ULTRA SUPERCRITICAL - The McIlvaine Company by pengxuebo

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									ULTRA SUPERCRITICAL
Pulverized Coal-Fired Steam Generators
August 13, 2009
                                                       Introduction

     Q: What is Ultra Supercritical (USC)?
     A: Not universally defined, but generally can be
     considered to be >3800 psig and >1100 F final steam
     conditions
     Q: Why Consider Ultra Supercritical?
     A: Dramatic Improvement in Plant Efficiency
                   Economic Pressures – Fuel Prices
                   Environmental Pressures
                      Clean Air Act
                      Clear Skies
                      Local BACT
                      Future CO2
                   Social/Political Pressures
                   Quest for Permit
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August 13, 2009
                                                Introduction

                  CYCLE HEAT RATE IMPROVEMENT




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                                                            Operating Results

                                 Supercritical: Evolution
         Early Supercritical Units had problems
                 Lengthy start-ups
                 Poor load following flexibility
                 Poor availability
                 Slagging/fouling/corrosion
   Some of those problems not related to supercritical but
    other boiler evolution issues
   Most early design issues have been effectively addressed
    and availability has improved, though maintenance costs
    are relatively high
   Current supercritical designs in Europe and Japan have
    availability and maintenance commensurate with
    subcritical units
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August 13, 2009
                                                                Operating Results

         Availability of Subcritical versus Supercritical Units – N. America
                                   (Data from NERC 1982-1997)




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                                                     Operating Results

    Availability Data for Supercritical verses Subcritical Units (Europe)




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                                                                                     Design Criteria


   Size
             Current commercial range from 300-1100 MW

 Steam Conditions
             Trade off efficiency gains (fuel savings) vs. capital cost
             Example: Change from 1000/1000 to 1100/1100 results in 3-5% overall increase in plant cost

 Fuel
             More difficult fuels (often less expensive) require designs higher in capital costs

 Feedwater Temperature
             Affected by cycle design

 Operating Requirements
             Base load, load following, cycling, on-off peaking

 Emissions Limits
             Current and future, including CO2


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August 13, 2009
                                       Advanced Designs and Materials


      Recent Activities Assessing Ultra Supercritical Designs and
                               Materials
   DOE/NETL - Cost and Performance Baseline for Fossil Energy Plants – 2007
   EPRI – CoalFleet Guideline for Advanced Pulverized Coal Power Plants – 2008
   EPRI - Engineering and Economic Assessment of Ultra-Supercritical Pulverized
    Coal Power Plants for Near Term Development – Ongoing
   Thermie (Europe)
   Japanese Program
   U.S. - DOE and State of Ohio
   Shandong Technical Exchange – Henan Design Institute – Henan Province,
    PRC


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August 13, 2009
                                       Advanced Designs and Materials


                  Ultra Supercritical: Current State-of-the-Art


           Latest Units in Europe 4000 psig, 1105/1110 F
           China moving up to 3800 psig, 1120/1135 F
           Most aggressive unit in Japan 3950 psig, 1121/1153 F
           U.S. Market generally around 3700 psig, 1080/1080 F
           Most advanced U.S. plant in Engineering Phase at
            3800 psig, 1112/1135 F

           With advanced materials and careful design, Ultra
            Supercritical units have maintenance and availability
            similar to more recent standard supercritical units.
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August 13, 2009
                  Advanced Designs and Materials




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                                                   Advanced Design and Materials

Significant Issues with Ultra Supercritical Project Implementation
 Long term validation of materials
         ASME/ASTM Re-rating of materials: Grade 91, 92, 122, 23, etc.
         Creep-Rupture, exfoliation, corrosion resistance
    Fabrication
         Welding procedures, heat treatment, bending, etc.
    Construction
         Qualified crafts, qualification of procedures, tight Q/A
    Compatibility of valves, fittings and appurtenances
         Many shapes, valves, etc. not available in advanced materials



     Above issues present risks to project costs, schedule, and
    performance which are significant in comparison to standard
                subcritical or supercritical cycles.
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August 13, 2009
                                                                   Future Generation USC

             Increase steam conditions to further improve efficiency:
                   For typical US facility, efficiencies up to 48% (HHV) achievable
                   Benefits include:
                      − Reduced emissions (including CO2)
                      − Lower CO2 capture costs per MWh


             Materials for advanced boilers:


                                                AD700 Program
                      Current                     UltraGen II             UltraGen III

                  1150°F (630°C)                1295°F (700°C)           1400°F (760°C)

                   Ferritic Steels             Austenetic alloys          Nickel based
                                               and nickel based           super alloys
                                                 superalloys

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August 13, 2009
                                                                                                           Future Generation USC

       100,000 Creep-Rupture Stress for USC Boiler Materials




 P.J. Maiasz, I.G. Wright, J.P Shingeldecker, T.B. Gibbons, and R.R. Romanosky, “Defining the Materials Issues and Research for Ultra-Supercritical Steam Turbines,” Proceedings to the
 Fourth International Conference on Advances in Materials Technology for Fossil Power Plants (Hilton Head, SC, Oct. 25-28, 2004). ASM-International, Materials Park, OH, 2005.     13

August 13, 2009
                                           Future Generation USC


                  Beyond Advanced Steam Conditions

        Double Reheat
        Reduction of Boiler Exit Gas Temperature
        Low Level Exit Gas Heat Recovery
        Coal Drying
        Combustion Air Preheating
        Feedwater Heater External Desuperheater
        Multi-Pressure Condenser
        Maximizing Cooling Tower Performance
        Optimized Turbine Cycle for Ambient Conditions
        Variable Speed Drives

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August 13, 2009

								
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