Presented by - Storm Technologies, Inc.

1 Presented by:Stephen K. StormStorm Technologies, Inc. (USA)John GuffreParagon AirheaterTechnologies (USA)June 8-10, 2010, Amsterdam, HollandIntroduction TheAirheateraccountsfor~10%ofaunit FD Fans ID Fans Pulverizers BurnersThe Airheater impacts the efficiency of most plant equipment Precipitators Bag houses Boiler Operation Environmental Equipment (SCR, FGD)Evaluating Air Heater Performance Airheaterleakagecanoccurfromdifferentpat hs. Path1:Normalairflowpath Path2:Normalgasflowpath PathA:AmbientFDfanleakingdirectlytotheAP HGasOutlet PathB:Pre-heatedFDfanairflowshortcircuit ingtheAPH PathC:AmbientFDfanairleakingaroundairhea ter.

2 PathD:HotgasexitingboilerLeakage paths through aregenerative air heaterGases Leaking Past the SealsBypass Seal Leakage passing the axial seals into the gas flowBypass Seal Leakage passing around the APH into the warm air flowBypass Seal Leakage passing around the APH into the cold gas flowHot Radial Seal LeakageCold Radial Seal LeakageGAS SideAIR SideCircumferential leakage through an air heaterSample Grid Considerations Test grid should be reasonably spaced with 1 point per square meters (or 7-9 per sq ft) More test points do not substitute for insufficient number of test Grid Layout for Rectangular DuctTest Grid Layout for Circular DuctNon-Uniform Test Grid Additional test points needed if suspected of more than average leakage near radial seals or expansion joints.

3 The additional points may need to represent a smaller of a Non-Uniform Test Grid Near an Air Heater Radial SealMeasuring Air Heater (%) LeakageOut 2In 2 Out 2 Out GasGas pOut GasInAir Out GasGas pCorrectedOut GasTCT%40T 60% TCLeakage%T eLeakag Less Flow M ass GasTTCFlow M assAir TTCE fficiencyTransfer Heat CorrectedOut GasIn GasGas pIn Air,OutAir Air p HPEfficiencyM otor EfficiencyFan )Pressure(" StaticFlow(ACFM )nConsumptioPower Air In-Leakage calculation: Corrected gas outlet temperature: Heat transfer efficiency: Fan efficiency:Measuring Air Heater AQd Approximate leakage rates: Equation designed to calculate flows through large defined shape openings.

4 Provides closer approximation than traditional Crack Flow EquationsPressure Difference (PA)Flow Rate (m3/s)Discharge Coefficient (= for a Flat Plate Orifice)Cross Sectional Area of Opening (m2)Air Density (kg/m3)Measuring Air Heater PerformanceStatic Pressure1, 2, 3, 4 Velocity Head2, 3, 4 Oxygen Concentration3, 4 Temperature1, 2, 3, 4 Testing Locations Needtoknowthefollowing: Tempinandoutbothairsides O2beforeandaftergasside Airandgasflowsbeforeandafterairheater VelocityheadsneedtobemeasuredTheoretical vs. Measured Airflow0200,000400,000600,000800,0001,00 0,0001,200,0001,400,0001,600,0001,800,00 02,000,000 TotalSecondary OFAP rimarykg/hrTheoretical Airflow vs.

5 Measured Air at 15% Excess AirTheoreticalMeasuredTheoretical vs. Measured Airflow on a 460 MW unitTheoretical airflow vs. Actual combustion airflow audits should be considered Direct Effect of the APH on Fuel Consumption and CO2 Emissions Airheaterresponsibleforatleast10%ofaunit sthermalefficiency Excessiveleakagecandeterioratenetuniteff iciencyaswellasreducepowergeneration AirHeaterPerformancecorrelatesdirectlywi thexcessCO2emissionsDesign Considerations(5) Key Points: Reduction Savings & TransferAir SideFlue Gas SideLeakage OverviewBypassSealsRadialSealsBypassSeal sAir Heater Leakage Majordrawbackofregenerativeairheater Undesiredleakageinherenttodesign Difficulttoseal InherentthermaldistortionCold end of RotorLeakage Path (HOT)

6 Hot End of RotorThermal Turn-downBlue = Cold Condition of RotorYellow = Hot Condition of RotorLeakage Solutions Replaceoriginalsealswithnewerhighperform anceradialseals Reinforcecircumferential/bypasssealsOrig inal Style Radial Seal DesignLeakage SolutionsDuraMaxTMRadial SealLeakage SolutionsContinuous Contact DURAMAX Seal (before & after sector plate contact)DuraMaxTMRadial SealAir FlowOEM Circ/Bypass SealLeakage SolutionsDURAFLEX Circumferential SealDuraMaxTMRadial SealOriginal Style Circumferential SealLeakage Reduction Case ,a500 MWcoalfiredplantinTexas, (AMPS)After (AMPS)3A ID FAN5724593B ID FAN6914683A FD FAN1311253B FD FAN12811323% Reduction in total fan amps with full contact radial sealsAir Heater Leakage020406080100020406080100 Power Consumption (%)Volumetric Flow (%)

7 Power Consumption vs Volumetric Flow Erosion/Abrasiveness AshVelocity Turbulence BasketElementTypeDesign Considerations Outer ring basket erosionHeavy gage NF-6 element (right) and Lighter gage typical hot end elementBasicerosionequation:nxxVMCE quationErosion ReducingAirHeaterOutletGasTemperature Recommendedairheatersoperatedatlowexitga stemp Coldendelementlayerisintendedassacrifici allayer IncreasedElementDepth Addedduringbasketreplacement Suppliercalculatetemperaturechanges EnvironmentalControlEquipmentRelationshi pstoConsider SCRP erformance ABSplugging ESPV elocity FGDP erformanceDesign Considerations