Method and system for SCR Optimization

• US 20060042525A1
• Filed: 12/15/2004
• Published: 03/02/2006
• Est. Priority Date: 08/27/2004
• Status: Active Grant

• Current Assignee: GE Digital Holdings LLC (GE Aerospace)
• Original Assignee: NeuCo Incorporated (General Electric Company)
• Inventors: Lefebvre, Wesley Curt, Kohn, Daniel W.
• Granted Patent: US 7,500,437 B2
• Time in Patent Office: Days
• US Class Current: 110/185
• CPC Class Codes: F23G 5/50 Control or safety arrangements
• CPC Class Codes: F23J 15/02 of purifiers, e.g. for removing noxious material traps for solid residues F23J3/04
• CPC Class Codes: F23J 2219/10 Catalytic reduction devices
• CPC Class Codes: F23J 3/00 Removing solid residues from passages or chambers beyond the fire, e.g. from flues by soot blowers
• CPC Class Codes: F23N 2241/10 Generating vapour
• CPC Class Codes: F23N 5/003 using detectors sensitive to combustion gas properties F23N5/02, F23N5/18 - F23N5/26 take precedence

Abstract

Methods and systems are provided for controlling SCR performance in a boiler. The boiler includes one or more generally cross sectional areas. Each cross sectional area can be characterized by one or more profiles of one or more conditions affecting SCR performance and be associated with one or more adjustable desired profiles of the one or more conditions during the operation of the boiler. The performance of the boiler can be characterized by boiler performance parameters. A system in accordance with one or more embodiments of the invention can include a controller input for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters. The boiler control variables include one or more current profiles of the one or more conditions. The system also includes a system model that relates one or more profiles of the one or more conditions in the boiler to the boiler performance parameters. The system also includes an indirect controller that determines one or more desired profiles of the one or more conditions to satisfy the performance goal for the boiler. The indirect controller uses the system model, the received data values and the received performance goal to determine the one or more desired profiles of the one or more conditions. The system model also includes a controller output that outputs the one or more desired profiles of the one or more conditions.

Claims

1. A system for controlling SCR performance in a boiler, the boiler including one or more generally cross sectional areas, each cross sectional area being characterized by one or more profiles of one or more conditions affecting SCR performance and being associated with one or more adjustable desired profiles of said one or more conditions during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, comprising:

a controller input for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters, said boiler control variables including one or more current profiles of said one or more conditions;

a system model that relates one or more profiles of said one or more conditions in the boiler to the boiler performance parameters;

an indirect controller that determines one or more desired profiles of said one or more conditions to satisfy the performance goal for the boiler, said indirect controller using the system model, the received data values and the received performance goal to determine the one or more desired profiles of said one or more conditions; and

a controller output that outputs the one or more desired profiles of said one or more conditions.

2. The system of claim 1 wherein said one or more conditions include NOx distribution.

3. The system of claim 1 wherein said one or more conditions include NH₃ distribution.

4. The system of claim 1 wherein said one or more conditions include catalyst activity.

5. The system of claim 1 wherein said one or more conditions include temperature conditions.

6. The system of claim 1, wherein said one or more conditions include NOx distribution, NH₃ distribution, or catalyst activity,

the system further comprising one or more of an SCR cleaning subsystem, an NH₃ injection subsystem, and a combustion subsystem, each in communication with the controller output for receiving one or more of desired catalyst activity profiles, desired NOx profiles, and desired NH₃ profiles in the boiler, respectively,

the SCR cleaning subsystem including one or more sootblowers and a controller for instructing the one or more sootblowers to maintain the one or more desired catalyst activity profiles;

the NH₃ injection subsystem including one or more NH₃ injectors and a controller for instructing the one or more NH₃ injectors to maintain the one or more desired NH3 profiles;

the combustion subsystem including one or more fuel and air injectors and a controller for instructing the one or more fuel and air injectors to maintain the one or more desired NOx profiles in the boiler.

7. The system of claim 1, further comprising a performance monitoring system in communication with said controller input, the performance monitoring system including at least one performance sensor to measure the data values, said performance monitoring system providing the data values to the indirect controller.

