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Super Critical TechnologyIn NTPC India– A brief overview

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Presentation Outline

A Brief Introduction to Indian Power Scenario / NTPC

Super Critical Technology in NTPC

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Currently India has Power Generating Capacity of about 127,925 MW

Generating Capacity (MW)Thermal 84,024 66 %

Hydro 33,810 26 %

Nuclear 3,900 3 %Renewable 6,191 5 %TOTAL 127,925* 100.0%

Source: Ministry of Power, GOI

Coal 69,408 82.5%

Gas 13,582 16.1%

Diesel 1,202 1.4%

Thermal 84,024 100.0%

*Excluding Captive generation capacity of appx. 15000 MW

Thermal:Fuel Mix (MW)

Central Sector 32%

State Sector 56%

Private Sector 12%

(70,821 MW)

(41,673 MW)(15,431 MW)

About 88% of Capacity is owned by Central/State Governments

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A Brief Introduction to NTPC The largest power generation company in India

under Central Government Current installed capacity – 29,144 MW 18 coal based and 8 gas based power plants Setting up hydro power plants, developing coal

mines for captive use, and exploring oil / gas blocks in consortium with partners

Subsidiary & JV companies for taking up power generation, trading, and distribution business and for setting up of small hydro plants

Setting up coal based power plant in Srilanka

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A Brief Introduction to NTPC

FORWARD INTEGRATION

LATERAL INTEGRATION

RELATED DIVERSIFICATION

• HYDEL POWER ~9,000 MW BY 2017

• NUCLEAR POWER 2000 MW BY 2017

• RENEWABLES~1000 MW BY 2017

• R&M OF POWER STATIONS

• JV FOR CAPTIVE POWER

• POWER TRADING

• POWER DISTRIBUTION

• SIX COAL MINE BLOCKS (~47 MTPA CAP.) ALLOCATED

• ONE OIL/GAS BLOCK ALLOCATED.

• GLOBALISATION

SETTING UP OF POWER PLANTS ABROAD

INTERNATIONAL CONSULTANCY

• SECTORAL SUPPORT•PIE •APDRP•RURAL ELECTRIFICATION•TRAINING UNDER DRUM

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Clean Coal Technologies in NTPC

New Technologies

Renewable

Environment Management

Efficiency Improvement

Green Power

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Clean Coal Technologies in NTPC

Mature Clean Coal Technologies Supercritical/Ultra Supercritical Circulating Fluidized Bed Combustion

Clean Coal Technologies under Development Integrated Gasification Combined Cycle

Environmental Impact Mitigation Technologies NOx,SOx and SPM control

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Clean Coal Technologies in NTPCSl No

Technology Efficiency Improvement

Environmentalbenefit

1 Super critical /USC Technology √ √

2 FBC Technologies √

3 IGCC √ √

4 Low NOx burners, Over Fire Air √

5 Environmental mitigation Technologies(ESP, DeNOx, DeSOx, Ash Utilization etc)

√

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Super Critical Technology will improve efficiency

6000C/6000C (eff = 39.9 %)

Base Efficiency=37.6 % (Gross, GCV)

5370C/5370C (eff = 38.2%)

5370C/5650C (eff = 38.5%)

5650C/5650C (eff = 38.8%)

6000C/6000C (eff = 39.4%)

Effic

ienc

y %

5370C / 5370C

170 246 316 MS Pressure Kg/cm2

5650C/5930C (eff = 39.1%)

Efficiency figures corresponds to boiler efficiency of 85% on GCV basis

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SUPERCRITICAL ADVANTAGES

Enhancements Plant efficiency 0.69% to 1.64% Fuel tolerance More tolerant to coal quality changes

Reductions Coal Consumption Ash production CO2

SO2

Nox Improvements Startup time Sliding Pressure Operation Load following capability

1.79% to 4.24%

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ENVIRONMENTAL ASPECTS

Reduction in CO2, SO2 and NOx between 1.79% to 4.24%

Reduction for 500 MW at 68.5% PLF per year is - CO2 78300 tons - SO2 365 tons - Nox 71 tons

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Implementation of Supercritical Technology NTPC

In 1999 NTPC appointed an International consultant “EPDC, Japan” to study for adoption of super critical technology in NTPC

EPDC evaluated supercritical technology from technical, economical and environmental point of view for Indian perspective.

