Combustion diagnostics method and system

• US 6,389,330 B1
• Filed: 06/16/1998
• Issued: 05/14/2002
• Est. Priority Date: 12/18/1997
• Status: Expired due to Fees

• Current Assignee: Reuter-Stokes, Inc. (General Electric Company)
• Original Assignee: Reuter-Stokes, Inc. (General Electric Company)
• Inventors: Khesin, Mark J.
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): SCHUSTER, KATHARINA W
• Application Number:
  US09/097,959
• Time in Patent Office: 1,428 Days
• Field of Search: 700/274, 700/266, 431/14, 431/79, 431/12, 431/75, 431/76, 431/18, 250/554, 250/339.15, 374/142, 324/671
• US Class Current: 700/274
• 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 5/082 using electronic means

Abstract

Combustion variables are diagnosed using sensors to measure turbulence in the post-flame zone as well as in the flame envelope of a combustor. Output signals from the sensors are processed and a set of statistical functions are calculated which are correlated with specific combustion variables, such as the concentration of unburned carbon in fly ash. A special sensor mounting box provides reliable long-term operation in harsh combustor environment, without a supply of cooling or protective air flow.

Claims

1. A method for analyzing operation of a combustor comprising the steps of:

(a) monitoring radiation emitted from flue gas in a post-flame zone of the combustor; and

(b) analyzing an AC component of the monitored radiation to determine at least one combustion parameter based thereupon.

2. The method as claimed in claim 1, wherein:

step (a) includes the step of monitoring radiation emitted from flue gas in a plurality of locations in the post-flame zone of the combustor;

step (b) includes the step of determining a plurality of combustion parameters, each combustion parameter being determined based upon an AC component of the radiation emitted from the flue gas in one of the plurality of locations; and

and further comprising the step of;

(c) adjusting at least one operating parameter of at least one combustion device until the plurality of combustion parameters achieve a predetermined profile.

3. The method as claimed in claim 1, wherein step (b) includes the steps of:

(b1) generating a function having a shape that changes in response to changes in the AC component of the monitored radiation; and

(b2) analyzing at least one characteristic of the function to determine the at least one combustion parameter.

4. The method as claimed in claim 3, wherein:

step (a) includes the step of producing a signal indicative of the monitored radiation; and

step (b1) includes the steps of;

converting the signal into a frequency-domain amplitude spectrum, and

generating the function in response to a content of the frequency-domain amplitude spectrum.

5. The method as claimed in claim 4, further comprising the step of:

(c) correlating the at least one combustion parameter with at least one combustion variable.

6. The method as claimed in claim 5, wherein step (c) includes the step of correlating the at least one combustion parameter with an amount of unburned carbon in fly ash.

7. The method as claimed in claim 1, wherein:

step (a) includes the step of producing a signal indicative of the monitored radiation; and

step (b) includes the steps of;

(b1) converting the signal into a frequency-domain amplitude spectrum, and

(b2) determining at least one combustion parameter based upon at least one characteristic of the frequency-domain amplitude spectrum.

8. The method as claimed in claim 1, wherein step (b) includes the step of analyzing at least one characteristic of a time-domain signal produced in response to the monitored radiation.

9. The method as claimed in claim 1, further comprising the step of:

(c) correlating the at least one combustion parameter with at least one combustion variable.

10. The method as claimed in claim 9, wherein step (c) includes the step of correlating the at least one combustion parameter with an amount of unburned carbon in fly ash.

11. A method for analyzing operation of a combustor comprising the steps of:

(a) monitoring radiation emitted from flue gas in a post-flame zone of the combustor;

(b) analyzing an AC component of the monitored radiation according to a first algorithm;

(c) analyzing the AC component of the monitored radiation according to a second algorithm; and

(d) combining results of the first and second algorithms to determine at least one combined combustion parameter.

12. The method as claimed in claim 11, wherein:

step (b) includes the step of determining at least one first combustion parameter based upon the AC component of the monitored radiation;

step (c) includes the step of determining at least one second combustion parameter based upon the AC component of the monitored radiation; and

step (d) includes the step of combining the first and second combustion parameters to determine the at least one combined combustion parameter.

13. The method as claimed in claim 12, wherein step (d) includes the step of multiplying the first and second combustion parameters to determine the at least one combined combustion parameter.

