Attachment.doc

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ACKNOWLEDGEMENT
We hereby take this opportunity to thanks NTPC Tanda for giving us this
opportunity to conduct our training in NTPC Tanda. We are grateful to
Shri S N Shukla (Supdt. TMD), for allowing us to conduct our training in
the Control and Instrumentation department. We are heartily indebted to
our project guide P S Rawat ( Engr. TMD) for providing us with detailed
in depth knowledge and very useful information about the process and
system used in the plant. His support was instrumental in our training
being fruitful. We are also thankful to the entire officer and staff of NTPC
Tanda for extending a helping hand whenever we need it.
DEEPAK VERMA

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CONTENT
S.No. Description Page No.
1 Brief description of Tanda thermal project 3
2 Production of electricity 5
3 Description of thermal plant 9
4 Basic cycle of a power plant 10
5 Control and instrumentation unit 11
6 Important equipment of plant 14
7 Future prospects of NTPC Tanda 31

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BRIEF DESCRIPTION OF TANDA THERMAL
PROJECT
Geographical location:-
The Tanda Thermal Power Project is located about 185kms from Lucknow.
It is nearly 55kms from Faizabad. The nearest rail ahead is Akhbarpur (now
called as Ambedkarnagar). The project lies in the Ambedkarnagar district
and is about 22kms from the nearest railway station.
The complete project is situated on the bank of Saryu River. The climate
conditions are quite favourable with greenery all around.
Features:-
● The plant has been designed by M/s. Desein
● The installed capacity is 4 X 110 MW
The water requirement of the station is met from the Saryu River through
Mehripur pumping Station constructed for feeding Mehripur Pump Canal.
The coal linkages for the station have been provided from North Karnpura &
BCCL. The power generation is evacuated through 220kV feeders connected
to Sultanpur (2 feeders), Basti & Gorakhpur (1 each) 220kV substations.
The total area of the power house including colony is 235 hectares and the
land for ash disposal is 170 hectares.
✓ The main plant equipments like boiler, turbine and generator have been
supplied by M/s BHEL
✓ Generator-transformer has been supplied M/s NGEF
✓ CHP(Coal Handling Plant) has been supplied by M/s TRF
✓ Cooling Towers by Paharapur Cooling Towers

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✓ C&I(Control & Instrumentation sets) have been supplied by M/s ILK
✓ DM(De-mineralized) plant has been set up by M/s. WATCO,
Hyderabad
The designed boiler efficiency, turbine heat rate and unit heat rate are 84.7%
and 2172.8kcal/kWh & 2565.3kcal/kWh respectively.
The designed HHV of coal is 3850kcal/kg and the boiler is designed to work
at worst quality of coal having HHV of 3400kcal/kg.
Tanda plant PLF:-

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2000 2006 2008
PRODUCTION OF ELECTRICITY
The means and steps involved in the production of electricity in a coal-fired
power station are described below.

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Coal handling plant:
The coal, brought to the station by train or other means, we use wagon tripler
for putting the coal on the conveying belt which consists of mechanical
equipment and motor to drive it. Coal travels from the coal handling plant by
conveyer belt to the coal bunkers. There are magnetic separator and magnet
detecting device placed at conveyer to remove the magnetic element coming
with coal and to indicate magnetic element by the two devices respectively.
Now the coal is collected at certain place which is called stacking, from
where it is fed to the pulverizing mills which grinds it as fine as face powder.
The finely powdered coal mixed with pre-heated air is then blown into the
boiler by fan called Primary Air Fan where it burns, more like a gas than as a
solid in convectional domestic or industrial grate, with additional amount of
air called secondary air supplied by Forced Draft Fan. As the coal has been
grounded so finely the resultant ash is also a fine powder. Some of this ash
binds together to form lumps which fall into the ash pits at the bottom of the
furnace. The water quenched ash from the bottom of the furnace is conveyed
to pits for subsequent disposal or sale. Most of ash, still in fine particles form
is carried out of the boiler to the precipitators as dust, where it is trapped by
electrodes charged with high voltage electricity. The dust is then conveyed
by water to disposal areas or to bunkers for sale while the cleaned flue gases
pass on through ID Fan to be discharged up the chimney.
Way of producing steam by the boiler:
Coal
Handling
Plant,
CHP
Switch
Gear &
Switch
Yard
Turbines &
Generators
Boil
ers
Electrostatic
Precipitator,
ESP

