Steam turbines and its associated systems(ntpc ramagundam)

National Thermal Power Corporation limited
RAMAGUNDAM

INDUSTRIAL oriented Mini project/INTERNSHIP
on
“Steam turbine & itS aSSociated SyStemS”
CERTIFICATE
This is to certify that
MD.ABDUL - H.NO:14WJ1A03H2
Of
MECHANICAL ENGINEERING DEPARTMENT
GURUNANAK INSTITUTIONS TECHNICAL CAMPUS
HYDERABAD
(B.TECH, 3rd
, Year) have done A MINI PROJECT/INTERNSHIP on “STEAM
TURBINE AND ITS ASSOCIATED SYSTEMS” under my guidance and supervision
at RSTPS, NTPC Limited Ramagundam” to their partial academic requirement
From: 07-03-2017 to 22-03-2017. Performance of the project trainee is satisfactory.
PROJECT GUIDE: PROJECT COORDINATER:
Mr.D.KUMARA SWAMY Mr.G.BHASKER
(ENGINEER) AGM (TMD) I/C
NTPC Ltd., RAMAGUNDAM NTPC Ltd., RAMAGUNDAM

ACKNOWLEDGEMENT
I wish to take the opportunity to express my deep gratitude to all the people who
have extended their co-operation in various ways during our project work.
We would like to express our deep felt gratitude to the management of NTPC,
Ramagundam for having permitted us to do the training.
It is my pleasure to acknowledge the help of all these individuals. I thank with gratitude
Mr.G.PRAVEENKUMAR(MANAGER,HR-EDC),MR.G.BHASKAR(AGM-
TMD),Mr.MVRSHARMA(Dy.MANAGER-EDC),Mrs.CH.SUJATHA(OFFICER
EDC),and Mr. SYEDYOUSUF (Sub-officer-EDC) for their cooperation and help to
complete my training in NTPC Ramagundam .I express my sincere thanks to my project
guide Mr.KUMARSWAMI (Dy.Manager,TMD) for his valuable guidance, co-
operation and encouragement in every step during our project. It was a pleasant and
challenging experience to work under his guidance with his constant monitoring and
advice for the completion of the project

ABSTRACT
Steam turbine is an excellent prime mover to convert heat energy of steam to
mechanical energy. Of all heat engines and prime movers the steam turbine is
nearest to the ideal and it is widely used in power plants and in all industries where
power is needed for process.
In power generation mostly steam turbine is used because of its greater thermal
efficiency and higher power-to-weight ratio. Because the turbine generates rotary
motion, it is particularly suited to be used to drive an electrical generator – about
80% of all electricity generation in the world is by use of steam turbines.
Rotor is the heart of the steam turbine and it affects the efficiency of the steam
turbine. In this project we have mainly discussed about the working process of a
steam turbine. The thermal efficiency of a steam turbine is much higher than that of
a steam engine.

INDEX
1. INTODUCTION TO NTPC
2. STEAM POWER PLANT
3. RANKINE CYCLE
4.TURBINE AND ITS AUXILIARIES
4.1) STEAM TURBINE.
4.2) TURBINE COMPONENTS
5. CLASSIFICATION OF TURBINE
5.1) HP TURBINE
5.2) IP TURBINE
5.3) LP TURBINE
6. SPECIFICATIONS OF TURBINE
7. BEARINGS
7.1) FRONT BEARING PEDESTAL
7.2) HP REAR BEARING PEDESTAL
7.3) IP REAR BEARING PEDESTAL
7.4) LP TURBINE REAR BEARING PEDESTAL
8. TURBINE LUBRICATION SYSTEM
9. SPECIFICATION OF LUBRICATION SYSTEM
10.TURBINE EFFICIENCY
11.CONCLUSSION.

1.INTRODUCTION TO NTPC
Power is an important infrastructure in developing countries. Power development in
INDIA received a big boost with the dawn of National Thermal Power Corporation
Limited(NTPC)NTPC is established on 7th, of November 1975 to construct ,operate
and maintain large capacity power developing stations.
With the vision “To be one of the world’s largest and best power utilities, powering
India’s growth” this corporation is on the run is maintaining its impeccable record by
consistently generating quality and reliable power. NTPC became
“Maharatna Company” in 2010.
Leader in power sector: NTPC with an installed capacity of 41,184 MW (including
5,364 MW through JVs) comprising of 23 NTPC Stations (16 Coal based stations, 7
combined cycle gas/liquid fuel based stations), 7 Joint Venture stations (6 coal based
and one gas based) and 2 renewable energyprojects.41,249 MW is generating 26.5% of
the countries entire power requirement. So it is recognized as the India’s largest power
utility.
VISION
“To Be the World's Largest and Best Power Producer, Powering India's Growth.”
Mission:
“Develop and provide reliable power, related products and services at competitive
prices, integrating multiple energy sources with innovative and eco-friendly
technologies and contribute to society.”
Profile of RSTPS:
NTPC Ramagundam, a part of National Thermal Power Corporation, is a 2600
MW Power station situated at Ramagundam in Karimnagar district in the Indian state of
Andhra Pradesh, India. It is the current largest power station in South India. It is the
first ISO 14001 certified "Super Thermal Power Station" in India.Availability of power
in the southern region at certain duration was not as per the demand.
As there was an imbalance in the power developed from that being generated, the
annual reports were made during 1984-1985 to 1988-1989 which made evident that an
installation of large capacity power station was must to meet the growing requirements.