8. The system of claim 1, wherein said system model is a neural network.

9. The system of claim 1, wherein said system model is a mass-energy balance model.

10. The system of claim 1, wherein said system model is a genetically programmed model.

11. A system for determining one or more desired operating settings for one or more devices affecting SCR performance in a fossil fuel boiler, the operation of the one or more devices being characterized by adjustable operating settings, the performance of the boiler being characterized by boiler performance parameters, comprising:

a controller input for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters;

a system model that relates operating settings for said one or more devices to the boiler performance parameters;

an indirect controller that determines one or more desired operating settings for said one or more devices to satisfy the received performance goal for the boiler using the system model, and using the received performance goal for the boiler and the received data values; and

a controller output that outputs the one or more desired operating settings for said one or more devices.

12. The system of claim 11 wherein said one or more devices includes one or more NH3 injectors.

13. The system of claim 11 wherein said one or more devices includes one or more fuel and air injectors.

14. The system of claim 11 wherein said one or more devices includes one or more SCR sootblowers.

15. The system of claim 11 wherein said one or more devices include one or more devices for adjusting the temperature of gases generated by a furnace in said boiler.

16. The system of claim 11 further comprising a performance monitoring system in communication with said indirect controller, including a performance sensor to measure the data values, said performance monitoring system providing the data values to the indirect controller.

17. The system of claim 11 wherein said system model is a neural network.

18. The system of claim 11 wherein said system model is a mass-energy balance model.

19. The system of claim 11 wherein said system model is a genetically programmed model.

20. The system of claim 11 wherein said one or more devices comprise SCR sootblowers, NH₃ injectors, or fuel and air injectors,

wherein said controller output is in communication with said one or more devices,

wherein said SCR sootblowers operate according to desired sootblower operating settings,

wherein said NH₃ injectors operate according to desired NH₃ injector operating settings,

wherein said fuel and air injectors operate according to desired fuel and air injector operating settings.

21. A system for determining one or more desired profiles of one or more conditions affecting SCR performance in a boiler, said boiler having one or more generally cross sectional areas, each being characterized by one or more profiles of said one or more conditions and being associated with one or more adjustable desired profiles of said one or more conditions during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, comprising:

a controller input for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters, said boiler control variables including one or more current profiles of said one or more conditions;

a direct controller that determines one or more desired profiles of said one or more conditions to satisfy the performance goal for the boiler, said direct controller using the received data values and the received performance goal to determine said one or more desired profiles of said one or more conditions; and

a controller output that outputs said one or more desired profiles of said one or more conditions.

22. The system of claim 21 wherein said one or more conditions include NOx distribution at a cross-sectional area.

23. The system of claim 21 wherein said one or more conditions include NH₃ distribution at a cross-sectional area.

24. The system of claim 21 wherein said one or more conditions include catalyst activity at a cross-sectional area.

25. The system of claim 21 wherein said one or more conditions include temperature conditions at a cross-sectional area.

26. The system of claim 21 further comprising a performance monitoring system in communication with said controller input, the performance monitoring system including at least one performance sensor to measure the data values, said performance monitoring system providing the data values to the direct controller.

27. The system of claim 21 wherein said direct controller is a neural network.

28. The system of claim 21 wherein said direct controller is a mass-energy balance.

29. The system of claim 21 wherein said direct controller model is genetically programmed.

30. The system of claim 21 wherein said one or more conditions include NOx distribution, NH₃ distribution, or catalyst activity,

the system further comprising one or more of an SCR cleaning subsystem, an NH₃ injection subsystem, and a combustion subsystem, each in communication with the controller output for receiving one or more of desired catalyst activity profiles, desired NOx profiles, and desired NH₃ profiles, respectively,

the SCR cleaning subsystem including one or more sootblowers and a controller for instructing the one or more sootblowers to maintain the one or more desired catalyst activity profiles;

the NH₃ injection subsystem including one or more NH₃ injectors and a controller for instructing the one or more NH₃ injectors to maintain the one or more desired NH₃ profiles;

the combustion subsystem including one or more fuel and air injectors and a controller for instructing the one or more fuel and air injectors to maintain the one or more desired NOx profiles.

