This document provides an overview of the mechanical maintenance department's balance of plant systems at a power plant. It describes the various systems including the boiler, fuel oil systems, cooling water system, and compressed air system. The boiler section describes the boiler's design and working, including its two passes, partitions, superheaters, and role in heating water to produce supercritical fluid to power the turbine. The fuel oil system provides auxiliary ignition energy to initially fire the boiler before it can sustain combustion from coal alone. The cooling water system circulates water to condense turbine exhaust and cool motor windings.

1. Mechanical
Maintenance
Depar tment -
Balance of
Power
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2. BALANCE OF PLANTS
 Boi ler
 Fuel Oi l Pump House
 CW Pump House
 Compressed Air System
 Hydrogen Plant
 Raw water pump house
 DG Set
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3. BOILER
74 meters long.
two passes with platen super heaters.
The boiler's four corners are designated as
A,B,C,D for communication purpose

4. FIRST PASS
At bottom, leftover ash eliminated from
chimney and electrostatic precipitator (esp) is
collected in bottom ash hopper
collected ash mixed with water is sent to the
ash water pond.

5. FIRST PASS
From 22 metres to 37 meters the furnace is
situated
The furnace is divided into17 partitions
designated as AA, A, AB, B, BC till HH from top
to bottom.
Partitions designated with single letters have
inlets through which raw materials like coal,
air, water and different oils are sent through.
Oils are pumped using oil guns.

6. From 56metres to 74 the final super heaters
exist along with platen heaters and roof
heaters.
There exist water walls all along the boiler.
There exist soot blowers at particular height to
blow the ash that is left over after combustion
process

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8. SECOND PASS
 Contains the economiser, low temperature super heater, low
temperature re-heater, air pre heater, force draf t fan, induced
draf t fan and scanner fan.
 The second pass focuses primarily on increasing ef ficiency.

9. WORKING OF A BOILER
The boiler is initiated by firing light diesel oil
(LDO) along with air and coal.
LDO is pumped through the oil guns that are
situated at the eight corners in a tangential
direction.
 LDO is used until the temperature reaches 400
degrees Celsius after which high fluid oil (HFO) is
used.
The gases that are produced after combustion of
coal are called flue gas which is used up in
economizer and Pre-heaters

10. FIRST PASS
The dam water enters through the economiser
through feed pump.
Gets pre heated in the economizer and enters the
bottom ring header from where the water enters
the spiral water walls in the boiler in pass 1.
 The water walls heat the water and send them
over to roof heater and then to low temperature
super heater next to the platen heater and then
to final super heater where most of it is
converted to super critical fluid.

11. SECOND PASS
This super critical fluid comes back to boiler
to reheat through re-heater line.
This liquid passes through the economiser in
pass 2 then to low temperature re-heater
Then back to final super heater

12. The soot blowers blow the ash with help of
steam to the bottom ash hopper.
The air preheater heats the secondary air
along with primary air so that the efficiency is
increased. Secondary air is used when there is
excess need of air in the furnace. This
secondary air is blown through force draft fan.
The scanner fan present in the boiler is used
to cool the sensors present in the boiler
The induced draft fan is used to remove or
suck the flue gas from the boiler

14. FUEL OIL SYSTEM
 Providing Auxiliary Ignition Energy to coal -air mixture
 Total Ignition Energy = Inherent Ignition Energy + Auxiliary
Ignition Energy
 When heat becomes stable, heat avai lable from combustion
of coal exceeds Total Ignition Energy, no more Auxiliary
Energy is required
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15. FUEL OIL HANDLING SYSTEM
 Unloading through Unloading pumps.
 Storing in Storage tanks.
 Transferring to Day oi l Tanks
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16. TYPES OF OIL USED
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17. COOLING WATER SYSTEM
 Circulate CW in condenser and condensing turbine exhaust
system
 Discharge valve is hydraulic operated
 Discharge water used to cool motor windings
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18. CW PUMP SPECIFICATION
 Manufacture KIRLOSKAR BROTHERS LIMITED
 Pump type BHM135, Single stage, Sel f water lubr icat ing pump
 Motor Rat ing 3600 KW
 Speed 330 RPM (NOM)
 Make WEG
 Motor Weight 35300 KG
 Pump Discharge 39825 M^3/HR
 Total Head 26 M
 Pump Ef f iciency 92 %
 Pump Input 3049.73 KW
 Type Three phase induct ion motor
 Power 3600 kw
 Speed 330 rpm
 Frequency 50Hz
 Duty S1
 Vol tage 11kv
 Cur rent 245.5 amp
 Insulat ion class F
 Ef f iciency 96( -2%)
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