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TNEBOne of the best performing Power Utilities
• REVENUE COLLECTION EFFICIENCY IS AT 99%
• TRANSMISSION AND DISTRIBUTION LOSS IS LOW AT 18%
• MAXIMUM WINDMILL CAPACITY – 3456 MW
(4TH PLACE IN THE WORLD, 1ST PLACE IN INDIA)
• INCIDENCE OF POWER THEFT IS VERY LOW
• PLANT LOAD FACTOR OF THERMAL STATIONS ARE VERY HIGH
• ONE OF THE FEW STATES, WHICH DO NOT HAVE POWER CUTS
(courtesy:Power Line magazine, June-2007)
TNEB POWERING TAMIL NADU ’S PROGRESS
• Glorious Past• Dynamic Present• Promising Future
Over 50 Years (1957 – 2007 ), Tamil Nadu Electricity Board has powered the State of Tamil Nadu to become one of the most progressive States in our country in socio – economical aspects as well as in all the fronts (viz.,) Agriculture, Industrial Production and Service sectors.On this occasion of its GOLDEN JUBLEE on 1st July
2007, it reaffirms its, commitment for the sustained and fruitful services to the state of Tamil Nadu.
(courtesy:Power Line magazine, June-2007)
TNEB
• TNEB STEPPING IN THE GOLDEN JUBLEE YEAR ( 1957 – 2007 ) INSTALLED CAPACITY IN MW
HYDRO - THERMAL - GAS - WIND MILL - PURCHASE - TOTAL -
2174 2970 423 1361 4257
11185
INSTALLED CAPACITY IN MW
TOTAL 11185 MW
HYDRO
2174
THERMAL
2970GAS
423
CENTRAL
SHARE
2960
PRIVATE
SECTOR
1297
WIND
MILL
1361
INSTALLED THERMAL CAPACITY
STATION 1.Basin Bridge (Dismantled) 2.Ennore 3.Tuticorin 4.Mettur 5.North Chennai
NO OF UNITS
2 2 2 3 5 4 5
EACH UNIT MW 15 30
60 110 210 210 210
TOTAL MW
30 60
120 330 1050 840 630
YEAR 1953 1958 1970 1972 1979 1987 1994
PROPOSED THERMAL PROJECTSSTATION
North Chennai Metter Ennore Tutucorin
NO OF UNITS
1 1 1 2
CAPACITY MW
500
500 500 500
GAS / COMBINED CYCLE
STATION
BASIN BRIDGE
KOVIKALAPPAL
VALUTHUR
KUTTALAM
GAS
MW
4X30
70
60
64
STEAM
MW
-
37
35
37
TOTAL
MW
120
107
95
101
YEAR
1996
2001
2003
2004
PURCHASE OF POWERSTATION MADRAS ATOMIC POWER STATION (KALPAKKAM ) NEYVELI TS-I NEYVELI TS-II NEYVELI TS –I (EXPANSION)
NO OF UNITS
2
6 3 7 2
EACH UNIT MW 235
50 100 210 210
TOT MW
470
300 300 1470 420
YEAR
1983
1962 1967 1986 2003
INDEPENDENT POWER PROJECTS
STATIONGMR VASAVI (BB)
SAMALPATTI
PILLAIPERUMAL NALLUR
SAMAYA NALLUR
NEYVELI ZERO UNIT
ABAN POWER LTD
FUELNaphtha
Diesel
Gas /Naphtha
Diesel
Lignit
Gas
MW196
106
321
106
250
113
YEAR1998
2001
2001
2001
2002
2005
ATOMIC POWER STATIONS
STATION
MADRAS(Kalpakkam)
KAIGA
NO OFUNITS
2
2
EACHUNITMW235
220
TOTAL
470
440
YEAR
1983
2000
IS / ISO 9001:2000
CERTIFIED POWER PLANT
TAMIL NADU ELECTTRICITY BOARD
METTUR THERMAL POWER STATION
METTUR THERMAL POWER STATION
• INSTALLED CAPACITY
4 X 210 MW
• Mettur TPS is the one and
only inland thermal power
station of Tamil Nadu
Electricity Board.
