1. A
Seminar Report
On
SURATGARH SUPER THERMAL
POWER STATION
Submitted in partial fulfillment for the
Award of degree of
Bachelor of Technology
In
Electrical Engineering
2012-13
Submitted By: Submitted To:
Name of Student- ASHOK KHOJA Mr. Manoj Chhimpa
Roll No:- 05 Assistant Professor
B.Tech, Final year Deptt.of Electrical Engg.
Department of Electrical Engineering
GOVT. ENGINEERING COLLEGE BIKANER
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3. ACKNOWLEDGEMENT
I Ashok Khoja 4th year student of ENGINEERING COLLEGE BIKANER
consider training to be a challenging job and the completion Of my practical training, I would
like to thank all the personalities who have helped me in the completing the work.
I greatly thankful the help of :
Department: :
Mr. MANOJ CHHIMPA, Mr. NAVIN PALIWAL, Mr. GANESH P. PRAJAPAT
STPS.
Mr.B.P.Gautam(SE), Mr.G.l.Garg(XEN), Mr.H.kTomar(AEN)
For their valuable lectures and their contribution. They not Only delivered me the practical
knowledge but also provided parental attitude towards me during my practical work. Thanks are
due to all Engineers and working staff and my college department without the help of which I
would not be reach at this point.
I am equally obliged to all those Engineers Technical personnel and operators at S.T.P.S. who
gave me their valuable time and rendered practical knowledge in my training period. And at last
I want to thank my colleagues. Without their help guidance and suggestions it was not possible
to produce this training report.
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4. CONTENT
Serial No. Title Page No.
I Main page i
II Certificate ii
III Acknowledgement iii
IV Contents iv-v
V List of Figures vi
VI List of Tables vii
VII Abbreviation viii
1. SURATGARH SUPER POWER STATION 1-3
1.1 An Introduction 1-2
1.2 Future Expension
1.3 Installed Capacity
2. PLANT FAMILIARIZATION
2.1 Turbine
2.2 Boiler
2.3 Condenser.
2.4 Coal Handling Plant
2.5 Ash Handling Plant
2.6 Generator
3. CONTROL AND INSTRUMENTATION CIRCLE
3.1 SWAS PACKAGE
3.2 ATRS PACKAGE
3.4 DDC PACKAGE
3.5 FSSS PACKAGE
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5. LIST OF FIGURES
Serial No. Title Page No.
1. Combined Cycle Process 6
2. Bratyon cycle 8
3. Combustion chamber 11
4. Layout of Gas Turbine 12
5. Gas Turbine & Generator 15
6. Waste heat recovery boiler 18
7. Rankine Vapour power cycle 22
8. Rankine cycle 23
9. Combined Turbine &Generator 26
10. Switchyard 32
11. Isolator 33
12. Circuit Breaker 34
13. Lighting Arrester 35
14. Current Transformer 35
15. Potential Transformer 36
16. Protective Relays 36
17. Bucchloz Relay 40
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6. LIST OF TABLES
Serial no. TABLE Page No.
1. Coal based power plant 4
2. Coal based power plant(joint ventures) 5
3. Gas based power plant 5
4. Technical specification of compressor 10
5. Technical specification of Gas Turbine 13
6. Technical specification of Generator 14
7. Technical specification of of gas 28
8. Technical specification of generator transforme r 41
9. Technical specification of auxiliary transformer 42
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7. ABBREVIATION
1. SURATGARH SUPER POWER STATION
1.1 An Introduction
Suratgarh thermal power station is the first super thermal plant of rajasthan.Suratgarh Super
Thermal Power Station is owned by Rajasthan RajyaVidhyutUtpadan Nigam Ltd. and is situated
near village riyanwali about 25 KM from Suratgarh town, an ideal location for setting up a
thermal power station in the state having regards to the availability of land, water, transmission
network proximity to broad gauge railway and being an important load centre for north west
Rajasthan. The techno-economic clearance for the prefect was issued by CEA in June 1991 – the
planning commission accorded investment sanction for the project in Nov. 91 for a total
estimated cost of Rs. 1253.31 crores on prices prevailing in Sept. 1990.
