Method and system for incorporating an emission sensor into a gas turbine controller

• US 7,032,388 B2
• Filed: 11/17/2003
• Issued: 04/25/2006
• Est. Priority Date: 11/17/2003
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Healy, Timothy Andrew
• Primary Examiner(s): Casaregola, Louis J.
• Application Number:
  US10/712,991
• Publication Number:
  US 20050107941A1
• Time in Patent Office: 890 Days
• Field of Search: 60/39, 602/81, 607/72, 607/73, 608/03
• US Class Current: 60/772
• CPC Class Codes: F02C 9/28 Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed F02C9/30 - F02C9/38, F02C9/44 take precedence
• CPC Class Codes: F05D 2270/082 with as little NOx as possible
• CPC Class Codes: F05D 2270/083 by monitoring combustion conditions
• CPC Class Codes: F05D 2270/0831 indirectly, at the exhaust
• CPC Class Codes: F23N 2225/10 stack temperature
• CPC Class Codes: F23N 2241/20 Gas turbines
• CPC Class Codes: F23N 2900/05003 Measuring NOx content in flue gas
• CPC Class Codes: F23N 5/003 using detectors sensitive to combustion gas properties F23N5/02, F23N5/18 - F23N5/26 take precedence
• CPC Class Codes: F23N 5/04 using bimetallic elements
• CPC Class Codes: F23N 5/08 using light-sensitive elements

Abstract

A method for determining an estimated operating parameter for a gas turbine including the steps of: determining an estimated operating parameter using an algorithm have an input from a sensor, wherein the algorithm includes a trim factor; determining a first trim factor based on a comparison of the first estimated operating parameter and the output of the sensor when a condition of the sensor is in a first mode, and during a subsequent determination of the estimated operating parameter, applying the first trim factor to subsequently determine the estimated operating condition if the condition of second sensor is in a second mode.

Claims

1. A method for determining an estimated operating parameter for a system comprising:

a. determining a first estimated operating parameter using an algorithm having an input from at least one sensor, wherein said algorithm includes a trim factor;

b. determining a current trim factor based on a comparison of the first estimated operating parameter and the output of another sensor measuring a current actual value of the operating parameter, when the another sensor is in a first mode, and

c. during a subsequent determination of the estimated operating parameter, applying previously determined current trim factor to subsequently determine the estimated operating parameter if the condition of the at another sensor is in a second mode.

2. A method as in claim 1 wherein the estimated operating condition is a emission level at an exhaust of a gas turbine and the sensor is single emission sensor.

3. A method as in claim 2 wherein the algorithm is a emissions transfer function having as inputs a compressor discharge and a combustion firing temperature.

4. A method as in claim 1 wherein the second mode of the sensor is an unhealthy sensor mode and the first sensor mode is a healthy sensor mode.

5. A method as in claim 1 wherein the current trim factor is a ratio of a prior estimated operating parameter and the output of the another sensor, when the sensor condition is in the first mode.

6. A method as in claim 1 wherein the previously determined current trim factor is a ratio of an estimated operating parameter determined from a preceding determination of the estimated operating parameter and of a prior output of the another sensor when the sensor condition was in the first mode.

7. A method as in claim 1 wherein the another sensor directly measures an actual operating parameter corresponding to the estimated operating parameter.

8. A method as in claim 1 wherein the estimated operating parameter is an estimated emission level, and the another sensor includes an emissions sensor sensing an actual emission level.

9. A method as in claim 1 wherein the another sensor includes a nitrogen oxide (NOx) emission sensor.

10. A method for determining an estimated operating emission level for an exhaust of a gas turbine comprising:

a. periodically determining an estimated emission level from an output of emissions transfer algorithm, wherein said algorithm includes a trim factor;

b. determining a current trim factor based on a ratio of a current output of a healthy emission sensor monitoring the exhaust and of the estimated emission level from a prior determination, and

c. applying a prior trim factor previously applied to determine the estimated operating condition if the emission sensor is unhealthy.

11. A method as in claim 10 wherein said emissions transfer algorithm receives inputs from at least one of a group of input parameters consisting of:

compressor discharge temperature, specific humidity of ambient air, fuel split ratio and combustion firing temperature.

12. A method as in claim 10 wherein said emission sensor is a single sensor.

13. A method as in claim 10 wherein said emission sensor is deemed unhealthy during calibration of the sensor.

14. A method as in claim 10 wherein said emission sensor is deemed unhealthy while said sensor is operating outside of a predetermined range.

15. A method as in claim 10 wherein said emission sensor is deemed unhealthy during a period of steady state gas turbine operation and after said trim factor has been determined for said steady state operation.

16. A method as in claim 10 further comprising suspending said emission sensor when said sensor is deemed unhealthy.

17. A method as in claim 10 wherein the sensor is a nitrogen oxide (NOx) emission sensor.