• The station is situated in
the left flank of the Ellis
Surplus course of the
Stanley Reservoir,
Mettur Dam
Unit
No
Date of first
synchronisationDate of first coal firing
I 07.01.1987 25.04.1987
II 01.12.1987 30.12.1987
III 22.03.1989 10.06.1989
IV 27.03.1990 29.03.1990
INSTALLED CAPACITY 840 MW ( 4 X 210 MW )
METTUR TPS UNITS COMMISSIONING DATES
THERMAL POWER PLANT• THE PROCESS IN A THERMAL
POWER PLANT MAY BE BROADLY DIVEDED INTO THREE BLOCKS
1. STEAM GENERATION IN BOILER
2. ELECTRICITY GENERATION IN TURBO GENERATORS
3. ELECTRICITY TRANSMISSON THROUGH TRANSFORMERS & HT LINES
MAJOR EQUIPMENTS IN A THERMAL POWER PLANT
• BOILER & ITS AUXILRIES• TURBINE & ITS AUXILRIES• GENERATOR & ITS AUXILRIES• CONDENSER• FEED PUMP• WATER TREATMENT PLANT• COAL HANDLING PLANT• ASH HANDLING SYSTEM• COOLING WATER SYSTEM• CONTROL ROOM• SWITCH YARD AND ELECTRICAL LOAD
DESPATCHING
COAL HANDLING PLANTMAIN EQUIPMENTS
• WAGON TIPPLERS
• CONVEYORS
• PRIMARY CRUSHERS
• SECONDARY CRUSHERS
• COAL STOCK YARD
• STACKER CUM RECLAIMER MACHINES
COAL LINKAGE
• Mettur TPS is getting its coal supply from Mahanadhi Coal
fields, Orissa.
• Coal from Paradeep Port, Orissa is conveyed through ship to
Ennore Port and from there by Rail to Mettur.
• 4 Nos. Wagon tipplers have been erected to tip the coal
wagons.
• The coal is fed into the coal bunkers through mechanical
conveyor system.
• There are two streams of coal conveyors with 1500 T/hr
capacity each.
COAL LINKAGE TO MTPSTALCHAR COLLIERIES TO PARADEEP TALCHAR COLLIERIES TO PARADEEP
PORT PORT -- BY TRAINBY TRAINPARADEEP PORT TO CHENNAI PORT PARADEEP PORT TO CHENNAI PORT -- BY BY
SHIPSHIPCHENNAI PORT TO METTUR THERMAL CHENNAI PORT TO METTUR THERMAL
POWER STATION POWER STATION -- BY TRAINBY TRAIN
WAGON TIPPLER
PRIMARY CRUSHER
CAPACITY :1500 TPH
OUTPUT PRODUCT SIZE :150 mm
SCREEN DIA :4082mm
MOTOR :260KW
SCREEN PLATES :158 Nos
LIFTING SHELVES :40 NOS
SPECIAL BEAM RAIL :18 NOS
SCREEN RPM :13 RPM
PRIMARY CRUSHER
SECONDARY CRUSHER
• TYPE : RING TYPE GRANULATOR
2NOS IN ONE MACHINE
• CAPACITY : 850 MT/HR• OUT PUT SIZE : < 25MM
• DRIVE : ‘V’ BELT DRIVE WITH GUARD
• MOTOR : 1000 HP,1440 RPM
• CRUSHER ROTOR SPEED : 600 RPM• CRUSHER RINGS : 32 Nos TOOTHED, 30 Nos PLAIN
COAL STOCK YARD & STACKER CUM RECLAIMER MACHINE
� The daily requirement of coal for the Station is 14000 T
� There is a coal yard with a space to stack 4.5 lakh tones of coal which is sufficient to meet one month’s requirementof all the 4 Boilers
� There are two stacker-cum-reclaimers machines in the yard to stack the crushed coal and to retrieve the coal to the bunkers whenever necessary.
STACKER CUM RECLAIMING MACHINE
• CAPACITYSTACKING : 1500 MT/HR
RECLAIMING : 1000MT/HR• BUCKET WHEEL
SPEED : 5.42 RPMBUCKETS : 8 NOS
VOLUME : 600 LTRSCUTTING CIRCLE DIA : 6.5 MTRS
BOWL MILL
Bowl Mill Type : XRP 803with classifierX : Supply Frequency (50 cycles/sec)R : Founder’s Name (Raymond)P : Pressurized Mill80 : Diameter of Bowl in Inches3 : Number of rollersNo of Mills/Boiler : 6 NosBase Capacity : 39.68 T/HrMill Motor : 340 KW
6.6 KV 990
rpm
UTILITY BOILERS
Steam conditions used have been mainly sub-critical although
a significant number of plants were built during 1960s and
1970s with super-critical steam conditions.
From Non-RH Type, The Technology today has Advanced to
Double Reheat Type. However, the Preference has Come Down
Over The Years For Double Reheat.
Operating pressures have also increased to above 300
atmospheres. To achieve better efficiencies.
Boilers have been designed to take care of the deterioration in
coal quality over the years resulting in bigger furnaces, large
size pulverisers and large size auxiliaries.
INDUSTRIAL BOILERS
Unit sizes have grown in capacities from 10 t/h. to
300 t/h., pressure from 15 ata to 120 ata,
temperatures from 200oc to 530oc, burning various
types of fuels.
Industrial boilers are designed with bi-drums or
single drum depending on the pressure.
For paper plants, unit size of chemical recovery
boilers have increased to burn about 675 tons per
day of dry solids from 140 tons/day of dry solids.