31. A system for determining one or more desired operating settings for one or more devices affecting SCR performance in a fossil fuel boiler, the operation of the one or more devices being characterized by adjustable operating settings, the performance of the boiler being characterized by boiler performance parameters, comprising:

a controller input for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters, wherein at least one of said boiler control variables comprises a measurement of NH₃ distribution;

a direct controller that determines one or more desired operating settings for said one or more devices to satisfy the received performance goal for the boiler using the received performance goal for the boiler and the received data values; and

a controller output that outputs the one or more desired operating settings for said one or more devices.

32. The system of claim 31 wherein at least one of said boiler control variables comprises a measurement of NOx distribution.

33. The system of claim 31 wherein at least one of said boiler control variables comprises a measurement of catalyst activity.

34. The system of claim 31 wherein said one or more devices includes one or more NH₃ injectors.

35. The system of claim 31 wherein said one or more devices includes one or more fuel and air injectors.

36. The system of claim 31 wherein said one or more devices includes one or more SCR sootblowers.

37. The system of claim 31 wherein said one or more devices include one or more devices for adjusting the temperature of gases generated by a furnace in said boiler.

38. The system of claim 31 further comprising a performance monitoring system in communication with said direct controller, including a performance sensor to measure the data values, said performance monitoring system providing the data values to the direct controller.

39. The system of claim 31 wherein said system model is a neural network.

40. The system of claim 31 wherein said system model is a mass-energy balance model.

41. The system of claim 31 wherein said system model is a genetically programmed model.

42. A system for controlling SCR performance in a fossil fuel boiler, said boiler including one or more generally cross-sectional areas, each cross-sectional area defining a profile of a condition at said cross-sectional area, the system comprising:

one or more devices associated with said one or more cross-sectional areas for adjusting the profile at a cross-sectional area, said one or more devices operating in accordance with adjustable operating parameters;

one or more sensors associated with said one or more cross-sectional areas for detecting conditions at said one or more cross-sectional areas; and

an indirect controller that determines operating settings for the one or more devices,

said indirect controller including a system model that relates operating settings for the one or more devices to desired profiles of said conditions,

said indirect controller having a controller input in communication with said one or more sensors,

said indirect controller using the conditions detected by said one or more sensors, the system model, and the desired profiles to determine operating settings for the one or more devices,

the indirect controller further including a controller output in communication with said one or more devices to transmit said operating settings to said one or more devices.

43. The system of claim 42 wherein said one or more devices include an SCR sootblower associated with at least one of said one or more cross-sectional areas for cleaning a surface in a catalyst bed to adjust a catalyst activity profile, an NH₃ injector associated with at least one of said one or more cross-sectional areas to inject NH₃ in said boiler and to adjust a NH₃ profile, and a fuel and air injector associated with at least one of said one or more cross-sectional areas to inject fuel and air in said boiler and adjust a NOx profile;

wherein said one or more sensors associated with at least one of said one or more cross-sectional areas detect a NOx level, an NH₃ level, and catalyst activity at said one or more cross-sectional areas;

wherein said indirect controller includes a system model that relates operating settings for the SCR sootblower to a desired catalyst activity profile, operating settings for the NH₃ injector to a desired NH₃ profile, and operating settings for the fuel and air injector to a desired NOx profile;

wherein the indirect controller uses the NOx levels, the NH₃ levels and the catalyst activity detected by said one or more sensors, the system model, and the desired catalyst activity profile, the desired NH₃ profile, and the desired NOx profile to determine operating settings for the SCR sootblower, the NH₃ injector, and the fuel and air injector, respectively; and

wherein the controller output of the indirect controller communicates with said SCR sootblower, NH₃ injector, and air and fuel injector to transmit said SCR sootblower operating settings to said SCR sootblower, said NH₃ injector operating settings to said NH₃ injectors, and said fuel and air operating settings to said fuel and air injectors.

44. A method for determining one or more desired profiles of one or more conditions in a boiler, the boiler having one or more generally cross-sectional areas, each cross-sectional area being characterized by a profile of a condition and being associated with a desired profile of the condition during the operation of the boiler, the performance of the boiler being characterized by one or more boiler performance parameters, the method comprising the steps of:

(a) implementing a controller with a system model that relates the one or more profiles in the boiler to the performance of the boiler;

(b) obtaining a performance goal for the boiler;

(c) receiving data corresponding to the boiler performance parameters and boiler control variables;

(d) determining an operating point corresponding to the performance goal using the system model;

(e) determining one or more desired profiles associated with the operating point using the system model; and

(f) communicating the one or more desired profiles to one or more subsystems operable to adjust one or more profiles.

