscosities, composition, concentration or mixture ratios of fuels
• 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:

during engine starting;

selectively routing exhaust gases of the engine to the hydrocarbon retaining system to store exhaust hydrocarbons and operating with spark advance close to a peak torque timing; and

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

2. The method of claim 1 further comprising during starting, operating with a stoichiometric or rich exhaust air-fuel ratio, where the air-fuel ratio is enleaned as an amount of hydrocarbons stored in the hydrocarbon retaining system increases.

3. The method of claim 2 where, engine starting includes when temperature of an emission control device is less than a threshold, the method further comprising, during warm engine restarts, routing exhaust gases to an emission control device and commencing purging of the hydrocarbon retaining system.

4. The method of claim 1 further comprising routing exhaust gases to a catalytic emission control device in the exhaust after the catalytic emission control device reaches a threshold temperature, and enleaning exhaust air-fuel ratio when transitioning from routing exhaust gases to the hydrocarbon retaining system to routing exhaust gases to the catalytic emission control device.

5. The method of claim 1 further comprising varying an ending of the routing to store exhaust hydrocarbons responsive to at least a fuel property.

6. The method of claim 1 further comprising varying an initiating of the selective purging of stored hydrocarbons responsive to an operating condition.

7. A method of operating an engine having an intake, an exhaust and a hydrocarbon-retaining system, the engine combusting fuel and the exhaust including a catalytic emission control device, the method comprising:

during an engine start when catalytic emission control device is below a light-off temperature;

in a first mode, routing exhaust gases to the hydrocarbon retaining system and operating during at least a portion of first mode with spark at first timing, and a first exhaust air-fuel ratio;

in a second mode, bypassing the hydrocarbon retaining system and operating during at least a portion of the second mode with spark at a second timing more retarded than first timing or a second exhaust air-fuel ratio leaner than the first exhaust air-fuel ratio.

8. The method of claim 7, where the first timing is close to MBT timing, and the first air-fuel ratio is stoichiometric or rich.

9. The method of claim 7, where the second mode is performed after the first mode, and where the first mode is performed at lower temperature of the emission control device than the second mode.

10. The method of claim 7, where the first mode is performed during a first engine start, and the second mode is performed during a second engine start.

11. The method of claim 10, where during the second start, the hydrocarbon retaining system has a greater amount of hydrocarbons stored than during the first start.

12. The method of claim 7, where in the first mode, the first air-fuel ratio is lean during a first portion, and stoichiometric or rich during a second portion of the first mode.

13. The method of claim 7, where the hydrocarbon retaining system include a first and second hydrocarbon retaining device, the method further comprising determining degradation of the hydrocarbon retaining system in response to an exhaust air-fuel ratio during purging.

14. The method of claim 7, wherein in the first mode, at least one cylinder operates with a lean combustion air-fuel ratio, and at least one cylinder operates with a rich combustion air-fuel ratio.

15. A method of operating an engine having an intake, an exhaust, and a hydrocarbon-retaining system, the engine combusting fuel, the method comprising:

during engine starting;

selectively routing exhaust gases of the engine to the hydrocarbon retaining system to store exhaust hydrocarbons and operating with exhaust air-fuel ratio slightly rich; and

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

16. The method of claim 15 wherein during engine starting, ignition timing is substantially at MBT timing even when catalyst temperature is below a light-off temperature.