• SUB-CRITICAL
• DRUM TYPE
• NATURAL CIRCULATION
• SINGLE RE-HEAT
• TILTING TANGENTIAL CORNER FIRED
• DRY BOTTOM
• BALANCED DRAFT
• DIRECT FIRED PULVERIZED COAL WITH BOWL MILL
• COAL IS THE PRIMARY FUEL & OIL IS USED AS SECONDARY FUEL
• THE FUEL FIRING IS DONE BY BURNERS FROM THE FOUR CORNERS OF THE FURNACE. THE POSITIONING OF THE GUNS ARE SO DESIGNED THAT THE FIRING OCCURS TANGENTIALLY
MAJOR CLASSIFICATION OF POWER BOILERS
MAIN EQUIPMENTS
BOILER
• The boilers of the Power
Station were supplied by
M/S B.H.E.L., Trichy.
Main Parameters
• Capacity :700 T/Hr
• Temperature : 540°C
• Pressure : 137 kg/cm2BOILER
BOILER CIRCUITS• WATER AND STEAM CIRCUIT
• AIR AND FLUE GAS CIRCUIT
• COAL AND ASH CIRCUIT(Supporting fuel
LDO & HFO)
• COOLING WATER CIRCUIT
FEED WATER TO STEAM
Economiser
LTSH
Platen SH
RH FINAL SH
Drum1 11 12 13 14 2 7 3L
3R
4R
4L
5
6
8
D
own
Come
rs
Furnace
Uprisers
Bottom Ring Header
EH I/L
EH O/L
LLCV
FLCV A
FLCV B
To SH / RHAttemperation
Feed Water
from BFP
Economiser Vent
Drum vents
E2 E1
WAT
ER
WA
LL
WAT
ER
WA
LL
9
10
SH attemperator
Steam to HPT inlet
RH attemperator Steam from HPT outlet
To IPT inlet
E
C
O
R
C
E
C
O
D
R
A
I
N
FLOW DUE TO DENSITY DIFFERENCE
CIRCULATION RATIO = TOTAL FEEDWATER FLOW THRO CIRCUIT
TOTAL STEAM GENERATED IN THE CIRCUIT
•WATER CIRCUIT Consists of
1. Economiser
2. Boiler Drum
3. Water Wall Tubes
STEAM GENERATOR
• Steam Generator covers the whole unit,
encompassing water wall tubes, super
heaters, air heaters and economiser
SCHEME OF STEAM GENERATION IN BOILER- Process of steam generation in boilers (Water pre-heating to the saturation temperature is done in an economizer, the formation of steam takes place in evaporating heating surfaces and steam superheating is carried out in a super-heater)
- In these process water in the economizer and steam in the super-heater come only once in contact with the heating surfaces
- The economizer offers hydraulic resistance to the motion of water, which must be overcome by provision of high head in the feed pump
- The pressure developed by the feed pump must exceed the pressureat the entry to the zone of steam generation by the magnitude of the hydraulic resistance of the economizer
- The motion of steam in the super-heater is due to pressure gradient between the zone of steam generation and the steam turbine
- The combined motion of water and steam in evaporating tubes which has to overcome the hydraulic resistance of these can be effected in various ways:
ECONOMISER
• Function:
Absorbing the flue gas temperature to heat
the feed water to its sensible heat.
• Arrangements:
– Staggered (fin or plain tube)
– In-line (plain)
ECONOMISER BANKS
Eco inter headers
REPLACEMENT OF ECONOMISER ASSEMBLIES
DRUM & ITS INTERNALS
Function:
• Separating the steam from steam water mixer and discharging it
• It houses all internals used for steam purification after being separated
DRUM INTERNALS
Turbo separators (100 Nos.)
Screen Dryers
Economizers feed pipes (2 Nos.)
Continuous Blow Down(CBD) collection pipe
Emergency Blow Down(EBD) pipe
Phosphate dosing pipes
BOILER DRUM WITH OPENING FOR RISERS
OPENING OPENING OPENING OPENING
FOR RISERFOR RISERFOR RISERFOR RISER
DRUM
Water Wall TubesWater Wall TubesWater Wall TubesWater Wall Tubes
FUNCTION: • It forms the furnace wall eliminating exposed
refractory surfaces.• heating & evaporating the feed water supplied to
the boiler from economizer.• It consists of vertical tubes connected at top &
bottom headers.• 50% of the heat is absorbed by water wall by
radiation
WATER WALL PANEL TUBES
WATER WALL TUBES
FLAME
Combustion in Tangential Corner Firing
Furnace
• The furnace pressure in the boilers is maintained by
the use of both forced draught fans and induced
draught fans.
• The circulation of water is natural, i.e. from the drum
through the down comers and then through the
upraises to the water walls .
• As the water flows down through the down comers
and fills the water walls, due to the firing in the
furnace it gets converted into steam and rises due to
lesser density.
