Zonal Combustion Tuning System Central District's 13TH Annual Power Generation Conference Florida Department of Environmental Protection July 30, 2009

2 / GE / GE Confidential and Proprietary © 2008 General Electric Company All rights Reserved Data in this presentation is for indication and discussion purposes only and may not be representative of results to be expected in specific applications.

3 / GE / GE Confidential and Proprietary Agenda Zonal Combustion Principles Zonal System –Features –Application –Reliability Operating Experiences and Achievements

Zonal Combustion Principles

5 / GE / GE Confidential and Proprietary ~ Coal Supply Coal Crusher Mill Coal Silos Air Heater Stack ID Fan FD Fan Turbine Generator Poor Combustion Zonal TM Combustion Monitors in Boiler Backpass Boiler Combustion Performance Issues Excessive attemperation High LOI High CO /Opacity Reduced efficiency High NO x Local slagging Local corrosion Excessiv e FEGT Local hot spots Increased O 2 Poor Combustion = Increased Boiler Issues = Poor Plant Performance

6 / GE / GE Confidential and Proprietary Good Combustion, Bad Combustion The Principles of Zonal Combustion Tuning Comfort Zone Initial A/F σ FEGT Improved A/F σ Performance Parameters Minimum local A/F limits average O2 Improved A/F σ Fuel Savings & CO 2 Credits & Compliance Availability & Output Output, Throughput & Fan Power Ash Sales & Efficiency Availability & CO compliance

7 / GE / GE Confidential and Proprietary Approaches to NOx Control Technique Operational Modifications Low Excess Air Reduced Air Preheat Fuel Biasing Burners Out of Service(BOOS) Combustion Equipment Modifications Flue Gas Recirculation (FGR) Overfire Air (OFA) Steam Inject ion Low-NO x Burners (LNB) Reburning Post-Combustion Techniques Selective Non-Catalytic Reduction (SNCR) Selective Catalytic Reduction (SCR) Nat. GasFuel OilCoal XXX X X X X XX X X XXX XX XXX XXX X X X X

8 / GE / GE Confidential and Proprietary Benefits of Combustion Tuning Great Benefits and Returns Increase Availability Reduce Emissions Improve Heat Rate Maximized Output Further Upside –Stable and Predictable Operation –Integrated with Mercury Removal –Reduce or avoid slag additives Chart Based on Specific Improvement of : Excess O 2 : 0.5% reduction Emissions (NOx): 15% reduction Heat Rate: 0.5% improvement Peak Power: 2.3% increase Availability: 3 outage days avoided *Benefits and improvements are site-specific. Actual results may vary.

The Zonal Combustion System

10 / GE / GE Confidential and Proprietary Zonal Combustion Modules #1 Zonal Combustion Monitoring System CO/O 2 Combustion Sensors Central Operator Interface Intuitive Graphic HMI Displays* #2 Zonal Combustion Tuning Advisor Library of Zonal Models Burner/OFA Influence Identification Fuel/Air Adjustment Advice Map Profile Correction Advice Zonal Grid Zonal Advisor * Software Modules built on iFIX HMI/SCADA

11 / GE / GE Confidential and Proprietary Combustion Monitoring Application TDL Combustion completed. Good tracing to burners. Reduced air in-leakage. Air in-leakage, non uniform flow and poor tracing to burners. Incomplete combustion. Recirculation zones and non uniform flow.

12 / GE / GE Confidential and Proprietary Zonal Combustion Tuning Advisor Built on Predominant Fluid Structure Predominant Burner Path Lines Zonal Combustion Monitoring System Burners/OFA Burner-to-Sensor Models Capture Fluid Structure

13 / GE / GE Confidential and Proprietary T-Fired Fluid Stratification Suited to Zonal Tuning 4 1

14 / GE / GE Confidential and Proprietary Zonal Monitoring System Designed for Reliability Zonal base analyzer technology has; Decades in similar applications 1000s installed world wide High reliability Zonal Analyzer ZCA-30 status Deployed January 2007 Over 330,000 hrs of operation as of Apr 28, 2009 Mean time to maintenance event: –> 19 months –Low Spec Limit > 12 2 Sigma, 95% PI SitesA - U1B - U3C - U1D - U5D - U6E - U1 LocationDenmarkMN, USAUT, USAUK SC, USA Trials1-4/0711/07 – 3/085 – 10/07NA 11/08 - 1/09 Systems12 Pts 6/088 pts 1/0910 Pts 10/078 Pts 7/08 Pending Zonal Installations

15 / GE / GE Confidential and Proprietary GEs Zonal Combustion Monitoring Application Experience Sensors applicable to Coal, Oil and Gas Coal Type – Bituminous or Subbituminous Ash < 30% Moisture < 30% Sulfur < 3% (up to 4%) Biomass co-firing to < 30% Gas Temperature: 900 °F to 1200 °F (1500 °F maximum) Ambient environments Electronics rated 0 to 60 °C, avoid exposure to severe weather. –Installations to –20 °C but not recommended. Sensor rated–18 to 93 °C.

