System for dynamically detecting fuel leakage

• US 7,392,792 B2
• Filed: 08/21/2006
• Issued: 07/01/2008
• Est. Priority Date: 08/21/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Puckett, Daniel Reese
• Primary Examiner(s): Gimie; Mahmoud
• Application Number:
  US11/506,912
• Publication Number:
  US 20080041331A1
• Time in Patent Office: 680 Days
• Field of Search: 123/456, 123/198.D, 123/295, 731/19.A, 731/15, 73/40, 73/491
• US Class Current: 123/456
• CPC Class Codes: F02D 2041/225 Leakage detection
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/38 of the high pressure type

Abstract

A fuel control system for an engine is disclosed. The fuel control system may have a source of pressurized fuel and at least one injector configured to receive and inject the pressurized fuel. The fuel system may also have a sensor configured to generate a signal indicative of an actual fuel pressure at the at least one injector, and a controller in communication with the sensor. The controller may be configured to determine a desired fuel pressure at the at least one injector, and compare the signal to the desired fuel pressure. The controller may also be configured to initiate a leak detection sequence in response to the comparison.

Claims

1. A fuel control system, comprising:

a source of pressurized fuel;

at least one injector configured to receive and inject the pressurized fuel;

a sensor configured to generate a signal indicative of an actual fuel pressure at the at least one injector; and

a controller in communication with the sensor, the controller being configured to;

determine a desired fuel pressure at the at least one injector;

compare the signal to the desired fuel pressure; and

initiate a leak detection sequence in response to the comparison,

wherein the leak detection sequence includes continuing to operate the at least one injector during the leak detection sequence.

2. The fuel control system of claim 1, wherein:

the sensor generates the signal continuously during operation of the fuel system; and

the signal is continuously compared to the desired fuel pressure during operation of the fuel system.

3. The fuel control system of claim 1, wherein the controller is further configured to determine a required adjustment of the source that results in the actual fuel pressure substantially matching the desired fuel pressure.

4. The fuel control system of claim 3, wherein the controller is further configured to:

compare the required adjustment to a historical adjustment; and

derate operation of the fuel system when the required adjustment is greater than the historical adjustment by a predetermined amount.

5. The fuel control system of claim 4, further including a pressure relief valve configured to relieve the fuel control system of excessive pressures, wherein the controller is configured to track the time elapsed following a pressure relieving event.

6. The fuel control system of claim 5, wherein,

if:

the tracked time elapsed is less than a predetermined length of time; and

the required adjustment is greater than the historical adjustment by the predetermined amount;

then;

the difference between the actual fuel pressure and the desired fuel pressure is determined to be due to the pressure relieving event; and

operation of the fuel system is blocked from derate.

7. The fuel control system of claim 4, wherein the historical adjustment is continuously updated and periodically reset.

8. The fuel control system of claim 4, wherein:

the controller is further configured to implement the required adjustment only if the required adjustment is within the predetermined amount of the historical adjustment; and

the required adjustment is only implemented during a zero fueling event.

9. The fuel control system of claim 1, wherein:

the leak detecting sequence includes stopping the source from pressurizing and utilizing the signal to determine pressure decay; and

the at least one fuel injector is operational during the leak detection sequence.

10. A method of detecting leaks in a fuel system, the method comprising:

pressurizing fuel;

sensing a pressure of the fuel;

determining a desired pressure of the fuel;

comparing the sensed pressure and the desired pressure to determine a required pressurizing adjustment;

comparing the required pressurizing adjustment to a historical pressurizing adjustment; and

implementing the required pressurizing adjustment only if the required pressuring adjustment is within a predetermined amount of the historical pressurizing adjustment.

11. The method of claim 10, wherein sensing includes continuously sensing.

12. The method of claim 10, further including blocking the pressurizing of fuel if the required pressuring adjustment exceeds the historical pressurizing adjustment by the predetermined amount.

13. The method of claim 12, further including:

selectively relieving the pressure of the fuel; and

tracking the elapsed time following the selectively relieving, wherein

if;

the tracked time elapsed following the selective relieving is less than a predetermined length of time; and

the required pressurizing adjustment exceeds the historical pressurizing adjustment by the predetermined amount;

then;

the difference between the sensed pressure and the desired pressure is determined to be due to the selective relieving; and

the method further includes limiting the required pressurizing adjustment during implementation.

14. The method of claim 12, further including continuously updating and periodically resetting the historical pressurizing adjustment.

15. The method of claim 10, wherein determining a required pressurizing adjustment includes:

stopping the pressurizing of fuel; and

sensing a pressure decay.

16. A power system, comprising:

an engine having at least one combustion chamber;

a source driven by the engine to pressurize fuel;

an injector disposed to inject the pressurized fuel into the at least one combustion chamber;

a pressure relief valve configured to relieve of excessive fuel pressures;

a sensor configured to continuously generate a signal indicative of an actual fuel pressure at the injector; and

a controller in communication with the sensor, the controller configured to;

determine a desired fuel pressure at the injector;

compare the signal to the desired fuel pressure to determine a required adjustment of the source; and

implement the required adjustment in response to the required adjustment being within a predetermined amount of a historical pressurizing adjustment.

17. The power system of claim 16, wherein:

the controller is further configured to track the time elapsed following a pressure relieving event; and

if;

the tracked time elapsed is less than a predetermined length of time; and

the required adjustment exceeds the historical pressurizing adjustment by the predetermined amount;

then;

the difference between the actual fuel pressure and the desired fuel pressure is determined to be due to the pressure relieving event; and

the required adjustment is limited during implementation.

18. The power system of claim 16, wherein the historical pressurizing adjustment is continuously updated and periodically reset.

19. The power system of claim 16, wherein determining a required adjustment of the source includes stopping the source from pressurizing, and determining pressure decay.

20. The power system of claim 16, wherein the controller is further configured to derate the engine in response to a detected leak.