SYSTEMS AND METHODS FOR LIMITED EMISSIONS REFUELING

• US 20170217753A1
• Filed: 02/02/2016
• Published: 08/03/2017
• Est. Priority Date: 02/02/2016
• 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.
• Granted Patent: US 10,364,763 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 15/03504 adapted to avoid loss of fuel or fuel vapour, e.g. with vapour recovery systems
• CPC Class Codes: B60K 15/03519 Valve arrangements in the vent line
• CPC Class Codes: B60K 2015/0319 with electronic systems, e.g. for controlling fuelling or venting for LPG tanks B60K2015/03013
• CPC Class Codes: B60K 2015/03375 to improve security
• CPC Class Codes: F02D 41/0045 Estimating, calculating or determining the purging rate, amount, flow or concentration
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system

Abstract

A method is presented, comprising, during a first condition, including an active refueling event, receiving an indication of hydrocarbon breakthrough from the fuel vapor canister; and restricting flow of fuel vapor through a fuel vapor canister vent pathway responsive to the indication of hydrocarbon breakthrough. Restricting the fuel vapor canister vent pathway will cause fuel tank pressure to increase, thus triggering an automatic shutoff of a refueling dispenser. In this way, the refueling event may be terminated without releasing significant quantities of hydrocarbons into the atmosphere.

Claims

1. A method comprising:

during a first condition, including an ongoing refueling event, receiving an indication of hydrocarbon breakthrough from a fuel vapor canister; and

restricting flow of fuel vapor through a fuel vapor canister vent pathway responsive to the indication of hydrocarbon breakthrough.

2. The method of claim 1, further comprising:

updating one or more fuel system parameters following termination of the refueling event.

3. The method of claim 2, wherein the one or more fuel system parameters comprise a fuel vapor canister purge schedule.

4. The method of claim 1, wherein restricting flow of fuel vapor through a fuel vapor canister vent pathway comprises closing a canister vent valve coupled within the fuel vapor canister vent pathway.

5. The method of claim 1, wherein restricting flow of fuel vapor through a fuel vapor canister vent pathway comprises closing a fuel tank isolation valve coupled between a fuel tank and the fuel vapor canister.

6. The method of claim 1, wherein the indication of hydrocarbon breakthrough from the fuel vapor canister comprises an output of a hydrocarbon sensor coupled within the fuel vapor canister vent pathway increasing above a threshold.

7. The method of claim 1, wherein restricting flow of fuel vapor through a fuel vapor canister vent pathway responsive to the indication of hydrocarbon breakthrough comprises restricting flow of fuel vapor through the fuel vapor canister vent pathway regardless of fuel fill level.

8. The method of claim 7, further comprising:

receiving a request for a refueling event;

opening a fuel tank isolation valve coupled between a fuel and a fuel vapor canister; and

removing access restrictions to a fuel filler neck responsive to an absolute fuel tank pressure decreasing below a threshold.

9. The method of claim 8, wherein the first condition comprises active limited emission refueling parameters.

10. The method of claim 9, wherein limited emission refueling parameters are activated in response to a local regulation for the jurisdiction in which the refueling event takes place.

11. The method of claim 8, further comprising:

during a second condition, including an active refueling event, maintaining non-zero flow of fuel vapor through a fuel vapor canister vent pathway regardless of an indication of hydrocarbon breakthrough, including even when the indication of breakthrough is generated.

12. The method of claim 11, wherein the limited emission refueling parameters are inactive during the second condition.

13. The method of claim 11, further comprising:

during a third condition, receiving a refueling request; and

maintaining the fuel tank isolation valve closed.

14. The method of claim 13, wherein the third condition comprises active limited emission refueling parameters and a canister load above a threshold.

15. The method of claim 14, further comprising:

indicating that the fuel vapor canister must be purged prior to enabling a refueling event.

16. The method of claim 15, further comprising:

receiving an indication that the limited emission refueling parameters have been overridden;

receiving a second request for a refueling event;

opening the fuel tank isolation valve; and

removing access restrictions to the fuel filler neck responsive to an absolute fuel tank pressure decreasing below a threshold.

17. A fuel system for a vehicle, comprising:

a fuel vapor canister vent pathway comprising a load conduit coupled to a fuel tank and a vent conduit coupled to atmosphere;

one or more valves coupled within the fuel vapor canister vent pathway;

a hydrocarbon sensor coupled within the vent conduit;

a human machine interface configured to receive a refueling request from a vehicle operator and further configured to receive input from the vehicle operator indicating whether limited emissions refueling parameters are active; and

a controller configured with instructions stored in non-transitory memory, that when executed, cause the controller to;

depressurize the fuel tank via the fuel vapor canister vent pathway responsive to an indication that a refueling request has been received by the human machine interface;

responsive to an indication that limited emissions refueling parameters are active, monitor an output of the hydrocarbon sensor during a refueling event; and

close one or more valves coupled within the fuel vapor canister vent pathway responsive to the output of the hydrocarbon sensor increasing above a threshold.

18. The fuel system of claim 17, wherein the controller is further configured with instructions stored in non-transitory memory, that when executed, cause the controller to:

responsive to an indication that limited emissions refueling parameters are inactive, maintaining the one or more valves coupled within the fuel vapor canister vent pathway in an open conformation regardless of the output of the hydrocarbon sensor.

19. The fuel system of claim 18, wherein the controller is further configured with instructions stored in non-transitory memory, that when executed, cause the controller to:

responsive to an indication that limited emissions refueling parameters are active and a fuel vapor canister load is above a threshold, receiving an indication that a refueling request has been received by the human machine interface;

maintaining fuel tank pressure; and

indicating that a fuel vapor canister purge event must occur prior to enabling a refueling event.

20. A method for a vehicle, comprising:

receiving a request for a refueling event;

receiving an indication that limited emissions refueling parameters are active;

venting a fuel tank to atmosphere via a fuel vapor canister;

allowing access to a fuel filler neck responsive to an absolute fuel tank pressure decreasing below a threshold;

monitoring an output of a hydrocarbon sensor coupled between the fuel vapor canister and atmosphere; and

responsive to the output of the hydrocarbon sensor increasing above a threshold, restricting flow of fuel vapor between the fuel tank and atmosphere regardless of a fuel fill level in the fuel tank.