OPERATION & MAINTENANCE
STEAM CIRCULATION SYSTEM
This system consists of
– Riser tubes
– Super-heaters
– Re-heater &
– De-super heaters etc.,
• Riser is a tube through which water & steam
mixture pass from an upper water headers to
drum.
SUPER HEATERS
Classified according to the position or heat received from flue
gas:
- Positioning of Super heater: Mainly depends on steam parameters and
the arrangements of evaporating tubes.
- SH coil ends are welded to round-section headers.
- SH tubes are bent into coils with a bending radius of not less than 1.9d.
- Multi-pass coils are employed in high-pressure boilers.
- With multi-pass coils, there may be not enough places on a header for
welding the tube ends. Furthermore the header wall may be weakened.
- Depending on the direction of flows of steam and gas SH may be parallel
flow, counter flow or mixed flow.
- A counter flow SH develops the highest temperature gradient between steam and gas, which makes it possible to diminish the heating surface
area and metal used for fabrication.
RE-HEATER
• Steam after expansion in HP turbine is heated to
the rated temp 540 °C at constant pressure.• It consists of pendant assemblies and placed in
medium temperature region.
• It consists of CRH, HRH lines, Desuperheating
and safety valves.
BOILER TUBE LENGTH & AREA
• WATER WALL - 21.21 KM
• ECONOMISER - 19.5 KM
• LTSH - 37.29 KM
• PSH - 10.6 KM
• FSH - 9.9 KM
• SCW - 13.1 KM
• RE-HEATER - 26.1 KM
• TOTAL - 137.62 KM
FANS
• A fan continuously moves mass of air, gas or vapour at the desired velocity by the action of its rotor.
• For achieving this objective there is a slight increase in the gas pressure across the fan rotor.
• However, the main aim of a fan is to move a gas without an appreciable increase in pressure.
PRIMARY AIR FANS (PA FAN)
• The purpose of primary fans is to provide air that is used
to transport the pulverized coal from the mills and also to
warm up the coal to remove any moisture content that
might present in the coal.
• The primary air flowing out of PA fan is divided into 2
portions, one portion enters the regenerative air pre-
heater and comes out as hot air,while the 2nd portion is
cold air and both sent to the mill.Depending upon the
temp.requirement of the coal at mill outlet the flow of
primary air is controlled by dampers.
OPERATION & MAINTENANCE
PA FAN-SPECIFICATIONType : NDV 22 TIEFSTACKND – Radial fanV – Single suction simply supported fan22 – Nominal Diameter of Impeller in dmTIEFSTACK – Type of impeller• Capacity : 1250 KW• Fan make :BHEL• Flow : 70 m3 / s• Speed :1480 RPM• Discharge Pr. : 1210 mmwc• Regulation : Inlet Damper Control• Direction : Clock wise from MNDE• Bearings : Journal Bearings• Lubrication : FDE - Forced lubrication
: FNDE - Sump lubrication• No. of fans : 2 Nos.in parallel
BOILER AUXILIARIES
FORCED DRAUGHT FANS (FD FAN)
• The main function of forced draught fan is to provide air for
combustion in addition to the air supplied by the primary air
fan.The air from the FD fans known as secondary air, is supplied
to the furnace through regenerative air pre-heater, wind box and
finally through secondary air damper controls.
• Two FD fans are provided for each Boiler
• It supplies secondary air to furnace for complete combustion of fuel for more than stochiometric ratio 4%
• It also supplies inlet air to scanner air fan for scanners cooling and oil guns cooling
OPERATION & MAINTENANCE
SPECIFICATIONTYPE : AN 18 e 6AN - AXIAL NON PROFILED BLADES18 - NOMINAL DIAMETER OF IMPELLER IN DMe6 - TYPE OF DIFFUSER• Capacity : 1250 KW
� Flow : 132.2 m3 / s
� Discharge Pr. : 665 mmwc
� Speed : 1480 RPM
� Regulation : Inlet Guide Vane Control
� Direction : Counter Clock wise from MNDE
� Fan make : BHEL
� Bearings : Anti friction Bearings
� Lubrication : Grease lubrication
� No. of fans : 2 Nos.in parallel
INDUCED DRAFT FAN
• It induces the exhaust flue gas through chimney to atmosphere• It controls the balanced draft system• VARIABLE SPEED HYDRAULIC COUPLING• It supports ID fan motor to overcome its initial torque• It regulates the speed of ID fan as per unit load• SPECIFICATION OF HYDRAULIC COUPLINGType : 1150 SVNL 21 – 18.5 TWorking oil pr. - 16 barLub oil pr. - 0.3 to 0.6 barPrimary coupling - HBK 180Secondary coupling - SBLK 180Motor Speed - 740 rpmFull load slippage - 3.8 %Max output speed - 711 rpm
INDUCED DRAFT FAN SPECIFICATIONType : NDZV 31 SIDORND - Radial fanZV - Double suction simply supported fan31 - Nominal Diameter of impeller in dmSIDOR - Type of impeller• Capacity : 1500 KW• Flow : 230 m3 / s• Discharge pr. : 400 mmwc• Variable speed : 710 RPM max• Regulation : Variable speed Hydraulic coupling (VOITH make)• Direction : Counter Clock wise from MNDE• Fan make : BHEL• Bearings : Journal bearings• Lubrication : Sump lubrication• No. of fans : 2 Nos.in parallel
Most popular design is Two-pass.
