COMBUSTION OPTIMIZATION FOR FOSSIL FUEL FIRED BOILERS

• US 20040191914A1
• Filed: 03/28/2003
• Published: 09/30/2004
• Est. Priority Date: 03/28/2003
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Seeker, William Randall, Payne, Roy, Gauthier, Philippe Jean, Widmer, Neil Colin
• Granted Patent: US 7,838,297 B2
• Time in Patent Office: Days
• US Class Current: 436/55
• CPC Class Codes: F23N 1/022 using electronic means
• CPC Class Codes: F23N 2221/00 Pretreatment or prehandling
• CPC Class Codes: F23N 2221/10 Analysing fuel properties, e.g. density, calorific
• CPC Class Codes: F23N 3/042 using electronic means
• 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 5/006 the detector being sensitive to oxygen
• CPC Class Codes: Y10T 436/12 Condition responsive control

Abstract

A method of optimizing operation of a fossil fuel fired boiler includes, in an exemplary embodiment, providing a plurality of sensors positioned in different spatial positions within the fossil fuel fired boiler. The method also includes recording sensor outputs, identifying spatial combustion anomalies indicated by sensor outputs, identifying burners responsible for the spatial combustion anomalies, and adjusting air flow of responsible burners to alleviate the spatial combustion anomalies.

Claims

1. A method of optimizing operation of a fossil fuel fired boiler, the boiler comprising a plurality of burners, each burner receiving fossil fuel and combustion air, said method comprising:

(a) providing a plurality of sensors positioned in different spatial positions within the fossil fuel fired boiler;

(b) recording sensor outputs;

(c) identifying spatial combustion anomalies indicated by sensor outputs;

(d) identifying burners responsible for the spatial combustion anomalies; and

(e) adjusting air flow of responsible burners to alleviate the spatial combustion anomalies.

2. A method in accordance with claim 1 further comprising balancing burner fuel flow.

3. A method in accordance with claim 2 wherein balancing burner fuel flow comprises adjusting burner air flow and then adjusting burner fuel flow.

4. A method in accordance with claim 2 wherein balancing burner fuel flow comprises adjusting burner fuel flow and then adjusting burner air flow.

5. A method in accordance with claim 1 further comprising repeating (b) through (e) until a uniform spatial combustion is achieved to optimize operation of the boiler.

6. A method in accordance with claim 2 wherein the boiler further comprises at least one fuel mill, and balancing burner fuel flow further comprises:

monitoring and adjusting mill fuel flow; and

monitoring and adjusting burner fuel flow.

7. A method in accordance with claim 1 wherein identifying spatial combustion anomalies further comprises examining spatial combustion data from the plurality of sensors.

8. A method in accordance with claim 1 wherein identifying burners responsible for the spatial combustion anomalies comprises tracing the burners to corresponding sensors, tracing the burners comprising at least one of computational flow modeling, isothermal flow modeling, and empirically by adjusting individual burner air settings and noting changes to sensor output data.

9. A method in accordance with claim 1 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of reducing excess air to individual burners and increasing fuel to individual burners to determine the burners that are causing the combustion anomalies.

10. A method in accordance with claim 1 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of reducing excess air to all burners and increasing fuel to all burners to determine the burners that are causing the combustion anomalies.

11. A method in accordance with claim 1 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of reducing excess air to individual groups of burners and increasing fuel to individual groups of burners to determine the burners that are causing the combustion anomalies.

12. A method in accordance with claim 6 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of increasing mill fuel flow at constant mill air flow, increasing mill fuel flow at constant boiler air, and increasing mill fuel flow at a constant boiler air to fuel ratio to determine the burners that are causing the combustion anomalies.

13. A method in accordance with claim 6 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of reducing windbox air flow at constant mill fuel flow, reducing windbox air flow at constant boiler fuel flow, and reducing windbox air flow at a constant boiler air to fuel ratio to determine the burners that are causing the combustion anomalies.

14. A method in accordance with claim 9 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies further comprises:

recording burner settings;

determining if anomalies trace to burners with most biased air settings;

maximizing a feed air pressure drop at a mean damper setting; and

adjusting burner air settings to alleviate combustion anomalies caused by responsible burners.

15. A method in accordance with claim 14 wherein each burner comprises an inner and an outer spin vane, burner registers, and adjusting burner air settings to alleviate the spatial combustion anomalies comprises:

adjusting inner and outer spin vanes on individual burners; and

adjusting burner registers to determine responsible burners.

16. A method in accordance with claim 15 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises:

adjusting a secondary air damper; and

adjusting an over fire air damper.

17. A method in accordance with claim 6 further comprising:

reducing a boiler load;

determining if burner fuel balance remains within acceptable parameters at reduced boiler load;

determining if there are any other combustion anomalies; and

determining burner and mill fuel set points as a function of load with burner air settings constant.

18. A method in accordance with claim 1 further comprising developing a spatial combustion data model at the optimized conditions defined by readings from the plurality of sensors.