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8. The updated cost of the project is estimate at Rs. 2300 crores of including IDC. It has generation
capacity of 1500 MW and installed with six Units of 250 MW each. It is a coal base thermal
station. Water and coal required in a large amount. Coal isreceived here from coal-fields of MP
areas through railways and water is receivedfrom INDIRA GANDHI CANAL. The supply of
coal is from MP, Jarkhandby rail. About 18000 tonne coal required per day for whole unit and
each unit consumes 150tonnes coal per day. About 2x3 km2 area covered by plant and
approximately 1800 employees works in aplant including chief engineer to labour. The supply
electricity to the northernRajasthan, Ratangarh, Bikaner, Ganganagar.
1.2 FUTURE EXPENSION
It has been decided to set up 2 X 660 MW super critical units (Unit # 7 & 8) atSSTPS. For this
purpose about 446 Hectare land has been identified adjacent to theexisting 6 X 250 MW plant.
This land is under process of acquisition. M/s TEC havebeen appointed consulting engineers for
this project. The state Govt. has also accorded its inpriciple approval for setting up in future, two
additional units of 2 X 660 MW (UNIT # 9& 10) also based on super critical technology.
1,3 INSTALLED CAPACITY
Following is the unit wise capacity of the plant:
Stage Unit NO. Installed Date of Comisioning Status Capacity(MW)
Stage I 1 May,1998 Running 250
Stage I 2 March, 2000 Running 250
Stage II 3 October, 2001 Running 250
Stage II 4 March, 2002 Running 250
Stage III 5 June, 2003 Running 250
Stage IV 6 May,2010Running 250
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9. 1.3.1 SANCTION OF SCHEMES (STAGE-I to V)
Stage Unit No. Capacity (MW) Cost (Rs.Crore)
1 1&2 2*250 2300
2 3&4 2*250 2057
3 5 1*250 753
4 6 1*250 1117
Total 5127
1.3.2 COMMISIONING TARGETS AND ACHIEVEMENTS
Units Zero Date Target Actual Date Date of Date of Remark
Coal Firing Commercial
Operation
1. June-1991 Mar.-1997 10-May- 04-Oct-1998 01-Feb-1998
1998
2. June-1991 Sep-2000 28-Mar-2000 07-Jun-2000 01-Oct-2000 Commissioned
6 month ahead
of schedule
3. Jun-1999 Mar-2002 29-Oct-2001 08-Dec-2001 15-Jan-2002 Commissioned
6 month ahead
of schedule
4. Jan-1999 Sep-2002 25-Mar-2002 17-Jun-2002 19-Aug-2003 Commissioned
6 month ahead
of schedule
5. Feb-2001 Jun-2003 30-Jun-2003 30-Jun-2003 19-Aug-2003 Commissioned
of 29 month
6. Jun-2006 Oct-2008 31-Mar-2009 24-Aug-09 30-Dec-2009
PLANT OVERVIEW:-
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10. 2. PLANT FAMILIARIZATION
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11. 2.1 TURBINE
2.1.1 Introduction:
Steam turbine is a rotating machine which CONVERTS HEAT ENERGY OF
STEAM TO MECHANICAL ENERGY.
In India, steam turbines of different capacities, varying from 15 MW to 500
MW, are employed in the field of thermal power generation.
2.1.2 Basic Principles:
The Thermal Power Plants with steam turbine uses Rankine cycle. Rankine cycle is a
vapour power cycle having two basic characteristics:
1. The working fluid is a condensable vapour which is in liquid phase during part
of the cycle and
2. The cycle consists of a succession of steady flow processes, with each
processes carried out in a separate component specially designed for the
purpose. Each constitute an open system, and all the components are
connected in series so that as the fluid circulates through the power plant each
fluid element passes through a cycle of mechanical and thermodynamic
stages.
The turbine is of tandem compound design with separate HP, IP and LP cylinder.
The HP & IP turbines are of single flow type while LP turbine is of double flow type;
the turbine is condensing type with single reheat. It is basically engineered on
reaction principle with throttle governing. The stages are arranged in HP, IP and LP
turbines, driving alternating current full capacity Turbo generators.