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Initially we maintain a certain temperature inside the boiler. We pass mixture
of oil and air which is ignited by igniter placed at the corner of the boiler. Oil
used in this purpose may be HSD, HFO and LSHS. After reaching a certain
temperature we pass powdered coal inside the boiler. This produces lots of
heat which helps in producing steam. The steam super-heated in further
tubes (Super Heater) and reaches a temperature about 540 degree centigrade
and about 135 kg per square centimetre pressure and then it passes to the
turbine where it is discharged through the nozzles on the turbine blades.
As the steam strikes on the turbine blades, shaft of the turbine gets
movement due to so it starts rotation and reaches a speed about 3000 rpm.
Then we control the speed of shaft by controlling the passes of powdered
coal to the boiler. The shaft of turbine is mechanically coupled with the shaft
of the generator due to so generator’ s shaft also rotates with a speed about
3000 rpm. The rotor is housed inside the stator having heavy coils of copper
bars in which electricity is produced through the movement of the magnetic
field created by movement of shaft i.e. rotor. The electricity passes from the
stator winding to the step-up transformer which increases its voltage so that
it can be transmitted efficiently over the power lines of the grid.
The steam which has given up its heat energy is changed back into water in
the condenser so that it is ready for re-use. The condenser contains many
kilometres of tubing through which the colder is constantly pumped. The
steam passing around the tubes looses the heat and is rapidly changed back
to water. But the two lots of water (i.e. boiler feed water & cooling water)
must NEVER MIX. The cooling water is drawn from the river, but the boiler
feed water must be absolutely pure, far purer than the water we drink, if it is
not to damage the boiler tubes.
To condense the large quantities of steam, huge and continuous volume of
cooling water is essential. In most of the power stations the same water is to
be used over and over again. So the heat which the water extracts from the
steam in the condenser is removed by pumping the water out to the cooling
towers. The cooling towers are simply concrete shells acting as huge

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chimneys creating a draught (natural/mechanically assisted by fans) of air.
The water is sprayed out at the top of towers and as it falls into the pond
beneath it is cooled by the upward draught of air. The cold water in the pond
is then circulated by pumps to the condensers. Inevitably, however, some of
the water is drawn upwards as vapours by the draught and it is this which
forms the familiar white clouds which emerge from the towers seen
sometimes.
Why bother to change steam from the turbine back into water if it has to be
heated up again immediately? The answer lies in heat law of physics which
states that the boiling point of water is related to pressure. The lower the
pressure, the lower the temperature at which water boils. The turbine
designer want as low boiling point of water as possible because he can only
utilize the energy of the steam – when the steam changes back into water he
can get NO more work out of it. So a condenser is built, which by rapidly
changing the steam back into water creates a vacuum. This vacuum results in
a much lower boiling point which, in turns, means he can continue getting
work out of the stem well below 100 degree Celsius at which it would
normally change into water.
DESCRIPTION OF THERMAL PLANT
The plant is in fact designed on the modern concept of unit system. Each of
the turbo-generator is connected to its individual steam generating plant. The
steam turbine has inlet steam pressure of about 130kg/cm2 and super heat
type with a reheat temperature of 540 0C. Regenerative feed heating with 8
stages heaters have been adopted. There are two high pressure feed water
heaters connected with the exhaust of the H.P. turbine and the second one
from an extraction of M.P. turbine.

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Constant pressure de-aeration is adopted for de-aeration and is fed from
auxiliary system header of the plant which maintains the de-aeration pressure
of 6kg/cm2 under all load conditions.
There are five low pressure heaters – two connected to the LP (Low
Pressure) turbine. The heat input from the grand steam condenser and the
ejector condenser is also recovered to improve the cycle efficiency. Drip
pump is also used to pump the drain from the 3rd LP (Low Pressure) heater
back to the condensate system. This also adds to the efficiency of the system.
Drains from various stages of steam turbine are treated so that the maximum
thermodynamics benefit is derived.
The plant is also provided with automatic control features. The operation of
the Coal Handling, Ash Handling, Water treatment Plant, River water Intake
pump is provided with remote as well as local manual control features to
cope with the requirements of such large units.
BASIC CYCLE OF A POWER PLANT
For proper functioning of a power plant, its working operation has been
divided into following main operation cycles.
✓ Steam cycle
✓ Feed water cycle
✓ Condensate water cycle
✓ Primary air cycle
✓ Flue gas cycle
✓ Secondary air cycle