As the basic inputs availability’s like coal, land and water were in abundant a
mammoth thermal station was setup to fulfill the requirements at Ramagundam named
Ramagundam Super Thermal Power Station (RSTPS) .
Foundation:
Ramagundam Super Thermal Power Station is third in the series of super
thermal powerstations set up by NTPC. Late Shri.Morarji Desai, the former Prime
Minister of India, laid foundation stone for this project on 14th November 1978. This
station consists of 3x200MWunits referred as stage-1 and 3x500MW units referred as
stage-2 and 1x500MW units, as stage-3, making a total capacity of 2600MW.
Plant location and Lay out:
While planning for the future the total area presently is about 10,231 acres based
on unit composition of 3x200MW+3x500MW+1x500MW. The area is covered between
longitudes 79deg-52min and 79deg-30min. With in the latitudes 18deg-35min and
18deg-52min with a lot remaining for setting up of additional units as per the future
demands
Fuel requirements:
The entire requirement of coal for the plant was proposed to be met from the near
by Singareni Collieries Mines which are about 13km away from the plant. The mines
were possessing about 1800million tones of coal at the time of installation. A dedicated
MGR system having a length of 53km has been developed to haul the coal from nearby
open cast mines.
Water Requirements:
At the time of making feasible report several alternatives were considered for
meeting thewater requirements of cooling water. A detailed study indicated that it
would not be possible tomeet it through direct circulation so a dam was proposed. The
Pochampad dam was built on river Godhavari. Measures were taken to ensure that
station is not required to be closed under closure ofirrigation canal or during droughts.
Water requirement of the plant during such conditions can bemet for 9-10 weeks
without any replacement from the distributor canal.

Ash Disposal:
Large area of land is required for the disposal of the waste like coal ash. Ash being
generated from the plant is pumped in slurry from through pipelines to the ash pod at
Kundanpalli,which are 5km away from the power station. The ash disposed is utilized
in various forms.
Environmental Control:
Station is equipped with highly efficient ESP system and with tall chimney of about
225mheight. Effluent treatment plant was also installed for reuse of decants ash water
from ash pad.
Evacuation of Power:
The power generated from the station is evacuated through seven no’s 400kv / four
no’s200kv /two no’s 132kv over head transmission lines.
Distribution of Electricity:
Total Capacity of Ramagundam NTPC is 2600 MW of stage 1, 2 & 3 ( i.e. 1, 2,3, &
4,5, 6unit’s ) distributing electricity to following states in MEGA WATT.
STATE MW %AGE
ANDHRA PRADESH 610 29%
TAMIL NADU 470 22%
KARNATAKA 347 16%
KERALA 245 12%
GOA 100 5%
PODICHERY 50 2%
Remaining 250 MW is used to any state, now it is used for A.P.

FLOW-CHART REPRESENTATION OF GENERATOR STAGES AT NTPC,
RAMAGUNDAM
NTPC RAMAGUNDAM
STAGES OF
GENERATION
STAGE-I
200MW X 3
MADE: ANSALDO,
ITALY
STAGE-II
500MW X 3
MADE:
BHEL,HARDWAR.
STAGE-III
500MW X 1
MADE:
BHEL, HARDWAR.

STEAM POWER PLANT
It is the electrical power generating unit, converts mechanical energy produced by
high enthalpy steam to electrical energy.
A thermal power station is a power plant in which the prime mover is steam driven.
steam power plant works based on rankine cycle.
Energy conversion:
The generation of electricity from coal can be classified into the following stages:
• Coal to steam
• Steam to mechanical energy
• Mechanical energy to electrical energy
Here coal which is chemical form of energy is burnt to convert water into steam,
this steam is used to rotate the turbine where thermal energy is converted into kinetic
energy, this kinetic energy is fed to generator where electrical energy is produced.It is
known for ages that when coal is burnt it releases heat energy. The same phenomenon
when chemically represented
C + O2 → CO2 + heat energy (395 KJ/mole)
In the boiler chemical energy is converted into thermal energy by heating water and
converting into steam. The steam produced in the boiler expands in the turbine which
converts thermal energy into kinetic energy.
This motion of turbine rotor is transmitted to generator in which thermal energy is
converted into electrical energy which is transmitted to various load centers.
Boiler Generato
r
Turbine
Chemic
al
Energy
Thermal
Energy
Kineti
c
Energ
y
Electrical
Energy

OVERVIEW OF THERMAL POWER PLANT

RANKINE CYCLE
The Rankine cycle closely describes the process by which steam-operated heat
engines commonly found in thermal power generation plants generate power.The
Rankine cycle is an idealised thermodynamic cycle of a heat engine that converts heat
into mechanical work. The heat is supplied externally to a closed loop, which usually
uses water as the working fluid. The Rankine cycle, in the form of steam engines,
generates about 90% of all electric power used throughout the world,
RANKINE CYCLE:
The simplest way of overcoming the inherent practical difficulties of the
Carnotcycle without deviating too much from it is to keep the processes 1-2 and 2-3 of
the latterunchanged and to continue the process 3-4 in the condenser until all the vapour
has been converted into liquid water. Water is then pumped into the boiler upto the
pressure corresponding to the state 1 and the cycle is completed. Such a cycle is known
as the Rankinecycle. This theoretical cycle is free of all the practical limitations of the
Carnot cycle.
Figure
Figure (a) shows the schematic diagram for a simple steam power cycle which
works on theprinciple of a Rankinecycle.TheRankine cycle comprises the following
processes.
Process 1-2: Constant pressure heat transfer process in the boiler
Process 2-3: Reversible adiabatic expansion process in the steam turbine
Process 3-4: Constant pressure heat transfer process in the condenser and
Process 4-1: Reversible adiabatic compression process in the pump.