2.1.3 Specification
Type - Tandem compound condensing Reaction
Rated output of turbine - 250 KW
Rated speed - 3000 RPM
Main steam temperature - 537 C
Rated pressure - 150 kg/cm
2.1.4 TURBINE COMONENTS
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12. Casing or Cylinders:
A casing is essentially a pressure vessel which must be capable of withstanding the maximum
working pressure and temperature that can beproduced within it. The working pressure aspects
demand thicker and thicker casingand the temperature aspects demand thinner and thinner
casings.
1. H.P Turbine Casing: The principal parts of the HP turbine casing are andaxially split
inner shell, enclosing the rotor and outer shell of a barrel-typeconstruction. The barrel
type of cylinder construction ensures symmetry of thewall thickness around the axis
of rotation and hence the wall thickness itself isrelatively less than that used in other
type of construction.
2. I.P. Turbine Casing: The IP turbine is split axially and is of single shelldesign. The
outer casing accommodates a double flow inner casing. Thesteam coming from the
reheater is passed into the inner casing via admissionbranches which are
symmetrically arranged in the top and bottom halves ofthe outer casing.
3. L.P Turbine Casing: The LP turbine is of double flow type. The casing is oftriple
shell, fabricated construction. The outer casing consists of the front andrear end walls,
two longitudinal girders and a top cover. The inner shell of theinner casing acts as the
guide blade carriers for the initial stages of theturbine. The guide blade carriers of the
LP stage groups are so designed that,together with the inner casing, they form annular
ducts which are used forextractions.
2.1.5 TURBINE GOVERNING SYSTEM
The main purpose of governor is to maintain this desired speed of turbine during fluctuations of
load on thegenerator by varying steam input to the turbine.The governing system in addition to
ensuring the fallingload-speed characteristics of the turbine also ensures the following functions:
1. The run up the turbine from rest to rated speed and synchronizing with the grid.
2. Meeting the system load variations in a predetermined manner, when running in parallel with
other machines.
3. Protecting the machine by reducing the load or shutting off completely in abnormal and
emergency situations. The governing system also includes other devices to protect the turbine
from abnormal condition that may arise during operation.
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13. 2.1.5.1 By-pass Governing:
In this system, in general, the steam is supplied through aprimary valve and is adequate to meet a
major fraction of the maximum loadwhich is called economic load loads less than this, the
regulation is done bythrottling steam through this valve. When the load on the turbine exceeds
thiseconomic load which can be developed by the unthrttole full flow through theprimary valve,
a secondary valve, is opened and throttled steam is supplieddownstream, bypassing the first stage
and some high-pressure stages. Thissteam joins the partially spent steam admitted through the
primary valve,developing additional blade torque to meet the increased load.
2.1.5.2 Governing of Reheat Turbine:
In reheat turbines in cases of partial of full load ow off even after the HP control valves are fully
closed the entrained steam in the reheatersand hot reheat line is more than enough to speed up
the turbine above over speedlimits. Hence it is necessary to provide stop valves and interceptor
valves on hotreheat line before IP turbine. While the stop valve is operated controlled similar to
HP control valve but at a higher speed range by a secondary of pre-emergencygovernor as it is
called. The valve remains full open at rated speed and startsclosing at about 3% overspeed and is
fully closed at about 5% over speed..
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14. 2.2 BOILER
2.2.1 Introduction:
The boiler is the main part of any thermal power plant. It converts the fuel energy intosteam
energy. The fuel may be furnace oil, diesel oil, natural gas or coal. The boilersmay be fired from
the multiple fuels.The boiler installed in S.T.P.S. are made by M/s BHEL . Each of the boilers
are singledrum, tangential fired water tube naturally circulated over hanged, balanced draft,dry
bottom reheat type and is designed for pulverizing coal firing with a max. Continuous steam
output of 375 tons/hour at 138 kg/cm2 pressure and 540 degreecent. Temp. The thermal
efficiency of each boiler at MCR is 86.8 %. Four no. Of bowlmills have been installed for each
boiler. Oil burners are provided for initial start upand stabilization of low load .Two E.S.P. (one
for each boiler) is arranged to handle flue gases from the respective boilers. The gases from
E.S.P.aredischarged through180 meters high chimney. I.D. fan and a motor is provided near the
chimney toinduce the flue gases.