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Steam cycle: - This cycle basically deals with the flow of steam at
different pressure and temperature to different turbines namely HP, MP and
LP turbines which are connected to the generator. It can be explained from
the figure shown below
Steam coming out from super heater at 540degree C and 139kg per square
cm. Three cylinders of 2 set of main stop and governing valve arrangement
on either side of HP casing and each set consist of one stop valve and 2
governing valve assembling series. The steam from the boiler is admitted the
reheater where it heated at original temp. The reheated steam is taken to IP
casing through combined stop and interceptor valve arrangement at either of
IP casing. The exhaust from the IP casing has taken directly the LP casing.
The steam expanded in the LP turbine to a very low blade pressure which is
maintained by the condenser below atmospheric pressure about 3% of
makeup water is required to condensate the losses of cooling water due to
evaporation in cooling tower. Finally steam exhausted by LP turbine is
condensed in the surface type condenser type cooling water following

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through a large no. of tubes. The HP, IP &LP turbine coupled in series and
mechanical power generated from steam transmitted to generator.
Feed water cycle:-
this cycle deals with the flow of water to boiler feed pump from feed storage
tank, which is later fed to the boiler drum passing through high pressure
heater and economizer
This system plays an important role in the supply of feed water to the boiler
at requisite pressure and steam/water ratio. This system starts from boiler
feed pump to feed regulating station via HP heaters

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Boiler feed pump: this pump is horizontal and barrel design driven by an
electric motor through a hydraulic coupling. All the bearings of the pump
and motor are forced lubricated by oil lubricating system. The feed pump
consists of pump barrel into which is mounted the inside starter, together
with rotor. Water cooling and oil lubricating are provided with their
accessories. The brackets of the radial bearing of the suction side and the
radial and thrust bearing of the discharged side are fixed to low pressure.
High pressure heater: these are regenerative feed water heater operating at
high pressure and located by the side of turbine. It is connected in series on
feed water side and by such arrangement the feed water after feed pump
enters the hp heater. the steam supply to these heater from the bleed point of
the turbine through motor operated valves.
Condensate water cycle: - It deals with the water flowing through the
condenser which plays an important role in increasing the efficiency of the
plant. It consists of a feedback path from main ejector to hot well.
The steam after condensing in the condenser known as condensate, is
extracted out of the condenser hot well by condensate pump and taken to the
de-aerator through ejectors, gland steam cooler and series of LP heaters

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Condensate pump: the function of these pumps is to pump out the
condensate to the deaerator taken to the de-aerator through ejectors, gland
steam cooler and series of LP heaters. This pump is rated generally for 160
cubic meter/hour at a pressure of 13.2 kg/cm square.
LP heater: - there are four LP heaters in which 4 extractions are used.
These heaters are equipped with necessary safety valves in the steam space
level indicator. The condensate flows in the u tube in 4 passes and extraction
steam washes the outside tubes.
Deaerator: - the inner corrosion can be prevented by removing dissolved
gases from the feed water. it can be achieved by embodying into the boiler
feed system a deaerating unit whose function is to remove the dissolved
gases. it works on two principles:: Henry law and solubility law.
Solubility law: solubility of gases decreases with increase in pressure and /or
decrease in pressure.
Henry law: the mass of gas with definite mass of liquid will dissolve at the
given temperature and is directly proportional to the partial pressure of the
gas in contact to liquid.
Primary air cycle: - In this cycle, air is used to carry pulverized coal
from mill to the burning zone of boiler.
Flue gas cycle: - In this cycle, gas containing waste materials are
removed from the system using various techniques like electrostatic
precipitator, ID fans etc. The flue gas, before being removed is used to heat
the primary and secondary air.
Secondary Air cycle: - In this cycle, fuel is mixed with air (known as
secondary air) for proper burning of coal.