Fig(b) Ttemperature and entropy graph of Rankine cycle

TURBINE AND ITS AUXILIARIES
STEAM TURBINE :
A steam turbine is a mechanical device that extracts thermal energy from
pressurized steam, and converts it into useful mechanical work.
TURBINE COMPONENTS
Rotor: shaft, moving blades, shrouds, Tennons, balancing drum, shaft gland seals
Casing : barrel casing, inner casing, outer casing, guide blades, diaphragms, nozzle
Seals : peak seals/tip seals, inter-stage seals, gland seals, balancing drum area seals
Steam pipe line inlet & exhaust
Control valves & stop valves
Drains : casing drain, drain before & after control/stop valves
Extraction lines: drains, NRV, extraction block valves
ROTOR:
The rotor is main prime mover which converted heat energy to mechanical energy.
The rotor is designed to must withstand
• Centrifugal load due to its own mass & stage components such as blades,
shrouds, tie wires etc.
• The torque due to expansion of steam in the steam path and the work done on
• blading rotor
• Rotor must transmit the torque to other rotor chain & generator
• Must capable of withstand cyclic stresses developed due to rotation.
• Must capable of withstand thermal stresses for continues operation.
• The rotor must be thermal stable and resist tendency to bow in allowable
limit during operation
• There are three type of rotor practically used in utility are, mono-block, built
up & welded rotors.

CASING
The stationary blades are mounted in casing directly in reaction turbine. The root
form grooves produced on the inner surface of the casing of blade carrier .The
stationary /guide blades assembled and locked into the casing /blade carrier.
BLADING:
The entire turbine is provided with reaction blading. The stationary and
moving blades of the HP and IP sections and the front rows of the LP turbine are
designed with integrally milled inverted T-roots and shrouds. The last stages of the LP
turbine are fitted with twisted drop-forged moving blades with fir-tree roots engaging in
grooves in the shaft with last stage stationary blades made from sheet steel.
SEALING GLANDS
To prevent west full steam leakages, inter-stage seals and tip seals provided in
reaction design and radial seal and peak seal provided in impulse designSteam is
supplied to the sealing chamber at 1.03 to 1.05 Kg/sq.cm abs and at temperature 130
deg.C To 150 deg.C from the header.
Air steam mixture from the last sealing chamber is sucked out with the help of a
special steam ejector to gland steam cooler. Provision has been made to supply live
steam at the front sealing of H.P. and I.P. rotor to control the differential expansion,
when rotor goes under contraction during a trip or sharp load reduction.
BARRINGGEAR
Barring gear (or "turning gear") is the mechanism provided to rotate the turbine
generatorshaft at a very low speed after unit stoppages. Once the unit is "tripped" (i.e.,
the steam inlet valveis closed), the turbine coasts down towards standstill. When it stops
completely, there is a tendencyfor the turbine shaft to deflect or bend if allowed to
remain in one position too long. This is becausethe heat inside the turbine casing tends
to concentrate in the top half of the casing, making the tophalf portion of the shaft hotter
than the bottom half. The shaft therefore could wrap or bend bymillionths of inches.
This small shaft deflection, only detectable by eccentricity meters, would be enough
tocause damaging vibrations to the entire steam turbine generator unit when it is
restarted. The shaftis therefore automatically turned at low speed (about one percent
rated speed) by the barring gearuntil it has cooled sufficiently to permit a complete stop.
The primary function of barring gear is rotate the turbo generator rotors slowly and
continuously During startup and shutdown periods when changes in rotor temperature
occurs .Shaft system is rotated by double row blade wheel which is driven by oil
provided by AOP.

A manual barring gear is also provided with hydraulic gear Barring speed
210/240rpm
Barring Gear specifications:
(a) Speed : 80 to 120 rpm
(b) Drive : Turbine lub oil (Hydraulic turbine)
(c) Cut in / Cut out speed : 210 / 240 rpm
(d) Location : Front pedestal
EMERGENCY STOP VALVE & CONTROLE VALVE
The main steam is admitted through the main steam inlet passing first the main stop
valves and then the control valves. From the control valves the steam passes to the
turbine casing.The HP turbine is fitted with two main stop and control valves. One main
stop valve and one control valve with stems arranged at right angles to each other are
combined in a common body .The main stop valves are spring-action single-seat valves
;the control valves, also of single –seat design , have diffusers to reduce pressure loses .
These valve combinations are located at both sides of the turbine with their stems
horizontal. The HP valves are connected to the turbine by easily separable collar
couplings, which contain self-sealing U-rings as sealing elements. The IP turbine has
two reheat stop and control valves. The reheat stop valves are spring-action single-seat
valves. The control valves, also spring-loaded, have diffusers. The control valves
operate in parallel and are fully open in the upper load range. In the lower load range,
they control the steam flow to the IP turbine and ensure stable operation even when the
turbine-generator unit is supplying only the station load. The reheat stop control valves
are supported free to move in response to thermal expansion on the foundation cover
plate below the operating floor and in front of the turbine-generator unit. All valves are
actuated by individual hydraulic servo motor
COUPLINGS
Shaft is made in small parts due to forging limitation and other technological and
economic reason,so coupling is required between any two rotors
In 500 MW turbine generator consists of 3 cylinders e.g. High Pressure, intermediate
pressure and low-pressure turbine, one generator and one exciter and all are coupled
to each other by solid couplings. The rotating part of each component is supported
inbearings and the axial position of the shaft is determined by a thrust bearing
andthere is only one thrust bearing, which determines the entire axial position of

theturbine generator. On large turbines, the high torque is to be transmitted so the
use of flexible couplings become impractical. So rigid couplings are used between
the turbine shafts, so that the entire shaft behaves as one continuous rotor.
Coupling between
• HP Turbine & IP turbine
• IP Turbine & LP Turbine
• LP Turbine & Generator
• Generator & Exciter
• Main Oil Pump & HP Turbine
CLASSIFICATION OF TURBINE

