HYBRID VEHICLE FUEL VAPOR CANISTER

• US 20150090233A1
• 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: Dudar, Aed M., Yang, Dennis Seung-Man
• Granted Patent: US 10,156,210 B2
• Time in Patent Office: Days
• US Class Current: 123/520
• CPC Class Codes: F02M 2025/0881 with means to heat or cool the canister
• 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 25/0809 Judging failure of purge control system
• CPC Class Codes: F02M 25/0827 by monitoring engine running conditions
• 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

Abstract

Embodiments for controlling fuel vapors are provided. In one example, a method comprises initiating a purge of a fuel vapor canister responsive to a temperature profile at a vent side of the fuel vapor canister. In this way, release of fuel vapors to the atmosphere may be reduced.

Claims

1. A method, comprising:

initiating a purge of a fuel vapor canister responsive to a temperature profile at a vent side of the fuel vapor canister.

2. The method of claim 1, wherein initiating the purge responsive to the temperature profile at the vent side of the fuel vapor canister comprises initiating the purge responsive to a temperature of fuel vapor canister near a vent port of the fuel vapor canister increasing to a peak temperature and then subsequently decreasing in temperature.

3. The method of claim 2, wherein the purge is initiated when the peak temperature is identified.

4. The method of claim 2, wherein initiating the purge responsive to the temperature profile at the vent side of the fuel vapor canister comprises initiating the purge responsive to a temperature profile identified based on feedback received from a temperature sensor positioned adjacent to a vent port of the fuel vapor canister, the vent port fluidically coupling the fuel vapor canister to atmosphere.

5. The method of claim 1, further comprising, prior to initiating the purge, routing fuel vapors from a fuel tank to the fuel vapor canister to trap the fuel vapors in the fuel vapor canister.

6. The method of claim 5, wherein initiating the purge comprises opening a canister purge valve to draw fresh air into the fuel vapor canister and purge the trapped fuel vapor to an engine for combustion.

7. The method of claim 6, wherein the engine is installed in a hybrid vehicle configured to receive motive force from the engine or a motor, and wherein initiating the fuel vapor canister purge further comprises starting the engine.

8. The method of claim 6, further comprising, after opening the canister purge valve, activating one or canister heaters to maintain the fuel vapor canister at a designated temperature.

9. A hybrid vehicle system, comprising:

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

a fuel vapor canister configured to trap fuel vapor released from the fuel tank;

a vent line coupling the fuel vapor canister to atmosphere;

a purge line coupling the fuel vapor canister to the engine;

a temperature sensor positioned in the fuel vapor canister near a vent port coupling the fuel vapor canister to the vent line; and

a controller storing instructions for;

detecting bleed-through of fuel vapor out of the fuel vapor canister based on output of the temperature sensor; and

if bleed-through is detected,

opening a canister purge valve positioned in the purge line to route the trapped fuel vapor to the engine; and

if the hybrid vehicle is currently propelled by a motor and not the engine, starting the engine prior to opening the canister purge valve.

10. The system of claim 9, further comprising a plurality of heaters embedded in the fuel vapor canister, and wherein the controller stores instructions for activating at least one heater of the plurality of heaters if bleed-through is detected.

11. The system of claim 10, wherein the plurality of heaters comprises a first heater positioned near a vent port of the fuel vapor canister, the vent port coupling the fuel vapor canister to the vent line, and a second heater positioned near a purge port of the fuel vapor canister, the purge port coupling the fuel vapor canister to the purge line.

12. The system of claim 11, wherein the controller stores instructions for activating the first heater prior to activating the second heater.

13. The system of claim 10, further comprising when the hybrid vehicle is propelled by the motor and not by the engine, adjusting the plurality of heaters to maintain a temperature the fuel vapor canister at a designated temperature, and wherein activating the at least one heater of the plurality of heaters comprises adjusting the at least one heater to increase the temperature of the fuel vapor canister above the designated temperature.

14. The system of claim 9, further comprising a fuel tank isolation valve positioned in a fuel line coupling the fuel tank to the fuel vapor canister, and wherein the controller stores instructions to open the fuel tank isolation valve during a fuel tank refill event to route the fuel vapors from the fuel tank to the fuel vapor canister.

15. A method for managing fuel vapors in a hybrid vehicle configured to be propelled by a motor or by an engine, the method comprising:

during non-purge conditions while the engine is inactive, detecting fuel vapors exiting a fuel vapor canister to atmosphere based on a temperature of an atmosphere side of the fuel vapor canister reaching a peak temperature; and

if fuel vapor exiting the fuel vapor canister is detected, starting the engine and opening a canister purge valve to route fuel vapor in the fuel vapor canister to the engine for combustion.

16. The method of claim 15, wherein detecting fuel vapor based on the temperature of the atmosphere side of the fuel vapor canister comprises determining the temperature of the atmosphere side of the fuel vapor canister based on output from a temperature sensor positioned near a vent port coupling the fuel vapor canister to atmosphere.

17. The method of claim 15, further comprising, during the non-purge conditions while the engine is inactive, routing fuel vapors from a fuel tank to the fuel vapor canister.

18. The method of claim 15, wherein routing fuel vapors from the fuel tank to the fuel vapor canister comprises opening a fuel tank isolation valve when fuel tank pressure exceeds a threshold.

19. The method of claim 15, further comprising, if fuel vapor is detected, activating one or more heaters embedded within the fuel vapor canister.

20. The method of claim 19, wherein activating one or more heaters comprises activating the one or more heaters successively in a direction of purge flow through the fuel vapor canister.