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IMPORTANT EQUIPMENTS OF PLANT
I. Mechanical Equipments:-
a.) Steam generating unit:-
Each steam is of semi outdoor, natural circulation, balanced draft type
designed to burn coal in pulverized form. It is direct fired type meeting the
requirements of latest Indian Boiler Regulation. It has a boiler rating of
375/380 tonnes per hour of steam at a super-heater outlet, at a steam
condition of 139kg/cm2 and a temperature of 5400C.
A re-heater is provided for reheating the exhaust steam from high pressure
system of the turbine to 5400C. The boiler furnace and the gas passages are
designed for low pressure in order to minimize the corrosion & slugging
effect. Closed pitched bore wall tubes with membrane/skin type construction
is adopted for the steam generator furnace walls to ensure maximum
availability and efficiency at MCR not less than 86%.
The unit is provided with two forced draft and two induced draft fans driven
by constant speed electric motors. Each fan is rated for 60% of MCR rating.
Regulation of draft system is by inlet vane control for Forced Draft fan. Shut
off dampers is equipped with pulverized coal firing air fans, coal air pipes,
burners, etc. Four – five pulverized mills are provided for each steam
generator out of which 3 – 4 are capable of meeting MCR with design coal.
Flame scanner is also provided. Furnace Surface Safeguard Supervisor
(FSSS) system is also provided to reduce the risk of explosions and back
fires in the steam generators.
For flame stabilization as well as operation at lower loads, oil burners are
provided. Light oil/gas pilot torch system is adopted for ignition of furnace
oil and pulverized coal.

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b.) Mechanical Dust Collector & Electrostatic Precipitators:-
Combined – mechanical dust collector & electrostatic precipitator are
provided to arrange arresting of fly ash in order to reduce particle. Efficiency
of about 98% is achieved in this combined system.
c.) Turbine Generator Unit:-
A standard multi-stage, tandem compound extraction type, reheat type,
condensing turbine with seven uncontrolled extractions, operating at
3000rpm is designed to operate with steam condition of 130kg/cm2 at 5350C
at the throttle with reheating at an intermediate stage of 5350C and the
exhaust against a condenser pressure of 0.092kg/cm2 absolute is provided
and is directly coupled to a hydrogen cooled horizontal shaft, totally
enclosed rotating field type generator, designed to generate at 11,000kV,
50Hz, 3-phase with suitable high frequency excitation system. The turbine
and the generator have a nominal rating of 1, 10,000kW and 1, 25,000kVA
respectively at 2kg/cm2 H2 (gauge) pressure.
The turbine is provided with hydraulic (oil) governing system. The turbo-
generator is complete with all auxiliary systems and equipments, lubrication
systems, shaft, gland seal system, motor operated turning gear. All necessary
protective and supervisory instruments are provided to ensure trouble free,
safe and efficient operations of the units. The turbine – generator is
manufactured by M/s. BHEL.
d.) Condensing Equipments:-
Turn surface condenser of identical design, capable of maintaining a vacuum
of about 0.92kg/cm2 while condensing the steam at maximum rating of the
turbine is provided. These tubes are of aluminium–brass and tube sheet is of

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aluminium-bronze. The condensers are spring mounted and directly
connected to the exhaust flange of the turbine with its axis to the right angles
to that of the turbine.
One starting ejector and two 100%
capacity running ejectors are provided to create and maintain the vacuum in
the condenser by taking out air and other non-condensable gases.
e.) De-aerating heater & Closed heaters:-
The unit is provided with a de-aerating heater and proper capacity of a feed
water tank of approximately 14min storage capacity when machine is
running at full load.
The tray type de-aerator is designed to keep
the oxygen content to 0.007ppm so that the oxygen content in the boiler feed
pump water is kept below any chemical detection.
Steam from extraction line and auxiliary heater
is supplied to the de-aerator which maintains a constant pressure of 6kg/cm2
abs. and the boiler feed pump at the constant pressure irrespective on the
load on the turbo-generator. The feed tank of de-aerator heater is placed on a
suitable elevation to provide sufficient NPSH for the boiler pumps. Level
controllers & communication through level switches is provided to keep the
level of the condensate in the storage tank at a preset value.
Regenerative in the storage on the
condensate is carried out in seven stages by steam of non-regulated
extraction from the turbine and tapping from cold reheat lines. The high
pressure cold heaters are both drain cooling and de-superheating zones in
addition to normal condensing zones. The low pressure feed water heaters
are equipped with only drain cooling and condensing zones.
f.) Boiler :-
● A steam generator is complex integration of following accessories:
1. Economiser 7. Div panels