- Because, fuel is supplied and gases are removed at
the bottom which is convenient for the removal of liquid
slag.
- Draft fans are mounted on the zero level so that their
vibration is not transferred to the boiler structure
Disadvantages:
1. The heating of convective surfaces and the
concentration of ash over the cross section of the
convective shaft may be uneven because the gases are
turned by 180 deg.
2. Convective shaft and second-pass pressure parts
erosion is more due to gas direction.
INDUCED DRAUGHT FAN
• The Induced Draught Fans are provided to evacuate
the flue gas and to maintain vacuum inside the
furnace to ensure effective combustion.
• The ID fan is driven by a constant speed induction
motor. The speed variation of ID fan is effected using
hydraulic coupling. The oil used in the hydraulic
coupling is cooled by water which is circulated by a
separate pump.
OPERATION & MAINTENANCE
AIR POLLUTION• Life on earth, weather it is of human being, of
animal, or of vegetation, is affected by air pollution. One of prime causes for the air pollution is mushroom growth of industries the developing and developed countries. Thermal power stations which burn coal as fuel and handle huge quantum of ash, may greatly pollute the environment, unless otherwise the particulate matter content in the flue
gas is separated-out fully.• In order to restrict the emission within the limits,
thermal power stations are bound to upkeep there
ash precipitator in good condition .
TYPES OF PRECIPITATOR• Mechanical type of precipitators• Electrostatic precipitators• ADVANTAGES OF ESP• Low pressure drop in the flue gas stream,• Less power consumption• Easy control• Sustained high collection efficiency• Capacity to handle particles of all sizes• Easy maintenance.• BAPCON• B : BHEL• A : Advanced• P : Precipitator• CON : Controller
CORONA DISCHARGE
The emitting electrode being a wire of small diameter with radius of curvature, creates a high intensive electric field surrounding itself.The electron in the outer orbits of flue gas atoms which travel close to the electrodes gain sufficient energy by virtue of the high intensity electric field. When atoms collide with each other or with the surface of the emitting electrode, the outer orbit electrons acquire adequate energy to get themselves released from the bondage of these atoms. The electrons thus liberated, are accelerated towards the collecting plate due to the local electrical field.
WORKING PRINCIPLE OF ESP
WORKING PRINCIPLE OF ESP contd…
• As they move,they gain more energy and bombard on other atoms which results in liberation of more number of electrons.Moreover, the atoms which lose electrons, become positively charged and are attracted by negatively charged discharge electrodes . When they collide with these electrodes, they make enough radiation to ionise the gas molecules. Thus, some sort of chain reaction takes place, nearer to the discharge electrodes resulting in a flood of electrons which starts moving towards the collecting electrodes.This process is known as the “corona discharge”.
ELECTRONNAUTRALGAS MOLECULEUPOSITIVE IONNEGATIVE IONDUST PARTICLEUNCHARGED
DUST PARTICLE
FIELD CHARGING
• While the electrons stream away from the discharge electrodes, the encounter with flue gas molecules and dust particles.When gas molecules receives electrons they are ionised with negative charge and migrate towards the positive electrode, they get collected over dust particles which obstruct their way. The dust particles go on collecting the ionised gas molecule and once it has accumulated sufficient negative charge, they are attracted by the positively charged collecting electrodes.
SPECIFICATION
• NO. OF RECTIFIER : 24 Nos. / Boiler• NO. OF FIELDS : 24 Fields / Boiler• NO. OF HOPPERS : 48 Nos.• NO. OF COLLECTING
ELECTRODES : 5292 / Boiler• NO. OF EMMITING
ELECTRODES : 31104 / Boiler• NO. OF CRM MOTORS : 12 Nos./ Boiler• NO. OF ERM MOTORS : 24 Nos./ Boiler
SPECIFICATION• GAS FLOW RATE : 363.1 m3 / s at 145 0 C
• DUST CONCENTRATION : 51.18 g / Nm 3
• TYPE OF PRECIPITATOR :FAA-6X36-2X72125-2
• COLLECTION EFFICIENCY : 99.64 %
• PRESSURE DROP : 15 MMWC
• VELOCITY OF GAS : 1.0025 m / s
• TREATMENT TIME : 21.55 sec
• POLUTION LIMIT : 150 mg /Nm3
ASH DISPOSAL
• A dyke has been constructed across the Perumpallam valley over an area of 1268 acres.
• The dyke consists of Upper Ash Dyke, Lower Ash Dyke and Two settling ponds in series.
