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super critical power plant

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Super critical power plants operate above the critical point where there is no distinction between liquid and gas phases. They have higher efficiencies of around 45-47% compared to 38% for subcritical plants due to higher turbine inlet temperatures and pressures above 240 atm. Once-through boilers without drums are better suited for supercritical conditions as they allow forced circulation through all sections compared to drum-type boilers. Super critical plants improve efficiency but have higher capital costs.

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Super critical power plant BY SRIDURGA 08761A0351
contents  Introduction  Critical condition  Super critical parameters  Necessity  Comparison of sub critical and super critical plants  Types of boilers  Drum type boiler  Once through boiler  Advantages of once through  Conclusion
What is super critical power plant??? The power plant which operates above the critical condition is a ”SUPER CRITICAL POWER PLANT”
Definition of critical Condition CRITICAL CONDITION IS THERMODYNAMIC EXPRESSION DESCRIBING THE STATE OF A SUBSTANCE BEYOND WHICH THERE IS NO CLEAR DISTINCTION BETWEEN THE LIQUID AND GASEOUS PHASE.
super critical power plant
WHY ADVANCED SUPERCRITICAL? • Efficiency of the Rankine Cycle increases with increasing Turbine inlet Temperature and Pressure • Cycle efficiency of typical sub-critical plant is 38% whereas today’s supercritical technology increases this to around 45-47%
super critical power plant
super critical power plant
super critical power plant
Sub-Critical vs Super Critical Description Sub Critical Super Critical Full Load Pressure <190 atm >240 atm Flow in Water wall 2-Phase 1-Phase Cycle efficiency Base + 2 - 3 % Approx Fuel saving Base +8 - 10 % Approx Boiler weight Base + 10 % Stages of reheat 1 2 Preferred
Types of boilers  Drum type  Once-through type
Design Types NATURAL CONTROLLED STEAM DRUM TO SUPERHEATER ECON. CIRC. PUMP FURNACE WALLS ONCE THROUGH SEPARATOR • Natural circulation - well suited for < 175 kg/cm2 ECON. • Controlled circulation - optimum solution for reliable high-pressure subcritical operation • Once-through technology CIRC. PUMP • Suitable for sub and supercritical cycles DISTRIB. HEADER
Drum type boiler  Natural Circulation Boiler Circulation through water walls by thermo-siphon effect  Controlled Circulation Boiler At higher operating pressures (just below critical pressure levels), thermo-siphon effect supplemented by pumps to ensure safety of furnace wall tubes. Super Critical Boilers
Drum type boiler  Steam generation essentially takes place in furnace water walls  Fixed evaporation end point - the drum  Steam -water separation takes place in the drum  Separated water mixed with incoming feed water and fed back to water wall lower drum by means of boiler water circulating pumps (BWCPs). Super Critical Boilers
Once Through Boiler-Concept Once through system Super Critical Boilers
Once Through Boiler  Once -through forced flow through all sections of boiler (economizer, water walls & super heater)  Feed pump provides the driving head  Suitable for sub critical & super critical pressures Super Critical Boilers
Once-thru Boiler Major differences from Drum type boiler :  Evaporator system  Low load circulation system  Separator
Once - thru Boiler Low load circulation system :  The excess flow over the once-thru flow separated in separator .  Recirculated back to the boiler directly by the dedicated circulating pump.
LOW LOAD SYSTEM WITH CIRCIRCULATION PUMP
Once -thru Boiler Separator :  Separates steam and water during the circulating mode operation  Runs dry in once through flow mode.  Smaller in size compared to drum in a drum type boiler
Once -through Boiler Advantages :-  Better suited for sliding pressure operation  Steam temperature can be maintained over wider load range under sliding pressure  Conservation of fuel resources.  Shorter start up time  Improvement in Efficiency
conclusion Super critical power plants are the efficient plants to produce greater out put although it has some drawbacks ….
super critical power plant

More Related Content

super critical power plant

  • 1. Super critical power plant BY SRIDURGA 08761A0351
  • 2. contents  Introduction  Critical condition  Super critical parameters  Necessity  Comparison of sub critical and super critical plants  Types of boilers  Drum type boiler  Once through boiler  Advantages of once through  Conclusion
  • 3. What is super critical power plant??? The power plant which operates above the critical condition is a ”SUPER CRITICAL POWER PLANT”
  • 4. Definition of critical Condition CRITICAL CONDITION IS THERMODYNAMIC EXPRESSION DESCRIBING THE STATE OF A SUBSTANCE BEYOND WHICH THERE IS NO CLEAR DISTINCTION BETWEEN THE LIQUID AND GASEOUS PHASE.
  • 6. WHY ADVANCED SUPERCRITICAL? • Efficiency of the Rankine Cycle increases with increasing Turbine inlet Temperature and Pressure • Cycle efficiency of typical sub-critical plant is 38% whereas today’s supercritical technology increases this to around 45-47%
  • 10. Sub-Critical vs Super Critical Description Sub Critical Super Critical Full Load Pressure <190 atm >240 atm Flow in Water wall 2-Phase 1-Phase Cycle efficiency Base + 2 - 3 % Approx Fuel saving Base +8 - 10 % Approx Boiler weight Base + 10 % Stages of reheat 1 2 Preferred
  • 11. Types of boilers  Drum type  Once-through type
  • 12. Design Types NATURAL CONTROLLED STEAM DRUM TO SUPERHEATER ECON. CIRC. PUMP FURNACE WALLS ONCE THROUGH SEPARATOR • Natural circulation - well suited for < 175 kg/cm2 ECON. • Controlled circulation - optimum solution for reliable high-pressure subcritical operation • Once-through technology CIRC. PUMP • Suitable for sub and supercritical cycles DISTRIB. HEADER
  • 13. Drum type boiler  Natural Circulation Boiler Circulation through water walls by thermo-siphon effect  Controlled Circulation Boiler At higher operating pressures (just below critical pressure levels), thermo-siphon effect supplemented by pumps to ensure safety of furnace wall tubes. Super Critical Boilers
  • 14. Drum type boiler  Steam generation essentially takes place in furnace water walls  Fixed evaporation end point - the drum  Steam -water separation takes place in the drum  Separated water mixed with incoming feed water and fed back to water wall lower drum by means of boiler water circulating pumps (BWCPs). Super Critical Boilers
  • 15. Once Through Boiler-Concept Once through system Super Critical Boilers
  • 16. Once Through Boiler  Once -through forced flow through all sections of boiler (economizer, water walls & super heater)  Feed pump provides the driving head  Suitable for sub critical & super critical pressures Super Critical Boilers
  • 17. Once-thru Boiler Major differences from Drum type boiler :  Evaporator system  Low load circulation system  Separator
  • 18. Once - thru Boiler Low load circulation system :  The excess flow over the once-thru flow separated in separator .  Recirculated back to the boiler directly by the dedicated circulating pump.
  • 19. LOW LOAD SYSTEM WITH CIRCIRCULATION PUMP
  • 20. Once -thru Boiler Separator :  Separates steam and water during the circulating mode operation  Runs dry in once through flow mode.  Smaller in size compared to drum in a drum type boiler
  • 21. Once -through Boiler Advantages :-  Better suited for sliding pressure operation  Steam temperature can be maintained over wider load range under sliding pressure  Conservation of fuel resources.  Shorter start up time  Improvement in Efficiency
  • 22. conclusion Super critical power plants are the efficient plants to produce greater out put although it has some drawbacks ….