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2. Boiler drums 8. Platen SH
3. Down comers 9. Reheater
4. Burners
5. Bottom ring header 11. APHs
6. Water walls
Economiser:-
• Boiler Economiser is feed-water heaters in which the heat from waste
gases is recovered to raise the temperature of feed-water supplied to the
boiler.
• It preheats the feed water by utilizing the residual heat of the flue gas.
• It reduces the exhaust gas temperature and saves the fuel.

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Boiler drum:-
• It is an enclosed Pressure Vessel
• Heat generated by Combustion of Fuel is transferred to water to
become steam
● Serves two main functions.
● Separating heat from the mixture of water and steam.
● It consists of all equipments used for purification of the steam after
being separated from water.
Boiler drum level control:-
● Important for both plant protection and equipment safety.
● Maintain drum up to level at boiler start-up and maintain the level at
constant steam load.
● Decrease in this level will uncover boiler tubes and get overheated and
damaged.
● Increase in this level will make separation between steam and
moisture difficult within drum.
● Controlled circulation is required to maintain the difference in the
density between water and steam with increase in pressure.
Down comers:-
● It carries water from boiler drum to the ring header.
● They are installed from outside the furnace to keep density difference
for natural circulation of water & steam.
● Heating and evaporating the feed water supplied to the boiler from the
economiser.

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Water wall:-
• These are membrane walls, no. of tubes are joined.
• Vertical tubes connected at the top and bottom of the Headers.
• Receives water from the boiler drum by down – comers.
Advantage:-
• Increase in efficiency
• Better load response simpler combustion control.
• Quicker starting and stopping
• Increased availability of boiler.
• Heat transfer is better
• Weight is saved in refractory and structure
• Erection is made easy and quick
g.) HP & LP Bypass System:-
Provision of HP & LP bypass system is proposed having a capacity of 40%
steam bypass, making the unit suitable for quick restart as well as peaking
purposes. This has been necessary on account of grid conditions which
shows very acute storage of peaking.
II. Electrical Equipments:-
a.) Generator:-

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The generator is directly coupled with its respective turbine normally rated
for 110 MW at 0.88 power factor (i.e. 125 MVA), 11kV, 3 phases, 50Hz.
The hydrogen cooling mechanism is used for the generator. The neutral point
of the generator is earthed through a single phase Distribution Transformer,
the secondary of which is shunted through a suitable resistance.
The excitation system consists of high frequency AC mains and pilot
exciters directly driven from the main shaft, silicon rectifying unit and
associated control gears.
b.) Generator Transformer:-
The generation voltage of 11kV is stepped up to 220kV by generator-
transformer (in short GT) whose low voltages side is directly connected with
the generator through an isolated phase bus duct. The rating of generator-
transformer is 125MVA, 11/220kV, 3 phase, 50 Hz having an ON/OFF
cooling. The high voltage side of the transformer is connected to the 220kV
system in 220kV switchyard.
c.) Unit Transformer:-
The bus-duct leading from the generator to the GT is tapped off conveniently
for connection to high voltage side of Unit Auxiliary Transformer used for
stepping down the voltage to 6.6kV for supplying power to the unit auxiliary
loads of the power station. The rating of the UAT is 15MVA, 11/6.6kV, 3-
phase, 50 Hz.
d.) Start-up cum Reserve Transformer:-
Each of the four units draw its start up power from the 220kV system
through two/three windings common start-up cum reserve transformer rated