• The ash slurry is pumped into the dyke.Ash settles down and the water flows into the primary pond and then to the secondary pond from where clear water is let into the river Cauveri.
• The effluent water is tested for very high degree of purity in accordance with the standards fixed by TNPCB.
DRY ASH DISPOSAL THROUGH SILOS• 90% of the ash content in the coal is collected as dry ash
• MTPS got the National award for the second place in Dry
Fly Ash utilization for the year 2005-06
AIR PRE HEATER
IT PREHEATS THE PRIMARY & SECONDARY AIR FROM
THE WASTE EXHAUST FLUE GAS LEAVING AFTER THE ECONOMISER TO IMPROVE THE BOILER EFFICIENCY
SPECIFICATION OF REGENERATIVE( LJUNGSTORM TYPE ) APH
27 VIM (T) 1850 (2000)27 - Nominal diameter of APH in feetVI - Vertical InvertedM - Modular design(T) - Tri sector1850 - Heating element depth including 3 layers in mm2000 - Heating element depth with Future Element in mm
ADVANTAGE OF AIR HEATERIN ADDITION TO INCREASE IN BOILER EFFICIENCY THE OTHER ADVANTAGE
• STABILITY OF COMBUSTION IS IMPROVED BY USE OF HOT AIR.
• INTENSIFIED AND IMPROVED COMBUSTION.• PERMITTING TO BURN POOR QUALITY COAL.• INTENSIFIED COMBUSTION PERMITS FASTER
VARIATION AND FLUCTUATIONS.• HOT AIR CAN BE USED FOR DRYING THE COAL
AS WELL AS FOR TRANSPORTING THE PULVERIZED COAL TO BURNT.
GENERAL LAYOUT OF THERMAL POWER STATION
PSH
RH
LTSH
ECO
DRUM
STEAM GENERATOR
HP HEATERS
BOILER FEED PUMP
DEAERATOR
LP HEATERS
CONDENSER
CONDENSATE
EXTRACTION PUMP
GENERATOR
LPTSIPTHPT
SUPERHEATED STEAM TO
HPT
RE-HEATED STEAM TO IPT
STEAM TO LP
TURBINES
Steam to heater
TURBINE• Main technical data:Rated output (measured at generator terminals) : 210 MWRated main steam and reheat steam temperature : 535 °CRated main steam pressure : 130kgf/cm2Max. Steam Flow(at valve wide open) : 670 tons/hrNo. of heaters in regenerative feed water heating cycle: 8(including
Deaerator)No. of extraction lines : 7Final feed water temperature : 242 °COverall length of Turbine : 20307 mmOverall width of Turbine : 8530 mmTotal weight of Turbine : 560 TonsGeneral :-
The steam turbine of BHEL make is a condensing type, tandemcompound, three cylinder, horizontal, disc and diaphragm (impulse) type with nozzle governing. Turbine is coupled to directly driven A.C. Generator.
LMW-TURBINE
• The Turbo
Generators were
supplied by
M/s BHEL Hardwar.
• The turbine is a three
stage turbine.
• Speed of the
Turbine :3000 RPM
• Temperature : 535°C
MAIN EQUIPMENTS - TURBINE
TURBINES
TURBINE
HP TURBINE
No.Of STAGES: 12
IP TURBINE
No.Of STAGES:11
LP TURBINES
No.Of STAGES: 2 X 4
MAIN EQUIPMENTS OF TURBINE
• 1. Main Turbine.
• 2. Oil system.
• 3. Condenser
• 4. Cooling water system.
• 5. Hot well & Condensate system
• 6. HP Heaters & LP Heaters
• 7. Feed Water system
Feed water heaters
1. OPEN HEATERS:
bled steam is allowed to mix with feed water Deaerator is one of the open heater
2. CLOSED HEATERS: (steam is not allowed to mix with water)
• Feed water flows through the tubes in the heater and the bled steam condenses on the outside of the tubes in the shell.
• The condensate sometimes called HEATER DRIP, then passes through the next lower pressure heater
• High pressure & low pressure heaters
TG BEARINGS & OIL SYSTEM• Seven journal bearings. • Thrust bearing is located at HPT along with the journal bearing.• An oil system from turbine MOP or SOP provides lubrication
to the bearings. • During supply failure, DCLOP provides lubrication to the
bearings. • Jack Oil Pump(JOP) is used to lift the Turbine shaft for Barring
gear operation.• Main Oil Tank(MOT) is for storage of oil system, support JOP,
AC & DC Lube oil Pumps & Starting Oil Pump (SOP) and receive the drain oil from the bearings.
• Oil coolers are used to reduce the oil temp before admitting to the bearings.
• Oil vapour fan removes vapour in the oil.• Governing oil is supplied from Main Oil Pump (MOP)
/Starting Oil Pump(SOP)
WHY CONDENSER IS REQUIRED• The steam after doing work in LPT was converted into water in
Condenser and send back to the Boiler.• By recycling, the requirement of DM water & cost is reduced.