45. The method of claim 44 wherein said one or more profiles include one or more of a NOx profile, an NH₃ profile, and a catalyst activity profile in said boiler, and

wherein step (f) comprises communicating one or more of a desired NOx profile to a fuel and air injection subsystem, a desired NH₃ profile to an NH₃ injector subsystem, and a desired catalyst activity profile to an SCR sootblower subsystem.

46. The method of claim 44, wherein said system model is implemented using historical data about the operation of the boiler.

47. The method of claim 44, wherein said system model is implemented using a neural network.

48. The method of claim 44, wherein said system model is implemented using a mass-energy balance.

49. The method of claim 44, wherein said system model is implemented using genetic programming.

50. The method of claim 44, further including the step of storing information about the control move and corresponding measured boiler performance values and retraining the system model using the stored information.

51. A method for determining desired operating settings for one or more devices affecting SCR performance in a boiler, the operation of the one or more devices being characterized by one or more operating parameters, the performance of the boiler being characterized by one or more boiler performance parameters, the method comprising the steps of:

(a) implementing a controller with a system model that relates the operating parameters of the one or more devices to the boiler performance parameters;

(b) obtaining a performance goal for the boiler;

(c) receiving data corresponding to the boiler performance parameters and boiler control variables;

(d) determining an operating point corresponding to the performance goal using the system model;

(e) determining operating settings of said one or more devices associated with the operating point using the system model;

(f) determining a control move using the operating settings determined in step (e) for directing the boiler to the operating point; and

(g) communicating said control move to said one or more devices to adjust operating parameters of said one or more devices.

52. The method of claim 51 wherein said devices include an SCR sootblower, an NH₃ injector, and a fuel and air injector.

53. The method of claim 51 wherein said system model is implemented using historical data about the operation of the boiler.

54. The method of claim 51 wherein said system model is implemented using a neural network.

55. The method of claim 51 wherein said system model is implemented using a mass-energy balance.

56. The method of claim 51 wherein said system model is implemented using genetic programming.

57. The method of claim 51 further including the step of storing information about the control move and corresponding measured boiler performance values and retraining the system model using the stored information.

58. The method of claim 51 wherein said control move is part of a sequence of control moves for incrementally reaching the set of desired operating settings for said one or more devices.

59. A method for controlling one or more profiles of conditions in a boiler, the boiler having one or more generally cross-sectional areas in the boiler, each cross-sectional area having a profile of a condition and being associated with a desired profile during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, the method comprising the steps of:

(a) providing a direct controller that determines one or more desired profiles in relation to a boiler performance goal;

(b) obtaining a performance goal for the boiler;

(c) determining whether the performance goal is satisfied by current boiler performance;

(d) when the performance goal is not satisfied, identifying the generally closest operating region in which the performance goal would be satisfied, the operating region being associated with one or more desired profiles; and

(e) outputting the one or more desired profiles.

60. The method of claim 59 wherein said one or more profiles include one or more of a catalyst activity profile, an NH₃ profile, and a NOx profile.

61. The method of claim 60 wherein said cross-sectional areas are associated with one or more of an SCR sootblower that operates in accordance with SCR sootblower operating parameters, an NH₃ injector that operates in accordance with NH₃ injector operating parameters, and an air and fuel injector that operates in accordance with air and fuel injector operating parameters, and

wherein the method further comprises the steps of adjusting the sootblower operating parameters to attain a desired catalyst activity profile, adjusting the NH₃ injector operating parameters to attain a desired NH₃ profile, or adjusting the air and fuel operating parameters to attain a desired NOx profile.