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for 30/10/20 MVA, 220/33/6.6 kV, 3 phase, 50Hz. The transformer supplies
the 33kV load requirements. This transformer also meets the requirement of
station loads like coal & ash handling, compressed air and water treatment
plant, station lightening and other common services as well as act as a
standby source of power to unit auxiliaries.
e.) L.T Auxiliary Transformer:-
For further step down of 6.6kV power from the reserve system for utilization
at medium voltage 16 nos. 1000kVA, 6.6kV/415V, 3-phase, 50Hz
transformers have been envisaged. The actual requirement is assessed after
detail design of the system.
Power for station illumination, unit wise is provided by five 300kVA,
6.6kV/415V, 3-phase, 4 wire transformers.
f.) DC Supply System:-
A station battery unit, complete with battery charger and control &
distribution system is installed as required for supply to all loads either for
normal operation or during any emergency conditions.
Exact rating is however determined after the detail study of all loads and
their durations.
g.) Switchgear:-

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The drives for auxiliary equipment rated 150kW and above are operated at
6.6kV and drives having a rating below 150kW are operated at 415V, 3-
phase, and 4-wire system having a provision for single phase 230V. For
starting up of these motors suitable switchgears/starters are provided.
1. 6.6 kV Switchgears→ 6.6 kV power received from either Unit
Auxiliary Transformer or Reserve Transformer are connected to
respectively 6.6kV switchgear bank through suitable breakers for
further distribution to motors and to transformers for further step
down to 415V.
2. 415 V Switchgear→ The 415V supply from each 1000kVA
transformer are connected to a suitable 415V bus having its
distribution for different motors and starters. Motors capacity above
90kW are controlled by a 415V breaker from respective bus and that
of lower capacity by magnetic contractors grouped together in a sheet
metal cubicle for a number of motors, termed MCC. Protection and
control for individual motors is provided there.
h.) 220kV Switch Yard:
Generator Transformer step-up the 11 kV voltage generated by the Generator
to 220 kV. This voltage is used to charge the three buses in the Switch yard
which follows Double Bus Bar with Transfer Bus Scheme.
Switch yard provides protection between generator transformer and
transmission lines.
Major components of 220 kV Switch yard is:
● Buses (Bus #1, Bus #2 & Transfer Bus).
● Isolators.
● Circuit breaker.(Air Blast Circuit Breaker)
● Current Transformer (CT).
● Capacitor Voltage Transformer (CVT).

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● Wave Tape.
● Potential Transformer (PT).
● Bays(4-Transmission line , 4-GT , 2-Station transformer , 1-Bus coupler ,
1- Transfer Bus)
The 4 Transmission lines are Basti Line, Gorakhpur Line, Sultanpur-I Line
and Sultanpur-II Line.
III. Auxiliary systems:
The following auxiliary systems for the 4X110 MW as envisaged is
described below:-
a.) Coal Handling System:-
Railway is only the means of transport of coal to this power station. Annual
coal requirement for 4X110 MW units is estimated to be approximately
13.70 lakhs mega tonnes. The coal yard in the layout is adequate for about
30 days storage with two coal stock piles and considering 3800 MT of coal
requirement daily.
Considering inadequate & irregular coal movement by railways it is
adequate to have a marshalling yard capable of handling two rakes a day
normally & three rakes occasionally. Railway siding and marshalling yard is
capable of meeting this requirement.
The coal handling system consists of two wagon tipplers with integral
weight bridge and marshalling equipment for unloading coal into hoppers.
Duplicate belt conveyor system each rated 600 tons/hr feeds coal from the
tippler hoppers to Crusher House. There are two crushers, each rated
600tons/hr. Crushed coal is either stacked in crusher coal yard or conveyed
straight to power house. Duplicate conveyor system carries coal to the top of
boiler bunkers. To stackers/re-claimers are there for stacking and re-claiming
of coal each rated 600 tons/hr.

