Fuel systems and methods for controlling fuel systems in a vehicle with multiple fuel tanks

• US 8,539,938 B2
• Filed: 03/12/2009
• Issued: 09/24/2013
• Est. Priority Date: 03/12/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Elwart, Shane, Kerns, James Michael
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): NAJMUDDIN, RAZA NEHAL
• Application Number:
  US12/403,259
• Publication Number:
  US 20100229966A1
• Time in Patent Office: 1,657 Days
• Field of Search: 123/575, 123/576, 123/577, 123/578, 123/515, 123/516, 123/518, 123/519, 123/521, 123/525, 123/526, 123/527, 123/529, 123/198.D, 123/198.DB, 123/520, 137/255, 137/256, 137/262, 137/263, 137/264, 137/265, 137/266, 137/267, 137/587, 137/589, 137/312, 137/571, 220/746, 220/749, 220/750, 220/4.14, 731/143.8, 73/492
• US Class Current: 123/575
• CPC Class Codes: F02M 25/00 Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding secondary air to fuel-air mixture F02M23/00; adding exhaust gases F02M26/00; fuel-injection apparatus operating simultaneously on two or more fuels or on a liquid fuel and another liquid F02M43/00
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system
• CPC Class Codes: F02M 37/0088 Multiple separate fuel tanks or tanks being at least partially partitioned
• CPC Class Codes: Y10T 137/4673 Plural tanks or compartments with parallel flow
• CPC Class Codes: Y10T 137/469 Sequentially filled and emptied [e.g., holding type]
• CPC Class Codes: Y10T 137/479 Flow dividing compartments
• CPC Class Codes: Y10T 137/7758 Pilot or servo controlled
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

Fuel systems and methods for controlling fuel systems in a vehicle with multiple fuel tanks are provided. An exemplary vehicle fuel system includes a first fuel tank including a first pressure sensor, and a second fuel tank. The system may further include a fuel tank isolation valve positioned to selectively decouple the first fuel tank and the second fuel tank. The system may further include an electronic controller configured to identify which of the first fuel tank and second fuel tank includes a fuel system leak by selectively decoupling the first fuel tank and the second fuel tank via the fuel tank isolation valve, responsive to an identification of the fuel system leak.

Claims

1. A method for controlling a fuel system of a vehicle, the method including:

decoupling, via an electronic controller, a first fuel tank including a first fuel type and a second fuel tank including a second fuel type, responsive to an identification by the controller of a fuel system leak; and

identifying, via the controller, which of the first fuel tank and the second fuel tank includes the fuel system leak.

2. The method of claim 1, wherein the decoupling includes:

closing a canister isolation valve positioned downstream of the first fuel tank, and

closing a fuel tank isolation valve positioned downstream of the second fuel tank and upstream of the canister isolation valve.

3. The method of claim 2, wherein closing the fuel tank isolation valve includes closing the fuel tank isolation valve before a minimum pressure point of a pressure of the first fuel tank.

4. The method of claim 1, further comprising storing the first fuel type in the first fuel tank, and storing the second fuel type in the second fuel tank, wherein the decoupling is carried out when the first fuel type is stored in the first fuel tank and the second fuel type is stored in the second fuel tank.

5. The method of claim 1, further comprising:

setting an expected pressure signal based on one or more of the first fuel type and a first fuel quantity in the first fuel tank, and

receiving a pressure signal from a first pressure sensor in the first fuel tank at the electronic controller.

6. The method of claim 5, wherein the identifying includes:

identifying that the first fuel tank has the fuel system leak when a difference between the pressure signal and the expected pressure signal is above a difference threshold, and

identifying that the second fuel tank has the fuel system leak when the difference between the pressure signal and the expected pressure signal is below the difference threshold.

7. The method of claim 5, wherein the pressure signal is a pressure reduction rate, and the expected pressure signal is an expected pressure reduction rate.

8. The method of claim 1, wherein the fuel system leak is identified by performing a first leak detection test on the fuel system, and wherein a canister isolation valve is closed and a fuel tank isolation valve is open during the first leak detection test.

9. A method for controlling a fuel system of a vehicle comprising:

setting a first expected pressure signal based on one or more of a fuel type and a fuel quantity in a first fuel tank;

setting a second expected pressure signal based on one or more of a fuel type and a fuel quantity in a second fuel tank, wherein fuel type is detectable by a fuel type sensor in a fuel reservoir located upstream of the first fuel tank and the second fuel tank;

receiving a first pressure signal from a first pressure sensor in the first fuel tank, at an electronic controller;

receiving a second pressure signal from a second pressure sensor in the second fuel tank at the electronic controller;

identifying that the first fuel tank has a fuel system leak when a difference between the first pressure signal and the first expected pressure signal is above a first difference threshold; and

identifying that the second fuel tank has a fuel system leak when a difference between the second pressure signal and the second expected pressure signal is above a second difference threshold.