2.2.2 Circulation System:
It is essential to provide an adequate flow of water and/or of water-steam mixture for an efficient
transfer of heat from furnace to the working fluidand to prevent ‘burn-outs’. This is irrespective
of the mode of circulation being used.In STPS NATURAL type of circulation system are used.
2.2.2.1 Natural Circulation:
In this type, no external pumping device is used for the movement of the fluid.The difference in
densities in contents of fluids in down comers from the drum andrisers in the furnaces is used to
effect the movement of fluids. This type of circulationis employed in most of the utility
boiler.The movement of the steam and water will increase with increased heat inputto a
maximum value or so called end point, after which further increase in heatabsorption will result
in a decrease in flow. One of the characteristics of natural circulation is its tendency to provide
the highestflow in the tubes with the greatest heat absorption.
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15. 2.2.3 Heat Transfer in Boiler
In boiler heat energy is released from the combustion of fossil fuels and theheat is transferred to
different fluids in the system and a part of it is lost or left out asunutilized.
There are three modes of heat transfer :
1. Conduction
2. Convection
3. Radiation
Heat energy is transferred from a heat source to a heat receiver by one ormore of these modes for
which heat source should be at a higher temperature thanthe receiver. In superheater tube with
high temperature region but does not directly viewthe flame. Here the heat is transferred from
flue gas to superheater tube metal byconvection and by non-luminous radiation and in the tube
metal by conduction and tothe steam by forced convection. The power plant boilers are large
capacity steam generators used purely forthe electrical power generation.
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16. 2.2.4 Boiler Pressure Parts:
2.2.4.1 Economizer:
Economiser is a feed water heater.It uses the heat produced by the flue gases forthis purpose.The
feed water is passed through the economiserbefore supplying it tothe boiler and economiser
absorbs a part of heat from the flue gas to increase thetemperature of the feed water.
2.2.4.2 Super Heater:
The steam produced in the boiler has got moisture content so it is dried andsuperheated (ie steam
temperature is increased above boiling point of water)by the flue gases on the way to
chimney.Super heating ensures two benefits at first theoverall efficiency of the system is
increased and secondly the corrosion to the turbine blades due to condensation in later stages is
prevented.The superheated steam fromsuperheater is fed to steam turbine by means of a main
valve.
2.2.4.3 Steam Flow:
Saturated dry steam from the drum follows the course that is:
Steam cooled wall roof tubes –steam cooled side wall tubes – extended steam
cooled side wall tubes – front steam cooled wall tubes – steam cooled roof and
rear wall tubes- super heater rear horizontal assemblies – super heater de-super
heater- platen super heater – pendant super heater.
Super heated steam from the pendant super heater outlet header goes to the turbine via the main
steam lines. After passing through the high-pressure stages of the turbine, steam is returned to
the re-heater via the cold reheat lines. The reheat de-super heaters are located in the cold reheat
lines.
Reheat flow through the unit is as follows:
Front pendant re heater – rear pendant re-heater. After being reheated to the design temperature,
the reheated steam is returned to the low-pressure section of the turbine via the hot reheat line.
2.2.4.4 Reheater:
Reheater are provided to raise the temperature of the steam from which partof energy already
been extracted by HP turbine
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17. .
The reheater is composed of two stages or section, the front pendant verticalspaced platen
section and the rea5r pendant vertical spaced platen section.The rear pendant vertical spaced
section is located above the furnace archbetween the water- cooled screen tubes and rear water
wall hanger tubes. The front pendant vertical spaced plated section is located between the
rearwaterwall hanger tubes and the superheated platen section.All reheater drains and vents are
opened before lighting off.
2.2.5 Water Colled Furnaces:
Bharat Heavy Electrical Limited has developed the modern water-cooled furnace. Furnace is the
primary part of boiler where the chemical energy available in the fuelis converted to thermal
energy by combustion. Furnace is designed for efficient andcomplete combustion. Major factors
that assist for efficient combustion are time ofresidence (fuel) inside the furnace, temperature
inside the furnace and turbulencewhich causes rapid mixing between fuel and air.
It has following Advantage:
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18. In furnace not only combustion but also heat transfer is taking placesimultaneously.
