Systems and methods for detection of vehicle misfueling

Patent metadata

Field	Value
Publication number	US-10611625-B2
Application number	US-201715595835-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	May 15, 2017
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

Methods and systems are provided for identifying misfueling in a vehicle fuel tank when an incorrect fuel type is provided. In one example, a method may include routing fuel vapors from a vehicle fuel tank to a fuel vapor storage canister and monitoring a temperature profile of a fuel system canister during a refueling operation, and when an actual temperature profile is below an expected temperature profile, misfueling is identified. Further, responsive to an indication of misfueling, further addition of fuel is disabled during the refueling event.

First claim

The invention claimed is:

1. A method, comprising:
responsive to misfueling of a fuel tank identified based on an actual temperature profile at a fuel system canister during a refueling event relative to an expected temperature profile, the expected temperature profile based on a fuel level in the fuel tank, disabling further addition of fuel during the refueling event, wherein indicating misfueling includes indicating that an actual fuel being received in the fuel tank is different from a desired fuel.

2. The method of claim 1 , wherein disabling further addition of fuel during the refueling event includes raising a pressure in a filler neck configured to receive fuel from a fuel dispenser by closing one or more of a fuel tank isolation valve coupling the fuel tank to the fuel system canister and a vent valve coupling the fuel system canister to atmosphere.

3. The method of claim 1 , wherein the actual fuel has a lower volatility than the desired fuel.

4. The method of claim 1 , wherein the actual temperature profile is estimated via one or more thermocouples spaced along a vapor flow path within the fuel system canister.

5. The method of claim 4 , wherein the fuel level in the fuel tank during the refueling event is inferred based on an output of the one or more thermocouples.

6. The method of claim 4 , wherein the fuel tank is coupled to an engine of a hybrid electric vehicle, and wherein the one or more thermocouples are spaced symmetrically or asymmetrically along the vapor flow path within the fuel system canister.

7. A method, comprising:
responsive to misfueling of a fuel tank identified based on an actual temperature profile at a fuel system canister during a refueling event relative to an expected temperature profile, the expected temperature profile based on a fuel level in the fuel tank, disabling further addition of fuel during the refueling event, wherein the actual temperature profile is estimated via one or more thermocouples spaced along a vapor flow path within the fuel system canister, and wherein the expected temperature profile includes an expected temperature gain and an expected inflection point for each of the one or more thermocouples as a function of time since a start of the refueling event, the expected temperature profile further based on a volatility of the fuel.

8. The method of claim 7 , wherein the expected temperature profile based on the fuel level in the fuel tank includes, as the fuel level in the fuel tank increases during the refueling event, increasing the expected temperature gain.

9. The method of claim 7 , wherein the expected temperature gain and the expected inflection point for each of the one or more thermocouples is further based on a position of the one or more thermocouples within the fuel system canister relative to a vapor inlet and a vapor outlet of the fuel system canister.

10. The method of claim 7 , wherein indicating misfueling further includes indicating misfueling responsive to an actual temperature gain of the actual temperature profile being lower than the expected temperature gain of the expected temperature profile.

11. The method of claim 10 , wherein the indicating further includes indicating misfueling responsive to an actual inflection point of the actual temperature profile being earlier than the expected inflection point of the expected temperature profile.

12. A method, comprising:
while receiving fuel in a fuel tank,
monitoring a temperature change at each of a plurality of temperature sensors spaced along a vapor flow path within a carbon canister;
responsive to the temperature change at each of the plurality of temperature sensors being higher than a corresponding threshold, continuing to receive the fuel in the fuel tank by maintaining a valve coupling the fuel tank to the carbon canister open; and
responsive to the temperature change at any one of the plurality of temperature sensors being lower than the corresponding threshold, discontinuing further receipt of the fuel in the fuel tank by closing the valve, and indicating that the fuel is an incorrect fuel.

13. The method of claim 12 , wherein the corresponding threshold includes a distinct threshold for each of the plurality of temperature sensors, and wherein the corresponding threshold is adjusted based on a fuel level in the fuel tank, an ambient temperature, and a position of each of the plurality of temperature sensors along the vapor flow path.

14. The method of claim 13 , wherein indicating that the fuel is an incorrect fuel responsive to the temperature change being lower than the corresponding threshold includes indicating that the fuel is an incorrect fuel responsive to a weighted temperature change, wherein the temperature change of a first of the plurality of temperature sensors located more downstream of a canister vapor inlet is weighted higher than the temperature change of a second of the plurality of temperature sensors located less downstream of the canister vapor inlet.

15. The method of claim 12 , wherein indicating that the fuel is an incorrect fuel includes indicating that the fuel received in the fuel tank has a lower volatility than a desired fuel.

16. The method of claim 12 , wherein discontinuing further receipt of the fuel in the fuel tank further includes raising a pressure at a filler neck configured to receive fuel in the fuel tank from a fuel dispenser by closing the valve.

Assignees

• Ford Global Tech Llc

Inventors

• Dudar Aed

Classifications

• B67D7/342 Primary

  by discriminating the kind of liquid by analysis or by physical properties, e.g. vapour-pressure · CPC title

• F02M25/0872 Primary

  Details of the fuel vapour pipes or conduits · CPC title