FUEL SYSTEM FOR A MULTI-FUEL ENGINE

• US 20120048242A1
• Filed: 08/24/2010
• Published: 03/01/2012
• Est. Priority Date: 08/24/2010
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Surnilla, Gopichandra, Basmaji, Joseph, Pursifull, Ross Dykstra
• Granted Patent: US 8,590,510 B2
• Time in Patent Office: Days
• US Class Current: 123/497
• CPC Class Codes: F02D 13/0207 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0219 by shifting the phase, i.e. the opening periods of the valves are constant
• CPC Class Codes: F02D 19/022 to adjust the fuel pressure, temperature or composition
• CPC Class Codes: F02D 19/024 by controlling fuel injectors
• CPC Class Codes: F02D 19/0628 Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 19/0634 Determining a density, viscosity, composition or concentration F02D19/087 takes precedence
• CPC Class Codes: F02D 19/0689 for in-cylinder direct injection
• CPC Class Codes: F02D 19/0692 Arrangement of multiple injectors per combustion chamber
• CPC Class Codes: F02D 19/0694 operating with a plurality of fuels
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 2041/3881 with multiple common rails, e.g. one rail per cylinder bank, or a high pressure rail and a low pressure rail
• CPC Class Codes: F02D 41/3809 Common rail control systems common rail apparatus F02M55/025, F02M63/0225
• CPC Class Codes: F02M 39/02 Arrangements of fuel-injection apparatus to facilitate the driving of pumps; Arrangements of fuel-injection pumps; Pump drives
• CPC Class Codes: F02M 43/00 Fuel-injection apparatus operating simultaneously on two or more fuels, or on a liquid fuel and another liquid, e.g. the other liquid being an anti-knock additive
• CPC Class Codes: F02M 53/00 Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
• CPC Class Codes: F02M 63/0001 Fuel-injection apparatus with specially arranged lubricating system, e.g. by fuel oil lubrication of engines F01M
• CPC Class Codes: F02M 63/029 per cylinder bank, e.g. storing different fuels or fuels at different pressure levels per cylinder bank
• CPC Class Codes: F02M 69/046 for injecting into both the combustion chamber and the intake conduit
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

Methods and systems are provided for operating an engine fuel system including fuels of different fuel types. A first fuel type is delivered for port injection upon circulation through a high pressure pump when direct injection of a fuel is not requested to cool and/or lubricate the high pressure pump.

Claims

1. A method of operating an engine fuel system, comprising:

supplying a first type of fuel solely from a first fuel tank to a second fuel pump and to a group of port fuel injectors via a first fuel pump, an output of the second fuel pump in communication with a group of direct injectors; and

supplying the first type of fuel from the second fuel pump outlet to the group of port fuel injectors.

2. The method of claim 1, where the first fuel pump is an electrically powered low pressure fuel pump and where the second fuel pump is a mechanically powered high pressure pump.

3. The method of claim 2, where the second fuel pump supplies the first fuel type to the group of port fuel injectors via a valve coupling the group of direct injectors to the group of port fuel injectors.

4. The method of claim 1, further comprising deactivating the group of direct injectors and a third fuel pump.

5. The method of claim 1, where the first type of fuel is supplied to the second fuel pump in response to a level of a second type of fuel in a second fuel tank falling below a threshold level.

6. The method of claim 1, where the first type of fuel is supplied to the second fuel pump in response to a temperature of the second fuel pump exceeding a threshold temperature.

7. The method of claim 1, where the first type of fuel is supplied in response to at least an engine operating condition, including an engine load.

8. The method of claim 1, where an output of the first fuel pump is adjusted to provide a fuel pressure to a first rail of the group of port injectors, the first fuel type being supplied to the group of port injectors from both the outlet of the second fuel pump and the outlet of the first fuel pump in parallel and concurrently, at least some of the fuel from the outlet of the first fuel pump provided to the group of fuel injectors by bypassing the second fuel pump.

9. A method of operating an engine fuel system, comprising:

during a first condition, delivering a first type of fuel solely from a first fuel tank to a first port injector and a second fuel pump via a first fuel pump, the second fuel pump outlet communicating with a first direct injector and the first port injector;

during a second condition, delivering the first fuel type solely from the first fuel tank to the first port injector via the first fuel pump while bypassing the second fuel pump; and

during a third condition, delivering the first fuel type solely from the first fuel tank to the first direct injector via the first fuel pump and the second fuel pump.

10. The method of claim 9, where the first fuel pump is a lower pressure fuel pump while the second fuel pump is a higher pressure fuel pump.

11. The method of claim 10, where the first fuel pump is electrically-driven and the second fuel pump is mechanically driven.

12. The method of claim 10, where during the first and second conditions, the first direct injector and a third fuel pump are deactivated, where the third fuel pump is coupled to a second fuel tank.

13. The method of claim 10, where the first condition includes one or more of a temperature of the second fuel pump exceeding a threshold temperature.

14. The method of claim 11, where the third condition includes a fuel level in a second fuel tank falling below a threshold.

15. The method of claim 11, where the fuel system includes a solenoid valve located downstream of the first fuel pump and upstream of the second fuel pump in a direction of fuel flow, and wherein during first condition, the solenoid valve is opened, and wherein during the second and third conditions, the solenoid valve is closed.

16. A fuel system for an internal combustion engine, comprising:

a first fuel tank storing a first fuel type;

a second fuel tank storing a second fuel type;

a group of port fuel injectors in communication with a group cylinders;

a group of direct injectors in communication with the group of cylinders;

a first low pressure fuel pump in communication with the first fuel tank;

a high pressure fuel pump in communication with the group of port fuel injectors via a solenoid valve, and further communicating with the group of direct injectors; and

a control system configured with instructions for;

supplying the first fuel type solely from the first fuel tank to the group of port fuel injectors via the first low pressure fuel pump and the high pressure fuel pump; and

supplying the first fuel type solely from the first fuel tank to the group of direct injectors via the first low pressure fuel pump and high pressure fuel pump.

17. The fuel system of claim 16, where the supplying the first fuel type to the group of port fuel injectors via the first low pressure fuel pump and the high pressure fuel pump is in response to a request for cooling or lubrication of the high pressure fuel pump.

18. The fuel system of claim 16, where the supplying to the group of direct injectors via the first low pressure fuel pump and the high pressure fuel pump is in response to a fuel level in the second fuel tank falling below a threshold.

19. The fuel system of claim 16, where the first fuel type includes at least some gasoline and the second fuel type includes at least some ethanol.

20. The fuel system of claim 16, where a first fuel passage fluidly couples the first fuel tank to the group of port fuel injectors, and where a second fuel passage fluidly couples the second fuel tank to the group of direct injectors, and where the high pressure fuel pump communicates with the group of port fuel injectors via a solenoid valve, and where a second low pressure fuel pump is in communication with the second fuel tank and the high pressure fuel pump.