The maintenance work involved in repairing the fire bricks is practicallyeliminated.
Due to heat transfer in the furnace the flue gas leaving the furnaces isreduced to the acceptable
level to the superheating surfaces.
2.2.6 Soot Blower:
Steam has mainly been used as the soot blowing medium, but recently theused low-pressure air
as a soot blowing medium has been introduced as this offers anumber of advantage.
2.2.7 Air and Gas Path:
2.2.7.1 General:
The total air flow through the unit is handled by two numbers axial reactionforced draft fans and
two numbers axial reaction primary air fans. The flue gasproduced in the furnace from
combustion of fuel is evacuated by two numbers radialdouble suction Induced draft fans. The
schematic of air and flue gas system isenclosed.
2.2.7.2 Air System:
1.Combustion Air (Secondary Air): The forced draft fans supply therequired secondary
air for combustion. This air is preheated by two no. RPAH. Control of secondary air flow
is done byFD fan blade pitch control. The distribution of hot secondary air to the wind
boxcompartments is controlled by “Secondary air dampers”.
2. Air for Drying and Transportation of pulverized coal (Primary Air): Thecold
primary air fans supply the air required for drying the coal in the tubemills/mixing box
and for transporting the pulverized fuel from both ends of thetube mill to the coal
burners. The primary air is heated in the primary sectorsof the Rotary RAPH. The control
for the primary air pressure is achieved through PA fan inletdampers.
3.Scanner Cooling Air: Each boiler is provided with 20 no. VISIBLE
LIGHTSCANNER. The two no. of scanner air fans are provided to supply therequired
air for cooling these flame scanners. The supply of air is taken fromFD fan discharge.
The air is filtered and boosted to the required pressure bythe scanner air fans.
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19. Additionally an emergency air supply connection fromatmosphere is provided for
supplying the cooling air to the scanners in caseboth FD fans trip.
4.Seal Air: Six no. of seal air fans are (2 nos. per mill) are provided for eachboiler. The
sealing air is required for mill trunounim mill discharges valves andgravimetric feeders,
of the two seal air fans provided for each tube mill, one isin operation and the other
standby. The seal air takes suction from theatmosphere.
2.2.7.3 Gas System:
The flue gases produced in the furnace as a result of combustion, travels upward in the furnace,
across the horizontal pass and downward throughthe second pass of the boiler to the air
preheater.Two no. of Induced draft fans are provided to evacuate the flue gasfrom furnace to the
chimney. The ID fans are provided with hydraulic coupling and inlet damper control.
PRESERVATION OF BOILERS: Atmospheric corrosion of ferrous materials proceeds
rapidly in the presenceof oxygen and moisture. The oxides produced are objectionable and can
betransported to critical heat transfer areas as well as to the turbine. Pit type corrosioncan also
occur in walls. In large boilers, with numerous complex circuits and bends, itis practically
impossible to completely dry the boiler in preparation for storage.
2.2.8 FUEL OIL BURNING SYSTEM:
2.2.8.1 Fuel Oil Atomization:
Atomizes the process of spraying the fuel oil into fine mist, for better mixing of the fuel with the
combustion air. While passing through the spraynozzles of the oil gun, the pressure energy of the
oil converts into velocity energy,which breaks up the oil stream into fine particles. for
satisfactory atomization theviscosity shall be less than 15-20 centistokes.
2.2.8.2 Air Colled Oil Guns:
The atomized assembly of an operating oil gun is protected from the hot furnace radiation by the
flowing fuel oil and steam which keeps it relativelycool. The oil gun assemblies supplied for this
project have been designed for aircooing provision.
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20. 2.2.9 AIR PREHEATER:
Air preheater is a heat exchanger in which air temp. is raised by transferring heatfrom other
fluids such as flue gas . Since air heater can be successfully employed toreclaim heat from flue
gas at lower temp. level ,then it is possible with economizer theheat ejected to chimney can be
reduced to a great extent thus increasing the efficiencyof a boiler.