EPDC recommended supercritical technology for India and suggested following parameter.

Main steam pressure 246 kg/cm2, Temperature-538/566 deg C

NTPC implemented supercritical technology for two plants i.e Sipat-I (3X660MW) and Barh-I (3X660MW) with above parameter.

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Supercritical Technology Analysis

Technology - Mature and established Availability - Same as sub-critical Project Implementation- Essentially same as sub-critical O&M - By & large same as sub-critical Reduced Environmental Impact Most preferred parameters- 246 Kg/cm2-538oC/566oC Materials proven and already in use Indigenous Supplier of Supercritical Technology are

under developing stage.

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SUPERCRITICAL VS SUBCRITICALMAJOR DESIGN DIFFERENCE

Boiler- Once Through instead of drum type and use of superior material in certain pressure parts

Piping- Reduced diameter. Superior Material. Turbine- Increase in thickness of various parts to suit higher

parameters Feed Heaters-Increased thickness of tubes, water boxes and tube

plate BFP-Increased motor rating. Higher thickness of certain parts Boiler Control- Change in philosophy Water Chemistry- No blow down. 100% flow CPU. Different chemistry

control. No new superior material is used. Only the quantity of superior

material increases.

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Super Critical Technology - Efficiency Improvements Sub - critical units Super - critical units

Old Recent Plant-I Plant-II Plant-IIIUnit Size 500 MW 500 MW 660 MW 660 MW 660 MWMS Pressure kg/cm2 170 170 247 247 247

MS Steam Temp(O C) 537 537 537 537 565

RH Steam Temp (O C) 537 565 565 565 593

Gross Efficiency (HHV) % 38.00 38.26 38.84 39.14 39.96

Plant Turbine Heat Rate CO2 Emission / MW SO2 Emission / MW

500 MW(170 bar/537 C/537 C)

BASE BASE BASE

500 MW(170 bar/537 C/565 C)

0.7% 0.7 % 0.7 %

660 MW (246 bar/537 C/565 C)

2.6% 2.6 % 2.6 %

660 MW(246 bar/565 C/593 C)

5.1% 5.1 % 5.1 %

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NTPC is adopting Super Critical Technology

NTPC adopted supercritical technology for unit size over 500 MW insteps as under:

PLANTS IN ADVANCE STAGE OF CONSTRUCTION

3 x 660 MW Sipat STPP Stage-I

3 x 660 MW Barh STPP Stage-I

UPCOMING PLANTS

Barh-II, Bihar – 2x660 MW (Order Placed)

North Karanpura, Jharkhand – 3x660 MW

Darlipali, Orissa – 4x800 MW

Lara, Chattisgarh – 5x800 MW

Cheyyur, Tamilnadu – 3x800 MW

Marakanam, Tamilnadu – 4x800 MW

Tanda-II, Uttar Pradesh - 2x660 MW

Meja, Uttar Pradesh - 2x660 MW

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Heat Rate Improvement Efforts in NTPC

P = 150 ataMST = 537RHT = 537)

P = 170 ataMST = 537RHT = 537)

P = 170 ataMST = 537RHT = 537

P = 170 ataMST = 537RHT = 565

P = 247 ataMST = 537RHT = 565

P = 280 ataMST = 600RHT = 620)

P = 247 ataMST = 565RHT = 593

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

200 LMZ(1978)

200 KWU(1979)

500 KWU(1982)

500 KWUMod

(1998)

500 HighRH (2006)

660 SC(2004)

660/800SC (2008)

660/800USC

(2012)

HR

Imp

rove

men

t (%

)