Different types of turbines regarding pressure variation
A typical steam turbine has 3 major portions, to extract maximum possible energy
ofsteam and convert it into mechanical energy. Though they are portions of a turbine
but are referredas turbine as the process of exposing vanes to steam and acquiring.
They are:
a)High pressure turbine
b)Intermediate pressure turbine
c) Low pressure turbine

HIGH PRESSURE TURBINE
HPTURBINECASING:
Hp turbine has two casings
Outer casing: a barrel-type without axial or radial flange. Barrel-type casing suitable
for quick startup and loading.
The inner casing: cylindrical, axially split.
The inner casing is attached in the horizontal and vertical planes in the barrel casing so
that it can freely expand radially in all directions and axially from a fixed point (HP-
inlet side). This Turbine is of double cylinder construction. . The inner casing is axially
split and kinematic ally supported by outer casing. It carries the guide blades. The space
between casings is filled with the main steam. Because of low differential pressure,
flanges and connecting bolts are smaller in size.
Outer casing is barrel type without anyaxial/radial flanges. This kind of design prevents
any mass accumulation and thermal stresses. Alsoperfect rotational symmetry permits
moderate wall thickness of nearly equal strength at all sections.
Barrel design facilitates flexibility ofoperation in the form of short start-up times and
higher rate load changes even at high steamtemperature conditions. For a typical
500MW, at HPT the temperature of steam would be around 540°C and pressure 170
kg/cm2

HP ROTOR:
The HP rotor is machined from single Cr-Mo-V steel forging with integral discs. In
all the moving wheels, balancing holes are machined to reduce the pressure
difference across them, which results in reduction of axial thrust. First stage has
integral shrouds while other rows have shrouding.

INTERMEDIATE PRESSURE TURBINE(IPT)
IP TUBINE CASING
Intermediate Pressure turbine is of double flow construction. Attached to axially
split out casing is aninner casing axially split, kinematic ally supported and carrying
the guide blades. The hot reheatsteam enters the inner casing through top and
bottom center. Arrangement of inner casing confineshigh inlet steam condition to
admission breach of the casing. The joint of outer casing is subjectedto lower
pressure and temperature at the exhaust. For a typical 500MW, at IPT the
temperature ofsteam would be around 540°C and pressure 170kg/sq.c.Both are
axially split and A double flow inner casing is supported in the outer casing and
carries the guide blades, Provides opposed double flow in the two blade sections
and compensates axial thrust. Steam after reheating enters the inner casing from
top& bottom.
1 . T u r b i n e R o t o r 5 . I n n e r C a s i n g L o w e r P a r t
2 . O u t e r C a s i n g U p p e r P a r t 6 . E x t r a c t i o n Z o n e
3 . O u t e r C a s i n g L o w e r P a r t 7 . I n l e t N o z z l e
4 . I n n e r C a s i n g U p p e r P a r t

IP Rotor:
The IP rotor has seven discs integrally forged with rotor while last four discs are
shrunk fit. The shaft is made of high creep resisting Cr-Mo-V steel forging while
the shrunk fit disc are machined from high strength nickel steel forgings. Except the
last two wheels, all other wheels have shrouding riveted at the tip of the blades. To
adjust the frequency of the moving blades, lashing wires have been provided in
some stages

LOW PRESSURE TURBINE
LP CASING:
The LP turbine casing consists of a double flow unit and has a triple shell welded
casing. The shells are axially split and of rigid welded construction. The inner shell
taking the first rows of guide blades is attached kinematically in the middle shell.
Independent of the outer shell, the middle shell, is supported at four points on
longitudinal beams.
Steam admitted to the LP turbine from the IP turbine flows into the inner
casingfrombothsides
1 . O u t e r C a s i n g U p p e r P a r t 5 . I n n e r S h e l l L o w e r H a l f
2 . D i f f u s e r , U p p e r H a l f 6 . O u t e r S h e l l L o w e r H a l f
3 . O u t e r S h e l l , U p p e r H a l f 7 . D i f f u s e r L o w e r H a l f
4 . I n n e r S h e l l , U p p e r H a l f 8 . O u t e r C a s i n g L o w e r H a l f

LP ROTOR:
The LP rotor consists of shrunk fit discs a shaft. The shaft is a forging of Cr-Mo-V
steel while the discs are of high strength nickel steel forgings. Blades are secured to the
respective discs by riveted fork root fastening.In all the stages lashing wires are
providing to adjust the frequency of blades. In the last two rows satellite strips are
provided at the leading edge of the blades to protect them against wet steam erosion.

