Method and apparatus for controlling stationary gaseous-fueled internal combustion engines

• US 7,455,058 B2
• Filed: 07/14/2006
• Issued: 11/25/2008
• Est. Priority Date: 10/26/2005
• Status: Expired due to Fees

• Current Assignee: Raymond A. Raffesberger
• Original Assignee: Raymond A. Raffesberger
• Inventors: Raffesberger, Raymond A.
• Primary Examiner(s): Cronin; Stephen K
• Assistant Examiner(s): HUFTY, JOHN PAGE
• Application Number:
  US11/486,719
• Publication Number:
  US 20070089719A1
• Time in Patent Office: 865 Days
• Field of Search: 123/527, 123/672, 123/694, 123/703, 701/109
• US Class Current: 123/694
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F01N 2560/025 for measuring or detecting O2, e.g. lambda sensors
• CPC Class Codes: F02D 19/023 to adjust the fuel mass or volume flow
• CPC Class Codes: F02D 31/002 controlling air supply
• CPC Class Codes: F02D 35/0053 by means of a carburettor
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02D 41/1456 with sensor output signal being linear or quasi-linear with the concentration of oxygen
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method and system is disclosed which relates to controlling a stationary gaseous-fueled internal combustion engine. The method may include measuring an air to fuel ratio of the engine, calculating a difference between the measured air to fuel ratio and a desired air to fuel ratio for the engine, and automatically controlling an air to fuel mixture supplied to the engine in accordance with the calculated difference to enable the engine to run at substantially the desired air to fuel ratio.

Claims

1. A method of controlling a stationary gaseous-fueled internal combustion engine, comprising:

measuring an air to fuel ratio of the engine;

calculating a difference between the measured air to fuel ratio and a desired air to fuel ratio for the engine; and

automatically controlling an air to fuel mixture supplied to the engine in accordance with the calculated difference to enable the engine to run at substantially the desired air to fuel ratio,

wherein measuring the air to fuel ratio utilizes a wideband oxygen sensor,

wherein measuring the air to fuel ratio includes utilizing a wideband oxygen sensor interface electrically connected to the wideband oxygen sensor,

wherein the wideband oxygen sensor interface provides an output voltage proportional to the measured air to fuel ratio according to the following equation;

measured air to fuel ratio=(2*output voltage)+10.

2. A method of controlling a stationary gaseous-fueled internal combustion engine, comprising:

measuring an air to fuel ratio of the engine;

calculating a difference between the measured air to fuel ratio and a desired air to fuel ratio for the engine; and

automatically controlling an air to fuel mixture supplied to the engine in accordance with the calculated difference to enable the engine to run at substantially the desired air to fuel ratio,

wherein automatically controlling the air to fuel mixture includes comparing the difference with at least one threshold band,

wherein the at least one threshold band includes a first threshold band, a second threshold band, and a third threshold band.

3. The method of claim 2, wherein the air to fuel mixture is not adjusted if the difference is within the first threshold band.

4. The method of claim 2, wherein the air to fuel mixture is adjusted at a first rate if the calculated difference is outside the first threshold band and within the second threshold band.

5. The method of claim 4, wherein the air to fuel mixture is adjusted at a second rate if the calculated difference is outside the second threshold band and within the third threshold band, the second rate being greater than the first rate.

6. The method of claim 5, wherein the air to fuel mixture is adjusted at a third rate if the calculated difference is outside the third threshold band, the third rate being greater than the second rate.

7. The method of claim 2, wherein the air to fuel mixture is adjusted to increase the flow of fuel to the engine if the calculated difference is positive and outside the first threshold band.

8. The method of claim 2, wherein the air to fuel mixture is adjusted to decrease the flow of fuel to the engine if the calculated difference is negative and outside the first threshold band.

9. The method of claim 2, further comprising:

setting the threshold bands through a graphical user interface.

10. A method of controlling a stationary gaseous-fueled internal combustion engine, comprising:

measuring an air to fuel ratio of the engine;

calculating a lambda value using the measured air to fuel ratio;

calculating a difference between the calculated lambda value and a lambda set point for the engine; and

automatically controlling an air to fuel mixture supplied to the engine in accordance with the calculated difference to enable the engine to run at substantially the desired air to fuel ratio,

wherein measuring the air to fuel ratio utilizes a wideband oxygen sensor,

wherein measuring the air to fuel ratio includes utilizing a wideband oxygen sensor interface electrically connected to the wideband oxygen sensor,

wherein the wideband oxygen sensor interface provides an output voltage proportional to the measured air to fuel ratio according to the following equation;

measured air to fuel ratio=(2*output voltage)+10.

11. A method of controlling a stationary gaseous-fueled internal combustion engine, comprising:

measuring an air to fuel ratio of the engine;

calculating a lambda value using the measured air to fuel ratio;

calculating a difference between the calculated lambda value and a lambda set point for the engine; and

automatically controlling an air to fuel mixture supplied to the engine in accordance with the calculated difference to enable the engine to run at substantially the desired air to fuel ratio,

wherein automatically controlling the air to fuel mixture includes comparing the difference with at least one threshold band,

wherein the at least one threshold band includes a first threshold band, a second threshold band, and a third threshold band.

12. The method of claim 11, wherein the air to fuel mixture is not adjusted if the difference is within the first threshold band.

13. The method of claim 11, wherein the air to fuel mixture is adjusted at a first rate if the calculated difference is outside the first threshold band and within the second threshold band.

14. The method of claim 13, wherein the air to fuel mixture is adjusted at a second rate if the calculated difference is outside the second threshold band and within the third threshold band, the second rate being greater than the first rate.

15. The method of claim 14, wherein the air to fuel mixture is adjusted at a third rate if the calculated difference is outside the third threshold band, the third rate being greater than the second rate.

16. The method of claim 11, wherein the air to fuel mixture is adjusted to increase the flow of fuel to the engine if the calculated difference is positive and outside the first threshold band.

17. The method of claim 11, wherein the air to fuel mixture is adjusted to decrease the flow of fuel to the engine if the calculated difference is negative and outside the first threshold band.

18. The method of claim 11, further comprising:

setting the threshold bands through a graphical user interface.