16 / GE / GE Confidential and Proprietary Zonal Combustion Monitoring Benefits of Zonal Approach Post combustion Close to furnace Zonal data traces to burners Low air in-leakage Ease of installation Robust technology Accurate measurements Accurate point data

Operating Experience and Achievements

18 / GE / GE Confidential and Proprietary Zonal Combustion System Installation Plant Western US 460 MW T-fired boiler Western Bituminous Coal Zonal Project Zonal Combustion Monitor Grid –2x5 sensor array Zonal Tuner Advisor –CCOFA yaw Issues Frequent Slagging Events New Corporate NOx and CO Mandates Zonal Combustion Topology Burner Adjustment s Burner-to- Sensor Models Boiler Zonal Sensor Grid

19 / GE / GE Confidential and Proprietary As-Found Conditions – Western US Boiler Normal Operation Typically High 3.6% Excess O 2 O 2 Imbalanced +/- 1% (ie. 10% ex air) Low average CO 37 ppm High NOx 0.4 lb/MMbt Reduced O 2 Operation O 2 reduced to 3.0% Low average CO 150 ppm High peak 900 ppm, fuel-rich zone Slagging severe at reduced O 2 Combustion Issues not be Detected by Stack CO

20 / GE / GE Confidential and Proprietary Zonal Combustion Tuning Event T-Fired, Western US Boiler O 2 average: 3.13% O 2 spatial variance: 0.32% CO average: 14 ppm CO spatial variance: 9 ppm

21 / GE / GE Confidential and Proprietary Ave 3.1% O 2 Ave 3.6% O 2 After (3/9/09) Before (6/12/08) Zonal Tuning Improvements T-Fired, Western US Boiler Before After Realized Benefits NOx25% Reduction O20.5% Reduction CO, ppm<50 ppm SlaggingNo events Efficiency0.5% Increase

22 / GE / GE Confidential and Proprietary Zonal Identified Air Leak at Boiler Nose Western US Boiler February 12, 2009 Unusual Zone of High O 2 & High CO Pinpointed likely leakage area Boiler taken of line for repair Repair verified by O 2 and CO return to normal Sensor 5

23 / GE / GE Confidential and Proprietary Zonal versus Plant O 2 Wall-Fired, Mid-West Boiler Excess O2, % CO, ppm Existing Plant Sensors Biased Low and Not Suitable for Tuning X X Plant O 2 probes located in these 3% O 2 Zonal O 2 (true) reads 3.8% Plant O 2 (biased low) read 3.0%

24 / GE / GE Confidential and Proprietary As-Found Zonal Combustion Conditions Wall-Fired, Mid-West Boiler Reduced Excess O2 Operation Zonal Excess O2 Average 3.2% O2 Imbalance 1.3% to 5.1% O2 Zonal Combustibles (~CO) Average 133 ppm Imbalance 0 to 1000 ppm Excess O2, % CO, ppm Reducing Excess O2 Results in Poor Local Combustion

25 / GE / GE Confidential and Proprietary Zonal Combustion Tuning Wall-Fired, Mid-West Boiler As Found Normal O 2 As Reduced O 2 Zonal Reduced O 2 Zonal monitoring provides ability to tune-out Poor Combustion Zonal CO Profiles

26 / GE / GE Confidential and Proprietary Zonal Combustion Tuning System Customer Reported Benefits Performance Engr expertise captured in Tuning Advisor With topographical mapping of both CO and O 2, plant is able to identify in-furnace problems. Plant is able to adjust the key handles, to avoid split O 2 and problematic O 2 distributions The unit is able to burn poorest coals without slag outages or significant slag buildup. 25% reduction in NOx levels Continuous operation within corporate CO limits without dropping load is possible Minimal variation in Oxygen levels allowing O 2 reduction in a 0.5% efficiency improvement A reduction of hot spots, fuel-rich combustion resulting in reduced forced outages.

27 / GE / GE Confidential and Proprietary Conclusions

28 / GE / GE Confidential and Proprietary Compelling Reasons to Optimize Combustion systems are more complex Retiring operator pool – new operators benefit from improved tools Changing fuel sources – compliance coal, low cost coals, biomass co-firing future Aging fleet and increasing electricity demand Stricter CO and NOx regulations... and Hg !!! Stiff penalties for emissions violations

29 / GE / GE Confidential and Proprietary Zonal Combustion Tuning System Summary Provide operators Useful Information Monitor End-Products of Combustion Monitor Local Combustion Conditions Capture Operator Expertise in Tuning and Operations Strive for Predictable Performance in: Emissions – CO, NOx, Opacity Availability – slagging, water wall wastage Output – Pressure drop, fan limits Heat Rate – Steam Gen, Attemperation, Heat Losses

30 / GE / GE Confidential and Proprietary Contact Information

31 / GE / GE Confidential and Proprietary Product Manager, Combustion Optimization - Neil Widmer (Work) (Mobile) - Contact Information

32 / GE / GE Confidential and Proprietary e