SPECIFICATIONS OF TURBINE
Main Turbine Specifications:-
(a) Make : BHEL
(b) Design : KWU, West Germany
(c) Type : three cylinders reheat condensing turbine.
(d) Stages : HPT 17 reaction stages.
IPT 12X2 reaction stages.
LPT 6X2 reaction stages.
(e) Valves : HPT 2 main stop and control valves.
IPT 2 reheat stop and control valve.
CRH line – 1 swing check valve.
LPBP – 2 bypass stop and control valves.
(f)Load:-
(i) Rated load : 500MW
(ii) Maxim. Load : 524.9 MW (valve wide open condition)
(g) Speed:-
(i) Rated Speed : 50 cps
(ii) Maxim. Speed : 51.5 cps( no time limitation)
(iii) Minim. Speed : 47.5 cps( no time limitation)
(iv) Speed exclusion
range (without load) : 7 to 47.5 cps
(h) Extraction Valves:-
Extraction 1 : No valve
Extraction 2 : 1 check valve with actuator and 1 check
valve without actuator.

Extraction 4.1 : 2 check valves with actuator.
Extraction 4.2 : 2 check valves with actuator.
Extraction 6 : no valve.
Steam Pressure and Temperatures (Rated)
Pressure ( Bar ) Temperatures (o
C )
Initial steam 166.7 537
Before 1st
stage of
HPT
154.4 537
HP cylinder exhaust 44.0 336.4
IP cylinder stop
valve inlet
39.6 537
Extraction 6 44.0 336.7
LP cylinder exhaust 0.1026 46.4
Turbine Extractions
Extractions Source Going To
1 LPT – 5th
stage
LPH – 1
2 LPT – 3rd
stage
LPH – 2
3 LPT – 2nd
stage
LPH – 3
4 IPT exhaust Deaerator and TDBFP –

A/B
5 IPT – 7th
stage
HPH – 5A/5B
6 CRH HPH – 6A/6B , TDBFP
– A/B
Casing temperature limiting values
Alarm M/C Must be shut
down at
HP turbine casing exhaust 485℃ 500℃
Outer casing of LP cylinder
(spray water to LP turbine must be
switched on at 90o
C )
90℃ 110℃
Temperature difference
Between upper & lower casing of
HPT,middle
±90℃ ±100℃
ITP top / bottom Diff. temp. ( FRONT ) ±30℃ ±45℃
ITP top / bottom Diff. temp. ( REAR ) ±30℃ ±45℃
Feed heater out of service
Operation with feed heater out
of service
Main Steam
flow , Kg / s
LOADF
MW
Extraction A6 = 0 395 500
Extraction A6 = 0 , A5=0 400 526.6
Weights(Tons)
HP IP LP
Cylinder assembly 94.6 T 41.2 79.6
Rotor(with balding ) 16.3 T 23.1 T 90 T
Stop and C.V. 20.9 T 32.2 T -
(i) Turbine overall length : 19.94m
Turbine overall width : 15.1 m

BEARINGS
A bearing is a machine element that constrains relative motion and reduces friction
between moving parts to only the desired motion.Two types of bearings have been used
Journal bearing-6no.s
Thrust bearing-1no.
Bearings are usually forced lubricated and have provision for admission of jacking oil.
Journal Bearing
The function of the journal brg.is to support the turbine rotor.The journal
brg.Consists of the upper & lower shells, bearingcap, Spherical block, spherical support
and key. Thebrgshell are provided with ababbit face brg is pivot mounted on the
spherical support to prevent the bending movement on the rotor. A cap which fits in to
the corresponding groove in the brg shell prevents vertical movement of the brgshell.
Thebrg shells are fixed laterally by key. Each key is held in position in the brg pedestal
by 2 lateral collar. The Temperature of the brg bodies is monitored by thermocouple.
Upper and lower shell can be removed without the removal of Rotor. To do this shaft is
lifted slightly by means of jacking device but within the clearance of shaft seal. The
lower bearing shell can be turned upward to the top position and removed.
ANCORE POINTS OF TURBINE:
Purpose of Taking care of thermal expansions and contractions of the machine
during thermal cycling.
The fixed points of the turbine are as follows:
• The bearing housing between the IP and LP turbines.
• The rear bearing housing of the IP turbine.
• The longitudinal beam of the I.P turbine.
• The thrust bearing in rear bearing casing of H.P turbine.
Size of Bearing
1 2 3 4
Diameter
(mm)
250 380 450 500

FRONT BEARING PEDESTAL
The Front Bearing Pedestal is located at the turbine side end of the turbine
generator unit.Its function is to support the turbine casing and bear the turbine rotor.
It houses the following components
• Journal bearing
• Hydraulic turning gear
• Main oil pump with hydraulic speed transducer
• Electric speed transducer
• Over speed trip
• Shaft vibration pick-up
• Bearing pedestal vibration pick-up
The bearing pedestal is aligned to the foundation by means of hexagon head screws
that are screwed in to it at several points.The space beneath the bearing pedestal is
filled with non shrinking grout. The bearing pedestal is anchored at to the foundation
by means of anchor bolts. The anchor bolt holes are filled with gravel, it gives a
vibration damping effect.

HP REAR BEARING PEDESTAL
The Bearing pedestal (2) is located between the HP and IP turbine.Its function is to
support the turbine casing and bear the HP IP rotor.
It houses the following components
• Combine Journal and Thrust bearing
• Thrust Bearing trip (electrical)
Combines journal and thrust bearing:
The magnitude and direction of axial thrust of the turbine depends on the load
condition The Journal bearing is elliptical sleeve bearing. The bearing liners are
provided with a machined babbitface. Located at each end of bearing shell,
babbitted thrust bad forms 2 annular surfaces. These collars and thrust pads permit
equal loading of thrust bearing. Thrust pads are of tilting type. Metal temperature of
the journal bearing and thrust pads is monitored by the thermocouples.

