GENERATION

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GENERATION RENOVATION MODERNISATION
R. K. Jain Director (Technical) NTPC Limited
India Electricity 2006 11th May, 2006
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INDIAN POWER SECTOR

• Present Status
• Per capita consumption about 600 units per annum
• Installed Capacity 1,24,287 MW (April, 2006)
• Indias Projected Growth is 7-8 of GDP
  Projected power requirement by year 2012
• Per capita consumption 1000 units per annum
• Installed capacity over 2,00,000 MW
• Projected power requirement by year 2032
• Per capita consumption about 3000 units per annum
• Installed capacity about 6,00,000 to 7,00,000 MW
• However government of India is targeting double
  digit growth rate (10) and hence projections are
  likely to get revised upwards. The above
  necessitates
• Sustainable Large Capacity Addition Program at
  higher efficiency
• Upgrading fleet of Old Power Stations which are
  inefficient and have poor availability

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RM and Re-powering

• India has large number of old plants which are
  inefficient and running below design capacity
• Operating pressure and temperature of these old
  plants are lower and there is no reheating in
  some of the units
• Fuel available at present is different from what
  plant were designed for
• Some of the equipments have degraded
• Re-powering of these plant can quickly increase
  the power generation at relatively lower cost to
  consumer
• Re-powering can increase the cycle efficiency
  and hence reduce emission of greenhouse gases and
  pollutants

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RM and Re-powering

• RM will involve up gradation of milling system,
  APH, ESP, firing system etc and refurbishment of
  turbine, condenser, pressure parts, fans etc.
• Re-powering may involve following changes in
  plant design
• Adoption of higher steam parameters
• Introduction of topping cycle, old turbine may be
  retained in bottoming cycle.
• Bottoming turbine cycle efficiency improvement by
  adoption of high efficiency blade design
• Thus, Renovation Modernization of old existing
  units is an important tool for capacity
  enhancement, life extension and improvement in
  availability, reliability efficiency.
• Re-powering is challenging from technology as
  well as engineering point of view and offers
  huge potential for capacity addition
  augmentation.

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RATIONALE FOR RM

• New Plants costly.
• Longer gestation period of new plant.
• Limited availability of new site.
• Old plants can be renovated and Modernised at
  lower costs and life extension achieved.
• Availability and efficiency can be improved.
• Minimum environmental impact and RR problems for
  additional capacity.
• RM is an efficiency improvement tool and can
  improve generation by 30, environment impact by
  47 and efficiency by 23 (Source TERI)

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APPROACH TO RM

• Depends on
• Age of the plant, its existing condition and
  generic problems in its inherited design
• Operational History Problems being faced to run
  the plant
• Major modifications carried out from the original
  design condition
• Type of fuel its cost
• To cater to changes in the input / output of the
  plant coal, water, power evacuation
• Source of availability of inputs for future
• Cost of generation
• Cost of Technology

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WHY RM?

• To restore the original rated parameters by one
  to one replacements
• Improve performance by introduction of new
  technology.
• To upgrade the units to comply with fast changing
  Environmental / statutory standards / guidelines.
• To cater to technological obsolescence.
• Mega RM Technology Upgrades. This would aim at
  both leveraging the technological advancements,
  as well as driving down the Cost Of Generation,
  while factoring in the emerging business scenario
  to meet the market determined price for power

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Technological Options

• Clean Coal Technology
• To reduce SOX ,NOX CO2 Emissions
• Energy extraction from coal
• PC fired
• Fluidized bed combustion-Reduces Sox, NOx
  Emissions
• Indirect combustion through coal gasification
• Sub Critical Steam Parameters To Supercritical
  Parameters
• Increase in Pressure and temperature to
  like 250bar and 565 deg C
• Re-powering Technology
• For better efficiency, pollution control and
  less cost besides life extension

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Technological Options

• BOILER AUXILIARIES
• Replacement/Augmentation Of Pressure Parts.
• Retrofitting/ Modifications Air Pre Heater.
• Augmentation Of Milling System.
• Provision Of Flame Scanners, ignitors.
• Renovation of Draft System.
• Retrofitting Of ESPs.

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Technological Options

• TG AUXILIARIES
• Replacement of turbine blades with latest
  design.
• Modernization of condensors by change in type
  and material of tubes, augmenting with tube
  cleaning mechanism.
• Modernisation of power cycle equipments with
  more efficient pumps and improved Regenerative
  Heaters.
• Modification of air evacuation system with
  Vacuum pumps.

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Technological Options

• Gas Turbine
• Inlet Air Cooling system.
• Online Compressor Washing System
• Dry Low NOx Burners.
• Improved metallurgy for improved life of Hot
  Gas Path Components
• Improved efficiency
• Thermal Barrier Coatings of Blades Vanes.
• Improved major inspection intervals.
• Multi Fuel Firing

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Technological Options

• ELECTRICAL
• Up gradation of insulation of rotating machines
  from Class B to Class F.
• Up gradation of protection systems including
  diagnostic tools.
• Replacement of HV , EHV circuit breakers with SF6
  / Vacuum breakers for stability and to overcome
  obsolescence.
• CI
• Modernization of obsolete CI systems with
  State- of-Art-Technology.
• MISCELLANEOUS
• Augmentation Of CHP
• Augmentation Of Water Treatment Plants
• Introduction of Ash Water Re-circulation System.