19. A method in accordance with claim 18 further comprising:

establishing rules for burner adjustments based on the spatial combustion data model; and

adjusting burner settings in accordance with the rules to maintain optimized operation of the boiler.

20. A method in accordance with claim 1 wherein the plurality of sensors comprises at least one of optical radiation sensors, LOI sensors, temperature sensors, CO sensors, CO₂ sensors, NO_x sensors, O₂ sensors, total hydrocarbons sensors, volatile organic compounds sensors, sulfur dioxide sensors, heat flux sensors, radiance sensors, opacity sensors, emissivity sensors, moisture sensors, hydroxyl radicals sensors, sulfur trioxide sensors, particulate matter sensors, and emission spectrum sensors.

21. A method of optimizing operation of a fossil fuel fired boiler, the boiler comprising a plurality of burners, each burner receiving fossil fuel, primary air, and secondary air, said method comprising:

(a) providing a plurality of sensors positioned in different spatial positions within the fossil fuel fired boiler, the plurality of sensors comprising at least one of LOI sensors and CO sensors;

(b) balancing burner fuel flow;

(c) recording sensor outputs;

(d) identifying spatial combustion anomalies indicated by sensor outputs;

(e) identifying burners responsible for the spatial combustion anomalies; and

(f) adjusting air flow of responsible burners to alleviate the spatial combustion anomalies.

22. A method in accordance with claim 21 further comprising repeating (c) through (f) until a uniform spatial combustion is achieved to optimize operation of the boiler.

23. A method in accordance with claim 22 wherein the plurality of sensors comprises at least one of optical radiation sensors, LOI sensors, temperature sensors, CO sensors, CO₂ sensors, NO_x sensors, O₂ sensors, total hydrocarbons sensors, volatile organic compounds sensors, sulfur dioxide sensors, heat flux sensors, radiance sensors, opacity sensors, emissivity sensors, moisture sensors, hydroxyl radicals sensors, sulfur trioxide sensors, particulate matter sensors, and emission spectrum sensors.

24. A method in accordance with claim 21 wherein the boiler comprises at least one fuel mill, and balancing burner fuel flow further comprises:

monitoring and adjusting mill fuel flow; and

monitoring and adjusting burner fuel flow.

25. A method in accordance with claim 21 wherein identifying spatial combustion anomalies further comprises examining spatial combustion data from the plurality of sensors.

26. A method in accordance with claim 21 wherein identifying burners responsible for the spatial combustion anomalies comprises tracing the burners to corresponding sensors, tracing the burners comprising at least one of computational flow modeling, isothermal flow modeling, and empirically by adjusting individual burner air settings and noting changes to sensor output data.

27. A method in accordance with claim 21 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises at least one of reducing excess air to individual burners and increasing fuel to individual burners to determine the burners that are causing the combustion anomalies.

28. A method in accordance with claim 27 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies further comprises:

recording burner settings;

determining if anomalies trace to burners with most biased air settings;

maximizing a feed air pressure drop at a mean damper setting; and

adjusting burner air settings to alleviate combustion anomalies caused by responsible burners.

29. A method in accordance with claim 28 wherein each burner comprises an inner and an outer spin vane, and burner registers, and adjusting burner air settings to alleviate the spatial combustion anomalies comprises:

adjusting inner and outer spin vanes on individual burners;

adjusting burner registers to determine responsible burners.

30. A method in accordance with claim 29 wherein adjusting responsible burner air flow to alleviate the spatial combustion anomalies comprises:

adjusting a secondary air damper; and

adjusting an over fire air damper.

31. A method in accordance with claim 22 further comprising:

reducing boiler load;

determining if burner fuel balance remains within acceptable parameters at reduced boiler load;

determining if there are any other combustion anomalies; and

determining burner and mill fuel set points as a function of load with burner air settings constant.

32. A method in accordance with claim 21 further comprising developing a spatial combustion data model at the optimized conditions defined by readings from the plurality of sensors.

33. A method in accordance with claim 32 further comprising:

establishing rules for burner adjustments based on the spatial combustion data model; and

adjusting burner settings in accordance with the rules to maintain optimized operation of the boiler.

34. A method in accordance with claim 21 further comprising identifying responsible overfire jets responsible for the spatial combustion anomalies.

35. A method in accordance with claim 34 wherein identifying responsible overfire jets responsible for the spatial combustion anomalies comprises at least one of reducing excess air to all burners and increasing fuel to all burners to determine overfire jets responsible for the spatial combustion anomalies.

36. A method in accordance with claim 21 further comprising identifying responsible reburn jets responsible for the spatial combustion anomalies.

37. A method in accordance with claim 36 wherein identifying responsible reburn jets responsible for the spatial combustion anomalies comprises at least one of reducing excess air to all burners and increasing fuel to all burners to determine reburn jets responsible for the spatial combustion anomalies.