• Higher the condenser vacuum, higher the work done in the Turbine.• Act as a storage tank for CEP.
• Dissolved air and non condensable gases in the water was removed in the condenser.
• COOLING WATER SYSTEM• OBJECTIVE OF COOLING WATER :
a) To condense the steam from LP Turbine
b) To cool the plant auxiliary equipments.
c) To flush the ash hoppers.
SOURCE OF COOLING WATER :River water taken from the Cauvery river
How vacuum created in the condenser.
• When condensing the Exhaust steam in Condenser as water at a vacuum of – 0.9 ksc, 15,000 times volume reduction is taken place between steam and water.
• Due to this high reduction of volume while condensing, vacuum is created inside the Condenser.
• Initial vacuum was created by Steam Ejectors/ Vacuum pump.
• Air was sucked by Steam Ejectors/vacuum pump through the line taken off from the condenser.
CONDENSER DETAILS• Condenser is located beneath the LPT.
• The used up steam from LPT is directly sent to condenser for condensing the steam to water.
• Cooling water received from CWPH is passed thro’ the cooling tubes to condense the steam.
• A Vacuum around – 665 mmHg is maintained inside the condenser.
• The condensed water(condensate) is collected in the hotwell
• The condensate is pumped to De-aerator thro’ Low Pressure heaters (LPH) by CEP
• Loss in the system was make up at condenser.
CONDENSER (FRONT)
CONDENSER TUBES
(7810 tubes on each side)PARTING PLANE
AIR COOLING ZONE
HOT WELLCEP
CONDENSATE EXTRACTION PUMP (CEP)• Mainly used to pump out condensate from Hot well
to De-aerator through LP heaters.• It will maintain the De-aerator level .• Two nos. pump available out of which one pump is
standby. • Driven by Electrical Motor of 500 KW capacity• Develops a pressure of 20 Ksc• Multistage (5 stages) vertical Centrifugal pump of
Capacity 675 T/Hr.
BFP BOILER FEED PUMP • The main function of BFP is to supply feed water to Boiler drum which
is under a Pr. of 160 Kg/Cm2 and to maintain the drum level .• Each pump can deliver 400 T/Hr.
• Water from De-aerator at a pressure of 7 Kg is connected to BFP Booster pump suction line which develops 15 Kg/Cm2.
• There are 3 nos. BFP available out of which one pump is standby • No. of stages : 6
• Driven by a Electrical motor of 3500 KW rating thro a variable speed scoop coupling.
• Feed Water from BFP is passed through HP heaters to pickup heat before admitting into the Boiler via Economizer.
• Certain minimum water flow will be established thro’ RC lines when the water flow to Boiler drum is less.
• Hydraulic coupling is provided • a.) to decouple when the pump ceases.
b.) To save energy & c.) To vary the flow & Pr
HIGH PRESSURE HEATERS (HPH)• The F.W pumped by BFP passes thro’ HPH 5, 6 & 7 in the
tube side to pickup heat .
• Extraction from HP outlet CRH is used in HPH-6 at shell side.
• Extraction from IPT is used in HPH-5 in shell side.• The drain condensate is cascaded from HPH-7 to HPH-6,
HPH-6 to HPH-5 and then send to de-aerator.• Protection to isolate the HPH independently if the shell
level goes to Very high level to protect water entry into the turbine.
• The regenerative Feed Water Heaters increases the cycle efficiency
NUMBER
OF
PUMP
SETS
PROGRESS OF AGRICULTURE PUMPSETS
25659411769533440
12775011033556
15673171768052
1645329
805616681205
0
500000
1000000
1500000
2000000
1 2 3 4 5 6 7 8 9 10
PLAN PERIOD
1st 1951-56
2nd 1956-61
3rd 1961-66
4th 1969-74
5th 1974-78
6th 1980-85
7th 1985-90
8th 1992-97
9th 1997-02
10th 2002-07
GENERATOR
Make M/S BHEL
• Voltage : 15.75 KV
• Capacity : 210 MW
• Coolant : Hydrogen gas
MAIN EQUIPMENTS
Stator water in let and out let line
( turbine end)
EVACUVATION OF POWER AT METTUR TPS SWITCHYARD
Neutral
• HYDROGEN GAS COOLING SYSTEM ADVANTAGES OVER AIR
• The density is lowest of all gases and is ¼ of that of air– Lesser windage and friction loss due to less density
– Requires less fan power
– Increase in efficiency
• The heat transfer capacity of hydrogen is about twice that of air– Increase in pressure increase in out put
– For every 1.0 ksc pressure increase 0.5% increase out put
– But more pressure will increase the density of gas in turn will increase the windage loss
ADVANTAGES OVER AIR• High thermal conductivity and specific heat ensures
effective heat removal from heated surfaces ( approx. 10 times that of air)– Reduction of machine size
– Reduction of size of hydrogen coolers• The degradation of insulation process cannot occur in
hydrogen atmosphere– Dirt and moisture free atmoshphere– Increase in machine life
HYDROGEN GAS CIRCULATION
•The stator core and the rotor conductors are cooled by High purity of hydrogen gas•Hydrogen enters the generator casing through an axially – oriented distribution pipe at the top•The rotor fans circulate hydrogen over the end windings and through the stator core, while parallel flow passes through the rotor.
