FUEL DELIVERY SYSTEM

• US 20190040818A1
• Filed: 08/07/2017
• Published: 02/07/2019
• Est. Priority Date: 08/07/2017
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Engfehr, Matthew J., Atterberry, Nathan P.
• Application Number:
  US15/670,006
• Publication Number:
  US 20190040818A1
• Time in Patent Office: Days
• CPC Class Codes: F02D 19/027 Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02D 41/1477 characterised by the regulation circuit or part of it,(e.g. comparator, PI regulator, output)
• CPC Class Codes: F02D 41/3094 the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder
• CPC Class Codes: F02D 41/3809 Common rail control systems common rail apparatus F02M55/025, F02M63/0225
• CPC Class Codes: F02M 21/0215 Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas
• CPC Class Codes: F02M 21/0239 Pressure or flow regulators therefor
• CPC Class Codes: F02M 21/0242 Shut-off valves; Check valves; Safety valves; Pressure relief valves
• CPC Class Codes: F02M 21/0245 High pressure fuel supply systems; Rails; Pumps; Arrangement of valves
• CPC Class Codes: F02M 21/0293 Safety devices; Fail-safe measures
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A fuel delivery system for a machine powered by Liquified Natural Gas (LNG) fuel is provided. The fuel delivery system includes a pressure sensor provided in fluid communication with a fuel supply line, a first valve provided in in association with a high-pressure fuel rail circuit, a second valve provided in association with a low-pressure circuit, and a controller. The controller is configured to receive a signal indicative of a pressure of the LNG fuel present in the fuel supply line. The controller is also configured to compare the pressure of the LNG fuel with a predetermined pressure threshold. The controller is further configured to control at least one of the first valve and the second valve to selectively supply the LNG fuel to the high-pressure fuel rail circuit and the low-pressure circuit based, at least in part, on the comparison.

Claims

1. A fuel delivery system for a machine powered by Liquified Natural Gas (LNG) fuel, the fuel delivery system comprising:

a pressure sensor provided in fluid communication with a main fuel supply line associated with the machine to determine pressure of the LNG fuel in the main fuel supply line;

a high-pressure fuel rail circuit, at an output of the main fuel supply line, that supplies the LNG fuel to fuel injectors of the machine for injection into respective cylinders of an engine of the machine, wherein the high-pressure fuel rail circuit includes a first fuel supply line at the output of the main fuel supply line, and a first valve in the first fuel supply line;

a low-pressure circuit, at the output of the main fuel supply line, that supplies the LNG fuel at a low pressure, the low pressure LNG fuel is pressurized and supplied via an intake manifold to at least one of the cylinders of the engine, wherein the low pressure circuit includes a second fuel supply line, distinct from the first fuel supply line, at the output of the main fuel supply line, and a second valve in the second fuel supply line; and

a controller provided in communication with the pressure sensor, the first valve, and the second valve, the controller configured to;

receive a signal indicative of the pressure of the LNG fuel present in the fuel supply line;

compare the pressure of the LNG fuel in the main fuel supply line with a predetermined pressure threshold; and

control at least one of the first valve and the second valve to selectively supply the LNG fuel to the high-pressure fuel rail circuit and the low-pressure circuit based, at least in part, on the comparison,

wherein the LNG fuel is supplied to the engine via the high-pressure fuel rail circuit for injection when the comparison is such that the pressure of the LNG fuel in the main fuel supply line exceeds the predetermined pressure threshold, and

wherein the LNG fuel is supplied to the engine via the low-pressure circuit and without injection when the comparison is such that the pressure of the LNG fuel in the main fuel supply line does not exceed the predetermined pressure threshold.

2. The fuel delivery system of claim 1, wherein controlling at least one of the first valve and the second valve further includes opening the first valve and closing the second valve based, at least in part, on the pressure of the LNG fuel exceeding the predetermined pressure threshold.

3. The fuel delivery system of claim 1, wherein controlling at least one of the first valve and the second valve further includes closing the first valve and opening the second valve based, at least in part, on the pressure of the LNG fuel dropping below the predetermined pressure threshold.