IP REAR BEARING PEDESTAL
The bearing pedestal is located between the HP and IP turbines. Its function is to
support the turbine casing and bear the HP and IP turbine rotors.
The bearing pedestal houses the following turbine components:
• Journal bearing
• Hand barring arrangement
• Differential expansion measurement device.
LP TURBINE REAR BEARING PEDESTAL
The bearing pedestal is situated between the LP turbine and generator.Its function is
to bear the LP rotor.
The bearing pedestal contains the following turbine components:
• Journal bearing

TURBINE LUBRICATION SYSTEM
Turbinelubrication systems supplies lubricant oil to various parts in the turbine.
Importance of lubrication system:-
• To reduce the wear and tear of the rotating elements.
• To maintain the temperature of the bearings
Purpose:-
• Lubricating and cooling the bearings.
• Lubrication of turbine.
• Cooling of bearings
• Sealing medium in Hydrogen cooling system
• Turbine barring gear operation.
• Working fluid in Governing system
Components:
• Main oil Pump.
• Auxiliary oil pump
• Emergency oil pump
• Jack oil pump
• Main Oil Tank
• Oil coolers
• Oil Filters
• Oil Injectors
• Centrifuge

MAIN OIL PUMP (MOP)
LOCATION:
This pump is mounted in the front bearing pedestal. It is coupled with turbine rotor
through a gear coupling. Oil suction from MOT Through two number of injectors
connected in series. It will takes over when turbine speed > 2800 rpm. It Supplies oil
for turbine bearing lubrication as well as for the turbine governing system.
AUXILIARY OIL PUMPS (AOPS)
The auxiliary oil pump is a vertical one stage rotary pump with a radial impeller and
spiral casing. It is fixed to the cover of the oil tank and submerges into the oil with
the pump body. It is driven by an electric motor that is bolted to the cover plate of
themain oil tank. The pump shaft has a sleeve bearing in the pump casing and a
groovedball bearing in the bearing yoke. The bearings are lubricated from the
pressurechamber of the pump; the sleeve bearing via a bore in the casing; the grooved
ballBearing via lube line. Lubricating system has two AOPs, AC motor

drivenVertical one stage rotary pump with radial impeller & spiral casing.It will
Supplies oil during turbo-set starting and stoppingwhen the turbine is running at
speed lower than 2800 rpm supplies oil to governing system as well as to the
lubrication system.It also serves as standby to main centrifugal oil pump.It has
Submerged pump body.
EMERGENCY OIL PUMP (EOP)
When main and full-load auxiliary oil pumps fail, the lubrication oil supply
ismaintained by a DC. driven emergency oil pump. This pump supplies oil directly
tothe lubricating oil line, bypassing the oil cooler and thus preventing damage to
thebearing shells. This is a centrifugal pump, driven by D.C. electric motor.
This automatically cuts in whenever there is failure of A.C. supply at power station
and or the lub oil pressure falls below a certain value. This pump can meet the
lubrication system requirement under the conditions mentioned above.
JACKING OIL PUMPS (JOPS)
It delivers a pressure of 120kg/cm2 for lifting of rotor. It has two pumps namely
JOP1 & JOP2.Both pumps are AC driven but in some of the plants one of the JOP is
DC driven also to lift the rotor assembly during TG start up and shut down.Suction
oil is from MOT.
OIL COOLER
Function of oil cooler is to cool the lubricating oil supplied to the bearings of turbine.
Oil cooler consists of the tube nest, the inner, outer shell and water boxes. The
tubenest through which the cooling water flows is surrounded by the oil space formed
bythe outer shell. The oil to be cooled enters the oil cooler and flows to the inner
shell.
This shell supports the large baffle plates which are provided with an opening in
thecentre. Between every two large plates there is a small intermediate plate which is
heldby the short tubes placed into the steel rods. The small intermediate plate is
smallerin diameter than the inner shell and leaves an annular gap. This arrangement
serve to achieve a cross-flow pattern forcing the oil flowing to the outlet branch to
flowthrough the middle of the large plates, while passing round the edge of the short
ones.
The inner oil shell with the large plates is attached to the lower tube plate into
whichthe finned cooling tubes are expanded. The water box with a cooling water

inletbranch is bolted to the lower type plate. The tube nest is free to expand upwards
inresponse to any thermal effect
Main purpose of oil cooler
• To cool the lubricating oil
• Consists of tube nest, inner & outer shell & water boxes
• The cooling medium for these coolers is circulating water.
The pressure of the cooling water is kept lower than that of oil to avoid its mixing
with oil in the event of tube rupture.
OIL TEMP.CONTROLLERfor maintaining the lub oil temp at rated value by
controlling the flow through the coolers.
VAPOUR EXTRACTION SYSTEM
The function of oil vapour exhauster is to produce a slight negative pressure in themain
oil tank and in the bearing casing and thus draw off the oil vapour.The exhauster and
the motor attached to it with flanges are a closed unit. The casingis constructed as a
spiral with aerodynamic features and is provided with supports forthe exhauster. The
motor is bolted to the cover of the casing. The main oil tank is designed to be air tight.
The extractors produce a slight vacuumin the main oil tank and the bearing pedestals to
draw off any oil vapour.
It has Two Vapour Extractor fans, Exhaust fans to
• Maintains -ve pressure inside MOT
• Removes oil fumes from the MOT.
OIL FILTER
Oil for the thrust bearing is passed through the duplex oil filter which can beswitched
over and cleaned during operation. It has Basket type filter inside the oil tank
MAIN OIL CENTRIFUGE
It is required for removing moisture from the turbine oil.A portion of oil is continuously
circulated through the centrifuge to remove the moisture from the oil.
MAIN OIL TANK
The main oil tank contains the oil necessary for the lubricating and cooling of
thebearings and for the lifting device. It not only serves as a storage tank but also

