Handwritten Text Recognition for manuscripts and early printed texts
ppt on NTPC kahalgaon ,bhagalpur ( bihar) BY AKHILESH & PRIYESH
1. A SUMMER TRAINING PRESENTATION 0N
NATIONAL THERMAL POWER PLANT
KAHALGAON (BIHAR)
SUBMITTED TO:Prof. R K Mathur sir
Dept. Of mechanical
SUBMITTED BY:
Akhilesh kumar
Roll No-11001184006
B.Tech(Mechanical engg.)
3. NTPC OPERATION &MAINTENANCE
Boiler Maintenance Department
Turbine Maintenance Department
Ash Handling Departament
Off-site Maintenance Departament
4. INTRODUCTION
India’s largest power company ,NTPC was set up in 1975 to accelerate
power development in india.NTPC is emerging as a diversified power
major with presence in the entire value chain of the power generation
,which is the mainstary of the company ,NTPC has already ventured into
consultancy.power trading,Ash utilisation and coal mining
kahalgaon super thermal power station (khstpp) is located in kahalgaon in
Bhagalpur district of bihar.The power plant is one of the coal based power
plant of NTPC.
CAPACITY :- The Total installed capacity of the plant is 2340 mw.
5. NTPC, Kshpp Project
Location : Kahalgaon ,Dist-Bhagalpur(Bihar),813214
Total Land : 3,360 acres
Land for plant : 883 acres
Land for township : 432 acres
Land for Ash dyke :1395 acres
Configuration : stage -1 (4*210 MW)
: stage -2: phase 1 (2*500 MW)
: Phase 2 (1*500 MW)
Sourse of coal : Rajmahal coal field of ECL
Fuel Requirement : 4.1 million ton per year stage -1
: 6.62 million ton per year for stage -2
: 3 million ton per year for stage -2
Sourse of water : Ganga River
6. NTPC
Make of water Requirement : 7500 m3/hr (stage-1)
: 6000 m3/hr (stage-2)
Cooling water system : closed cycles induced Draft cooling
tower
Approved capacity : stage 1. 840 mw + stage 2. 500 mw
Commersilation :unit 1.-(210 mw) march ,1992
: unit 2.- (210 mw) march, 1994
: unit 3.- (210 mw) march ,1995
: unit 4.- (210 mw) march , 1996
:unit 5.-(500 mw) march ,2007
:unit 6.- (500 mw) march ,2008
: unit 7- (500 mw) june, 2009
8. Coal Handling System Equipment
Wagon Trippler
Conveyor Belt
Pulleys
Take Ups
Skirt Board
Scrappers
Magnetic seprator
Vibrating screen
Crushers
9. CRUSHERS
To crush the coal from 200mmto 20mm size received
from vibrating screen
Crusher hammer are made of MAGNEESE STEEL .
Hammer row -4(stage 1)
(a)Row-1 & 2 =18 hammer each
(b)Row-3&4=20 hammers each
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No of hammer in each Crusher•stage-1 = 76 hammers
•stage-2 = 92 hammers
•Weight of each hammer=18.5kg
•Crushing motor rating -740kw/3.3kv
•Life of hammer =4 lac MT of coal
•Normal capacity=600 tons/hr
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10. CONVEYOR BELTS
Made of diff. Layers or piles of fabric duck with rubber
protected by a rubber cover on both sides & edges.
Fabric duck are designed to withstand tension created in
carrying the load .
Nylon rubber cover protect the fabric duck.
Material =fire resistant grade.
Belt Width=1600 mm.
Strength= 1000/1250 kN.
Belt speed=3.2-3 m/s.
Belt length=20km.
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11. PULLEYS
NTPC
•Made of mild steel.
• Rubber coating is used to increase friction
• factor between belt & pulley (rubber lagging
•Shell dia-500mm.
•Shaft dia-1400mm.
•Pulley length-1800mm.
•Shaft length-2350mm(bearing centre to
centre)
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12. DRIVE UNIT
NTPC
Motors coupled to reduction gear with the help
of flexible/fluid coupling on the high speed shaft of the
Gear box
Flexible coupling on the input side
TAKE UPS
Take up pulley to facilitates –
Necessary tension for the drive to operate the belt
Sag at a point where requires horse power will be
at a minimum and load will move with least
disturbance over idlers
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13.
