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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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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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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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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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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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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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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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

Coal Firing

Date of

Commercial

Operation

Remark

1. June-1991 Mar.-1997 10-May-

1998

04-Oct-1998 01-Feb-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

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of 29 month

6. Jun-2006 Oct-2008 31-Mar-2009 24-Aug-09 30-Dec-2009

PLANT OVERVIEW:-

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2. PLANT FAMILIARIZATION

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

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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

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.

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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.

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

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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..

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

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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.

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

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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.

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:

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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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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:

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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:

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

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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.

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

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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.

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:

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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

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:

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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.

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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