62. A method for adjusting operating settings of one or more devices affecting SCR performance in a boiler, said boiler having one or more generally cross-sectional areas, each of said one or more devices being associated with a cross-sectional area, each cross-sectional area having a profile of a condition and being associated with a desired profile, the performance of the boiler being characterized by boiler performance parameters, the method comprising the steps of:

(a) providing a direct controller that determines desired operating settings of said one or more devices in relation to a performance goal for the boiler;

(b) obtaining a performance goal for the boiler;

(c) determining whether the performance goal is satisfied by current boiler performance;

(d) when the performance goal is not satisfied, identifying the generally closest operating region in which the performance goal would be satisfied using the direct controller, the operating region being associated with desired operating parameters of said one or more devices;

(e) determining a control move using the desired operating parameters of said one or more devices for directing the boiler to the operating region; and

(f) communicating the control move to said one or more devices.

63. The method of claim 62 wherein said one or more devices include one or more of SCR sootblowers for controlling catalyst activity profiles, NH₃ injectors for controlling NH₃ profiles, and fuel and air injectors for controlling NOx profiles.

64. A method for adjusting operating settings for one or more devices affecting one or more profiles of conditions affecting SCR performance in a boiler, said boiler including one or more generally cross-sectional areas, each of said one or more devices being associated with a cross-sectional area, each cross-sectional area having a profile of a condition, the method comprising the steps of:

(a) providing an indirect controller with a system model that relates the operating settings of the one or more devices to respective profiles;

(b) providing data values to the indirect controller indicative of actual profiles;

(c) providing one or more desired profiles to the indirect controller;

(d) determining desired operating settings for said one or more devices, to attain the desired respective profiles using the indirect controller;

(e) determining a control move derived from the desired operating settings; and

(f) communicating the control move to said one or more devices.

65. The method of claim 64 wherein said one or more devices include one or more of SCR sootblowers for controlling catalyst activity profiles, NH₃ injectors for controlling NH₃ profiles, and fuel and air injectors for controlling NOx profiles.

66. A computer program product, residing on a computer readable medium, for use in determining one or more desired profiles of one or more conditions in a boiler, the boiler having one or more generally cross-sectional areas, each cross-sectional area being characterized by a profile of a condition and being associated with a desired profile of the condition during the operation of the boiler, the performance of the boiler being characterized by one or more boiler performance parameters, the computer program product comprising instructions for causing a computer to:

obtain a performance goal for the boiler;

receive data corresponding to the boiler performance parameters and boiler control variables;

determine an operating point corresponding to the performance goal using the system model;

determine one or more desired profiles associated with the operating point using the system model; and

communicate the one or more desired profiles to one or more subsystems operable to adjust one or more profiles.

67. A computer program product, residing on a computer readable medium, for use in determining desired operating settings for one or more devices affecting SCR operation in a boiler, the operation of the one or more devices being characterized by one or more operating parameters, the performance of the boiler being characterized by one or more boiler performance parameters, the computer program product comprising instructions for causing a computer to:

obtain a performance goal for the boiler;

receive data corresponding to the boiler performance parameters and boiler control variables;

determine an operating point corresponding to the performance goal using the system model;

determine operating settings of said one or more devices associated with the operating point using the system model;

determine a control move using the operating settings determined in step (e) for directing the boiler to the operating point; and

communicate said control move to said one or more devices to adjust operating parameters of said one or more devices.

68. A computer program product, residing on a computer readable medium, for use in controlling one or more profiles of conditions in a boiler, the boiler having one or more generally cross-sectional areas in the boiler, each cross-sectional area having a profile of a condition and being associated with a desired profile during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, the computer program product comprising instructions for causing a computer to:

obtain a performance goal for the boiler;

determine whether the performance goal is satisfied by current boiler performance;

when the performance goal is not satisfied, identify the generally closest operating region in which the performance goal would be satisfied, the operating region being associated with one or more desired profiles; and

output the one or more desired profiles.

69. A computer program product, residing on a computer readable medium, for use in adjusting operating settings of one or more devices affecting SCR performance in a boiler, said boiler having one or more generally cross-sectional areas, each of said one or more devices being associated with a cross-sectional area, each cross-sectional area having a profile of a condition and being associated with a desired profile, the performance of the boiler being characterized by boiler performance parameters, the computer program product comprising instructions for causing a computer to:

obtain a performance goal for the boiler;

determine whether the performance goal is satisfied by current boiler performance;

when the performance goal is not satisfied, identify the generally closest operating region in which the performance goal would be satisfied using the direct controller, the operating region being associated with desired operating parameters of said one or more devices;

determine a control move using the desired operating parameters of said one or more devices for directing the boiler to the operating region; and

communicate the control move to said one or more devices.