NTPC
SKIRT BOARD
Used with chutes at trail end.
Guides material centrally on the belt while loading
until it has settle down on the belt
SCRAPPERS
Placed at discharge pulley in order to clean the
carrying side of belt.
It avoids the wear of return idlers due to build up
material.
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14. BOILER MAINTENANACE DEPARTMENT
BOILER: Steam generating device for specific purpose.
Capable to meet variation in load demand.
Capable of generating steam in a range of operating pressure and temperature.
For utility purpose ,it should generate steam uninterrupediy at operating
pressure and temperature for running steam turbine.
BOILER/STEAM GENERATOR : Raw material for design of boiler
1.coal frommines 0 Generating heat energy
2. Ambient air 0 Air for combustion
3. Water from natutal resources (river ,ponds ) 0 Working fluid for steam
generation possessing heat energy
A 500 MW steam generator consumers about 8000 tonnes of coal every day.
It will be considered if it requires about 200 cubic meter of D M water in a day
.
It will produce about 9500 tonnes of carbon di- oxide evert day.
15. BOILER AUXILARIES
There are three part of Boiler :1.Milling system
2.Rotatory part
3.pressure part
1.MILLING SYSTEM: Coal Bunker:- These are in process storage silos used for storing crushed coal
from the coal handling system .generally,these are made of welded steel plates
normally these are six such bunker supplying coal of the corresponding mills
.Those are located on top of the mill so as aid in gravity feeding of coal.
Coal feeder:- Each mill is provided with a drag link chain/rotary /gravametic
feeder to transport raw coal from the bunker to the inlet chute leading to mill at
desired rate .
MILLS:- These are six mill (25persent capacity each) for every 200mw unit
,located adjacent to the furnace at (o) m level .There mills pulverise coal to be
desired fineness to be feed to the furnace for combustion.
It is used to crush the coal into powder form (80 micron).These are 10
mills for the 500mw unit ,located adjacent to the furnace at o level .These mills
pulverised coal to the desined fineness to be fed to the furnace for combustion.
18. NTPC
2.ROTATORY PART : P A Fan : The primary air fan (2 per unit -50 percent capacity
each ) are designed for handling atmospheric air upto a
temperature of 50 deg c .These fan are located at (0) m level
near the boiler .
F.D Fan :- The forced draft fans (2 per unit -50 percent
capacity each) are designed for handling secondary air for the
boiler .These fan are located at “o “ m level near the P A fan.
I D Fan:- There are two indused Draft fans per boiler located
between the electrostatic precipitator and the chimney .
These fans are used for sucking flue gas from furnace
19. TURBINE MAINTENANCE DEPARTMENT (TMD)
TURBINE :- A steam turbine is a rotating device which converts thermal
energy into mechanical energy.
OPERATING PRINCIPLE :- A steam turbine has two main part -1) cylinder
(stater) and the rotor . The cylinder or rotor is a steel or cast iron housing
usually divided at the horizontal centre line.its havies are bolted together for
easy access .The cylinder contains fixed blade carred by rotor .each fixed
biade set is mounted in diphram located in front of each disc on the rotor or
directly in the casing . A disc and diphram pair a turbine stage.steam turbine
can have many stage the rotor is a rotating shaft carries the moving blades .on
the outer edges of either disc or drum . The blade rotate as the rotor revolves
.The rotor of a large steam turbine consists of high intermediate ,low pressure
turbine section .
In a multiple stage ,steam at the high pressure and
high temperature enter s the first row of fixed blades or nozzle through an
inlet value .As the steam passes through the fixed blades or nozzles it expands
and its velocity increases the high velocity jet of steam strkes the first set of
moving blades.
20. 2
1
HPT
3
IP
T
4
5
6
7
LPT
GENERATOR
EXCITER
THREE STAGE TURBINE :
• HIGH PRESSURE TURBINE (HPT)
• INTERMEDIATE PRESSURE TURBINE (IPT)
• LOW PRESSURE TURBINE (LPT)
SEVEN NOS JOURNAL BEARINGS
BEARING N0. 2 THRUST CUM JOURNAL BEARING
FOUR NOS RIGID COUPLINGS BETWEEN
• HP-IP TURBINE
• IP-LP TURBINE
• LP-GENERATOR
•GENERATOR - EXCITER
CONDENSER
21. SINGLE STEAM FLOW OF TWO SHELL (CASING) DESIGN
OUTER CASING IS OF BARREL TYPE AND HAS NEITHER ON AXIAL OR RADIAL FLANGE.
