Natural gas leak detection through pressure loss in pneumatic starter and prelube

Patent metadata

Field	Value
Publication number	US-9777645-B2
Application number	US-201615186059-A
Country	US
Kind code	B2
Filing date	Jun 17, 2016
Priority date	Jun 17, 2015
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An internal combustion engine, a method of operating the internal combustion engine, and a controller are disclosed. The method may comprise measuring a first pressure at a first position in a fluid line containing pressurized fluid; comparing the first pressure to a first threshold; in response to the first pressure exceeding the first threshold, transmitting a signal to depressurize the fluid line; after transmitting the signal to depressurize the fluid line, measuring a second pressure in the fluid line and comparing the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold; and in response to the second pressure being less than the second threshold and exceeding the third threshold, transmitting another signal to depressurize the fluid line.

First claim

The following is claimed:

1. A method of operating an internal combustion engine, the method comprising:
measuring a first pressure at a first position in a fluid line containing pressurized fluid, the fluid line coupled to a first valve downstream of the first position and to a second valve upstream of the first position, each of the first valve and the second valve being in a closed position when measuring the first pressure;
comparing the first pressure to a first threshold;
in response to the first pressure exceeding the first threshold, transmitting a signal to depressurize the fluid line;
after transmitting the signal to depressurize the fluid line, measuring a second pressure in the fluid line and comparing the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold; and
in response to the second pressure being less than the second threshold and exceeding the third threshold, transmitting another signal to depressurize the fluid line.

2. The method of claim 1 , further comprising opening the first valve and the second valve to actuate a pump with the pressurized fluid.

3. The method of claim 2 , wherein the pump is a prelubrication pump or a starter pump.

4. The method of claim 1 , wherein the first valve is a prelubrication valve in a prelubrication system of the internal combustion engine or a starter valve in a starter system of the internal combustion system, and the second valve is a gas shutoff valve coupled to a gas supply line.

5. The method of claim 1 , wherein the pressurized fluid comprises a fuel gas, further comprising supplying the fuel gas at a high pressure to actuate a starter system or a prelubrication system of the internal combustion engine, and supplying the fuel gas at a low pressure for combustion by the internal combustion engine.

6. The method of claim 1 , further comprising closing the first valve, the second valve, and a third valve in the fluid line before measuring the first pressure at the first position, wherein the first valve is a prelubrication valve in a prelubrication system of the internal combustion engine, the second valve is a gas shutoff valve coupled to a gas supply line, and the third valve is a starter valve in a starter system of the internal combustion system.

7. The method of claim 1 , further comprising, in response to the second pressure being less than the third threshold, continuing operation of the internal combustion engine.

8. The method of claim 1 , further comprising, after transmitting the another signal to depressurize the fluid line:
measuring a third pressure in the fluid line;
comparing the third pressure to at least one of the second threshold and the third threshold; and
in response to the third pressure being less than the third threshold, continuing operation of the internal combustion engine.

9. The method of claim 8 , further comprising, in response to the third pressure exceeding the third threshold, providing a warning.

10. The method of claim 1 , wherein the signal to depressurize the fluid line is configured to open the first valve while the second valve is closed.

11. The method of claim 1 , further comprising, in response to the first pressure being less than the first threshold, providing a warning.

12. The method of claim 1 , further comprising, in response to the second pressure exceeding the second threshold, providing a warning.

13. An engine system comprising:
an internal combustion engine;
a fluid line including a first valve and a second valve upstream of the first valve;
a pump fluidly coupled to the fluid line downstream of the first valve and operable by pressurized fluid in the fluid line;
a pressure sensor; and
a controller communicatively coupled to the first valve, the second valve, and the pressure sensor, the controller being structured to:
measure a first pressure at a first position in the fluid line, the first position being between the first valve and the second valve, each of the first valve and the second valve being in a closed position;
compare the first pressure to a first threshold;
in response to the first pressure exceeding the first threshold, transmit a signal to depressurize the fluid line;
after transmitting the signal to depressurize the fluid line, measure a second pressure in the fluid line and compare the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold; and

in response to the second pressure being less than the second threshold and exceeding the third threshold, transmit another signal to depressurize the fluid line.

14. The engine system of claim 13 , wherein the controller is further configured to open the first valve and the second valve to actuate the pump with the pressurized fluid.

15. The engine system of claim 13 , wherein the pump is a prelubrication pump or a starter pump.

16. The engine system of claim 13 , wherein the pump comprises two pumps including a prelubrication pump and a starter pump, further comprising a third valve downstream of the second valve, the first valve configured to control flow of the pressurized fluid to the prelubrication pump, the third valve configured to control flow of the pressurized fluid to the starter pump, and the second valve configured to control flow of the pressurized fluid from a gas supply line to the first valve and the third valve.

17. The engine system of claim 13 , wherein the controller is further configured to, after transmitting the another signal to depressurize the fluid line:
measure a third pressure in the fluid line;
compare the third pressure to at least one of the second threshold and the third threshold; and
in response to the third pressure being less than the third threshold, continue operation of the internal combustion engine.

18. A controller for an engine system, the controller comprising:
an interface structured to communicate with a first valve, a second valve, and a pressure sensor of the engine system, the first valve positioned downstream of the second valve in a fluid line including a pump downstream of the first valve and operable by pressurized fluid in the fluid line, the controller structured to:
measure a first pressure at a first position in the fluid line, the first position being between the first valve and the second valve, each of the first valve and the second valve being in a closed position;
compare the first pressure to a first threshold;
in response to the first pressure exceeding the first threshold, transmit a signal to depressurize the fluid line;
after transmitting the signal to depressurize the fluid line, measure a second pressure in the fluid line and compare the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold; and

in response to the second pressure being less than the second threshold and exceeding the third threshold, transmit another signal to depressurize the fluid line.

19. The controller of claim 18 , wherein the controller is further configured to transmit signals to the first valve and to the second valve to open the first valve and the second valve and thereby actuate the pump with the pressurized fluid.

20. The controller of claim 18 , wherein the controller is further configured to, after transmitting the an

Assignees

• Cummins Inc

Inventors

• Evans Timothy R
• Kitchen Andrew G
• O'Neill Jeffrey S
• Leneave Michael A

Classifications

• F02D19/025 Primary

  Failure diagnosis or prevention; Safety measures; Testing · CPC title

• F01M2005/026

  with an auxiliary pump · CPC title

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• F02N11/108

  for diagnosis of the starter or its components · CPC title

• F02N7/00

  Starting apparatus having fluid-driven auxiliary engines or apparatus · CPC title