P = 130 ataMST = 537RHT = 537

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Vacuum

Un-burnt Carbon Loss

LCV /GCV

39.0%

39.8%

40.2%

42.6%

Impact of Local Conditions on Reported Efficiency

9% over base

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Type Supercritical, suitable for variable pressure operation with spiral or rifled/plain water wall tubing

Tower type or two pass type

Rating Flow (T/Hr) Temperature Deg C Pressure Kg/Cm2(a)

At SH Outlet 2225 540 256

At RH Outlet 1740 568 52.0

Flue gas temperature at air-heater outlet- 125 Deg C

Fuel GCV range 3000 to 4000 Kcal/kg with 10-16% moisture and 32 to 48% ash

Start up system

Start up system with one no. circulating pump is with alternate drain flow to condenser through flash tank .

Salient Features of the Steam Generator

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Boiler Pressure Parts MaterialUp to 400 Deg C Carbon steel to ASME A-106 Gr. B/C or SA

210C or equivalentUp to & including 550 deg C

Alloy steel to ASME SA-335:P-11/P-12/P-22/P-23; ASME SA-213:T-11/T-12/T-22/T-23 or equivalent.

Up to & including 605 deg C

Alloy steel to ASME SA-213:T-91/T-92 and ASME SA-335:P91 or approved equivalent.

Above 605 Deg C Austenitic stainless steel, SUPER 304H, TP 347H or approved equivalent.

Major Furnace Sizing Criteria Net Heat Input/Plan Area 4.75X106 Kcal/hr/m2 (Max)

Heat liberation rate 106920 Kcal/hr/m3(max

Burner zone heat release rate 1.36x106 kcal/hr/m2 (Max)

Heat input per burner 600X 105 kcal/hr (Max)

Furnace cooling factor 1.8X105 kcal/hr/m2(Max)

Furnace residence time 2.0 Sec(Min)

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Components Material246 ata /537 0 C

/5370 C246 ata /537 0 C/5650 C

246 ata /565 0 C / 5650 C

-- ata /600 0C / 6200 C

HP inner casing 15Cr1Mo1V 15Cr1Mo1V G-X12CrMoVNbN9-1 9-10% Cr Steel

HP stop and control valves

15Cr1Mo1V 15Cr1Mo1V G-X12CrMoVNbN9-1

IP inner casing 15Cr1Mo1V G-X12CrMoVNbN9-1 G-X12CrMoVNbN9-1 9-10% Cr Steel

IP stop and control valves 15Cr1Mo1V G-X12CrMoVNbN9-1 G-X12CrMoVNbN9-1

HP Rotor 25Cr1Mo1V 25Cr1Mo1V 25Cr1Mo1V 10% Cr Steel

IP Rotor 25Cr1Mo1V 25Cr1Mo1V 25Cr1Mo1V 10% Cr Steel

HPT Blades (Few initial stages)

18Cr11MoNiVNb 18Cr11MoNiVNb 18Cr11MoNiVNb

IPT Blades (Few initial stages)

18Cr11MoNiVNb 18Cr11MoNiVNb 18Cr11MoNiVNb

TURBINE COMPONENTS MATERIAL

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NEW MATERIAL

In addition to conventional material the following new materials are being adopted on recent-660MW supercritical units and to take care of higher temperature of steam parameters:

Super 304H SA-213 T23 SA-335 P23 SA-213 T92 SA-213 P92 SA 302 C

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Typical Tubing for 568 / 595 °C Steam Temperatures

OR AUSTENITIC

SUPER 304

Economiser

Primary RH

Primary SHFinal RH

Final SH

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Adoption of Clean Coal Technology: Conclusions

NTPC has already gone for adoption of higher size ( 660 MW)supercritical units and moving towards higher steam parameter forcoming projects.

Adoption of further higher size Ultra supercritical units with highersteam parameters for efficiency improvement is under study.

Detailed feasibility for adoption of IGCC technology for high ashIndian coal (For a demonstration plant of 100 MW capacity) isalready completed.

Increasing Operational Efficiency and introduction of reusableenergy sources

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Thank You