STORM ONE MORE TIME: FIRST APPLY THE FUNDAMENTALS! S T O R M T E C H N O L O G I E S, I NC.

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1 STORM S T O R M T E C H N O L O G I E S, I NC. ONE MORE TIME: FIRST APPLY THE FUNDAMENTALS! The right way to improve plant performance for best capacity, efficiency, reliability, turn down and minimal environmental emissions is to begin with the fundamentals. Presentation by: Dick Storm of Storm Technologies, Inc. RMEL Plant Management Conference June 14-15, 2012

2 COMBUSTION IN LARGE UTILITY FURNACE ~1,500 o F Peak Superheater Inlet Flue Gas Temperatures, Preferred ~2,200 o F ~750 o F Peak Furnace Temperatures up to 3,200 o F Typical Oxygen Analyzer Location

3 ACRONYMS, KEY WORDS & PHRASES Flame Quench Zone Carbon Quench Temperature ~1,400 F Excess Air or Theoretical Air The amount of air needed for complete stoichiometric combustion Stoichiometric or Theroretical Combustion is: The ideal combustion process during which a fuel is burned completely. Corrected to No Leakage APH exit gas temperature Representative Samples of Temperatures & flue Gas Analysis Ash Fusion Temperature From FD Fan To Stack Popcorn Ash LOI Loss on Ignition CIA Carbon in Ash UBC Unburned Carbon in Ash Point at which the combustion should be completed FEGT Furnace Exit Gas Temperature Bulk or Average Equal Areas Sampling/Measuring Furnace Residence Time Available time in the furnace for carbon burnout Three T s ~ Time Temperature Turbulence Reducing Atmosphere Air in-leakage Dilution Tramp Air Air Heater X Ratio

4 FURNACE EXIT SECONDARY COMBUSTION MOV 00243

5 Bulk Gas Phase ( Released in the Burner Belt) Volatiles FUEL FACTORS THAT OFTEN REQUIRE COMBUSTION TUNING Fuel HGI Fuel Moisture - HHV Fixed Carbon: Volatile Ratio Sulfur Content Nitrogen Content Ash Mineral Matter SO 2 NO X WW Wastage NH 4 HSO 4 formation Erosion Slag &Fouling ESP Performance LOI N N N HGI N N N CO 2 CO 2 Oxidized Char Products (Challenging upper furnace FEGT)

6 FURNACE RESIDENCE TIME & COMBUSTION Flame Quench Zone Heating and Minor Devolatilization Point at which combustion should be completed Ignition Major Devolatization Burning of Carbon To Stack Residence time of 1-2 seconds Time (Seconds)

7 LOW NO X FIRING EVOLUTION CHALLENGES 70 s High Intensity Burner Forgiving First Generation Low NO X Burner Sensitive 2 nd & 3 rd Generation Low NO X Burners Unforgiving w/ OFA / Staged Combustion Challenging!

8 HVT Temperatures ( F) Reheat Tube Metal Temperatures HIGH FLUE GAS TEMPERATURE PEAKS High flue gas temperature peaks and the corresponding peaks of individual tube temperatures. The point is, poor distribution of hot gas lanes, often correspond with overheated tube circuits HVT Temperature Front Wall Reheat Tube Temp

9 DEMANDS FOR IMPROVED SOOT BLOWING Higher FEGT due to the addition of LNB and OFA Lower ash fusion temperature and switching to or blend with: Low Sulfur coal (e.g. PRB) High Sulfur coal (East Bituminous) Molten ash particles begin to sinter on leading edge of pendant sections Traditional time-based soot blowing allows sintered deposits to bridge

10 OPTIMUM TEMPERATURES, TUNING & FLUE GAS OXYGEN LEVELS Temperature: ~1,500 o F Temperature: ~775 o F

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12 COMBUSTION OPTIMIZATION A FOUR STEP PROCESS

13 FURNACE EXIT HVT TESTING Flue Gas Analyzer Gas Conditioner Support Hanger Radiation Shield Digital Thermometer Thermocouple Water Out Water In Air In Thermocouple Connection Shield

14 COMPREHENSIVE EVALUATION Gross Turbine Cycle Heat Rate (GTCHR) Fuel Line Performance Measurements Mill Inlet Primary Airflow Calibrations Total Secondary Airflow Measurement & Calibration Furnace Exit Gas Temperature & Flue Gas Constituents Economizer Outlet Flue Gas Measurements ID Fan Discharge / Stack Inlet Flue Gas Measurements Stealth Loss Evaluation

15 TYPICAL STORM BURNER TESTING & TUNING LOCATIONS

16 CLEAN AIR TESTING

17 Recommended Primary Airflow Rate (blue line - Lbs./Hr.) & Measured Dirty Air Rates DIRTY AIRFLOW TESTING DIRTY AIRFLOW TESTING East Bend Station, Unit 2 Mill Outlet Fuel Line Measurements Vs. Recommended Air-Fuel Input Values 300, , , , , , , , ,000 40,000 55,000 70,000 85, , , ,000 Measured Coal Flow (Lbs./Hr.) Recommend Mill Inlet Primary Air-Fuel Ramp Baseline Test 1 Dirty air Test Results at 105Klbs/Hr.Coal Feede Test 2 Results at 120Klbs/Hr. 2-3 Pulverizer (Primary Airflow Local DP and Coal Flow Reading 2-5 Pulverizer (Primary Airflow Local DP and Coal Flow Reading 2-6 Pulverizer (Primary Airflow Local DP and Coal Flow Reading