14. The method as claimed in claim 11, wherein:

step (b) includes the step of analyzing at least one characteristic of a time-domain signal produced in response to the monitored radiation; and

step (c) includes the step of analyzing at least one characteristic of a function generated in response to a frequency-domain representation of the monitored radiation.

15. The method as claimed in claim 11, further comprising the step of:

(e) correlating the at least one combined combustion parameter with at least one combustion variable.

16. The method as claimed in claim 15, wherein step (e) includes the step of correlating the at least one combined combustion parameter with an amount of unburned carbon in fly ash.

17. A method for analyzing operation of a combustor comprising the steps of:

(a) monitoring radiation emitted within the combustor;

(b) producing a time-domain signal representing a measured amplitude of the monitored radiation;

(c) determining an average amplitude of the signal during a particular time period;

(d) counting at least one of;

a number of high peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is greater than a first threshold, and

a number of low peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is less than a second threshold; and

(e) using the at least one of the number of high peaks and the number of low peaks counted in step (d) to determine at least one combustion parameter.

18. The method as claimed in claim 17, further comprising the step of:

(f) correlating the at least one combustion parameter with at least one combustion variable.

19. The method as claimed in claim 18, wherein step (f) includes the step of correlating the at least one combustion parameter with an amount of unburned carbon in fly ash.

20. The method as claimed in claim 18, wherein step (f) includes the step of correlating the at least one combustion parameter with an amount of Nitrogen Oxides (NOx).

21. The method as claimed in claim 17, wherein step (a) includes the step of monitoring radiation emitted from flue gas in a post-flame zone of the combustor.

22. The method as claimed in claim 17, wherein step (a) includes the step of monitoring radiation emitted from a flame zone of the combustor.

23. A method for monitoring an amount of unburned carbon in fly ash comprising the steps of:

(a) monitoring radiation emitted from flue gas in a post-flame zone of a combustor; and

(b) analyzing the monitored radiation to determine the amount of unburned carbon in fly ash.

24. The method as claimed in claim 23, wherein step (b) includes the step of:

determining the amount of unburned carbon in fly ash based upon an AC component of the monitored radiation.

25. A method for analyzing operation of a combustor comprising the steps of:

(a) using a first radiation sensor, that is sensitive to a first portion of an electromagnetic spectrum, to monitor radiation emitted from flue gas in a post-flame zone of the combustor;

(b) using a second radiation sensor, that is sensitive to a second portion of the electromagnetic spectrum which is different from the first portion, to monitor radiation emitted from flue gas in the post-flame zone of the combustor; and

(c) analyzing outputs of each of the first and second radiation sensors to determine at least one combined combustion parameter.

26. The method as claimed in claim 25, wherein:

step (c) includes the steps of;

(c1) analyzing the output of the first radiation sensor to determine at least one first combustion parameter;

(c2) analyzing the output of the second radiation sensor to determine at least one second combustion parameter; and

(c3) combining the first and second combustion parameters to determine the at least one combined combustion parameter.

27. The method as claimed in claim 26 wherein step (c3) includes the step of multiplying the first and second combustion parameters to determine the at least one combined combustion parameter.

28. The method as claimed in claim 25, further comprising the step of:

(d) correlating the at least one combustion parameter with at least one combustion variable.

29. The method as claimed in claim 28, wherein step (d) includes the step of correlating the at least one combustion parameter with an amount of unburned carbon in fly ash.

30. A system for analyzing operation of a combustor comprising:

at least one radiation sensor arranged to monitor radiation emitted from flue gas in a post-flame zone of the combustor and to produce a signal indicative thereof; and

analyzing means for determining at least one combustion parameter based upon an AC component of the signal.

31. The system as claimed in claim 30, wherein the analyzing means includes:

means for processing the signal to generate a function having a shape that changes in response to changes in the AC component of the signal; and

means for analyzing at least one characteristic of the function to determine the at least one combustion parameter.

32. The system as claimed in claim 31, wherein the means for processing includes:

means for converting the signal into a frequency-domain amplitude spectrum, and

means for generating the function in response to a content of the frequency-domain amplitude spectrum.