Specification:
1. Heating element - Hot end, Hot intermediate, Cold end Materials - Carbon &Corten steel
2. Rotor main drive motor - 11 kW, 1450 rpm, 50 Hz Coupling - Fluid coupling 11.5 fcu
3.BearingGuide bearing : Spherical roller bearing
Support bearing : Spherical roller thrust
Thermostat: Burling thermostat
4.Oil capacity
Guide brg. Housing : 25 lt.
Support Brg. Housing: 150 lt.
Steam Coil Airpreheater
Number of steam Coil APH : 2 Nos per boiler
Installed position : Vertical
Design Pressure : 20 kg/cm2
Design Temperature : 2500C
Weight of One steam coil APH : 1950 kg.
2.3 CONDENSER:
2.3.1 The functions of condenser are:
1. To provide lowest economic heat rejection temperature from the steam. Thussaving on steam
required per unit of electricity.
2. To convert exhaust steams to water for reuse this saving on feed waterrequirement.
3. Deaeration of make-up water introduced in the condenser.
4. To form a convenient point for introducing makes up water.
IN STPS RVUN SURFACE CONDESER is used
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21. Surface Condenser:
This type is generally used for modern steam turbine installations. Condensation of exhaust
steam takes place on the outer surface of the tubes, whichare cooled by water flowing inside
them. The condenser essentially consists of a shell, which encloses the steam space.
Tubescarrying cooling water pass through the steam space. The tubes are supplied coolingwater
form inlet water box on one side and discharged, after taking away heat formthe steam, to the
outlet water box on the other side.Instead of one inlet and one outlet water boxes, the may be two
or more pair ofseparate inlet-outlet water boxes, each supplying cooling water to a separate
bundleof tubes. This enables cleaning and maintenance of part of the tubes while turbinecan be
kept running on a reduced load.
2.3.2 Description of Condenser:
The condenser group consists of two condensers, each connected with exhaust partof low
pressure casing. A by-pass branch pipe has interconnected these woecondensers. The condenser
has been designed to create vacuum at the exhaust ofsteam turbine and to provide pure
condensate for reusing as feed water for the boilers. The tube layout of condenser has been
arranged to ensure efficient heattransfer from steam to cooking water passing through the tubes,
and at the sametime the resistance to flow of steam has been reduced to the barest
minimum.350% capacity condensate pumping sets are installed for pumping the condensatefrom
condenser to the deaerator4 through low-pressure heaters. Two pumps are fornormal operation
and one works as stand by pump.
2.3.3 Material for Condenser Tubes:
Selection of tube material mainly on the quality of cooling water and thecost. Coppers alloys are
preferred as copper has very high heat transfer coefficient.But as copper has very little
mechanical strength; it has to be reinforced by alloyingwith other metals. Stainless steel tubes
has also been used and has good corrosion resistance thoughheat transfer coefficient is quite
lower htan the copper alloy.
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22. 2.3.4 Regenerative Feed Heating System:
If steam is bled from a turbine and is made to give up its latent and any superheat itmay possess,
to a heater this system is called regenerative, because the fluid givesup heat, which would be
otherwise wasted, to the fluid whilst in another state to raiseits temperature. The highest
theoretical temperature to which the feed water may beraised in the heater is the saturation
temperature of the bled steam. There is anoptimum point at which the steam is bled form the
turbine once a feed temperature isselected, a tapping point near the stop valve produces no gain
in efficiency as practically live steam is used for heating.
2.3.5 Regenerative System of 250 MW unit:
The regenerative system of the turbine consists of four low-pressure heaters, twogland coolers,
one deaerator and three high-pressure heaters. The condense isdrawn by condensate pumps from
the hot well of condenser and is pumped to thedeaerator through gland coolers and low pressure
heaters where it is progressivelyheated up by the steam extracted from seals and bled points of
the turbine. The drainof condensate steam on LP heaters No. 2,3 and 4 flows in cascade and is
ultimatelypumped into the main condenasate line after heater No.2 or flows to condenser.
Thefeed water after being deaerated in the deraerator is drawn buy the boiler feed pumpand
pumped to boiler through high pressure heaters where it is heated up by the bledsteam from the
turbine. The drain of condensed steam of HP heaters flows in cascade and under normal load
conditions flows to the deaerator.
2.3.6 HP-LP BYPASS SYSTEM:
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