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EXPECTED BENEFITS

• Increase in generation with improved performance
• Increase in safety, reliability, availability and
  operational flexibility
• Recapturing and/ or enhancing of unit capacity
• Extension of economic useful life by 15-20 years
  at comparatively lower capital cost
• Benefit by way of additional life
• Possibility of reducing cost of generation

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RM with Efficiency Increase
Increased power output resulting from efficiency
increase is free of fuel cost, free of
operational cost and free of emissions.
Rehabilitation
Rehabilitationw/o efficiency improvement
Fuel consumption per kWh
Rehabilitationwith efficiency improvement
0 20 40 years
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Mega RM

• Opting for higher steam pressure temperatures
  due to the availability of better material suited
  for these parameters improves heat rate and
  reliability
• Therefore, for old plant it may be worthwhile to
  consider mega RM schemes to bring these plants
  up to the contemporary state of the art plants in
  terms of efficiency and availability
• Typically, such mega RM may include up-rating,
  re-powering, higher process parameters resulting
  in enhanced efficiency, improved operational
  safety, reliability, advanced diagnostics etc.
• Mega RM typically consists of replacements of
  major equipment / systems of the plant at
  marginally higher cost longer shutdowns of the
  Units are inherent.

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Plans for RM

• The importance of RM was recognised by the
  Government of India way back in 1984 when PHASE-I
  RM Programme for 34 thermal power stations in
  the country was launched by the Central
  Electricity Authority as a Centrally Sponsored
  Scheme
• The Government of India has now accorded high
  priority to RM and Life Extension (LE) of old
  existing power plants.  The funds in the form of
  loan assistance at concessional interest rates
  are being provided by the Government through
  Power Finance Corporation (PFC) for RM works

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LIFE EXTENSION PROGRAMME DURING 10TH PLAN
S. No. PARTICULARS PARTICULARS
i) Number of thermal power stations 32
ii) Number of thermal units 106
iii) Estimated Cost Rs. 9200 crores
iv) Total Capacity involved 10,413 MW
v) Average PLF of the units before LE programme 49
vi) Anticipated PLF after completion. 75
vii) Anticipated additional generation/ annum 23700 MU
viii) Capacity expected after completion of LE works 10,747 MW
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RM PROGRAMME DURING 10TH PLAN
S.No. PARTICULARS PARTICULARS
i) Number of thermal power stations 13
ii) Number of thermal units 57
iii) Estimated Cost Rs.977 crores
iv) Total Capacity involved 14270 MW
S.No. PARTICULARS PARTICULARS
i) Number of thermal power stations 13
ii) Number of thermal units 57
iii) Estimated Cost Rs.977 crores
iv) Total Capacity involved 14270 MW
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11TH PLAN PROGRAMME
Sl. No. Particulars LEP RM
i) Number of thermal power stations 18 12
ii) Number of thermal units 34 31
iii) Estimated Cost Rs.6000 Crores Rs. 751 Crores
iv) Total capacity involved 6,000 MW 7,090 MW
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Thermal Units for RM in 10th and 11th Plan
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environmental control updating
availability improvement
efficiency upgrading
life extension
reduced fuel consumption
emissions within new norms
increased electrical output
improved reliability
operation free of restrictions
increased power output
reduced power generation cost
plus CDM BENEFITS
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Challenges in RM

• Limited Agencies for RM implementation in the
  country.
• Prohibitive cost of New Technologies impediment
  for introduction on wider scale.
• Unfavorable cost benefit analysis.
• RM activity to be linked with planned shut
  down.

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CDM Potential in RM

• Offers substantial CDM benefits through
  reduction/substitution of coal by
• Enhancement of efficiency by upgrading cycle
  parameters
• Co-firing of biomass with coal in coal fired
  furnaces

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RM SCENARIO IN NTPC

• Department formed in 1995 to Cater to RM of its
  own Stations
• RM is identified as Key Thrust Area as the many
  NTPC plants are crossing 1,00,000 operating hours
• RM of power plants of 10,799 MW capacity has
  been undertaken / in progress
• RM of power plants of 7,642 MW capacity is under
  planning
• The cost of RM may be up to Rs. 1.5 crores per
  MW depending on the life and condition of the
  plant.

• NTPC RM Project under CDM
• NTPC has taken up Badarpur RM project under CDM
• PIN is already prepared

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NTPCs EXPERIENCE SO FAR

• NTPC Talcher TPS (4x60 2x110 MW)
• RM Scope
• Extensive RLA and RM of SG and TG
• Retrofitting of existing ESP and addition of new
  fields
• Replacement of Static Excitation System, Power
  Control cables, replacement/ Retrofit of HT/LT
  Switchgear ,Augmentation of H2 plant
• Renovation of Cooling Towers
• Augmentation of Ash Handling
• New AWRS
• New Railway Siding inside the plant
• New Coal Handling Plant
• RM of Switchyard
• RM cost - Rs 1.50 Crs/MW
• PLF is around 88 as against 19 during takeover
  in Jun 1995.