33. The system as claimed in claim 30, wherein the analyzing means includes:

means for conventing the signal into a frequency-domain amplitude spectrum, and

means for determining the at least one combustion parameter based upon at least one characteristic of the frequency-domain amplitude spectrum.

34. The system as claimed in claim 30, wherein the analyzing means includes means for analyzing at least one characteristic of the signal in the time domain.

35. A system for analyzing operation of a combustor comprising:

at least one radiation sensor to monitor radiation emitted from flue gas in a post-flame zone of the combustor and to produce a signal indicative thereof;

first means for analyzing an AC component of the signal according to a first algorithm;

second means for analyzing the AC component of the signal according to a second algorithm; and

means for combining results of the first and second algorithms to determine at least one combined combustion parameter.

36. The as claimed in claim 35, wherein:

the first means for analyzing includes means for determining at least one first combustion parameter based upon the AC component of the signal;

the second means for analyzing includes means for determining at least one second combustion parameter based upon the AC component of the signal; and

the means for combining includes means for combining the first and second combustion parameters to determine the at least one combined combustion parameter.

37. The system as claimed in claim 35, wherein:

the first means for analyzing includes means for determining at least one characteristic of the signal in the time-domain; and

the second means for analyzing includes means for determining at least one characteristic of a function generated in response to a frequency-domain representation of the signal.

38. A system for analyzing operation of a combustor comprising:

at least one radiation sensor to monitor radiation emitted within the combustor and to produce a signal indicative thereof;

means for determining an average amplitude of the signal during a particular time period;

means for counting at least one of;

a number of high peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is greater than a first threshold, and

a number of low peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is less than a second threshold; and

means for using the at least one of the number of high peaks and the number of low peaks counted by the means for counting to determine at least one combustion parameter.

39. The system as claimed in claim 38, wherein the at least one radiation sensor is arranged to monitor radiation emitted from flue gas in a post-flame zone of the combustor.

40. The system as claimed in claim 38, wherein the at least one radiation sensor is arranged to monitor radiation emitted from a flame zone of the combustor.

41. A system for continuous, on-line monitoring of an amount of unburned carbon in fly ash generated by a combustor comprising:

at least one radiation sensor to monitor radiation emitted from flue gas in a post-flame zone of the combustor and to produce a signal indicative thereof; and

means for analyzing the signal to monitor the amount of unburned carbon in fly ash generated by the combustor.

42. The system as claimed in claim 41, wherein the means for analyzing includes means for determining the amount of unburned carbon in fly ash based upon an AC component of the monitored radiation.

43. A system for analyzing operation of a combustor comprising:

at least one first radiation sensor, that is sensitive to a first portion of an electromagnetic spectrum, to monitor radiation emitted from flue gas in a post-flame zone of the combustor;

at least one second radiation sensor, that is sensitive to a second portion of the electromagnetic spectrum which is different from the first portion, to monitor radiation emitted from flue gas in the post-flame zone of the combustor; and

analyzing means for determining at least one combined combustion parameter based upon outputs of each of the first and second radiation sensors.

44. The system as claimed in claim 43, wherein the analyzing means includes:

means for determining at least one first combustion parameter based upon the output of the at least one first radiation sensor;

means for determining at least one second combustion parameter based upon the output of the at least one second radiation sensor; and

means for combining the first and second combustion parameters to determine the at least one combined combustion parameter.

45. A computer-readable medium for use with a processor operatively coupled to at least one radiation sensor, the medium having a plurality of instructions stored thereon which, when executed by the processor, cause the processor to perform the steps of:

(a) calculating an average amplitude of a signal generated by the at least one radiation sensor during a particular time period;

(b) counting at least one of;

a number of high peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is greater than a first threshold, and

a number of low peaks in the signal that, during the particular time period, achieve an amplitude, relative to the average amplitude, that is less than a second threshold; and

(c) using the at least one of the number of high peaks and the number of low peaks counted in step (b) to determine at least one combustion parameter.

46. A computer-readable medium for use with a processor operatively coupled to at least one radiation sensor monitoring radiation emitted from flue gas in a post-flame zone of a combustor, the medium having a plurality of instructions stored thereon which, when executed by the processor, cause the processor to perform the step of:

(a) analyzing an output of the at least one radiation sensor to determine an amount of unburned carbon in fly ash.