fordeaerating the oil. The capacity of the tank is such that the full quantity of oil is
circulated not more than8 times per hour. This results in a retention time of approx. 7 to
8 minutes fromentry into the tank to suction by pumps. This time allows sedimentation
anddetainment of the oil. Oil returning to the tank from the oil supply system first flows
through a submergedinlet into the riser section of the tank where the first stage
deaeration takes place a the oil rises to the top of the tank. Oil overflows from the riser
section through the oilstrainer into the adjacent section of the tank where it is then
drawn off on the oppositeside by the suction pipe of the oil pumps.
Main oil tank has the following mountings:
• AC auxiliary oil pump : 2 nos.
• DC emergency oil pump : 1
• Shaft lift oil pumps : 3 nos.
• Oil injector : 1
• Oil vapour extractor : 2 no.s
1. Oil inlet
2. Suction pipe(injector)
3. AC AOP
4. AC standby AOP

5. DC EOP
6. JOPs
7. Main section drain
8. Riser section drain
9. Oil vapor exhauster
10. Connection for oil tank level indicator
11. Connection for fluid limit switch (SONAR)
12. Inspection hole
13. Cover of entrance to riser section
14. Inspection hole
15. Oil strainer cover
16. Oil strainer

LUBRICATION SYSTEM SPECIFICATION
LUBRICATION OIL SPECIFICATIONS
(a)Kinematic viscosity : 41.4 – 50 cst at 40 o
C,28cst at 50 o
C
(b)Viscosity index : min 98
(c) Flash point : 200o
C (min.)
(d) Pour point : -6o
C (max.)
(e) Emulsion char : 40-40-0 (20 minutes)
(f) Air release capacity : 4 minutes (max.)
(g) Rust preventing characteristic : 0-B max.
(h) Water content % by wt. : 0.01%
(i) Solid particles content : 0.05% max. by weight.
(j) Foaming tendency at 25o
C : (Max.) 400 Cm3
(k) Foaming stability : (Max.) 450 sec.
(l) Ash (% by weight) : Max. 0.01%
(m) Particle distribution : Min. 17/14 Code.
(n) Specific gravity : 0.85 g/cm2
at 50o
C
(o) Copper corrosion : Not worse than No.
MAIN OIL TANK
(a) MOT capacity : 25/40 m3
(b) 1st
oil filling : 47.5 m3
(c) Flushing oil quantity : 28.5 m3
(d) Highest oil level from top of tank : 750 mm
(e) Lowest oil level from top of tank : 750mm

OIL REQUIREMENT OF BEARINGS (dm3
/s)
(a) Bearing 1 : 0.8
(b) Bearing 2 : 15.4
(c) Bearing 3 : 4.55
(d) Bearing 4 : 9.29
(e) Gen. bearing Front : 7.92
(f) Gen. bearing Rear : 7.92
(g) Exciter bearing : 0.70
estimated oil requirement for the : 57.4
hydraulic barring gear
DUPLEX OIL FILTER(for brg. oil supply header)
(a) Number : 2x100 %
(b) Type : 2.68.2
(c) Size : 355/750
(d) Make : Boll &Kirch
(e) Filtration particle size : 37 m
JACKING OIL SYSTEM
(a) Safety valve setting : 200 bar
(b) Pressure regulating valve setting : 180 bar
Duplex oil filter(type 400 D 140
Make K&H Eppensteiner, Germany : 2x100 %
(d) Filtration particle size of filter element: 37 m

LUB OIL COOLERS
(a) Number : 2x100 %
(b) Cooling surface area : 640 m2
(c) Oil flow : 186.2 m3
/hr.
(d) Heat dissipating capacity : 1771 KW
(e) Oil inlet temp. : 65o
C
(f) Oil outlet temp. : 45o
C
(g) Oil side pr. drop : 4 mwc
(h) CW inlet temp. : 38o
C
(i) CW outlet temp. : 39.7o
C
(j) CW flow : 900 m3
(k) CW side pr. drop : 1.0 mwc
(l) Test pr. – oil side : 13.5 kg/cm2
(m) Test pr. – CW side : 15 kg/cm2
(n) Tube material : Admirality Brass
(o) Tube plates material : Carbon steel
(p) Casing and water boxes material : Carbon steel
TURBINE OIL CENTRIFUGE SYSTEM
Motor
Make Crompton Greaves
Rating (HP) 11/(15)
RPM 1470
Volts 415
Type 3Ø Induction motor