•Four hydrogen coolers are located horizontally inside the casing for cooling the hydrogen gas
•Regenerative heaters are provided for removing moisture from hydrogen gas.
Why Generators are cooled by Stator water ?
• Since , electron flow in a conductor in Zig Zagpath, conductor heats up
• If temperature increases, resistance value also increases, which in turn limits the voltage
• In order to increase the current carrying capacity of the conductors
• To reduce the degrading of stator coils and insulating materials
EVACUVATION OF POWER AT METTUR TPS
GOBI
INGUR
230 KV TUNNEL
DAM PH
SALEM 400 KV-I
SALEM 400 KV-II
METTUR AUTO SS
SINGARAPET
FEEDERS – 8 Nos.
15.75 KV
POWER TRANSFORMERGENERATOR
230 KV
INSTALLED CAPACITY Vs SUSTAINED DEMAND
PLAN
6090
615
8
657
8
6908
6908
6916
712
0
720
4
751
3
7924
8268 9
319
953
1
1003
1
367
6
394
8
436
0
442
4
487
5
491
8
5196
558
0
6290
668
7
695
7
722
8
747
3
8209
0
2000
4000
6000
8000
10000
12000
92-93 93-94 94-95 95-96 96-97 97-98 98-99 99-00 00-01 01-02 02-03 03-04 04-05 05-06Installed Capacity ( MW) Sustained Peak Demand(MW)
Though the installed capacity is more than the demand, actualgeneration is less due toi)Hydro Station are monsoon dependent and irrigation basedii)Statutory overhauling of Thermal & Hydro Units .
NUMBER
OF
TRANSFORMERS
PROGRESS OF DISTRIBUTION TRANSFORMERS
167120140860
11152284225
6366743666
37453173601000437730
50000
100000
150000
200000
1 2 3 4 5 6 7 8 9 10PLAN PERIOD
1st 1951-56
2nd 1956-61
3rd 1961-66
4th 1969-74
5th 1974-78
6th 1980-85
7th 1985-90
8th 1992-97
9th 1997-02
10th 2002-07
METTUR THERMAL POWER STATION-A JOURNEY TO EXCELLENCE
THE GOVT. OF INDIA’S MERITORIOUS PRODUCTIVITY REWARDS
&
GOLDEN SHIELDS FOR THE OUTSTANDING PERFORMANCESl.No Year Reward
1. 1992-93 Rs.15 Lakh & Certificate
2. 1993-94 Bronze medal
3. 1994-95 Bronze
4. 1995-96 Silver medal
5. 1996-97 Silver medal
6. 1997-98 Bronze medal
7. 1999-2K Silver medal
Sl.No Year Reward
8. 2000-01 Gold medal
9. 2001-02 Gold medal
10. 2002-03 Gold medal
11. 2003-04 Gold medal
12. 2004-05 Target achieved
13.14.
2005-062006-07
Target achieved
Target achieved
Some TNEB firsts
FIRST TO DEVELOP• Wind power in the country• A high head hydroelectric scheme (Pykara hydro station)
• Cascading-type hydroelectric station in a hill area (Kundah system)
• Cascading low-head barrage powerhouses across the Cauvery river
• Pumped storage hydro scheme to meet peak power demand (400 MW Kadambarai)
(courtesy:Power Line magazine, June-2007)
Some TNEB firsts• FIRST TO COMMISSION• Extra high voltage, gas-insulated substation in Chennai• Distribution control centre with SCADA in Chennai• 230 KV grid with a load despatch centre in Erode
FIRST TO INTRODUCE• RCC poles in LT and HT line work• Power line carrier communication in grid operation• Wireless communication system to attend to fuse-off calls
in Chennai• Complete rural electrification
(courtesy:Power Line magazine, June-2007)
BE HONEST AND BE FRANK TO BE ABLE TO SPEAK THE TRUTH
USEFUL POINTS TO IMPROVE YOUR “QUALITY OF LIFE ”
DO NOT EXPECT OTHERS TO DO WHAT YOU DO NOT WANT TO DOBE A WILLING STUDENT THROUGHOUT YOUR LIFELEARN EVERY DAYIF YOU DON’T KNOW, ASK
DO NOT PROCRASTINATE
KNOW SAFETY NO PAIN
NO SAFETY KNOW PAIN
Er.R.GABRIEL GERMANS, M.E., F.I.E.Chief Engineer / Mettur Thermal Power Station TNEB / Mettur Dam-6