DUE TO THE PERFECT SYMMETRIC DESIGN OF THE OUTER CASING AND UNIFORM WALL
THICKNESS AT ALL SECTIONS, PREVENTS MASS CONCENTRATIONS WHICH WOULD CAUSED
HIHG THERMAL STRESSES AND REMAINS LEAK PROOF DURING QUICK CHANGES IN
TEMPERATURE DURING START UP AND SHUT DOWN.
THE INNER CASING IS AXIALLY SPLIT IS ALMOST CYLINDRICAL IN SHAPE AS THE JOINTS
FLANGES ARE RELIEVED BY HIGHER PRESSURE ACTING FROM THE OUT SIDE.
CASING IS MADE OF CREEP RESISTING CHROMIUM-MOLYBDENUM-VANADUIUM (Cr-Mo-V)
STEEL CASTING.
THE TURBINE HAS 2 MAIN STOP VALVES (ESV) AND 2 CONTROL VALVES (CV)LOCATED
SYMMETRICALLY TO THE RIGHT AND LEFT OF THE CASING. THE VALVES ARE ARRANGED IN
PAIRS WITH ONE STOP VALVE AND ONE CONTROL VALVE IN A COMMON BODY. EACH ESV
AND CV HAS A DEDICATED HYDRAULIC SERVOMOTOR.
THE STEAM LINES FROM ESV & CV ARE CONNECTED TO THE INLET CONNECTIONS OF
THE OUTER CASING BY BREECH NUTS.
THE EXHAUST END OF HPT HAS A SINGLE OUT LET CONNECTION FROM BOTTOM.
22. • THE IP TURBINE IS OF DOUBLE FLOW CONSTRUCTION WITH TWO NOS
HORIZONTALLY SPLIT CASINGS ( INNER & OUTER CASING).
• THE HOT REHEATED (HRH) STEAM INTERS THE INNER CASING AT THE
MID SECTION FROM TOP AND BOTTOM AND EXPENDS IN OPPOSITE SIDE
IN TWO BLADE SECTIONS AND COMPENSATE AXIAL THRUST.
• THE INNER CASING CARRIES THE STATIONARY BLADING.
• THE IP STOP AND CONTROL VALVES 2 NOS ARE SUPPORTED ON THE
FOUNDATION COVER PLATE BELOW EL 17.00 M FLOOR IN FRONT OF
TURBINE –GEN UNIT.
• CASING IS MADE OF CREEP RESISTING CHROMIUM-MOLYBDENUMVANADUIUM (Cr-Mo-V) STEEL CASTING.
• THE SHAFT IS MADE OF HIGH CREEP RESISTANCE Cr-Mo-V STEEL
FORGING.
23. • LP TURBINE CASING CONSISTS OF DOUBLE FLOW UNIT AND HAS A TRIPLE SHELL
WELDED CASING.
• THE OUTER CASING CONSISTS OF FRONT AND REAR WALLS, TWO LATERAL
LONGITUDINAL SUPPORT BEAMS AND THE UPPER DOME AND CONNECTED TO
CONDENSER BY WELDING.
• THE INNER-INNER & INNER-OUTER CASING CARRIES THE TURBINE GUIDE
BLADES AND DIFFUSER.
• STEAM ADMITTED TO THE LP TURBINE INNER CASING FROM IP TURBINE FROM
BOTH LEFT AND RIGHT SIDE HORIZONTALLY. EXPANSION JOINTS ARE INSTALLED
IN THE STEAM PIPING TO PREVENT ANY UNDESIRABLE DEFORMATION OF THE
CASINGS DUE TO THERMAL EXPANSION OF THE STEAM PIPING.
24. HP TURBINE MOVING AND STATIONARY BLADES :
•
•
1.
2.
3.
•
•
•
HP TURBINE BLADING CONSISTS OF 17 REACTION STAGES WITH 50 %
REACTION.
BLADES ARE HAVING THREE MAIN PARTS :
AEROFOIL : IT IS THE WORKING PART OF THE BLADE WHERE STEAM
EXPANSION TAKES PLACE.