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NTPCs EXPERIENCE SO FAR

• NTPC Tanda TPS (4x110 MW)
• RM Scope
• Extensive RLA and RM of SG and TG
• ESP Renovation
• Replacement of 6.6 KV 11 KV Switch gear
• Replacement of LT Switch Gear
• Renovation of Fire Fighting system
• New Stacker Reclaimer
• Additional DM Stream
• New DDCMIS for Units 12 and Upgradation of DAS
  for Unit 4
• Clarification of CW Make up water system
  Effluent Treatment plant
• RM cost - Rs 1.17 Crs/MW
• PLF is around 85 as against 21 at the time of
  takeover in Jan 2000

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EXPERIENCE OF TECHNOLOGY UPGRADES

• The 60 MW boilers at Talcher TPS have been
  redesigned taking into account the current coal
  characteristics. Milling system have been
  upgraded.
• 
  
• The 110 MW Units at Kothagudam have been upgraded
  to 120 MW by PPIL with a Turbine HR less than
  2000 Kcal/Kwh.
• 
  
• 110 MW Unit at AECO, Sabarmati has been upgraded
  to 120 MW by NASL with Turbine HR improvement of
  approximately 140 Kcal/Kwh.
• No. of 200/210 MW LMZ Units have been upgraded to
  225 MW in other countries with considerable
  improvement in Heat rate. These are now being
  planned in India.

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Governments Initiatives
Partnership in Excellence CEA has identified 26
stations which are operating at a PLF of less
than 40. These stations would have a
Partnership in Excellence with better
performing utilities, so as to achieve an
improvement in performance in the shortest
possible time. Subsidized funds would be made
available for this programme through PFC / REC.
The target is to achieve a PLF of 60 in two
years time. Role of NTPC NTPC has been entrusted
the responsibility of 14 stations out of the
identified 26. Site office has been opened at all
the 14 stations and experts have been posted at
all sites. The teams will aim to implement the
customized OM systems and will carry out one
cycle of overhauls.
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Governments Initiatives

• RM of SEB stations
• The 10th Plan envisaged RM of an installed
  capacity of 11,055 MW with a target of achieving
  75-80 PLF and 20 years of Life Extension.
• Role of NTPC
• NTPC has taken up consultancy services for a few
  of these stations.
• NTPC initially took up four power stations for
  RM/LE (Total 1332.5 MW).
• Subsequently another six stations (1512.5 MW)
  were taken up for RM / Life Extension (LE) /
  Re-commissioning / Residual Life Assessment (RLA)
  
• Funds being provided by PFC / REC

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APDP-RM
Highlights of Achievement
Proj. PLF bef. PLF aft. imp. in PLF SOC bef. SOC aft. imp. in SOC APC bef. APC aft. imp. in APC
CTPS 3x140 MW 23.97 72.66 203.13 28.60 0.80 97.20 22.30 11.43 48.75
DTPS 1x140 MW 36.78 65.41 77.84 5.28 1.88 64.40 12.59 9.88 21.52
GTPS 2x210 MW 45.00 84.00 93.19 3.00 0.70 76.67 12.40 10.23 17.50
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International Best Practices in RM

• Internationally, RM program are focused on
  leveraging technological developments in various
  fields to upgrade candidate plants bring them
  at par with contemporary machines
• International best practices range from
  one-to-one replacements to Mega RM
• In USA and other advanced countries utilities
  have largely gone for Mega RM because of the age
  of their units rapid changes in their business
  environment which required them to remain
  competitive and efficient
• Hence, Mega RM schemes such as up-gradation of
  process parameters, improved balding in turbines,
  Re-powering, even installing machines of higher
  capacity on the same footprint were adopted

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Case Study of a German Power Plant

• Improvement of efficiency and environmental
  conditions by retrofitting the units
• This was mainly achieved due to using low NOx
  burners in boiler, redesigning of LP turbine and
  cooling tower modernisation
• The emission levels of the units was reduced
  drastically due to use of low NOx burners,
  installing Flue Gas Desulfurification plant and
  optimisation of operation of ESP
• Flue gas discharge through cooling towers,
  automatic concrete cutter for existing chimneys

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Conclusion

• Implementation of the RM Schemes has benefited
  the stations by way of
• Overcoming Technological obsolescence.
• Low cost capacity addition
• Extending the life of equipment / components.
• Complying with Statutory and Environmental Norms
• Sustaining availability and improved performance
• There is huge potential in India for RM
  activities because of large number of old plants
  which are inefficient and running below design
  capacity
• RM to be planned in advance before major
  deterioration or breakdown of unit
• Urgent need to enhance manufacturing capacity to
  handle load of RM / Creation of new
  manufacturing base

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