18 Isokinetic Coal Sampling ISOKINETIC COAL SAMPLING

19 COMBUSTION AIRFLOW DISTRIBUTION & CONTROL Over-Fire Air (15-20%) Secondary Air (55-65%)

20 FLUE GAS MEASUREMENTS (TYPICAL IMBALANCES) Oxygen Temperature CO NO X

21 HIGH FURNACE EXIT GAS TEMPERATURES CAN CONTRIBUTE TO OVERHEATED METALS, SUCH AS THESE SUPERHEATER ALIGNMENT CASTINGS THAT ONLY LASTED 1 YEAR DUE TO GREATER THAN 2,500 F. FURNACE EXIT GAS TEMPERATURES. FEGT ~ 2,150 F with a PC Fired Unit (Typical) Note: This is FEGT with Optimized Combustion

22 AIR IN-LEAKAGE AND X-RATIO Over-Fire Airflow Combustion Airflow to Burners Combustion Airflow to Pulverizers Boiler Exit Flue Gas (720 F) Air Heaters Air Heater Leakage Paths Radial Seals, Axial, Bypass, Circumferential, Tempering Airflow to Pulverizers APH Flue Gas Exit & APH Leakage Air Combustion Airflow to the Furnace Force Draft Fans

23 PERFORMANCE TESTING & INPUT OPTIMIZATION HVT Testing Location Secondary Air Testing Location Fuel Line Sampling Locations Economizer Outlet Testing Location APH Outlet Testing Location Primary Air Testing Location ID Fan Discharge Testing Location

24 (3) PART FLY ASH SIEVE/LOI ANALYSIS 200 MESH SIEVE (COARSE ASH) Place 50 grams of ash on the 200 MESH for sieve analysis DETERMINE L.O.I. OF RESIDUE ON 200 MESH SCREEN AND IN PAN L.O.I. OF FINE ASH MUST BE LESS THAN 2% (low volatile eastern fuels); or less than 0.2% ( high volatile western fuels) BOTTOM PAN (FINE ASH)

25 DRAFT LOSS & SYSTEM AIR IN-LEAKAGE MEASUREMENT -.5 w.c. -4 w.c. - 6 w.c. -20 w.c. -.5 w.c w.c. -10 w.c. -15 w.c w.c.

26 OPTIMIZING EXCESS AIR

27 Stack 1% 11% TYPICAL STEAM CYCLE LOSSES Typical Losses for a 2400psi / 1000 F / 1000 F Unit Based on a Heat rate = 9,571 Btu/kWh (or ~35% Thermal Efficiency) Stack Losses 49% Remember: 1kWh at 100% Efficiency = 3,413 BTU s Boiler Soot Blowing Leaks Cooling Tower 4% Auxiliary Horsepower To Drive FD Fan Pulverizers, Fans, and Environmental Equipment ID Fan

28 PERFORMANCE RELATIONSHIPS As Found Typical Neglect to the Firing system and/or Boiler in General Optimum Coal Fineness, Balanced Fuel Lines, Optimum Burner Tolerances / Control Slag Production, CO, NO X Total Combustion Optimization Program with Optimum Mill & Fuel Line Performance, Stoichiometric Firing Control, Optimized Air Heater Performance, Optimized Soot Blowing Sequences, Optimized Environmental Control Equipment, Performance Preservation Program in Place Carbon In Ash

29 22 Boiler Controllable Heat Rate Factors

30 TYPICAL PLANT RELIABILITY AND PERFORMANCE OPPORTUNITIES High furnace exit gas temperatures contribute to overheated metals, high desuperheating spray flows, excessive soot blower operation Reduced Lower Furnace Heat Absorption Air In-Leakage Fly ash Carbon losses Increased Mass flow through the precipitator decreases precipitator performance Coal Fineness Coal dribble/spillage due to throats that are too large Bottom ash carbon content; Bottom Ash Hopper - Air In-leakage High primary airflows contribute to unnecessarily high dry gas losses. Also poor fuel distribution, poor coal fineness & load Control ID Fan Capacity Limitations (due to high air in-leakage)

31 PERFORMANCE/TESTING/INSPECTIONS DRIVEN MAINTENANCE Program Introduction and/or Performance Preservation Planning Post Outage Testing Presentation and Overview Training & Implementation of a Performance Testing Program Post Outage Testing and Tuning Evaluation of the Plants Data & Test Results (Data Interpretation) Review of Plant Performance Opportunities & Outage Planning

32 ONE MORE TIME: FIRST APPLY THE FUNDAMENTALS! Thank You! Any Questions? Dick Storm Ph