ROOT : TI IS THE PORTION OF THE BLADE WHICH IS HELD WITH ROTOR OR
CASING
SHROUDS : END PORTION OF BLADES ARE HELD TOGETHER
THE STATIONARY AND MOVING BLADES OF ALL STAGES ARE PROVIDED WITH
INVERTED T-ROOTS. ALL THESE BLADES ARE PROVIDED WITH INTEGRAL
SHROUDS WHICH AFTER INSTALLATION FORM A CONTINUOUS SHROUD.
THE MOVING AND STATIONARY BLADES ARE INSERTED INTO THE
CORRESPONDING GROOVES IN THE SHAFT AND INNER CASING. THE
INSERTION SLOT IN THE SHAFT IS CLOSED BY A LOCKING BLADE WHICH IS
FIXED BY GRUB SCREWS.
SEALING STRIPS ARE CAULKED INTO THE INNER CASING AND THE SHAFT TO
REDUCE LEAKAGES LOSSES AT THE BLADE TIPS.
25. IP TURBINE MOVING AND STATIONARY BLADES :
• IP TURBINE BLADING CONSISTS OF 12 REACTION STAGES PER FLOW WITH 50 %
REACTION.
• THE STATIONARY AND MOVING BLADES OF ALL STAGES ARE PROVIDED WITH INVERTED
T-ROOTS. ALL THESE BLADES ARE PROVIDED WITH INTEGRAL SHROUDS WHICH AFTER
INSTALLATION FORM A CONTINUOUS SHROUD.
• THE MOVING AND STATIONARY BLADES ARE INSERTED INTO THE CORRESPONDING
GROOVES IN THE SHAFT AND INNER CASING. THE INSERTION SLOT IN THE SHAFT IS
CLOSED BY A LOCKING BLADE WHICH IS FIXED BY GRUB SCREWS.
• SEALING STRIPS ARE CAULKED INTO THE INNER CASING AND THE SHAFT TO REDUCE
LEAKAGES LOSSES AT THE BLADE TIPS.
26. LP TURBINE MOVING AND STATIONARY BLADES (FIRST 3
STAGES) :
• LP TURBINE BLADING CONSISTS OF 6 REACTION STAGES PER FLOW WITH 50
% REACTION.
• THE STATIONARY AND MOVING BLADES OF FIRST THREE STAGES ARE
PROVIDED WITH INVERTED T-ROOTS. ALL THESE BLADES ARE PROVIDED WITH
INTEGRAL SHROUDS WHICH AFTER INSTALLATION FORM A CONTINUOUS
SHROUD. FIRST THREE GUIDE BLADES ARE MOUNTED ON INNER-INNER CASING.
• THE MOVING AND STATIONARY BLADES ARE INSERTED INTO THE
CORRESPONDING GROOVES IN THE SHAFT AND INNER CASING. THE INSERTION
SLOT IN THE SHAFT IS CLOSED BY A LOCKING BLADE WHICH IS FIXED BY GRUB
SCREWS.
• SEALING STRIPS ARE CAULKED INTO THE INNER CASING AND THE SHAFT TO
REDUCE LEAKAGES LOSSES AT THE BLADE TIPS.
27. CONDENSER IS A SURFACE TYPE CONDENSER WITH TWO PASS ARRANGEMENT. COOLING
WATER IS PUMPED INTO EACH OF CONDENSER PASS BY VERTICAL CW PUMPS THROUGH THE
INLET PIPE. WATER ENTERS THE INLET CHAMBER OF FRONT WATER BOX AT THE BOTTOM
PASSES HORIZONTALLY THROUGH THE TITANIUM TUBES TO THE WATER BOX AT THE OTHER
END, TAKES A TURN PASSES THROUGH THE UPPER CLUSTER OF THE TUBES AND REACHES
THE OUT LET CHAMBER AT THE TOP IN THE FRONT WATER BOX AND LEAVES THE
CONDENSER THROUGH OUTLET PIPE.
STEAM EXHAUSTED FROM THE LP TURBINE WASHING THE OUTSIDE OF THE
CONDENSER TUBES LOSSES ITS LATENT HEAT TO THE COOLING WATER AND CONVERTED
INTO WATER IN THE STEAM SIDE OF THE CONDENSER. THIS CONDENSATE COLLECTS IN THE
HOT WELL, WELDED TO THE BOTTOM OF THE CONDENSER.
