System and Method for Purging Fuel Vapors Using Exhaust Gas

• US 20080110441A1
• Filed: 01/16/2008
• Published: 05/15/2008
• Est. Priority Date: 02/15/2006
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Cunningham, Ralph, Leone, Thomas
• Granted Patent: US 7,469,684 B2
• Time in Patent Office: Days
• US Class Current: 123/520
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02M 25/08 adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003
• CPC Class Codes: F02M 26/35 with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters
• CPC Class Codes: F02M 26/36 with means for adding fluids other than exhaust gas to the recirculation passage; with reformers
• CPC Class Codes: F02M 26/46 for determining the characteristics of gases, e.g. composition
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates

Abstract

A system for a vehicle, comprising of an engine, an air intake passage coupled to the engine, an exhaust passage coupled to the engine, a fuel vapor storage system fluidly coupled with the intake air passage and the exhaust passage, said fuel vapor storage system configured to store and release fuel vapors, a control system configured to during a first mode, route exhaust gas from the engine to the fuel vapor storage system via at least the exhaust passage, and during a second mode, route at least fresh air to the fuel vapor storage system to release fuel vapors from the fuel vapor storage system before being inducted into the engine via the air intake passage to be burned.

Claims

1. A system for a vehicle, comprising:

an engine;

an air intake passage coupled to the engine;

an exhaust passage coupled to the engine;

a fuel vapor storage system fluidly coupled with the intake air passage and the exhaust passage, said fuel vapor storage system configured to store and release fuel vapors;

a control system configured to;

during a first mode, route exhaust gas from the engine to the fuel vapor storage system via at least the exhaust passage; and

during a second mode, route at least fresh air to the fuel vapor storage system to release fuel vapors from the fuel vapor storage system before being inducted into the engine via the air intake passage to be burned.

2. The system of claim 1, wherein the fuel vapor storage system includes at least a charcoal or carbon canister.

3. The system of claim 1, wherein the first mode is performed during a first exhaust temperature condition and the second mode is performed during a second exhaust temperature condition different than the first exhaust temperature condition.

4. The system of claim 1, wherein the fuel vapor storage system includes a first end fluidly coupled with the air intake passage of the engine and a second end fluidly coupled with a fresh air passage fluidly coupled with ambient.

5. The system of claim 4, further comprising a valve arranged along the fresh air passage, where said control system configured to vary the position of the valve.

6. The system of claim 1, further comprising a valve configured to vary the amount of exhaust gas routed to the fuel vapor storage system, wherein said control system is configured to vary the position of the valve between the first mode and the second mode.

7. The system of claim 1, wherein the fuel vapor storage system is fluidly coupled with the air intake passage via a fuel vapor purging passage;

and wherein the system further comprises a fuel storage tank having a ullage space that is fluidly coupled with the fuel vapor purging passage between the fuel vapor storage system and the air intake passage.

8. The system of claim 1, wherein the first mode includes a different temperature of the fuel vapor storage system than the second mode.

9. A method for operating an engine of a vehicle, including at least a fuel tank and a fuel vapor storage system coupled to the engine, the method comprising:

during a first condition, adjusting an amount of exhaust gas fed to the fuel vapor storage system;

during a second condition, adjusting an amount of fresh air fed to the fuel vapor storage system and releasing fuel vapors stored in the fuel vapor storage system into at least said fed fresh air; and

routing at least said fresh air from the fuel vapor storage system to an intake manifold of the engine so that at least the fresh air is introduced into the engine to be burned carrying the released fuel vapors.

10. The method of claim 9, where said amount of fresh air is adjusted based on an exhaust air-fuel ratio of the engine.

11. The method of claim 9, where said amount of exhaust gas is adjusted based on an exhaust air-fuel ratio of the engine.

12. The method of claim 9, further comprising, during the second condition, adjusting an amount of the exhaust gas fed to the fuel vapor storage system.

13. The method of claim 9, wherein the first condition includes a different exhaust temperature than the second condition.

14. The method of claim 9, wherein the first condition includes a different temperature of the fuel vapor storage system than the second condition.

15. The method of claim 9, further comprising capturing fuel vapors generated from the fuel tank at the fuel vapor storage system before said releasing of the fuel vapors from the fuel vapor storage system.

16. A system for a vehicle, comprising:

an engine;

an air intake passage coupled to the engine;

an exhaust passage coupled to the engine;

a fuel vapor storage system including at least a carbon canister, said fuel vapor storage system configured to store and release fuel vapors;

a first passage fluidly coupling a first end of the fuel vapor storage system to the air intake passage;

a second passage fluidly coupling a second end of the fuel vapor storage system with the exhaust passage;

a fuel tank having a ullage space fluidly coupled with the first passage at a location that is between the air intake passage and the fuel vapor storage system;

a first valve arranged along the first passage;

a second valve arranged along the second passage;

a control system operatively coupled with the first and second valves and configured to;

during a first mode, route fuel vapors from the fuel tank to the fuel vapor storage system;

during a second mode, route exhaust gas from the engine to the fuel vapor storage system via at least the exhaust passage and the second passage by opening at least the second valve; and

during a third mode, route at least fresh air to the engine via at least the fuel vapor storage system, the first passage, and the air intake passage by opening at least the first valve so that fuel vapors routed to the fuel vapor storage system during at least the first mode are released and combusted in the engine.