System and method for detecting an abnormal situation associated with a heater

• US 7,536,274 B2
• Filed: 03/14/2005
• Issued: 05/19/2009
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Heavner, Louis W. III, Eryurek, Evren, Kavaklioglu, Kadir, Sharpe, Joseph H. Jr.
• Primary Examiner(s): Raymond; Edward
• Assistant Examiner(s): Charioui; Mohamed
• Application Number:
  US11/079,808
• Publication Number:
  US 20050267710A1
• Time in Patent Office: 1,527 Days
• Field of Search: 702/47, 702/50, 702/57, 702/98, 702/100, 702/116, 702/138, 702/179, 702182-185, 702/188, 702/115, 607/76, 251/129.07, 123/357, 417/1
• US Class Current: 702/183
• 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 5/16 using noise-sensitive detectors
• CPC Class Codes: F23N 5/242 using electronic means
• CPC Class Codes: G05B 23/024 Quantitative history assessment, e.g. mathematical relationships between available data; Functions therefor; Principal component analysis [PCA]; Partial least square [PLS]; Statistical classifiers, e.g. Bayesian networks, linear regression or correlation analysis; Neural networks

Abstract

A system for detecting abnormal situations associated with a heater in a process plant receives statistical data associated with the heater unit. The statistical data is analyzed to detect whether one or more abnormal situations associated with the heater exist. The statistical data may comprise statistical data generated based on pressure variables sensed by one or more pressure sensors associated with a furnace, a stack, a fuel supply, etc., associated with the heater. Additionally, the statistical data may comprise statistical data generated based on temperature variables sensed by one or more temperature sensors associated with the furnace, the stack, etc. If an abnormal situation is detected, an indicator of the abnormal situation may be generated.

Claims

1. A method for detecting an abnormal situation associated with a heater in a process plant, the method comprising:

receiving an indication of variability of fuel pressure associated with the heater, wherein the indication of variability of fuel pressure is calculated based on a fuel pressure variable generated by a fuel pressure sensor;

analyzing at least the indication of variability of fuel pressure to detect whether variability of the fuel pressure is increased; and

generating an indicator of a flame instability situation based on whether increased variability of the fuel pressure is detected.

2. A method as defined in claim 1, further comprising calculating statistical data indicative of variability of the fuel pressure wherein analyzing at least the indication of variability of fuel pressure includes analyzing the statistical data.

3. A method as defined in claim 2, wherein calculating the statistical data comprises filtering a fuel pressure signal and calculating at least one indication of a statistical event associated with the fuel pressure signal based on the filtered process signal.

4. A method as defined in claim 3, wherein calculating the statistical data further comprises at least one of trimming the fuel pressure signal prior to filtering the fuel pressure signal or trimming the fuel pressure signal after filtering the fuel pressure signal.

5. A method as defined in claim 2, wherein calculating the statistical data comprises calculating at least one statistical parameter based on a fuel pressure signal, wherein the at least one statistical parameter comprises at least one of a mean of the process signal, a standard deviation of the process signal, a variance of the process signal, a root-mean square of the process signal, a rate of change of the process signal, a range of the process signal, a maximum of the process signal, or a minimum of the process signal.

6. A method as defined in claim 2, wherein calculating the statistical data comprises calculating at least one indication of a statistical event associated with a fuel pressure signal, wherein the at least one indication of the statistical event comprises at least one of an indication that a spike in the fuel pressure signal occurred, an indication that a standard deviation of the fuel pressure signal is greater than a first threshold, an indication that the standard deviation of the fuel pressure signal is less than a second threshold, an indication that the fuel pressure signal includes cyclic oscillations, or an indication that the fuel pressure signal is erratic.

7. A method as defined in claim 1, further comprising calculating the indication of variability of fuel pressure based on a fuel pressure variable.

8. A method as defined in claim 7, wherein calculating the indication of variability of fuel pressure comprises calculating at least one statistical parameter based on a process signal, wherein the at least one statistical parameter comprises at least one of a standard deviation of the process signal, a variance of the process signal, a root-mean square of the process signal, a rate of change of the process signal, and a range of the process signal.

9. A method as defined in claim 7, wherein calculating the indication of variability of fuel pressure comprises calculating at least one indication of a statistical event associated with the fuel pressure, wherein the at least one indication of the statistical event comprises at least one of an indication that a spike in a fuel pressure occurred, and an indication that a standard deviation of the process signal is greater than a threshold.

10. A method as defined in claim 1, wherein receiving the indication of variability of fuel pressure comprises at least one of:

receiving statistical data generated by at least one sensor device;

receiving statistical data generated by a controller;

receiving statistical data generated by a server;

receiving statistical data generated by an advanced diagnostics block;

or

receiving statistical data generated by a statistical process monitoring block.

11. A method as defined in claim 1, further comprising:

receiving an indication of variability of floor draft pressure associated with a floor draft of a furnace;

analyzing at least the indication of variability of floor draft pressure to detect whether variability of the floor draft pressure is increased; and

wherein generating the indicator of the flame instability situation is further based on whether increased variability of the floor draft pressure is detected.