CONDENSER DESIGN DATA :
• COOLING WATER FLOW : 54300 M3/Hr.
• COOLING WATER SURFACE AREA : 35603 M2
• NO. OF COOLING TUBES : 24398 NOS ( CONDENSING ZONE:22688 NOS AND AIR COOLING
ZONE :1710 NOS)
•TUBE MATERIAL : TITANIUM SB-338 GRADE-II
• MAIN TUBE PLATE : MS WITH TITANIUM CLADED.
• WATER BOX : MS WITH FRE LINING ( GLASS FIBRE REINFORCED EPOXY LINING) OF 3MM
THICKNESS.
28. ASH HANDLING DEPARTMENT
WHAT IS ASH ?
Ash is the residue remaining after the coal has been
incinerated to constant weight under standard
conditions.
Ash is oxidised form of the mineral matters present in
coal.
Typical ash composition : SiO2, Al2O3, Fe2O3, CaO,
MgO etc.
Coal with more SiO2 & Al2O3, Ash MP > 1400ºC
Coal with more Fe2O3, CaO & MgO, Ash MP < 1100ºC
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29. WHY ASH HANDLING?
Ash
content of Indian coal used in power station is
about 30 to 40 %.
A typical 2000 MW station produce around 9000T to
12000T of ash per day.
This huge amount of ash needs to be disposed off
continuously.
Necessary care to be taken for preventing pollution
Ash
Handling system takes care the above requirement
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30. Fly Ash Handling System
FA is
collected from Air heater hopper, Eco hopper and
ESP hopper.
Either through flushing apparatus or hydrobactur system.
In Flushing apparatus system ash is allowed to fall in
flushing apparatus under gravitation.
Water jet in flushing apparatus carries away the ash to FA
trench
High pressure jets further carries it to FA sump.
Series pumping carries the ash slurry to FA pond.
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31. Bottom ash Handling System
BA can
be collected at furnace bottom as Wet or Dry form.
Wet bottom ash system consists of i)Trough seal, ii)BA
gate, iii)Hopper, iv)Scrapper Conveyer, v)Clinker grinder,
vi)BA trench, vii)BA tank, viii)BA pump, ix)BA pond.
Dry BA consists of i)Trough seal, ii)BA gate, iii)Hopper,
iv)Scrapper Conveyer, v)Clinker grinder, vi)Silo.
Trough seal : A channel around the furnace bottom
filled with water where the furnace bottom end is
immersed in water. This is to prevent air ingression in the
boiler during operation.
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35. Why water treatment?
Raw water contains many dissolved minerals and organic
materials.
At high temperature certain minerals left scaling on the
tube metal of the boiler and cause permanent damage.
Some dissolved minerals leads to corrosion of tube metals.
Some leads to foaming
At high pressure and temperature an element, silica can be
carried away with steam causing damage to turbine low
pressure stage.
A Thermal Power Station needs water of varying quality for
different process and hence the requirement.
The performance and life expectancy of the station greatly
depends on water chemistry compliance.
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36. Type of water treatment
the type of demineralization process chosen for a power
station depends on three main factors :
The quality of the raw water.
The degree of deionisation i.e. treated water quality
Selectivity of resins.
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37. Steps of treatment process
Aeration of raw water
Adding chemicals for bacteria removal
Adding chemicals for sedimentation of suspended
particles
Flocculation
Filtration
Ion Exchange process
water treatment process is generally made up of two
sections :
Pretreatment section
Demineralisation section
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38. Description
Stage-I
Tower Type
Stage-II
Induced Draft
Multi Fill
Counter Flow
Make
M/S Gammon
India
Circulating water flow 30,000
/ tower
M3/hr./tower.
Hot CW inlet temp.
43oC
Induced
Draft Multi Fill
Counter Flow
M/S NPCC
Ltd.
33,000 M3/hr.
Cold CW Out let temp. 33oC
33oC
Range
9oC
10oC
42oC
41. Maintenance practices in CT
Daily walk down monitoring of CT cells
Cold water basin cleaning
Algae removal from splash bars
Tree trimming /pruning at nearby CT area
Maintaining clean walkway around CT
Gear box to be run for an hour fortnightly during open
cycle
Prevention of air ingress at inspection door, transmission
shaft, oil piping, expansion joints etc
Fabricated nozzle fitting in hot water channel in CT ST # II