70. A computer program product, residing on a computer readable medium, for use in for adjusting operating settings for one or more devices affecting one or more profiles of conditions affecting SCR performance in a boiler, said boiler including one or more generally cross-sectional areas, each of said one or more devices being associated with a cross-sectional area, each cross-sectional area having a profile of a condition, the computer program product comprising instructions for causing a computer to:

provide data values to the indirect controller indicative of actual profiles;

provide one or more desired profiles to the indirect controller;

determine desired operating settings for said one or more devices, to attain the desired respective profiles using the indirect controller;

determine a control move derived from the desired operating settings; and

communicate the control move to said one or more devices.

71. A system for controlling SCR performance in a boiler, the boiler including one or more generally cross sectional areas, each cross sectional area being characterized by one or more profiles of one or more conditions affecting SCR performance and being associated with one or more adjustable desired profiles of said one or more conditions during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, comprising:

means for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters;

means for receiving data values corresponding to boiler control variables and to the boiler performance parameters, said boiler control variables including one or more current profiles of said one or more conditions;

means for relating one or more profiles of said one or more conditions in the boiler to the boiler performance parameters;

means for determining one or more desired profiles of said one or more conditions to satisfy the performance goal for the boiler, said indirect controller using the system model, the received data values and the received performance goal to determine the one or more desired profiles of said one or more conditions; and

means for outputting the one or more desired profiles of said one or more conditions.

72. A system for determining one or more desired operating settings for one or more devices affecting SCR performance in a fossil fuel boiler, the operation of the one or more devices being characterized by adjustable operating settings, the performance of the boiler being characterized by boiler performance parameters, comprising:

means for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters;

means for relating operating settings for said one or more devices to the boiler performance parameters;

means for determining one or more desired operating settings for said one or more devices to satisfy the received performance goal for the boiler using the system model, and using the received performance goal for the boiler and the received data values; and

means for outputting the one or more desired operating settings for said one or more devices.

73. A system for determining one or more desired profiles of one or more conditions affecting SCR performance in a boiler, said boiler having one or more generally cross sectional areas, each being characterized by one or more profiles of said one or more conditions and being associated with one or more adjustable desired profiles of said one or more conditions during the operation of the boiler, the performance of the boiler being characterized by boiler performance parameters, comprising:

means for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters, said boiler control variables including one or more current profiles of said one or more conditions;

means for determining one or more desired profiles of said one or more conditions to satisfy the performance goal for the boiler, said direct controller using the received data values and the received performance goal to determine said one or more desired profiles of said one or more conditions; and

means for outputting said one or more desired profiles of said one or more conditions.

74. A system for determining one or more desired operating settings for one or more devices affecting SCR performance in a fossil fuel boiler, the operation of the one or more devices being characterized by adjustable operating settings, the performance of the boiler being characterized by boiler performance parameters, comprising:

means for receiving a performance goal for the boiler corresponding to at least one of the boiler performance parameters and for receiving data values corresponding to boiler control variables and to the boiler performance parameters;

means for determining one or more desired operating settings for said one or more devices to satisfy the received performance goal for the boiler, said direct controller using the received performance goal for the boiler and the received data values; and

means for outputting the one or more desired operating settings for said one or more devices.

75. A system for controlling SCR performance in a fossil fuel boiler, said boiler including one or more generally cross-sectional areas, each cross-sectional area defining a profile of a condition/condition at said cross-sectional area, the system comprising:

one or more devices associated with said one or more cross-sectional areas for adjusting the profile at a cross-sectional area, said one or more devices operating in accordance with adjustable operating parameters;

means associated with said one or more cross-sectional areas for detecting conditions at said one or more cross-sectional areas; and

means for determining operating settings for the one or more devices,

said means for determining operating settings including a system model that relates operating settings for the one or more devices to desired profiles of said conditions,

said means for determining operating settings having a controller input in communication with said one or more sensors,

said means for determining operating settings using the conditions detected by said one or more sensors, the system model, and the desired profiles to determine operating settings for the one or more devices,

said means for determining operating settings further including a controller output in communication with said one or more devices to transmit said operating settings to said one or more devices.