12. A method as defined in claim 1, wherein receiving the statistical data comprises receiving a filtered value of a fuel pressure signal.

13. A method as defined in claim 1, further comprising generating an alert based on the indicator of the flame instability situation.

14. A method as defined in claim 1, further comprising adjusting a damper associated with the heater based on the indicator of the flame instability situation.

15. A method as defined in claim 1, further comprising adjusting a fuel supply valve associated with the heater based on the indicator of the flame instability situation.

16. A method according to claim 1, wherein generating the indicator of a flame instability situation comprises generating an indicator of a smoke release situation.

17. A method according to claim 1, wherein generating the indicator of a flame instability situation comprises generating an indicator of a flame-out situation.

18. The method as defined in claim 1, wherein the fuel pressure variable is indicative of fuel pressure in a fuel line.

19. A system for detecting an abnormal situation associated with a heater in a process plant, the system comprising:

a statistical data generator to generate statistical data based on at least a fuel pressure variable sensed by at least one sensor device associated with the heater, the statistical data indicative of variability of fuel pressure, wherein the at least one sensor device is a fuel pressure sensor; and

an abnormal situation detector to detect flame instability based at least on whether variability of the fuel pressure variable is increased.

20. A system as defined in claim 19, wherein the statistical data generator is included in at least one of a sensor device, a process controller, a server, an advanced diagnostics block, or a statistical process monitoring block.

21. A system as defined in claim 20, wherein the statistical data generator comprises at least one fuel pressure sensor device of the at least one sensor device associated with the heater.

22. A system as defined in claim 19, wherein the statistical data comprises statistical data calculated based on a filtered value of the fuel pressure signal.

23. A system as defined in claim 22, wherein the statistical data comprises statistical data calculated based on at least one of a trimmed and then filtered fuel pressure signal or a filtered and then trimmed fuel pressure signal.

24. A system as defined in claim 19, wherein the abnormal situation detector is configured to generate an indicator of flame instability if flame instability is detected.

25. A system as defined in claim 24, wherein the abnormal situation detector is configured to generate an alert if flame instability is detected.

26. A system as defined in claim 19, wherein the statistical data is further based on a floor draft pressure variable, wherein the statistical data is further indicative of variability of floor draft pressure, and wherein the abnormal situation detector is to detect flame instability further based on whether variability of the floor draft pressure variable is increased.

27. A system as defined in claim 19, wherein the statistical data comprises at least one statistical parameter, the at least one statistical parameter comprising at least one of a standard deviation of the fuel pressure variable, a variance of the fuel pressure signal, a root-mean square of the fuel pressure signal, a rate of change of the fuel pressure signal, or a range of the fuel pressure signal.

28. A system as defined in claim 19, wherein the statistical data comprises at least one indication of a statistical event, wherein the at least one indication of the statistical event comprises at least one of an indication that a spike in the fuel pressure variable occurred, an indication that a standard deviation of the fuel pressure variable is greater than a threshold or an indication that the fuel pressure variable is erratic.

29. A system as defined in claim 19, wherein the statistical data comprises a filtered value of the fuel pressure variable.

30. A system as defined in claim 19, wherein the abnormal situation detector comprises at least one of a rule-based engine, a pattern detector, a fuzzy logic system, or a neural network.

31. A system as defined in claim 19, wherein the abnormal situation detector is configured to detect a smoke release situation.

32. A system as defined in claim 19, wherein the abnormal situation detector is configured to detect a flame-out situation.

33. The system as defined in claim 19, wherein the fuel pressure variable is indicative of fuel pressure in a fuel line.

34. A method for generating an alarm associated with a heater in a process plant, the method comprising:

receiving a pressure variable sensed by a pressure sensor associated with the heater;

filtering the pressure variable using a high pass filter;

generating a root mean square value of the pressure variable;

comparing the root mean square value to a threshold; and

generating an alarm based on the comparison of the root mean square value to the threshold; and

wherein receiving the pressure variable comprises receiving at least one fuel pressure variable sensed by at least one pressure sensor associated with a fuel supply of the heater or receiving at least one floor draft pressure variable sensed by at least one pressure sensor associated with a floor draft of a furnace.

35. A method according to claim 34, wherein generating the alarm comprises generating the alarm based on a plurality of comparisons of root mean square values to the threshold.

36. A method according to claim 35, wherein generating the alarm if root mean square values are above the threshold for a period of time.

37. A method according to claim 34, further comprising at least one of trimming the pressure variable prior to filtering the pressure variable or trimming the pressure variable after filtering the pressure variable.

38. A tangible medium storing machine readable instructions capable of causing one or more machines to:

receive an indication of variability of fuel pressure associated with the heater, wherein the indication of variability of fuel pressure is calculated based on a fuel pressure variable generated by a fuel pressure sensor;

analyze at least the indication of variability of fuel pressure to detect whether variability of the fuel pressure is increased ; and

generate an indicator of a flame instability situation based on whether increased variability of the fuel pressure is detected.

39. The tangible medium as defined in claim 38, wherein the fuel pressure variable is indicative of fuel pressure in a fuel line.