Efficiency 89%
Oil pumps specification
M O P A O P D C E O P J a c k i n g O i l P p
N u m b e r 1 2 1 A C : 2 D C : 1
M a k e B H E L K S B K S B T u s h a k o T u s h a k o
T y p e 350 m³/hr ETA-150-50VL ETA-100-33VL T3 SA 38/46 T3 SA 38/46
C a p a c i t y ( d m 3
/ s ) 8 7 . 4 8 4 8 3 0 1 . 8 4 1 . 8 4
D i s c h . P r . ( b a r ) 8 . 4 6 . 7 2 . 3 1 7 8 1 7 8
S p e e d ( R P M ) 3 0 0 0 1 4 7 0 1 4 1 0 2 8 9 8 2 8 9 8
D r i v e T u r b i n e A C M o t o r D C M o t o r AC & DC Motor AC&DC Motor
M o t o r M a k e - Crompton Greaves Crompton Greaves Crompton Greaves Crompton Greaves
V o l t a g e ( V ) - 4 1 5 V 2 2 0 V 4 1 5 V 2 2 0 V
Motor Power (KW ) - 1 0 0 1 3 4 5 4 5
Rated Current (Amp.) - 1 5 7 9 7 7 6 2 3 4
D O R - Clockwise as viewed from top Clockwise as viewed fromtop Clockwise as viewed from top Clockwise as viewed from top

TURBINE EFFICIENCY
To maximize turbine efficiency the steam is expanded, generating work, in a no of
stages. Thesestages are characterized by how the energy is extracted from them and are
known as either impulse orreaction turbine. The most steam turbines use a mixture of
reaction and impulses designs: each stagebehaves as either one other, but the overall
turbine use both. Typically, higher pressure sections areimpulse type and lower pressure
stages are reaction type
Isentropic efficiency η by definition is given by
η = (hHP - hLP) / (hHP - hLPisen)
where
– hHP is the specific enthalpy of the steam at the turbine inlet
– hLP is the specific enthalpy of the steam at the turbine exhaust
– hLPisen is the specific enthalpy of the steam at turbine exhaust pressure but
after
– isentropic expansion from the HP conditions
EFFECT OF VARIOUS FACTORS ON TURBINE PERFORMANCE
The steam turbine performance will be get affected by various factors that damages
theturbine blades. This results in blade angle displacement from the actual positions,
damage of bladematerials by material waste deposits, corrosion and erosion on blades
by improper supply and purityof steam.
The development of modern, high-efficiency steam turbines has led to an increase
indeposition, erosion, and corrosion problems. Close tolerances in the turbines, the use
of high strengthsteels, and impure steam all contribute to these conditions.
TURBINE DEPOSITS:
Although several factors influence the formation of deposits on turbine components,
thegeneral effect is the same no matter what the cause. Adherent deposits form in the
steam passage, distorting the original shape of turbine nozzles and blades.These
deposits, often rough or uneven atthe surface, increase resistance to the flow of steam.
Distortion of steam passages alters steam velocities and pressure drops, reducing the
capacity and efficiency of the turbine. Where conditionsare severe, deposits can cause
excessive rotor thrust. Uneven deposition can unbalance the turbinerotor, causing

vibration problems.As deposits accumulate on turbine blades, stage pressures increase.
Figure shows the effectof gradual deposit buildup on stage pressure. The deposits were
caused by the use of contaminatedwater to attemperate the steam. In a fouled condition,
this 30-MW turbine lost over 5% of itsgenerating capacity.
Turbine deposits can accumulate in a very short time when steam purity is poor. The
turbinewas forced off-line by deposition only 3 months after it was placed in operation.
Carryover of boilerwater, resulting from inadequate steam-water separation equipment
in the boiler, caused this turbinedeposit problem.
Increasing Steam Turbine Power Generation Efficiency
With more than 1,300 steam-turbine power plants in the country at least 30 years old,
electric utilities and independent power producers today must optimize these plants to
improveefficiencies to reduce operating and maintenance (O&M) costs, and to remain
competitive. The aim of every steam turbine design is an optimum efficiency operation
characterizing anoptimal energy conversion. Overall efficiency of a steam turbine
power plant, however, stronglydepends on the turbine's performance. Thus any
improvement, however slight, can increase poweravailability, decrease equipment and
component costs, and generate sizeable operating savings.
Intoday's highly competitive and deregulated market, optimizing steam turbine
operation is no longera goal but, rather, a necessity for power producers to remain
competitive.For some aging steamturbinepower plants, refitting them with gas turbine
systems will boost availability. For others, however, it may be more cost-effective to
upgrade existing steam turbines rather than replace them.
Since a steam turbine's efficiency ultimately depends on its condition, relative to its
design, as a turbine's condition deteriorates with use its efficiency degenerates
proportionately. A thoroughevaluation of a steam turbine's design and operating
condition can help increase a plant's efficiencyby identifying improvements in one or
more of three areas:
– Combustion to improve fuel utilization and minimize environmental impact.
– Heat transfer and aerodynamics to improve turbine blade life and
performance.
– Materials to permit longer life and higher operating temperatures for more
efficientsystems.

CONCLUSION
Power is an important infrastructure in developing countries. Power development
in India received a big boost with the dawn of National Thermal Power
Corporation Limited Ramagundam Super Thermal Power Station is a plant with
switching station for Southern grid, distributing 400 KV Transmission lines,
Generating 2600 MW, having nearby South Godavari Coal fields of M/s. SCCL
mines, having Rail transport. Plant generating power occurs in 3 Stages. Stage -I
with 3 units of 200 MW capacities, stage-II with 3 units of 500 MW capacity and
Stage-III with 1 unit of 500 MW capacity.
We studied the working of 500MW steam turbine and its auxiliaries. We got
familiar with various systems in it. We surveyed and collected specifications of
various components involved in the steam turbine and its auxiliaries. We visited
the control room of unit IV and observed the continuous data monitoring of various
systems of unit-IV. The output power ranges from 515-520MW.The speed of the
turbine shaft usually ranges from 2850-3150 RPM.

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