High pressure common rail fuel system with gas injection

• US 7,950,370 B2
• Filed: 03/13/2008
• Issued: 05/31/2011
• Est. Priority Date: 03/13/2008
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Lucas, Michael A., Tegnelius, Lars, Benson, Donald J.
• Primary Examiner(s): Wolfe, Jr.; Willis R
• Assistant Examiner(s): Hoang; Johnny H
• Application Number:
  US12/047,434
• Publication Number:
  US 20090229572A1
• Time in Patent Office: 1,174 Days
• Field of Search: 123/446, 123/447, 123/456, 123/457, 123/496, 123/531, 123/27.GE, 123/525, 123/526, 701/104
• US Class Current: 123/435
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 19/0605 to adjust the fuel pressure or temperature
• CPC Class Codes: F02D 19/0623 Failure diagnosis or prevention; Safety measures; Testing
• CPC Class Codes: F02D 19/0642 at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions
• CPC Class Codes: F02D 19/0684 High pressure fuel injection systems; Details on pumps, rails or the arrangement of valves in the fuel supply and return systems
• CPC Class Codes: F02D 19/0694 operating with a plurality of fuels
• CPC Class Codes: F02D 19/08 simultaneously using pluralities of fuels F02D19/12 takes precedence
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• 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 63/0225 Fuel-injection apparatus having a common rail feeding several injectors F02M63/0003 takes precedence; Means for varying pressure in common rails; Pumps feeding common rails
• CPC Class Codes: F02M 67/005 fuel-gas mixture being compressed in a pump for subsequent injection into the engine
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A high pressure common rail fuel system is provided including a fuel supply, a high pressure pump assembly fluidly connected to receive fuel from the fuel supply, and a gas supply system fluidly connected to provide gas to the high pressure pump assembly to create a high pressure gas fuel mixture. A common rail fuel system is fluidly connected to the high pressure pump assembly to receive the high pressure gas fuel mixture.

Claims

1. A high pressure common rail fuel system, comprising:

a fuel supply;

a high pressure fuel pump assembly fluidly connected to receive fuel from the fuel supply;

a gas supply system including at least one gas supply line directly connected to the high pressure fuel pump assembly to provide gas to the high pressure fuel pump assembly to create a high pressure gas fuel mixture; and

a common rail fuel system fluidly connected to the high pressure fuel pump assembly to receive the high pressure gas fuel mixture.

2. The system of claim 1, wherein the high pressure pump assembly includes:

a variable restriction valve in fluid connection with the fuel supply;

at least one piston assembly;

at least one inlet check valve fluidly coupled to the at least one piston assembly and the variable restriction valve;

at least one outlet check valve fluidly coupled to the at least one piston assembly and the common rail fuel system, whereby the variable restriction valve controls a flow of fuel to the at least one inlet check valve.

3. The system of claim 2, wherein the gas supply system includes:

a gas supply;

another variable restriction valve fluidly coupled to the gas supply and the at least one inlet check valve, whereby said another variable restriction valve controls flow of gas to the at least one inlet check valve.

4. The system of claim 3, wherein the variable restriction valves of the high pressure pump assembly and the gas supply system are configured to regulate fuel and gas flow, respectively, via an electronic controller based upon one or more prescribed conditions.

5. The system of claim 4, wherein the one or more prescribed conditions includes engine speed, timing, engine temperature, exhaust flow temperature, exhaust flow pressure, and air/fuel mix parameters.

6. The system of claim 3, wherein the gas supply includes a compressed air supply.

7. The system of claim 3, wherein the gas supply system is configured to provide gas to the at least one inlet check valve at a pressure within a range of approximately 6-300 psi.

8. The system of claim 3, wherein the at least one inlet check valve is configured to provide a gas fuel mixture to the at least one piston assembly.

9. The system of claim 3, wherein the at least one piston assembly is configured to pressurize the gas fuel mixture.

10. The system of claim 9, wherein the gas fuel mixture is pressurized within a range of approximately 500-2600 bar.

11. The system of claim 1, wherein the common rail fuel system includes:

an accumulator;

a power cylinder;

at least one fuel injector in fluid connection with the accumulator, and in further contact with the power cylinder.

12. The system of claim 11, wherein the at least one fuel injector is configured to disperse the high pressure gas fuel mixture into the power cylinder.

13. The system of claim 12, wherein the high pressure gas fuel mixture is dispersed at a pressure of approximately 200 bar.

14. A method of reducing cavitation in a high pressure common rail fuel system, comprising:

providing a fuel supply to a high pressure fuel pump assembly;

delivering a gas supply to the high pressure fuel pump assembly;

mixing fuel and gas to form a gas fuel mixture;

pressurizing said mixture at a first pressure;

supplying the pressurized gas fuel mixture to a common rain fuel system; and

atomizing the gas fuel mixture.

15. The method of claim 14, further comprising:

providing the fuel supply to the high pressure pump assembly at a pressure within a range of approximately 6-300 psi.

16. The method of claim 14, further comprising:

delivering the gas supply to the high pressure pump assembly at a pressure within a range of approximately 6-300 psi.

17. The method of claim 14, further comprising:

mixing the fuel and gas to generate a gas fuel mixture of approximately gas at 1% volume of fuel at one atmosphere.

18. The method of claim 14, wherein the pressurizing step includes pressurizing the mixture at a pressure within a range of approximately 500-2600 bar.

19. The method of claim 14, further comprising:

atomizing the gas fuel mixture at approximately 200 bar.

20. The method of claim 14, further comprising:

automatically regulating the supply of fuel and gas to the high pressure fuel pump assembly.

21. The method of claim 20, further including automatically regulating the supply of fuel and gas based upon one or more prescribed conditions of the fuel system or an engine.

22. A system of claim 21, wherein the one or more prescribed conditions includes engine speed, timing, engine temperature, exhaust flow temperature, exhaust flow pressure, and air/fuel mix parameters.

23. A system for reducing cavitation in a high pressure common rail fuel system, comprising:

means for providing a fuel supply to a high pressure fuel pump assembly;

means for delivering a gas supply to the high pressure fuel pump assembly;

means for mixing fuel and gas to form a gas fuel mixture;

means for pressurizing the gas fuel mixture at a first pressure;

means for supplying the pressurized gas fuel mixture to a common rail fuel system; and

means for atomizing the pressurized gas fuel mixture.