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In the power house, over the bunkers, duplicate belt conveyors run, each
provided with a travelling tippler. Suitable arrangements are made for
magnetic separation of iron particles from coal at the inlet to the crusher
house. An automatic belt weighing system is provided at the power house
entry point to register the amount of coal fed into the bunkers.
For emergency, manual arrangements are made for unloading the coal from
wagons and conveying the same to the crusher house.
Necessary dust suppressing equipment and ventilation equipment is provided
as a part of the coal conveying system. The operation of the entire system is
controlled and supervised from control room. The system also has necessary
interlock & safety features. For the purpose of shunting, it has three diesel
locomotives.
b.)Fuel Oil System:-
The fuel oil is made available to the power station in tank wagon. The lighter
grade oil such as light diesel oil is made available for starting of boiler from
cold condition & furnace oil is made available for flame stabilisation
purpose during low load operation and during any other period when flame
stability is not satisfactory. The oil received from the tank wagon is pumped
into the storage tank. The railway siding facilities provided is able to
accommodate on the rake of tank wagons. Two storage tanks for heavy oil
and one for light oil is provided. Provision is made for heating the tanks,
steam tracing the piping and supply of heating steam to tank wagons.
Oil from storage tank is pumped into day oil tanks. The day oil tank is
located near the boiler. Pumps and heaters sets of suitable design then pump
the oil from day storage to the burner. Return oil is fed back into the day
tank. Similar installation is provided for the light oil but the day tank is not
present.

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b.) Ash Handling System:-
The ash disposal area is within the distance of 4~5kms from the power
station and this is a low lying area. The ash from the boiler hoppers is
conveyed to the ash disposal area either by direct sluicing or hydro-
pneumatic system. Boilers manufactured by M/s. BHEL or AVB are so
designed that it was possible to adopt either of the system for both fly as well
as bottom ash.
The ash disposal area has adequate
capacity for storage of ash for a 640 MW station for over 15 yrs without
reclamation. This area is now being used by Jaypee cement factory for
production of cement and ash bricks. However this area may also be used for
agriculture purposes by covering it with a layer of silt brought from the raw
water reservoir in future
c.) Cooling Water Management:-
The general arrangement & the system have been discussed earlier in the
report. Only the equipments involved in the mechanical system are described
below:-
Water from the raw water reservoir is pumped through clariflocculators. The
clarified water from these clarifloccolator flows to the cooling water basin
by gravity. A clarified pump is present which pumps the clarified water to
the DM plant. For this, three pumps are involved. The outlets from the
cooling water tower basins are connected to the common tunnel which takes
the water back to the power house. From this tunnel water is drawn through
the following pumps to the various equipments as follows:-
1. ) CW Pumps for circulating cooling water through turbine, condenser
and discharging the same to the op of the respective cooling towers. Two
CW Pumps each rated 50% capacity is installed.
2. ) Auxiliary Cooling Water Pumps for supplying cooling water to various
auxiliary equipment for their cooling. This water after circulation through
various bearings and heat exchangers leads to the CW discharge pipe

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from the condenser for cooling through the cooling tower. The number of
pumps in this case is also two, each of 50% capacity.
3. ) Ash Water Pumps for supplying water for ash handling. There are two
pumps per unit. Ash water is discharged to the ash disposal area but this
continues the part of cooling water blow-down as well and therefore
forms the part of total make-up water of the cooling tower.
e.) Water Treatment Plant:-
A demineralising plant is provided for supplying make-up water for the heat
cycle. Clarified water is pumped from the clarified water storage pit which
passes through pressure filter, activated carbon filter, caution exchanger,
degassifier, anion exchanger and mixed bed exchanger. There are four
streams each rated 30m3/hr. Adequate facilities are provided for unloading,
handling and storage of chemicals. Waste effluent is neutralised before it is
discharged to outside drain.
FUTURE PROSPECTS OF NTPC TANDA
NTPC Tanda is providing electricity to 3 different cities (Gorakhpur, Basti &
Sultanpur).At present time, plant is delivering electricity up to PLF 102% i.e.
generating power more than specified. In near future, generating capacity of
plant is going to be increased by two units of 660MW each. So NTPC is
playing a major role in development of INDIA
REGARDS:-
For the humble guidance and cooperation, we are thankful to
● Mr.Sanjeev Gupta (DGM)
● Mr.A.K.Mishra (DGM)
● Mr.Lalit Kr. Singh (DY.SUPT)

27
● Mrs.Seema Deo (Sr.Engineer)
● Mr.Sudhir Basista (Engineer)
● Mr.Anand Choudhry (Engineer)
● Mr. A.H.Rizvi (Engineer)
● Mr.Rahul Kr.Jaiswal (E.T.)
● Miss.Poonam kumari (E.T)
● Miss.Saroj (E.T)

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