HYBRID VEHICLE FUEL VAPOR CANISTER

• US 20150090232A1
• Filed: 09/27/2013
• Published: 04/02/2015
• Est. Priority Date: 09/27/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Peters, Mark W., Bunge, Mark Daniel, Heim, Michael G., Pearce, Russell Randall
• Granted Patent: US 9,797,347 B2
• Time in Patent Office: Days
• US Class Current: 123/520
• CPC Class Codes: F02D 19/0621 Purging of the fuel system
• CPC Class Codes: F02D 41/003 Adding fuel vapours, e.g. drawn from engine fuel reservoir
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02D 41/0037 for diagnosing the engine diagnosis of purge control systems F02M25/0809
• CPC Class Codes: F02D 41/004 Control of the valve or purge actuator, e.g. duty cycle, closed loop control of position
• CPC Class Codes: F02D 41/0042 Controlling the combustible mixture as a function of the canister purging, e.g. control of injected fuel to compensate for deviation of air fuel ratio when purging
• CPC Class Codes: F02D 41/0045 Estimating, calculating or determining the purging rate, amount, flow or concentration
• CPC Class Codes: F02M 25/0836 Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
• CPC Class Codes: F02M 25/0854 Details of the absorption canister
• CPC Class Codes: F02M 25/0872 Details of the fuel vapour pipes or conduits
• CPC Class Codes: F02M 25/089 Layout of the fuel vapour installation

Abstract

Embodiments for controlling fuel vapors are disclosed. In one example, a method comprises during a purge of a fuel vapor canister, adjusting a heater of the fuel vapor canister based on a rate of a purge flow exiting the fuel vapor canister and a concentration of hydrocarbons released from the fuel vapor canister. In this way, a fuel vapor canister purge efficiency may be increased.

Claims

1. A method comprising:

during a purge of a fuel vapor canister, adjusting a heater of the fuel vapor canister based on a rate of a purge flow exiting the fuel vapor canister and a concentration of hydrocarbons released from the fuel vapor canister.

2. The method of claim 1, wherein adjusting the heater based on the flow rate of the purge and the concentration of hydrocarbons released from the fuel vapor canister comprises activating the heater when the concentration of hydrocarbons released from the fuel vapor canister reaches a first threshold level.

3. The method of claim 2, wherein activating the heater further comprises, when the purge is initiated, delaying activation of the heater until the concentration of hydrocarbons released from the fuel vapor canister reaches the first threshold level.

4. The method of claim 2, wherein adjusting the heater comprises deactivating the heater when the concentration of hydrocarbons released from the fuel vapor canister reaches a second threshold level.

5. The method of claim 4, wherein the first threshold level is lower than the second threshold level.

6. The method of claim 4, further comprising determining the concentration of hydrocarbons released from the fuel vapor canister based on output from an oxygen sensor coupled between the fuel vapor canister and an engine.

7. The method of claim 4, further comprising determining the concentration of hydrocarbons released from the fuel vapor canister based on one or more of a temperature of the purge flow and a temperature of the fuel vapor canister.

8. The method of claim 1, further comprising initiating the purge by opening a canister purge valve to draw fresh air through the fuel vapor canister and route the hydrocarbons to an engine for combustion, the hydrocarbons desorbed by the fresh air.

9. The method of claim 1, wherein the heater is a first heater, and further comprising adjusting a second heater based on the rate of a purge flow exiting the fuel vapor canister and the concentration of hydrocarbons released from the fuel vapor canister.

10. The method of claim 9, wherein the first heater is positioned near a vent port coupling the fuel vapor canister to atmosphere, wherein the second heater is positioned near a purge port coupling the fuel vapor canister to an engine, and wherein adjusting the first heater and the second heater comprises activating the first heater prior to activating the second heater.

11. A vehicle system, comprising:

an engine configured to receive fuel from a fuel tank for combustion;

a fuel vapor canister configured to trap hydrocarbons in fuel vapor from the fuel tank;

a purge line coupling the fuel vapor canister to the engine, the purge line including a canister purge valve and a sensor;

a heater positioned in the fuel vapor canister; and

a controller storing instructions for;

opening the canister purge valve to initiate a purge of hydrocarbons from the fuel vapor canister to the engine; and

after the purge is initiated, activating the heater once output from the sensor indicates a concentration of hydrocarbons released from the fuel vapor canister has reached an upper threshold level.

12. The system of claim 11, wherein the controller stores further instructions for initiating the purge when a hydrocarbon load of the fuel vapor canister reaches a threshold load.

13. The system of claim 11, wherein the controller stores further instructions for deactivating the heater once output from the sensor indicates the concentration of hydrocarbons released from the fuel vapor canister has reached a lower threshold level.

14. The system of claim 11, wherein the sensor is one or more of a hydrocarbon sensor or a temperature sensor.

15. A method, comprising:

responsive to a load on a fuel vapor canister exceeding a threshold load, opening a canister purge valve to purge stored hydrocarbons from the fuel vapor canister to an engine; and

after the purge is initiated, activating a heater of the fuel vapor canister once a concentration of hydrocarbons released from the fuel vapor canister reaches an upper threshold level.

16. The method of claim 15, further comprising, adjusting the heater to maintain a temperature of fuel vapor canister at a designated temperature, the designated temperature based on one or more of a purge flow rate, the concentration of hydrocarbons, and hydrocarbon load of the fuel vapor canister.

17. The method of claim 15, further comprising deactivating the heater once the concentration of hydrocarbons released from the fuel vapor canister reaches a lower threshold level.

18. The method of claim 15, further comprising, when the load on the vapor canister does not exceed the threshold load, maintaining the canister purge valve closed and routing fuel vapors from a fuel tank to the fuel vapor canister.

19. The method of claim 15, wherein the heater is a first heater, and further comprising activating a second heater once the concentration of hydrocarbons released from the fuel vapor canister reaches the upper threshold level.