4. The fuel delivery system of claim 1, wherein the first valve is a throttle valve.

5. The fuel delivery system of claim 1, wherein the first valve is an electromechanically operated purge valve.

6. The fuel delivery system of claim 1, wherein the second valve is a shut-off valve.

7. A fuel delivery system for an engine powered by Liquified Natural Gas (LNG) fuel, the fuel delivery system comprising:

a pressure sensor provided in fluid communication with a main fuel supply line associated with the engine to determine pressure of the LNG fuel in the main fuel supply line;

a first fuel delivery circuit, at an output of the main fuel supply line, that supplies the LNG fuel to fuel injectors of the engine for injection into respective cylinders of the engine, wherein the first fuel delivery circuit includes a first fuel supply line at the output of the main fuel supply line, and a first valve in the first fuel supply line;

a second fuel delivery circuit, at the output of the main fuel supply line, that supplies the LNG fuel at a low pressure, the low pressure LNG fuel is pressurized and supplied via an intake manifold to at least one of the cylinders of the engine, wherein the second fuel delivery circuit includes a second fuel supply line, distinct from the first fuel supply line, at the output of the main fuel supply line, and a second valve in the second fuel supply line; and

a controller provided in communication with the pressure sensor, the first valve, and the second valve, the controller configured to;

receive a signal indicative of the pressure of the LNG fuel present in the fuel supply line;

compare the pressure of the LNG fuel in the main fuel supply line with a predetermined pressure threshold; and

control at least one of the first valve and the second valve to selectively supply the LNG fuel to the engine through the first fuel delivery circuit based, at least in part, on the pressure of the LNG fuel exceeding the predetermined pressure threshold, and the second fuel delivery circuit based, at least in part, on the pressure of the LNG fuel dropping below the predetermined pressure threshold,

wherein the LNG fuel is supplied to the engine via the first fuel delivery circuit for injection when the comparison is such that the pressure of the LNG fuel in the main fuel supply line exceeds the predetermined pressure threshold, and

wherein the LNG fuel is supplied to the engine via the second fuel delivery circuit and without injection when the comparison is such that the pressure of the LNG fuel in the main fuel supply line does not exceed the predetermined pressure threshold.

8. The fuel delivery system of claim 7, wherein the first fuel delivery circuit is a high-pressure fuel rail circuit.

9. The fuel delivery system of claim 7, wherein the second fuel delivery circuit is a low-pressure circuit.

10. The fuel delivery system of claim 7, wherein the first valve is a throttle valve.

11. The fuel delivery system of claim 7, wherein the first valve is an electromechanically operated purge valve.

12. The fuel delivery system of claim 7, wherein the second valve is a shut-off valve.

13. A method for delivering Liquified Natural Gas (LNG) fuel to an engine of a machine, the method comprising:

receiving a signal indicative of a pressure of the LNG fuel present in a main fuel supply line;

comparing the pressure of the LNG fuel in the main fuel supply line with a predetermined pressure threshold; and

controlling at least one of a first valve and a second valve to selectively supply the LNG fuel to the engine through a first fuel delivery circuit and a second fuel delivery circuit based, at least in part, on the comparison,

wherein the first fuel delivery circuit is at an output of the main fuel supply line and supplies the LNG fuel to fuel injectors of the engine for injection into respective cylinders of the engine, wherein the first fuel delivery circuit includes a first fuel supply line at the output of the main fuel supply line, and the first valve in the first fuel supply line,

wherein the second fuel delivery circuit is at the output of the main fuel supply line, supplies the LNG fuel at a low pressure, the low pressure LNG fuel is pressurized and supplied via an intake manifold to at least one of the cylinders of the engine, wherein the second fuel delivery circuit includes the second fuel supply line, distinct from the first fuel supply line, at the output of the main fuel supply line, and the second valve in the second fuel supply line,

wherein the LNG fuel is supplied to the engine via the first fuel delivery circuit when the comparison is such that the pressure of the LNG fuel in the main fuel supply line exceeds the predetermined pressure threshold, and

wherein the LNG fuel is supplied to the engine via the second fuel delivery circuit when the comparison is such that the pressure of the LNG fuel in the main fuel supply line does not exceed the predetermined pressure threshold.

14. The method of claim 13, wherein controlling at least one of the first valve and the second valve further includes opening the first valve and closing the second valve to supply the LNG fuel through the first fuel delivery circuit based, at least in part, on the pressure of the LNG fuel exceeding the predetermined pressure threshold.

15. The method of claim 13, wherein controlling at least one of the first valve and the second valve further includes closing the first valve and opening the second valve to supply the LNG fuel through the second fuel delivery circuit based, at least in part, on the pressure of the LNG fuel dropping below the predetermined pressure threshold.

16. The method of claim 13, wherein the first fuel delivery circuit is a high-pressure fuel rail circuit.

17. The method of claim 13, wherein the second fuel delivery circuit is a low-pressure circuit.

18. The method of claim 13, wherein the first valve is a throttle valve.

19. The method of claim 13, wherein the first valve is an electromechanically operated purge valve.

20. The method of claim 13, wherein the second valve is a shut-off valve.